Sample records for abbot prism chagas

  1. A Singular School: Abbot Academy, 1828-1973.

    ERIC Educational Resources Information Center

    Lloyd, Susan McIntosh

    This is the biography of a school: Abbot Academy of Andover, Massachusetts. One of the first educational institutions in New England to be founded for girls and women alone, Abbot had by far the longest corporate life of any: it opened its doors to seventy students on May 6, 1829 and endured until those same doors and all the material goods inside…

  2. Bathymetric and oceanic controls on Abbot Ice Shelf thickness and stability

    NASA Astrophysics Data System (ADS)

    Cochran, J. R.; Jacobs, S. S.; Tinto, K. J.; Bell, R. E.

    2014-05-01

    Ice shelves play key roles in stabilizing Antarctica's ice sheets, maintaining its high albedo and returning freshwater to the Southern Ocean. Improved data sets of ice shelf draft and underlying bathymetry are important for assessing ocean-ice interactions and modeling ice response to climate change. The long, narrow Abbot Ice Shelf south of Thurston Island produces a large volume of meltwater, but is close to being in overall mass balance. Here we invert NASA Operation IceBridge (OIB) airborne gravity data over the Abbot region to obtain sub-ice bathymetry, and combine OIB elevation and ice thickness measurements to estimate ice draft. A series of asymmetric fault-bounded basins formed during rifting of Zealandia from Antarctica underlie the Abbot Ice Shelf west of 94° W and the Cosgrove Ice Shelf to the south. Sub-ice water column depths along OIB flight lines are sufficiently deep to allow warm deep and thermocline waters observed near the western Abbot ice front to circulate through much of the ice shelf cavity. An average ice shelf draft of ~200 m, 15% less than the Bedmap2 compilation, coincides with the summer transition between the ocean surface mixed layer and upper thermocline. Thick ice streams feeding the Abbot cross relatively stable grounding lines and are rapidly thinned by the warmest inflow. While the ice shelf is presently in equilibrium, the overall correspondence between draft distribution and thermocline depth indicates sensitivity to changes in characteristics of the ocean surface and deep waters.

  3. James Abbot McNeill Whistler: "At the Piano."

    ERIC Educational Resources Information Center

    Hallenberg, Heather

    1987-01-01

    "At the Piano," an oil-on-canvas painting completed in 1859 by James Abbot McNeill Whistler, is used as the basis of a lesson designed to help junior high school students analyze the painting's mood, subject matter, and composition. (JDH)

  4. Mass balance reassessment of glaciers draining into the Abbot and Getz Ice Shelves of West Antarctica

    NASA Astrophysics Data System (ADS)

    Chuter, S. J.; Martín-Español, A.; Wouters, B.; Bamber, J. L.

    2017-07-01

    We present a reassessment of input-output method ice mass budget estimates for the Abbot and Getz regions of West Antarctica using CryoSat-2-derived ice thickness estimates. The mass budget is 8 ± 6 Gt yr-1 and 5 ± 17 Gt yr-1 for the Abbot and Getz sectors, respectively, for the period 2006-2008. Over the Abbot region, our results resolve a previous discrepancy with elevation rates from altimetry, due to a previous 30% overestimation of ice thickness. For the Getz sector, our results are at the more positive bound of estimates from other techniques. Grounding line velocity increases up to 20% between 2007 and 2014 alongside mean elevation rates of -0.67 ± 0.13 m yr-1 between 2010 and 2013 indicate the onset of a dynamic thinning signal. Mean snowfall trends of -0.33 m yr-1 water equivalent since 2006 indicate recent mass trends are driven by both ice dynamics and surface processes.

  5. Re-assessment of the mass balance of the Abbot and Getz sectors of West Antarctica

    NASA Astrophysics Data System (ADS)

    Chuter, S.; Bamber, J. L.

