6,999 research outputs found
A general theorem on the divergence of vortex beams
The propagation and divergence properties of beams carrying orbital angular
momentum (OAM) play a crucial role in many applications. Here we present a
general study on the divergence of optical beams with OAM. We show that the
mean absolute value of the OAM imposes a lower bound on the value of the beam
divergence. We discuss our results for two different definitions of the
divergence, the so called rms or encircled-energy. The bound on the rms
divergence can be expressed as a generalized uncertainty principle, with
applications in long-range communication, microscopy and 2D quantum systems.Comment: RevTex, published versio
Effect of pig weaning age and commingling after the nursery phase on humoral and behavioral indicators of well-being and on growth performance
Two hundred and sixteen pigs were weaned at 14 or 21 d of age to determine the effect of weaning age and commingling after the nursery phase on growth and behavior of pigs in a wean-tofinish facility. Pigs were divided into older and younger age groups and allotted 12 pigs/pen with nine replications of each group. At the end of the nursery phase (d 34 after weaning), one-half of the pigs in each group were removed and commingled for the grower/finisher phase and the other half remained in their original pens. Beginning at weaning (d 0), pigs were monitored via camera surveillance following weaning, commingling, and on d 65 after weaning. While in the nursery phase, older pigs had greater gain and feed intake than younger pigs, however, younger pigs were more efficient throughout the nursery phase than older pigs. Toward the end of the grower/finisher period, younger pigs had greater gain, feed intake, and gain:feed than older pigs and reached a common weight 4 d sooner. Younger pigs spent more time standing or moving during the nursery phase than older pigs. Immediately following commingling, the younger, unmixed pigs spent more time feeding. However on d 65 after weaning, the older, commingled pigs and younger, unmixed pigs spent more time feeding than older, unmixed pigs and younger, commingled pigs. In conclusion, younger pigs grew slower than older pigs during the nursery phase; however, younger pigs gained more during the finishing period. Additionally, weaning age and commingling influenced feeding behavior during the grower/finisher period
Implementing Reading and Writing in Secondary Mathematics
Literacy in secondary mathematics continues to be difficult for many. Mathematics teachers and researchers continue to develop support documents for secondary math teachers. It is important to utilize the literacy strategies already established by other content areas. It is feasible to adjust these strategies to suit the needs of mathematics students. Literacy across the content areas is a relatively new idea in education, but literacy in mathematics is even more foreign. It is necessary to use the available literacy strategies to develop materials applicable in the secondary mathematics classroom
Directly estimating non-classicality
We establish a method of directly measuring and estimating non-classicality -
operationally defined in terms of the distinguishability of a given state from
one with a positive Wigner function. It allows to certify non-classicality,
based on possibly much fewer measurement settings than necessary for obtaining
complete tomographic knowledge, and is at the same time equipped with a full
certificate. We find that even from measuring two conjugate variables alone,
one may infer the non-classicality of quantum mechanical modes. This method
also provides a practical tool to eventually certify such features in
mechanical degrees of freedom in opto-mechanics. The proof of the result is
based on Bochner's theorem characterizing classical and quantum characteristic
functions and on semi-definite programming. In this joint
theoretical-experimental work we present data from experimental optical Fock
state preparation, demonstrating the functioning of the approach.Comment: 4+1 pages, 2 figures, minor change
Behavioral Health among Asian American and Pacific Islanders: The Impact of Acculturation and Receipt of Behavioral Health Services on Depression and Anxiety
