645 research outputs found
Interconnect Challenges in Highly Integrated MEMS/ASIC Subsystems
Micromechanical devices like accelerometers or rotation sensors form an
increasing segment beneath the devices supplying the consumer market. A hybrid
integration approach to build smart sensor clusters for the precise detection
of movements in all spatial dimensions requires a large toolbox of interconnect
technologies, each with its own constraints regarding the total process
integration. Specific challenges described in this paper are post-CMOS
feedthroughs, front-to-front die contact arrays, vacuum-compliant lateral
interconnect and fine-pitch solder balling to finally form a Chip-Scale
System-in-Package (CSSiP).Comment: Submitted on behalf of EDA Publishing Association
(http://irevues.inist.fr/EDA-Publishing
Aneurysms of the intracranial segment of the ophthalmic artery trunk. case report and systematic literature review
Aneurysms arising from the ophthalmic artery trunk (OAT) are very rare, particularly in the artery's intracranial course. The onset of a subarachnoid hemorrhage (SAH) from a ruptured OAT aneurysm in this segment is extremely rare. We present a case and discuss the anatomy, clinical significance, and therapeutic options for an aneurysm at this site. We also retrospectively analyzed the record of a patient with a ruptured aneurysm of the intracranial segment of the OAT and conducted a comprehensive and systematic review of the PubMed and Scopus databases for literature on this pathology. Only one case report of SAH from an aneurysm of the intracranial segment of the OAT was published in the literature. Only in our case was the intracranial OAT segment aneurysm discovered in the acute phase of SAH. Conventional angiography with three-dimensional acquisition may help detect aneurysms at this level. Detailed knowledge of the anatomy of the OAT is of paramount importance for both surgical and endovascular approaches. Surgical treatment is complex because of difficulties in accessing the orbital region and the risk of optic nerve and vascular injuries. Endovascular treatment, when feasible, could be a good alternative to reduce the risk of loss of vision related to surgical manipulation
Time evolution of the behaviour of Brazilian legislative Representatives using a complex network approach
The follow up of Representative behavior after elections is imperative for a
democratic Representative system, at the very least to punish betrayal with no
re-election. Our goal was to show how to follow Representatives' and how to
show behavior in real situations and observe trends in political crises
including the onset of game changing political instabilities. We used
correlation and correlation distance matrices of Brazilian Representative votes
during four presidential terms. Re-ordering these matrices with Minimal
Spanning Trees displays the dynamical formation of clusters for the sixteen
year period, which includes one Presidential impeachment. The reordered
matrices, colored by correlation strength and by the parties clearly show the
origin of observed clusters and their evolution over time. When large clusters
provide government support cluster breaks, political instability arises, which
could lead to an impeachment, a trend we observed three years before the
Brazilian President was impeached. We believe this method could be applied to
foresee other political storms.Comment: 11 pages, 4 Figure
Sex and gender optometry: from retinal design to stereopsis
Scientific research in optometry aims to increase the ability to predict optical effects induced by lens fitting, allowing us to understand how geometrical concepts and physical phenomena translate into perceptual responses. It is possible, for instance, to investigate how differential perspective affects three-dimensional perception, indeed the ocular parallax error, that occurs as the eyes are separated horizontally by a certain distance (DAV), allows for the depth interval between two object points to be appreciated and transferred to the retina. In a study conducted at the University of Turin, the DAVs measured on a group of students were compared with the students’ stereo acuity values, with the aim of highlighting whether female subjects, whose DAVs are smaller than those of men, actually have less sense of depth. The measurement protocol and the results obtained will be explained. The research perspective is the parameterization of optometric tests to take into account differences due to gender, in order to detect any abnormalities more accurately
El Ministro de la Guerra : jefe del ejército español, en el dÃa dos de mayo de 1808 ante la historia
Copia digital. Madrid : Ministerio de Cultura. Subdirección General de Coordinación Bibliotecaria, 200
SPAD-502 readings in response to photon fluence in leaves with different chlorophyll content
The chlorophyll meter (SPAD-502) is widely used to estimate chlorophyll content, but non-uniform chloroplast distribution can affect its accuracy. This study aimed to assess the effect of photon fluence (F, irradiance x time of illumination) in leaves with different chlorophyll content and determine the effect of chlorophyll a/b on SPAD values of four tropical tree species (Croton draconoides Müll. Arg., Hevea guianensis Aubl., Hymenaea courbaril L. and Matisia cordata H.B.K.). There were also determined calibration equations for the chlorophyll meter and assessed the effect of F on SPAD values between 07:00 h and 17:00 h. Calibration equations were obtained after determining leaf chlorophyll content in the laboratory. Increases in F with time caused a reduction in SPAD values in species with a high chlorophyll content, with reductions of 20% in M. cordata and 10% in H. guianensis. Leaves of C. draconoides and H. courbaril had lower chlorophyll content and showed no changes in SPAD values with increase in F. The chlorophyll a/b ratio increased with SPAD values and the SPAD/chlorophyll relationship was best described by an exponential equation. It seems that F may affect SPAD values in leaves with high chlorophyll content, probably due to non-uniform chloroplast distribution at high irradiance. This indicates that SPAD values tend to be more accurate if recorded early in morning when irradiance is low
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