8,648 research outputs found
Hardy's nonlocality for generalized n-particle GHZ states
In this paper we extend Hardy's nonlocality proof for two spin-1/2 particles
[PRL 71 (1993) 1665] to the case of n spin-1/2 particles configured in the
generalized GHZ state. We show that, for all n \geq 3, any entangled GHZ state
violates the Bell inequality associated with the Hardy experiment. This feature
is important since it has been shown [PRL 88 (2002) 210402] that, for all n
odd, there are entangled GHZ states that do not violate any standard n-particle
correlation Bell inequality.Comment: LaTeX file, 8 pages, 2 eps figures; journal versio
Progress in compilation of the 1:2,000,000-scale topographic map
The application of special photogrammetric techniques has enabled the systematic mapping of Mars' topography at a scale of 1:2,000,000, using high-altitude Viking Orbiter pictures. In fiscal 86, compilation was completed of the 24 subquadrangles that make up the quadrangles MC-12, MC-13, MC-14, MC-15, MC-20, and MC-21. This work completes compilation of the 60 topographic maps covering the equatorial belt (lat. + or - 30 deg). The remaining 80 subquadrangles of Mars are planned to be completed within 3 years (27, 27 and 26 subquadrangles, in fiscal 87, 88, and 89, respectively). Elevations on all topographic maps are relative to the Mars topographic datum. The maps have a contour interval of 1 km and a precision of + or - 1 km. The equatorial-belt maps are Mercator projections having true scale at lat. + or - 27.476 deg. These maps provide more precise information than do those previously available and they will help in understanding the geologic processes that have shaped the Martian surface
Cops: Know Your Rights
Radars beeped, scans ran and the siren was ready for use. Taking the passenger seat in the Iowa State Campus Police car, flashbacks of “Reno 911” episodes ran through my mind as I imagined all of the sweet moves that would be thrown down on every freshman traveling with a backpack full of Keystone. Roaming through Campustown, we drove slowly, circling the mass of students traveling between parties and bar
Observed Behavioral Effects of Medical Treatment for Type B Aortic Dissections
Observed Behavioral Effects when Medically Treating Type B Aortic Dissections
Jordan Williams, James Wu, M.D.
July 21, 2014
Abstract
This study sought to identify possible behavioral effects from treatment of Type B aortic dissections with antihypertensive medications. A retrospective study of 104 patient records and charts was performed searching for eleven different behavioral effects compiled from listed side effects of five different classes of antihypertensive medications. This resulted in 57 patients with observed behavioral effects, and 47 patients with no observed behavioral effects. The median age of the patient population was 68 ± 16 years. Of the 57 patients with observed behavioral effects, the most frequent symptom seen was anxiety and restlessness. Although it was not possible in this study to prove an exact cause and effect relationship between the antihypertensive medications and the behavioral effects, this study is still significant. The pattern of behavioral symptoms identified in this study, as well as the lack of statistically sound research in this area, create a need for further randomized controlled studies in order to possibly improve patient outcomes by identifying other aspects of needed treatment.
Introduction
A Stanford Type B aortic dissection is an event where the wall of the descending aorta tears, diverting blood from the true lumen, into a newly created false lumen (Kouchoukos, Blackstone, Hanley, & Kirklin, 2013). Over time this can lead to an aortic aneurysm, and possibly even a rupture of the aorta. Type B dissections are further classified as complicated and uncomplicated. Complicated dissections are those that involve spinal cord, renal and/or visceral ischemia, as well as aortic rupture (Moulakakis , et al., 2014), while uncomplicated dissections involve none of the aforementioned events. Complicated dissections usually require surgical intervention, by an endovascular stent graft or open surgical repair.
The accepted treatment of uncomplicated Type B aortic dissections continues to be medical treatment utilizing antihypertensive medications. There are many types of antihypertensive medications used in treatments today, including anti-adrenergic (including alpha and beta blockers), diuretics, calcium channel blockers, angiotensin converting enzyme (ACE) inhibitors, angiotensin II receptor blockers (ARB), and drugs that are formed from combinations of all these types (Medications for Treating Hypertension, 2009). With the exception of the diuretics, all of the drugs described act on specific neurological pathways, for example ARB drugs block the angiotensin II receptor, thereby inhibiting angiotensin II from causing an increase in blood pressure.
