1,256 research outputs found
Pulmonar Vascular Changes in the Plain Chest Film of Cardiac Patients
The correct interpretation of chest film on cardiac patients is very important. The most important feature is the radiographic appearance of the pulmonary vascularity. Four different patterns of pulmonary vascularity are considered: normal, decreased, increased and uneven. The different diseases associated with each type are mentioned. From the pulmonary vascular pattern one can deduct hemodynamic data which are important for the diagnosis, grade of severity and follow-up
Photonic hydrophones based on coated fiber Bragg gratings
The development of underwater acoustic sensors with performances competitive with conventional piezoelectric hydrophones would overcome intrinsic limitations related to the piezoceramic technology. Optical fiber technology represents a valid platform to implement acoustic sensors for underwater scenarios. Here we report on recent numerical and experimental results obtained with photonic
hydrophones based on fiber-Bragg-grating (FBG) with ring shaped coatings. Our numerical results fully characterize the opto-acoustic response of the optical hydrophone, and highlight the key role played by the coating in enhancing significantly its sensitivity by comparison with a standard uncoated configuration. Furthermore, the analysis reveals that the hydrophone sensitivity spectrum exhibits characteristic resonances, which strongly improve the sensitivity with respect to its background level. Our experimental results confirmed the expected resonant behavior of such devices and are in good agreement with the numerical predictions. Optical hydrophones based on coated FBG exhibited an excellent capability to detect acoustic
waves in the acoustic frequency range, with extremely high sensitivities. By comparison with bare FBGs, sensitivity enhancements of up to three orders of magnitude were found, demonstrating the effectiveness of polymeric coatings in tailoring the acoustic response of FBG-based hydrophones
“I guess somebody already told you”: LGBTQ+ Students’ Experiences in Secondary School Contexts
This qualitative study is focused on the secondary educational experiences of Lesbian, Gay, Bisexual, Transgender, Queer/Questioning (LGBTQ+) youth. Based on the Gay Lesbian and Straight Education Network’s 2017 survey results, researchers asserted that the school climate remains hostile for LGBTQ+ youth (Kosciw et al., 2018). Three specific factors contributing to this adverse climate are: (a) students’ safety, (b) school policies, and (c) teacher inaction. Therefore, this qualitative study put forth the following research question: What can be learned from the secondary school experiences of genderqueer/gender nonbinary youth? This main question was followed with the following sub-questions: a) What did their experiences reveal about school connectedness?; b) How did they view their identity in relationship to their secondary school experiences?; and c) How did their school experiences inform how they view allies? The three participants included in this study self-identified as genderqueer or gender nonbinary and were 19 years old. These participants attended public middle and high school for some or all of their secondary schooling. The themes that emerged through both narrative analysis and multiple coding cycles include: 1) connections and disconnections to school; 2) positive teacher relationships; and 3) identity as a reflection of self. Based on my analysis of these themes using a queer theoretical framework, I propose to provide educators with professional development that will develop an awareness of heteronormative and gender normative cultures within schools. This professional development seeks to address how teachers have the opportunity to disrupt the heteronormative and gender normative culture
Plant and plan, care and grow. A hands-on exercise using the (inner) sustainable development goals to teach research methodology to final year sociology students
Etymologically, the word seminar comes from the Latin semen, which means
“seed”. Inspired by such linguistic archeology this text describes an exercise
developed with undergraduate sociology students, who were literally invited
to sow a seed and observe its growth over the course of a semester in which
they must design a sociological research project. Transversally, the students
perceived the exercise of germinating a plant as a metaphor for the
development of the research project as a living and dynamic reality,
highlighting the beginning, growth and maturation as key moments.
Additionally, students emphasized that observing the germination and
development of the plant allowed them to critically reflect on the different
stages of the research project, while allowing their own inner development,
namely with regard to the dimensions of “being”, “thinking”, “relating”,
“collaborating” and “driving change”
Data storage solutions for the federation of sensor networks
In the near future, most of our everyday devices will be accessible via some
network and uniquely identified for interconnection over the Internet. This
new paradigm, called Internet of Things (IoT), is already starting to influence
our society and is now driving developments in many areas.
There will be thousands, or even millions, of constrained devices that will
be connected using standard protocols, such as Constrained Application Protocol
(CoAP), that have been developed under certain specifications appropriate
for this type of devices. In addition, there will be a need to interconnect
networks of constrained devices in a reliable and scalable way, and federations
of sensor networks using the Internet as a medium will be formed.
To make the federation of geographically distributed CoAP based sensor
networks possible, a CoAP Usage for REsource LOcation And Discovery (RELOAD)
was recently proposed. RELOAD is a peer-to-peer (P2P) protocol that
ensures an abstract storage and messaging service to its clients, and it relies
on a set of cooperating peers that form a P2P overlay network for this purpose.