    2016-12-01

    Large discrepancies exist in mass balance estimates for the Getz and Abbot drainage basins, primarily due to previous poor knowledge of ice thickness at the grounding line, poor coverage by previous altimetry missions and signal leakage issues for GRACE. Large errors arise when using ice thickness measurements derived from ERS-1 and/or ICESat altimetry data due to poor track spacing, `loss of lock' issues near the grounding line and the complex morphology of these shelves, requiring fine resolution to derive robust and accurate elevations close to the grounding line. However, the advent of CryoSat-2 with its unique orbit and SARIn mode of operation has overcome these issues and enabled the determination of ice shelf thickness at a much higher accuracy than possible from previous satellites, particularly within the grounding zone. Here we present a contemporary estimate of ice sheet mass balance for the both the Getz and Abbot drainage basins. This is achieved through the use of contemporary velocity data derived from Landsat feature tracking and the use of CryoSat-2 derived ice thickness measurements. Additionally, we use this new ice thickness dataset to reassess mass balance estimates from 2008/2009, where there were large disparities between results from radar altimetry and Input-Output methodologies over the Abbot region in particular. These contemporary results are compared with other present day estimates from gravimetry and altimetry elevation changes.

  6. Reassessment of the mass balance of the Abbot and Getz sectors of West Antarctica

    NASA Astrophysics Data System (ADS)

    Chuter, Stephen; Martín-Español, Alba; Wouters, Bert; Bamber, Jonathan

    2017-04-01

    Large discrepancies exist in mass balance estimates for the Getz and Abbot drainage basins, primarily due to previous poor knowledge of ice thickness at the grounding line, poor coverage by previous altimetry missions and signal leakage issues for GRACE. This is particularly the case for the Abbot region, where previously there have been contrasting positive ice sheet basin elevation rates from altimetry and negative mass budget estimates. Large errors arise when using ice thickness measurements derived from ERS-1 and/or ICESat altimetry data due to poor track spacing, 'loss of lock' issues near the grounding line and the complex morphology of these shelves, requiring fine resolution to derive robust and accurate elevations close to the grounding line. This was exemplified with the manual adjustments of up to 100 m required at the grounding line during the creation of Bedmap2. However, the advent of CryoSat-2 with its unique orbit and SARIn mode of operation has overcome these issues and enabled the determination of ice shelf thickness at a much higher accuracy than possible from previous satellites, particularly within the grounding zone. We present a reassessment of mass balance estimates for the 2007-2009 epoch using improved CryoSat-2 ice thicknesses. We find that CryoSat-2 ice thickness estimates are systematically thinner by 30% and 16.5% for the Abbot and Getz sectors respectively. Our new mass balance estimate of 8 ± 6 Gt yr-1for the Abbot region resolves the previous discrepancy with altimetry. Over the Getz region, the new mass balance estimate of 7.56 ± 16.6 Gt yr-1is in better agreement with other geodetic techniques. We also find there has been an increase in grounding line velocity of up to 20% since the 2007-2009 epoch, coupled with mean ice sheet thinning rates of -0.67 ± 0.13 m yr-1 derived from CryoSat-2 in fast flow regions. This is in addition to mean snowfall trends of -0.33 m yr-1w.e. since 2006. This suggests the onset of a dynamic