Due to the fact that these drugs act to decrease blood pressure, changes in the patient’s perfusion may occur, especially if the patient was hypertensive before being diagnosed with the dissection. This change in perfusion then may result in a change in behavior, as the patient’s brain tissue is not receiving and exchanging the same amount of material over time as before. Because most of the prescribed antihypertensive medications act on neurological pathways, the drugs may also cause behavioral effects simply due to their mechanism of action. Patients may describe feeling, “dizzy” or “lightheaded”, among other symptoms, and in some cases may begin acting restlessly or even violently.
A literature review utilizing the key words “type B dissection”, “behavioral effects” and “medical treatment” revealed no studies done on the behavioral effects of treating Type B aortic dissections with antihypertensive medications. Furthermore this search revealed that there were no studies performed that compared the behavioral effects of different classes of antihypertensive medications being used to treat Type B aortic dissections (Chan, Lai, & Wright , 2014). A literature search using the key words “antihypertensive medication” and “behavioral effects” did result in articles published in the 1980’s and 1990’s, on the behavioral effects of various hypertensive medications. Most of these studies focused on the behavioral effects of one class of antihypertensive medication (Bird, Blizard, & Mann, 1990; Blumenthal , et al., 1988; Callender, Hodsman, Hutcheson, Lever, & Robertson, 1983; Conant , et al., 1989; McAnish & Cruickshank, 1990). However as one summary article stated, while these articles generally found no negative impacts on behavior, most of the articles utilized a patient sample of less than 20. (Muldoon, Manuck, Shapiro, & Waldstein, 1991). Therefore due to this finding, and the lack of research on the behavioral effects of treating type B aortic dissections medically, there is a need for further studies involving antihypertensive medications and their behavioral effects, especially when used to treat Type B aortic dissections.
The purpose of this study was to observe possible behavioral consequences of treating Type B aortic dissections medically, in order to determine the frequency of these behavioral consequences, and thus stimulate interest in further research involving randomized controlled trials.
Methods
This study was a retrospective study initially involving 244 patients selected from the hospital database. Patients were sorted based off of the following inclusion criteria: (1) Patient had to have Type B aortic dissection (versus Type A), (2) Patient had to be treated medically versus surgically, and (3) Patient could not have any history of behavioral disorders (stroke, dementia, etc.) before being treated for their Type B dissection. Of the 244 initial patients, 109 were found to present with type B aortic dissections. Of these 109, 104 patients were treated medically and did not have any major behavioral disorders prior to hospital treatment.
These patients’ medical records were then examined to determine if any behavioral changes after administration of antihypertensive medications could be observed. These changes were entered into a database, using the following selection options: anxiousness/restlessness, depression, disorientation, dizziness/lightheadedness, fatigue, hallucinations, headache, nausea, none found, shakes , slurred/garbled speech and syncope. These categories were selected from common side effects listed for the major classes of antihypertensive medications found on Harvard Medical School’s health publication site (Medications for Treating Hypertension, 2009). If a new behavioral category, not seen in prior patients was discovered while reviewing the patients’ charts, this was added to the category set as well. Behavioral effects for each patient were only recorded if they didn’t present with those symptoms prior to hospitalization. For example, if a patient had a history of fatigue and then experienced fatigue, nausea, and dizziness while being treated, then only nausea and dizziness were recorded. A histogram was then constructed to show the relative frequency of the behavioral effects observed, along with a pie chart that compared the number of patients with behavioral effects found to the number of patients that had not observed behavioral effects.
Results
Table 1 Summary of Patient Demographics
Total Patients with Medically Treated Type B Aortic Dissection
104
Number with Behavioral Effects
57
Number of Males
67
Number of Females
37
Date Range
2004-2014 (10 Years)
Age Range
21-94 (73 years)
Median Age
68 ± 16 years
Number of Deaths
10
Figure 1 This figure displays the frequency of a given behavioral effect seen in the study population
Figure 2 This figure depicts the relative amount of patients in which behavioral effects found, and patients in which no effects were found
These results show that the patients in this study were mostly in their upper 60’s. From the histogram (Figure 1), it can be seen that of the behavioral effects observed, anxiousness/restless had the highest frequency. However it can also be observed that 45% of the patients did not present with any behavioral effects (Figure 2). It is also interesting to note that no events of depression or syncope were observed in the patient population (Figure 1).
Conclusion
This study revealed that while almost half of the patients observed did not present with any behavioral effects, the other half presented most frequently with “anxiousness/restlessness”. These results are interesting because the fact that half of the patients did not present with any behavioral effects, seems to possibly concur with the findings of the studies performed twenty years prior on hypertensive medications, which either found no negative effect on behavior or possibly found a positive effect. However as stated before, these studies are advanced in age, utilized very small sample sizes, and were note done on patients being treated for type B dissections. Therefore their results could be unduly biased.