This protocol allows to define so-called Usages for applications to work
on top of this overlay network. The CoAP Usage for RELOAD is, therefore,
a way for CoAP based devices to store their resources in a distributed P2P
overlay. Although CoAP Usage for RELOAD is an important step towards
the federation of sensor networks, in the particular case of IoT there will be
consistency and efficiency problems. This happens because the resources of
CoAP devices/Things can be in multiple data objects stored at the overlay network,
called P2P resources. Thus, Thing resource updates can end up being
consuming, as multiple P2P resources will have to be modified. Mechanisms
to ensure consistency become, therefore, necessary.
This thesis contributes to advances in the federation of sensor networks by
proposing mechanisms for RELOAD/CoAP architectures that will allow consistency
to be ensured. An overlay network service, required for such mechanisms
to operate, is also proposed.Num futuro próximo, a maioria dos nossos dispositivos do dia-a-dia estarão
acessíveis através de uma rede e serão identificados de forma única para
poderem interligar-se através da Internet. Este novo paradigma, conhecido
hoje por Internet das Coisas (IoT), já está a começar a influenciar a nossa
sociedade e está agora a impulsionar desenvolvimentos em inúmeras áreas.
Teremos milhares, ou mesmo milhões, de dispositivos restritos que utilizarão protocolos padrão que foram desenvolvidos de forma a cumprir determinadas
especificações associadas a este tipo de dispositivos, especificações essas
que têm a ver com o facto destes dispositivos terem normalmente restrições
de memória, pouca capacidade de processamento e muitos possuirem limitações
energéticas. Surgirá ainda a necessidade de interligar, de forma fiável e
escalonável, redes de dispositivos restritos.(…
The Role of Nonsteroidal Anti-Inflammatory Drugs (NSAIDs) in the Management of the Post-Embolization Symptoms after Uterine Artery Embolization
Uterine artery embolization (UAE) is usually a very painful procedure. Although pain after the procedure can occur as a single symptom, it usually is associated with other symptoms such as nausea, vomiting, pelvic pain, general malaise, fever and leukocytosis that characterize the post-embolization syndrome. Management of the post-embolization symptoms and of pain in particular, is paramount if UAE is to be performed as an outpatient procedure. Different protocols have used analgesic and/or anti-inflammatory agents to control these symptoms. Nonsteroidal anti-inflammatory drugs (NSAIDs) are frequently used in association with analgesic drugs to control post-embolization symptoms. In our institution the patients start oral medication with NSAIDs the day before the procedure and continue it during and after UAE. We also mix NSAIDs with the embolizing particles. This enables a reduction in the inflammation present in the uterine fibroids and helps controlling the pain. The purpose of this paper is to review the importance of NSAIDs in the management of the post-embolization symptoms. We describe the protocol that we use in our institution that enables us to perform the procedure on an outpatient basis with same day discharge and good control of the post-embolization symptoms with oral NSAIDs and analgesics.publishersversionpublishe
Guided resonances in photonic quasicrystals
In this paper, we report on the first evidence of guided resonances (GRs) in
aperiodically-ordered photonic crystals, tied to the concept of "quasicrystals"
in solid-state physics. Via a full-wave numerical study of the transmittance
response and the modal structure of a photonic quasicrystal (PQC) slab based on
a representative aperiodic geometry (Ammann-Beenker octagonal tiling), we
demonstrate the possibility of exciting GR modes, and highlight similarities
and differences with the periodic case. In particular, we show that, as for the
periodic case, GRs arise from the coupling of the incident plane-wave with
degenerate modes of the PQC slab that exhibit a matching symmetry in the
spatial distribution, and can still be parameterized via a Fano-like model.
Besides the phenomenological implications, our results may provide new degrees
of freedom in the engineering of GRs, and pave the way for new developments and
applications.Comment: 12 pages, 8 figures, 1 table. Three figures added; Sec. 3.3
significantly expande
Experimental evidence of guided resonances in photonic crystals with aperiodically-ordered supercells
We report on the first experimental evidence of guided resonances (GRs) in
photonic crystal slabs based on aperiodically-ordered supercells. Using the
Ammann-Beenker (quasiperiodic, 8-fold symmetric) tiling geometry, we present
our study on the fabrication, experimental characterization, and full-wave
numerical simulation of two representative structures (with different filling
parameters) operating at near-infrared wavelengths (1300-1600 nm). Our results
show a fairly good agreement between measurements and numerical predictions,
and pave the way for the development of new strategies (based, e.g., on the
lattice symmetry breaking) for GR engineering.Comment: 10 pages, 5 figures (minor revisions
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