  7. Carlos Chagas: biographical sketch.

    PubMed

    Moncayo, Alvaro

    2010-01-01

    Carlos Chagas was born on 9 July 1878 in the farm "Bon Retiro" located close to the City of Oliveira in the interior of the State of Minas Gerais, Brazil. He started his medical studies in 1897 at the School of Medicine of Rio de Janeiro. In the late XIX century, the works by Louis Pasteur and Robert Koch induced a change in the medical paradigm with emphasis in experimental demonstrations of the causal link between microbes and disease. During the same years in Germany appeared the pathological concept of disease, linking organic lesions with symptoms. All these innovations were adopted by the reforms of the medical schools in Brazil and influenced the scientific formation of Chagas. Chagas completed his medical studies between 1897 and 1903 and his examinations during these years were always ranked with high grades. Oswaldo Cruz accepted Chagas as a doctoral candidate and directed his thesis on "Hematological studies of Malaria" which was received with honors by the examiners. In 1903 the director appointed Chagas as research assistant at the Institute. In those years, the Institute of Manguinhos, under the direction of Oswaldo Cruz, initiated a process of institutional growth and gathered a distinguished group of Brazilian and foreign scientists. In 1907, he was requested to investigate and control a malaria outbreak in Lassance, Minas Gerais. In this moment Chagas could not have imagined that this field research was the beginning of one of the most notable medical discoveries. Chagas was, at the age of 28, a Research Assistant at the Institute of Manguinhos and was studying a new flagellate parasite isolated from triatomine insects captured in the State of Minas Gerais. Chagas made his discoveries in this order: first the causal agent, then the vector and finally the human cases. These notable discoveries were carried out by Chagas in twenty months. At the age of 33 Chagas had completed his discoveries and published the scientific articles that gave him world

  8. Comparison of near fusional vergence ranges with rotary prisms and with prism bars.

    PubMed

    Goss, David A; Becker, Emily

    2011-02-01

    Common methods for determination of fusional vergence ranges make use of rotary prisms in the phoropter or prism bars out of the phoropter. This study compared near fusional vergence ranges with rotary prisms with those with prism bars. Fifty young adults served as subjects. Odd-numbered subjects had rotary prism vergences performed before prism bar vergences. For even-numbered subjects, prism bar vergences were done first. Base-in (BI) vergences were done before base-out (BO) vergences with both rotary prisms and prism bars. A coefficient of agreement was calculated by multiplying the standard deviation of the individual subject differences between rotary prisms and prism bars by 1.96, to approximate the range within which the 2 tests would agree 95% of the time. The lowest coefficient of agreement was 7.3Δ for the BI recovery. The others were high, ranging from 15.4Δ for the BO recovery to 19.5Δ for the BO break. Fusional vergence ranges determined by prism bars out of the phoropter cannot be used interchangeably with those determined by phoropter rotary prisms for the purpose of follow-up on individual patients or for the purpose of comparison with norms. Copyright © 2010 American Optometric Association. Published by Elsevier Inc. All rights reserved.

  9. Chagas disease in prehistory.

    PubMed

    Ferreira, Luiz F; Jansen, Ana M; Araújo, Adauto

    2011-09-01

    The classical hypothesis proposes that Chagas disease has been originated in the Andean region among prehistoric people when they started domesticating animals, changing to sedentary habits, and adopting agriculture. These changes in their way of life happened nearly 6,000 years ago. However, paleoparasitological data based on molecular tools showed that Trypanosoma cruzi infection and Chagas disease were commonly found both in South and North American prehistoric populations long before that time, suggesting that Chagas disease may be as old as the human presence in the American continent. The study of the origin and dispersion of Trypanosoma cruzi infection among prehistoric human populations may help in the comprehension of the clinical and epidemiological questions on Chagas disease that still remain unanswered.

  10. Carlos Chagas Discoveries as a Drop Back to Scientific Construction of Chronic Chagas Heart Disease

    PubMed Central

    Bestetti, Reinaldo B.; Restini, Carolina Baraldi A.; Couto, Lucélio B.

    2016-01-01

    The scientific construction of chronic Chagas heart disease (CCHD) started in 1910 when Carlos Chagas highlighted the presence of cardiac arrhythmia during physical examination of patients with chronic Chagas disease, and described a case of heart failure associated with myocardial inflammation and nests of parasites at autopsy. He described sudden cardiac death associated with arrhythmias in 1911, and its association with complete AV block detected by Jacquet's polygraph as Chagas reported in 1912. Chagas showed the presence of myocardial fibrosis underlying the clinical picture of CCHD in 1916, he presented a full characterization of the clinical aspects of CCHD in 1922. In 1928, Chagas detected fibrosis of the conductive system, and pointed out the presence of marked cardiomegaly at the chest X-Ray associated with minimal symptomatology. The use of serological reaction to diagnose CCHD was put into clinical practice in 1936, after Chagas' death, which along with the 12-lead ECG, revealed the epidemiological importance of CCHD in 1945. In 1953, the long period between initial infection and appearance of CCHD was established, whereas the annual incidence of CCHD from patients with the indeterminate form of the disease was established in 1956. The use of heart catheterization in 1965, exercise stress testing in 1973, Holter monitoring in 1975, Electrophysiologic testing in 1973, echocardiography in 1975, endomyocardial biopsy in 1981, and Magnetic Resonance Imaging in 1995, added to the fundamental clinical aspects of CCHD as described by Carlos Chagas. PMID:27223644