For the patients that did respond to the antihypertensive medications with some form of behavioral effect, the fact that the top three frequencies of behavioral effect were anxiety and restlessness, along with nausea and fatigue, could indicate areas where patients would need more medication or other treatment. Even though this study utilized a cohort of 104 patients, it was still performed at one location, and thus results could still be skewed based on the patient population surrounding the hospital. Also because this study was retrospective in nature, exact cause and effect cannot necessarily be proven between the antihypertensive medication and the behavioral effects.
Based on these findings, randomized controlled trials need to be performed in order to better understand the effects of hypertensive medications on behavior in hypertensive only patients. These results can then be used to study effects that may or may not present themselves in treating Type B aortic dissections medically. In conclusion, this and other studies could greatly enhance the treatment of people with Type B aortic dissections, by identifying critical needs of the patient that might currently be ignored. References
Bird, A., Blizard , R., & Mann, A. (1990). Treating hypertension in the older person: an evaluation of the association of blood pressure level and its reduction in cognitive performance. Journal of Hypertension, 147-52. Retrieved from http://www.druglib.com/abstract/bi/bird-as_j-hypertens_19900200.html
Blumenthal , J., Madden, D., Krantz, D., Light, K., McKee, D., Ekelund, L., & Simon, J. (1988). Short-term behavioral effects of beta-adrenergic medications in men with mild hypertension. Clinical Pharmacology and Therapeutics, 429-35. Retrieved from http://www.ncbi.nlm.gov/pubmed/3356086
Callender, J., Hodsman, G., Hutcheson, M., Lever, A., & Robertson, J. (1983). Mood Changes during captopril therapy for hypertension. A double-blind pilot study. Hypertension, 90-93. Retrieved from http://hyper.ahajournals.org/content/5/5_Pt_2/III90.short
Chan, K. K., Lai, P., & Wright , J. M. (2014). First-line beta-blockers versus other anithypertensive medications for chronic type B aortic dissection. Cochrane Database of Systematic Reviews . doi:DOI: 10.1002/14651858.CD010426.pub2
Conant , J., Engler , R., Janowsky, D., Maisel, A., Gilpin, E., & LeWinter, M. (1989). Central Nervous System side effects of beta-adrenergic blocking agents with high and low lipid solubility . Journal of Cardiovascular Pharmacology , 656-661. Retrieved from http://www.ncbi.nlm.nih.gov/pubmed/2471005
Kouchoukos, N., Blackstone, E., Hanley, F., & Kirklin, J. (2013). Kirklin/Barratt-Boyes Cardiac Surgery, 2 Vol Set. Elsevier Health Sciences. Retrieved 2014
McAnish , J., & Cruickshank, J. (1990). Beta-Blockers and Central Nervous System Side Effects. Pharmacology and Therapeutics , 163-197. Retrieved from http://www.ncbi.nlm.nih.gov/pubmed/1969642
Medications for Treating Hypertension. (2009, August). Harvard Women\u27s Health Watch. Retrieved from http://www.health.harvard.edu/newsletters/Harvard_Womens_Health_Watch/2009/August/Medications-for-treating-hypertension
Moulakakis , K., Mylonas , S., Dalainas, I., Kakisis, J., Kotsis, T., & Liapis, C. (2014). Management of complicated and uncomplicated acute type B dissection. A systematic review and meta-analysis. Annals of Cardiothoracic Surgery, 234-246. Retrieved from http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4052408/
Muldoon, M. F., Manuck, S. B., Shapiro, A. P., & Waldstein, S. R. (1991). Neurobehavioral effects of antihypertensive medications. Journal of Hypertension, 549-559. Retrieved from http://www.ncbi.nlm.nih.gov/pubmed/167945
Methods for detection and characterization of signals in noisy data with the Hilbert-Huang Transform
The Hilbert-Huang Transform is a novel, adaptive approach to time series
analysis that does not make assumptions about the data form. Its adaptive,
local character allows the decomposition of non-stationary signals with
hightime-frequency resolution but also renders it susceptible to degradation
from noise. We show that complementing the HHT with techniques such as
zero-phase filtering, kernel density estimation and Fourier analysis allows it
to be used effectively to detect and characterize signals with low signal to
noise ratio.Comment: submitted to PRD, 10 pages, 9 figures in colo
Bayesian inference of momentum and length dependence of jet energy loss
Using a simple model for medium modification of the jet function through a
parameterized form of the jet energy loss distribution, we carry out a
comprehensive Bayesian analysis of the world data on single inclusive jet
spectra in heavy-ion collisions at both RHIC and LHC energies. We extract the
average jet energy loss as a function of jet
transverse momentum for each collision system and centrality
independently. Assuming jet energy loss is proportional to the initial parton
density as estimated from the
pseudorapidity density of charged hadron multiplicity and
