Gain and Loss in Quantum Cascade Lasers

We report gain calculations for a quantum cascade laser using a fully self-consistent quantum mechanical approach based on the theory of nonequilibrium Green functions. Both the absolute value of the gain as well as the spectral position at threshold are in excellent agreement with experimental findings for T=77 K. The gain strongly decreases with temperature.Comment: 7 pages, 3 figures directly include

Mandatory HIV Testing of Accused Rapists: Whose Rights Are We Protecting? An Ethical and Legal Analysis

At times, the law appears confusing and unfair. Criminal defendants receive the strictest of all standards of review: guilt beyond a reasonable doubt. But why are the accused afforded greater constitutional protections than the victim? One reason may be found by examining the intent of the authors of the United States Constitution. Our founding fathers wanted Americans to escape the kind of persecution suffered under English rule. From its inception, the Constitution and the laws that followed were based on public policy and ethics. This legal precedence is used to interpret new laws. However, because of precedence, laws often do not reflect the prevailing public opinion of all Americans. Law may not always make sense, but it plays an important role in codifying and uniformly resolving many dilemmas, including biomedical and ethical issues. One such dilemma that has come under increasing scrutiny is whether an alleged sex offender may be forced to submit to an HIV test upon the victim\u27s request. Although the victim may wish to know whether she has been exposed to the deadly virus, the offender has a constitutional right against unreasonable searches and seizures. Using the hypothetical in Section II, this paper will attempt to explain and resolve this dilemma through ethical principles. This resolution will then be compared with the numerous statutes that address the issue and the courts\u27 resolutions

Mandatory HIV Testing of Accused Rapists: Whose Rights Are We Protecting? An Ethical and Legal Analysis

At times, the law appears confusing and unfair. Criminal defendants receive the strictest of all standards of review: guilt beyond a reasonable doubt. But why are the accused afforded greater constitutional protections than the victim? One reason may be found by examining the intent of the authors of the United States Constitution. Our founding fathers wanted Americans to escape the kind of persecution suffered under English rule. From its inception, the Constitution and the laws that followed were based on public policy and ethics. This legal precedence is used to interpret new laws. However, because of precedence, laws often do not reflect the prevailing public opinion of all Americans. Law may not always make sense, but it plays an important role in codifying and uniformly resolving many dilemmas, including biomedical and ethical issues. One such dilemma that has come under increasing scrutiny is whether an alleged sex offender may be forced to submit to an HIV test upon the victim\u27s request. Although the victim may wish to know whether she has been exposed to the deadly virus, the offender has a constitutional right against unreasonable searches and seizures. Using the hypothetical in Section II, this paper will attempt to explain and resolve this dilemma through ethical principles. This resolution will then be compared with the numerous statutes that address the issue and the courts\u27 resolutions

The Recurring Word in the Scientific Articles about the Role of Mg in Living Systems Is “Key”

Magnesium (Mg) is a versatile element involved in all aspects of life on our planet. In plants, beyond being the core of chlorophyll, Mg is central to many biochemical and physiological processes. Animals need Mg for their metabolic pathways and various physiological functions. Importantly, animals and plants share the feature of storing energy as Mg-ATP, the driving force of development, differentiation, and growth. Therefore, there is no doubt about the “key” role of Mg in shaping life on Earth

Prototypes of productivity tools for the jadescript programming language

Jadescript is an agent-oriented programming language built on top of JADE. So far, the focus of the development of the language was on design choices, on syntax refinements, and on the introduction of expressions and constructs for agent-related abstractions and tasks. In this paper, a proposal to achieve the crucial goal of making Jadescript suitable for professional use is presented. The success of Jadescript, as a solid language to build real-world agent-based software systems, is necessarily related to its effective integration with mainstream development tools. In this paper, some of the productivity tools developed to integrate Jadescript with a mainstream development environment are presented as a way to promote the successful adoption of the language towards the community of JADE users

Nonequilibrium Green's function theory for transport and gain properties of quantum cascade structures