Behavioral health models improve access to mental health care by integrating psychology and medicine. While integrated care is supported among the general population, less research focuses on the model with Asian American and Pacific Islanders (AAPIs). AAPIs are low treatment-seeking due to various barriers (e.g., limited English proficiency, stigma, insurance) and acculturation stressors. Using hierarchical linear modeling, this study examined longitudinal depression (PHQ-9) and anxiety (GAD-7) growth trajectories among AAPIs within a behavioral health model and the moderating impact of acculturation and frequency of behavioral health visits. The best fitting model was from a sample who (N = 354; 71.5% female) met the following inclusion criteria: (a) AAPI, (b) over 18 years of age, (c) engaged in three or more behavioral health visits, (d) PHQ-9 and GAD-7 scores at three or more time points, (e) proxy acculturation data. The sample was 39% Vietnamese, mean age was 55.84 (SD = 16.92), and behavioral health visits ranged from 3 to 12. Depression and anxiety growth trajectories indicated significant cubic functions (PHQ-9, β30 = -.077, p \u3c .001; GAD-7, β30 = -.045, p \u3c .001). For depression, there was a non-significant moderating effect of acculturation (β11 = .163, p = .468, β21 = -.005, p = .931, β31 = -.001, p = .770), but significant effect of frequency of behavioral health visits (β12 = .252, p = .005, β22 = -.080, p = .004, β32 = .005, p = .010). For anxiety, there was a non-significant moderating effect of acculturation (β11 = .255, p = .148) and frequency of behavioral health visits (β12 = .126, p = .075) on instantaneous rate of change (i.e., slope). There was a non-significant moderating effect of acculturation (β21 = -.018, p = .687) but significant effect of frequency of behavioral health visits (β22 = -.044, p = .035) on change to the rate of change. Both moderators were non-significant at the cubic level (β31 = -.008, p = .822, β32 = .003, p = .057). Depression and anxiety outcomes among AAPIs improved within the behavioral health model. Moderation by acculturation and frequency of behavioral health visits varied
Swim Lesson
This poem explores feelings of agency and resilience when a loved one passes away from disability complications. It problematizes the clean narrative of addiction and disavows the myth of overcoming chronic pain
Competitiveness Towards ASEAN Economic Community
ASEAN Economic Community will be the driving force of an economic integration within ASEAN countries, and between ASEAN countries and the rest of the world. Many believe the economic integration will realize ASEAN framework as a single market and production base, to increase competitive economic region, to support more equitable economic development, and as a stepping stone toward full integration into globaleconomy. Commitments of the implementation of AEC Blueprint by ASEAN member countries will be a crucial role to achieve the objective of the ASEAN Vision, Mission, and Targets
Normal form decomposition for Gaussian-to-Gaussian superoperators
In this paper we explore the set of linear maps sending the set of quantum
Gaussian states into itself. These maps are in general not positive, a feature
which can be exploited as a test to check whether a given quantum state belongs
to the convex hull of Gaussian states (if one of the considered maps sends it
into a non positive operator, the above state is certified not to belong to the
set). Generalizing a result known to be valid under the assumption of complete
positivity, we provide a characterization of these Gaussian-to-Gaussian (not
necessarily positive) superoperators in terms of their action on the
characteristic function of the inputs. For the special case of one-mode
mappings we also show that any Gaussian-to-Gaussian superoperator can be
expressed as a concatenation of a phase-space dilatation, followed by the
action of a completely positive Gaussian channel, possibly composed with a
transposition. While a similar decomposition is shown to fail in the multi-mode
scenario, we prove that it still holds at least under the further hypothesis of
homogeneous action on the covariance matrix
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A normative approach to transitions in energy demand: an energy justice and fuel poverty case study
Meeting emissions targets necessitates both the rapid transformation of our physical energy systems and the societies that surround or use them, influencing who uses which energy source, how, and when. Thus, it is inevitable that there will be winners and losers, including the people who, for a variety of reasons, cannot access or afford the benefits from those transitions. In this vein, making sure that all voices are represented in transitions plans and their actualisation is undoubtedly a question of social justice. Yet despite ongoing debates about ethics and justice, one social element missing from transitions frameworks is explicit, practice-oriented engagement with the energy justice concept; an omission that is arguably mirrored in practice. In this regard, this chapter serves a dual purpose. First, it reiterates and reaffirms the need for socially just transitions approaches in energy demand scholarship and explores the role of the energy justice concept in this. Second, through a case study of fuel poverty, it begins to explore what this may practically look like. We close with policy-relevant recommendations
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