  11. Carlos Chagas Discoveries as a Drop Back to Scientific Construction of Chronic Chagas Heart Disease.

    PubMed

    Bestetti, Reinaldo B; Restini, Carolina Baraldi A; Couto, Lucélio B

    2016-07-01

    The scientific construction of chronic Chagas heart disease (CCHD) started in 1910 when Carlos Chagas highlighted the presence of cardiac arrhythmia during physical examination of patients with chronic Chagas disease, and described a case of heart failure associated with myocardial inflammation and nests of parasites at autopsy. He described sudden cardiac death associated with arrhythmias in 1911, and its association with complete AV block detected by Jacquet's polygraph as Chagas reported in 1912. Chagas showed the presence of myocardial fibrosis underlying the clinical picture of CCHD in 1916, he presented a full characterization of the clinical aspects of CCHD in 1922. In 1928, Chagas detected fibrosis of the conductive system, and pointed out the presence of marked cardiomegaly at the chest X-Ray associated with minimal symptomatology. The use of serological reaction to diagnose CCHD was put into clinical practice in 1936, after Chagas' death, which along with the 12-lead ECG, revealed the epidemiological importance of CCHD in 1945. In 1953, the long period between initial infection and appearance of CCHD was established, whereas the annual incidence of CCHD from patients with the indeterminate form of the disease was established in 1956. The use of heart catheterization in 1965, exercise stress testing in 1973, Holter monitoring in 1975, Electrophysiologic testing in 1973, echocardiography in 1975, endomyocardial biopsy in 1981, and Magnetic Resonance Imaging in 1995, added to the fundamental clinical aspects of CCHD as described by Carlos Chagas.

  12. Treatment of Chagas Cardiomyopathy

    PubMed Central

    Botoni, Fernando A.; Ribeiro, Antonio Luiz P.; Marinho, Carolina Coimbra; Lima, Marcia Maria Oliveira; Nunes, Maria do Carmo Pereira; Rocha, Manoel Otávio C.

    2013-01-01

    Chagas' disease (ChD), caused by the protozoa Trypanosoma cruzi (T. cruzi), was discovered and described by the Brazilian physician Carlos Chagas in 1909. After a century of original description, trypanosomiasis still brings much misery to humanity and is classified as a neglected tropical disease prevalent in underdeveloped countries, particularly in South America. It is an increasing worldwide problem due to the number of cases in endemic areas and the migration of infected subjects to more developed regions, mainly North America and Europe. Despite its importance, chronic chagas cardiomyopathy (CCC) pathophysiology is yet poorly understood, and independently of its social, clinical, and epidemiological importance, the therapeutic approach of CCC is still transposed from the knowledge acquired from other cardiomyopathies. Therefore, the objective of this review is to describe the treatment of Chagas cardiomyopathy with emphasis on its peculiarities. PMID:24350293

  13. Heart transplantation for Chagas cardiomyopathy.

    PubMed

    Ramalho, Ana Rita; Prieto, David; Antunes, Pedro; Franco, Fátima; Antunes, Manuel J

    2017-11-01

    Chagas disease is an endemic disease in Latin America that is increasingly found in non-endemic areas all over the world due to the flow of migrants from Central and South America. We present the case of a Brazilian immigrant in Portugal who underwent orthotopic heart transplantation for end-stage Chagas cardiomyopathy. Immunosuppressive therapy included prednisone, mycophenolate mofetil and tacrolimus. Twelve months after the procedure she is asymptomatic, with good graft function, and with no evidence of complications such as graft rejection, opportunistic infections, neoplasms or reactivation of Trypanosoma cruzi infection. By reporting the first case in Portugal of heart transplantation for Chagas cardiomyopathy, we aim to increase awareness of Chagas disease as an emerging global problem and of Chagas cardiomyopathy as a serious complication for which heart transplantation is a valuable therapeutic option. Copyright © 2017 Sociedade Portuguesa de Cardiologia. Publicado por Elsevier España, S.L.U. All rights reserved.