The transport and gain properties of quantum cascade (QC) structures are investigated using a nonequilibrium Green's function (NGF) theory which includes quantum effects beyond a Boltzmann transport description. In the NGF theory, we include interface roughness, impurity, and electron-phonon scattering processes within a self-consistent Born approximation, and electron-electron scattering in a mean-field approximation. With this theory we obtain a description of the nonequilibrium stationary state of QC structures under an applied bias, and hence we determine transport properties, such as the current-voltage characteristic of these structures. We define two contributions to the current, one contribution driven by the scattering-free part of the Hamiltonian, and the other driven by the scattering Hamiltonian. We find that the dominant part of the current in these structures, in contrast to simple superlattice structures, is governed mainly by the scattering Hamiltonian. In addition, by considering the linear response of the stationary state of the structure to an applied optical field, we determine the linear susceptibility, and hence the gain or absorption spectra of the structure. A comparison of the spectra obtained from the more rigorous NGF theory with simpler models shows that the spectra tend to be offset to higher values in the simpler theories.Comment: 44 pages, 16 figures, appearing in Physical Review B Dec 200

Feasibility and safety of physical exercise in men with prostate cancer receiving androgen deprivation therapy and radiotherapy: A study protocol

Introduction Androgen deprivation therapy (ADT) and radiotherapy (RT) increase survival in selected patients with prostate cancer. Nevertheless, the side effects of these therapies are associated with an increased risk of accidental falls and fractures and a decreased quality of life. Preliminary evidence suggests that physical exercise can be a valid strategy to reduce the side effects of ADT and RT in men with prostate cancer. Despite this knowledge, most patients with prostate cancer are insufficiently active, and there is a lack of data on the safety and adherence to the recommended dose of physical exercise. This study protocol is designed to examine the feasibility and safety of a multicomponent experimental physical exercise intervention targeting psychophysical and cognitive functions and the quality of life in this population. Methods and analysis This is a pilot feasibility study. Twenty-five men currently treated with ADT and RT for prostate cancer will be invited to participate in a 20-week, multicomponent physical exercise intervention, including supervised and unsupervised exercise sessions and meeting the current recommendation for exercise in cancer. The primary outcomes are physical exercise feasibility (recruitment, adherence and drop-out rates) and safety (adverse events related and unrelated to the intervention). The secondary outcomes are muscle strength, balance, fatigue, symptoms of anxiety and depression, cognitive function, quality of life, and patient satisfaction. We will also record the number of accidental falls and fractures occurring during the intervention and at 1 year of follow-up. Ethics and dissemination The study has received ethics approval from The Area Vasta Nord Local Ethics Committee (Province of Reggio Emilia, 23 June 2020, Number 520/2020/SPER/IRCCSRE). Recruitment began in September 2020 and will be completed in September 2021. The results will be disseminated through scientific journals and conference presentations. Trial registration number NCT04500080

Dissipation and Decoherence in Nanodevices: a Generalized Fermi's Golden Rule

We shall revisit the conventional adiabatic or Markov approximation, which --contrary to the semiclassical case-- does not preserve the positive-definite character of the corresponding density matrix, thus leading to highly non-physical results. To overcome this serious limitation, originally pointed out and partially solved by Davies and co-workers almost three decades ago, we shall propose an alternative more general adiabatic procedure, which (i) is physically justified under the same validity restrictions of the conventional Markov approach, (ii) in the semiclassical limit reduces to the standard Fermi's golden rule, and (iii) describes a genuine Lindblad evolution, thus providing a reliable/robust treatment of energy-dissipation and dephasing processes in electronic quantum devices. Unlike standard master-equation formulations, the dependence of our approximation on the specific choice of the subsystem (that include the common partial trace reduction) does not threaten positivity, and quantum scattering rates are well defined even in case the subsystem is infinitely extended/has continuous spectrum.Comment: 6 pages, 0 figure

Dissipation and Decoherence in Nanodevices: a Generalized Fermi's Golden Rule

We shall revisit the conventional adiabatic or Markov approximation, which --contrary to the semiclassical case-- does not preserve the positive-definite character of the corresponding density matrix, thus leading to highly non-physical results. To overcome this serious limitation, originally pointed out and partially solved by Davies and co-workers almost three decades ago, we shall propose an alternative more general adiabatic procedure, which (i) is physically justified under the same validity restrictions of the conventional Markov approach, (ii) in the semiclassical limit reduces to the standard Fermi's golden rule, and (iii) describes a genuine Lindblad evolution, thus providing a reliable/robust treatment of energy-dissipation and dephasing processes in electronic quantum devices. Unlike standard master-equation formulations, the dependence of our approximation on the specific choice of the subsystem (that include the common partial trace reduction) does not threaten positivity, and quantum scattering rates are well defined even in case the subsystem is infinitely extended/has continuous spectrum.Comment: 6 pages, 0 figure