the effective system size given by the
number of participant nucleons , the scaled average jet energy
loss
for jet cone-size is found to have a momentum dependence that is
slightly stronger than a logarithmic form while the system size or length
dependence is slower than a linear one. The fluctuation of jet energy loss is,
however, independent of the initial parton density or the system size. These
are consistent with results from Monte Carlo simulations of jet transport in a
fast expanding quark-gluon plasma in high-energy heavy-ion collisions.Comment: 9 pages with 10 figure
Unusual field-induced transitions in exactly solved mixed spin-(1/2,1) Ising chain with axial and rhombic zero-field splitting parameters
The mixed spin-(1/2,1) Ising chain with axial and rhombic zero-field
splitting parameters in a presence of the longitudinal magnetic field is
exactly solved within the framework of decoration-iteration transformation and
transfer-matrix method. Our particular emphasis is laid on an investigation of
the influence of the rhombic term, which is responsible for an onset of quantum
entanglement between two magnetic states S_k^z = 1 and -1 of the spin-1 atoms.
It is shown that the rhombic term gradually destroys a classical ferrimagnetic
order in the ground state and simultaneously causes diversity in magnetization
curves including intermediate plateau regions, regions with a continuous change
in the magnetization as well as several unusual field-induced transitions
accompanied with magnetization jumps. Another interesting findings concern with
an appearance of the round minimum in the temperature dependence of
susceptibility times temperature data, the double-peak zero-field specific heat
curves and the enhanced magnetocaloric effect. The temperature dependence of
the specific heat with three separate maxima may also be detected when driving
the system through the axial and rhombic zero-field splitting parameters close
enough to a phase boundary between the ferrimagnetic and disordered states and
applying sufficiently small longitudinal magnetic field.Comment: 23 pages, 8 figure
The determination of planetary structure in tidally relaxed inclined systems
[Abridged] The recent discovery of a transiting planet on a non-circular
orbit with a massive highly eccentric companion orbiting HAT-P-13 offers the
possibility of probing the structure of the short-period planet. The ability to
do this relies on the system being in a quasi-equilibrium state in the sense
that the eccentricities are constant on the usual secular timescale, and decay
on a timescale which is much longer than the age of the system. Since the
equilibrium eccentricity is effectively a function only of observable system
parameters and the unknown Love number of the short-period planet, the latter
can be determined with accurate measurements of the planet's eccentricity and
radius. However, this analysis relies on the unlikely assumption that the
system is coplanar. Here we generalize our recent analysis of this fixed-point
phenomenon to mutually inclined systems and show that the fixed point of
coplanar systems is replaced by a limit cycle, with the average value of the
eccentricity decreasing and its amplitude of variation increasing with
increasing mutual inclination. This behaviour significantly reduces the ability
to unambiguously determine the Love number of the short-period planet if the
mutual inclination is higher than around 10^o. We show that for Q-values less
than 10^6, the HAT-P-13 system cannot have a mutual inclination between 54 and
126^o because Kozai oscillations coupled with tidal dissipation would act to
quickly move the inclination outside this range, and that the behaviour of
retrograde systems is the mirror image of that for prograde systems. We derive
a relationship between the equilibrium radius of the short-period planet, its
Q-value and its core mass, and show that given current estimates of e_b and the
planet radius, the HAT-P-13 system is likely to be close to coplanar [...]Comment: 24 pages, 14 figures, Accepted for publication in MNRAS. **NOTE
REFINED PREDICTION FOR MUTUAL INCLINATIO
Spaceborne synthetic-aperture imaging radars: Applications, techniques, and technology
In the last four years, the first two Earth-orbiting, space-borne, synthetic-aperture imaging radars (SAR) were successfully developed and operated. This was a major achievement in the development of spaceborne radar sensors and ground processors. The data acquired with these sensors extended the capability of Earth resources and ocean-surface observation into a new region of the electromagnetic spectrum. This paper is a review of the different aspects of spaceborne imaging radars. It includes a review of: 1) the unique characteristics of space-borne SAR systems; 2) the state of the art in spaceborne SAR hardware and SAR optical and digital processors; 3) the different data-handling techniques; and 4) the different applications of spaceborne SAR data
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