  14. Prism adaptation by mental practice.

    PubMed

    Michel, Carine; Gaveau, Jérémie; Pozzo, Thierry; Papaxanthis, Charalambos

    2013-09-01

    The prediction of our actions and their interaction with the external environment is critical for sensorimotor adaptation. For instance, during prism exposure, which deviates laterally our visual field, we progressively correct movement errors by combining sensory feedback with forward model sensory predictions. However, very often we project our actions to the external environment without physically interacting with it (e.g., mental actions). An intriguing question is whether adaptation will occur if we imagine, instead of executing, an arm movement while wearing prisms. Here, we investigated prism adaptation during mental actions. In the first experiment, participants (n = 54) performed arm pointing movements before and after exposure to the optical device. They were equally divided into six groups according to prism exposure: Prisms-Active, Prisms-Imagery, Prisms-Stationary, Prisms-Stationary-Attention, No Conflict-Prisms-Imagery, No Prisms-Imagery. Adaptation, measured by the difference in pointing errors between pre-test and post-test, occurred only in Prisms-Active and Prisms-Imagery conditions. The second experiment confirmed the results of the first experiment and further showed that sensorimotor adaptation was mainly due to proprioceptive realignment in both Prisms-Active (n = 10) and Prisms-Imagery (n = 10) groups. In both experiments adaptation was greater following actual than imagined pointing movements. The present results are the first demonstration of prism adaptation by mental practice under prism exposure and they are discussed in terms of internal forward models and sensorimotor plasticity. Copyright © 2012 Elsevier Ltd. All rights reserved.

  15. Optical switch using Risley prisms

    DOEpatents

    Sweatt, William C.; Christenson, Todd R.

    2003-04-15

    An optical switch using Risley prisms and rotary microactuators to independently rotate the wedge prisms of each Risley prism pair is disclosed. The optical switch comprises an array of input Risley prism pairs that selectively redirect light beams from a plurality of input ports to an array of output Risley prism pairs that similarly direct the light beams to a plurality of output ports. Each wedge prism of each Risley prism pair can be independently rotated by a variable-reluctance stepping rotary microactuator that is fabricated by a multi-layer LIGA process. Each wedge prism can be formed integral to the annular rotor of the rotary microactuator by a DXRL process.

  16. Optical Switch Using Risley Prisms

    DOEpatents

    Sweatt, William C.; Christenson, Todd R.

    2005-02-22

    An optical switch using Risley prisms and rotary microactuators to independently rotate the wedge prisms of each Risley prism pair is disclosed. The optical switch comprises an array of input Risley prism pairs that selectively redirect light beams from a plurality of input ports to an array of output Risley prism pairs that similarly direct the light beams to a plurality of output ports. Each wedge prism of each Risley prism pair can be independently rotated by a variable-reluctance stepping rotary microactuator that is fabricated by a multi-layer LIGA process. Each wedge prism can be formed integral to the annular rotor of the rotary microactuator by a DXRL process.

  17. Flavonoids and Chagas' Disease: The Story So Far!

    PubMed

    Nabavi, Seyed Fazel; Sureda, Antoni; Daglia, Maria; Izadi, Morteza; Rastrelli, Luca; Nabavi, Seyed Mohammad

    2017-01-01

    Chagas disease is one of the major health problems in Central and South America, which is caused by the parasitic protozoa, Trypanosoma cruzi. It is commonly transmitted by members of blood-sucking subfamily Triatominae. Chagas disease is associated with cardiac and gastrointestinal manifestations. Up to now, there are no effective vaccines for treatment of Chagas disease and benznidazole and nifurtimox are the only effective anti-Chagas drugs that cause different adverse and side effects. Therefore, much attention has been paid to natural products as novel therapeutic strategies for Chagas disease and its manifestations. Nowadays, some flavonoids could be considered as effective and safe bioactive natural products with potential anti-Chagas activity. Despite the increasing evidence, there is lack of review papers regarding the beneficial effects of flavonoids against Chagas disease and its manifestations. The aim of this paper is to review the available scientific data on the beneficial effects of flavonoids on Chagas disease and its manifestations published over the past two decades. Moreover, we provide an overview on etiology, transmission, epidemiology, clinical manifestations, and current treatment protocols of Chagas disease.

  18. Could Carlos Chagas' assumption on the relationship between goiter and chronic Chagas heart disease be correct? A historical reappraisal.

    PubMed

    Bestetti, Reinaldo B; Cardinalli-Neto, Augusto; Restini, Carolina B A; Couto, Lucelio B

    2016-01-01

    In 1910, Chagas divided the clinical manifestations of the chronic form of Chagas disease according to heart, Central Nervous System, and thyroid involvement, particularly the presence of goiter. Chagas emphasized the association of goiter with poor houses infested with kissing bugs, the similarity of the clinical picture with that of patients underwent partial thyroidectomy, and with the presence of thyroid sclerosis (inflammation) on histological examination. In addition, Chagas observed that all people living in poor houses infested by sucking bugs had goiter, contrasting with persons who lived in the same region, drinking the same water, but living in good houses, which did not have goiter. Furthermore, Chagas stressed the fact that people without any evidence of thyroid disease that migrated to live in poor houses in areas infested by sucking bugs developed thyroid disease some time later. Finally, and more importantly, Chagas emphasized the association of goiter with cardiac abnormalities in 80% of patients with chronic Chagas heart disease. Despite this, other authors working in different regions did not confirm such an association. A reappraisal of data from a work published in 1949 clearly shows that the presence of goiter was statistically associated with chronic Chagas heart disease and with chronic Chagas disease. Our paper highlights once more the grandiosity of Chagas' work, which has been proved to be correct even in the history of goiter, and justifies our claim for a posthumous Nobel Prize inasmuch as his work was not perceived by the Karolinska Institute. Copyright © 2015. Published by Elsevier Ireland Ltd.

  19. Applanation tonometry: interobserver and prism agreement using the reusable Goldmann applanation prism and the Tonosafe disposable prism.

    PubMed

    Ajtony, Csilla; Elkarmouty, Ahmed; Barton, Keith; Kotecha, Aachal

    2016-06-01

    To evaluate the levels of agreement between the standard reusable prism and a disposable prism, and to examine the agreement between ophthalmologists, nursing and technical staff when measuring intraocular pressure (IOP) using the Goldmann applanation tonometer. Three hundred eyes of 300 patients were recruited. IOP measurements were made in a randomised order by three observer groups consisting of ophthalmologists and ophthalmic technicians/nurses taken from a pool of clinicians working within a busy outpatient clinic. Agreement was calculated by Bland-Altman analysis, showing the mean difference and 95% limits of agreement (LoA) of measurements. The mean difference between the reusable and disposable prism IOP measurements was <0.5 mm Hg. The LoA ranged from ±3.1 to ±4.9 mm Hg, depending on the observer group. The interobserver variability was <1 mm Hg across all observer groups; the LoA was slightly higher for observers using the reusable prism (range between ±4.3 and ±5.6 mm Hg) compared with using the disposable prism (range between ±3.7 and ±5.4 mm Hg) across observer groups. There is an acceptable agreement between IOP measurements made with the reusable Goldmann tonometer prism and the disposable Tonosafe prism. Interobserver variability in IOP measurements within an outpatient setting is larger than that found within a research setting, and may be of a level that impacts on clinical decision-making. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

  20. Prism adaptation speeds reach initiation in the direction of the prism after-effect.

    PubMed

    Striemer, Christopher L; Borza, Carley A

    2017-10-01

    Damage to the temporal-parietal cortex in the right hemisphere often leads to spatial neglect-a disorder in which patients are unable to attend to sensory input from their contralesional (left) side. Neglect has been associated with both attentional and premotor deficits. That is, in addition to having difficulty with attending to the left side, patients are often slower to initiate leftward vs. rightward movements (i.e., directional hypokinesia). Previous research has indicated that a brief period of adaptation to rightward shifting prisms can reduce symptoms of neglect by adjusting the patient's movements leftward, toward the neglected field. Although prism adaptation has been shown to reduce spatial attention deficits in patients with neglect, very little work has examined the effects of prisms on premotor symptoms. In the current study, we examined this in healthy individuals using leftward shifting prisms to induce a rightward shift in the egocentric reference frame, similar to neglect patients prior to prism adaptation. Specifically, we examined the speed with which healthy participants initiated leftward and rightward reaches (without visual feedback) prior to and following adaptation to either 17° leftward (n = 16) or 17° rightward (n = 15) shifting prisms. Our results indicated that, following adaptation, participants were significantly faster to initiate reaches towards targets located in the direction opposite the prism shift. That is, participants were faster to initiate reaches to right targets following leftward prism adaptation and were faster to initiate reaches to left targets following rightward prism adaptation. Overall, these results are consistent with the idea that prism adaptation can influence the speed with which a reach can be initiated toward a target in the direction opposite the prism shift, possibly through altering activity in neural circuits involved in reach planning.

  1. [Integration design and diffraction characteristics analysis of prism-grating-prism].

    PubMed

    He, Tian-Bo; Bayanheshig; Li, Wen-Hao; Kong, Peng; Tang, Yu-Guo

    2014-01-01

    Prism-grating-prism (PGP) module is the important dispersing component in the hyper spectral imager. In order to effectively predict the distribution of diffraction efficiency of the whole PGP component and its diffraction characteristics before fabrication, a method of the PGP integration design is proposed. From the point of view of the volume phase holographic grating (VPHG) design, combined with the restrictive correlation between the various parameters of prisms and grating, we compiled the analysis software for calculating the whole PGP's diffraction efficiency. Furthermore, the effects of the structure parameters of prisms and grating on the PGP's diffraction characteristics were researched in detail. In particular we discussed the Bragg wavelength shift behaviour of the grating and a broadband PGP spectral component with high diffraction efficiency was designed for the imaging spectrometers. The result of simulation indicated that the spectral bandwidth of the PGP becomes narrower with the dispersion coefficient of prism 1 material decreasing; Bragg wavelength shift characteristics broaden the bandwidth of VPHG both spectrally and angularly, higher angular selectivity is desirable for selection requirements of the prism 1 material, and it can be easily tuned to achieve spectral bandwidth suitable for imaging PGP spectrograph; the vertex angle of prism 1, the film thickness and relative permittivity modulation of the grating have a significant impact on the distribution of PGP's diffraction efficiency, so precision control is necessary when fabrication. The diffraction efficiency of the whole PGP component designed by this method is no less than 50% in the wavelength range from 400 to 1000 nm, the specific design parameters have been given in this paper that have a certain reference value for PGP fabrication.

  2. Less-expensive Rochon prisms

    NASA Technical Reports Server (NTRS)

    Ammann, E. O.; Massey, G. A.

    1970-01-01

    Inexpensive Rochon prisms can be produced by substituting easily polished glass for one-half of the calcite. Reciprocal polarizing properties of a conventional Rochon prism are retained, and angular separation between ordinary and extraordinary rays is the same as in all-calcite prism.

  3. [Validity of the suicidality assessment instrument PRISM-S (Pictoral Representation of Illness Self Measure - Suicidality)].

    PubMed

    Ring, Mariann; Harbauer, Gregor; Haas, Sebastian; Schuetz, Christopher; Andreae, Andreas; Maercker, Andreas; Ajdacic-Gross, Vladeta

    2014-01-01

    In routine clinical practice the assessment of suicidality proves to be difficult and complex. The aim of the present study was to examine if PRISM can be used to measure validly the person's subjectively perceived suicidality. The nonverbal visualization technique PRISM (Pictoral Representation of Illness and Self Measure) has been developed by Büchi et al. (2002) to evaluate the perceived burden of suffering due to physical illness. The adapted version of PRISM used in our study is called PRISM-S (Pictoral Representation of Illness and Self Measure - Suicidality). 156 eligible inpatients, admitted voluntarily to the crisis intervention centre Winterthur, participated in the study. We used as gold standards the well established assessment tools the Beck Scale of Suicide Ideation (BSS) and the Depressive Symptome Inventory - Subscale (DSI-SS). The results showed high correlations between PRISM-S and the BSS (r = - 0,73) and the DSI-SS scores (r = - 0,76). Clinicians, general practitioners, psychiatrists and psychologists receive with PRISM-S a valid suicidality assessment tool that is very brief and easy to administer in clinical settings.

  4. Heart Transplantation for Chagas Cardiomyopathy.

    PubMed

    Benatti, Rodolfo D; Oliveira, Guilherme H; Bacal, Fernando

    2017-06-01

    Chagas cardiomyopathy (CC) is one of the chronic manifestations of Trypanosoma cruzi (T. cruzi) infection and is a major public health disease in Latin America. Since it is a chronic systemic infection, Chagas disease was long considered a potential contraindication for transplantation because of the risk of recurrence with immunosuppression. However, early South American experience in the 1980's established the feasibility of heart transplantation (HT) in patients with Chagas disease. Indeed, the first cardiac transplant for a recipient with CC was performed in 1985 in Brazil. Chagas etiology of heart failure has become the third most common indication for HT in South America. T. cruzi reactivation post-transplant is a common issue that requires prophylactic surveillance but responds well to appropriate therapy. Chagas reactivation has been associated with the potency of the immunosuppressive protocol and occurs more frequently after rejection episodes. Yet, many important questions regarding the management of Chagas HT candidates and recipients remain unanswered. For example, biventricular systolic failure is frequent in end-stage CC, but its impact on the modality of mechanical circulatory bridging has not been described. Also, there is no consensus regarding the most adequate immunosuppressive regimen that balances the risk of graft rejection and disease reactivation. The real efficacy and safety of HT for end-stage CC will only be appreciated when a Latin American transplant registry is established. This review covers the current state of the art of HT for CC. Copyright © 2017 International Society for the Heart and Lung Transplantation. Published by Elsevier Inc. All rights reserved.

  5. Composite Spectrometer Prisms

    NASA Technical Reports Server (NTRS)

    Breckinridge, J. B.; Page, N. A.; Rodgers, J. M.

    1985-01-01

    Efficient linear dispersive element for spectrometer instruments achieved using several different glasses in multiple-element prism. Good results obtained in both two-and three-element prisms using variety of different glass materials.

  6. Prism users guide.

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Weirs, V. Gregory

    2012-03-01

    Prism is a ParaView plugin that simultaneously displays simulation data and material model data. This document describes its capabilities and how to use them. A demonstration of Prism is given in the first section. The second section contains more detailed notes on less obvious behavior. The third and fourth sections are specifically for Alegra and CTH users. They tell how to generate the simulation data and SESAME files and how to handle aspects of Prism use particular to each of these codes.

  7. Abbot Ice Shelf, structure of the Amundsen Sea continental margin and the southern boundary of the Bellingshausen Plate seaward of West Antarctica.

    PubMed

    Cochran, James R; Tinto, Kirsty J; Bell, Robin E

    2015-05-01

    Inversion of NASA Operation IceBridge airborne gravity over the Abbot Ice Shelf in West Antarctica for subice bathymetry defines an extensional terrain made up of east-west trending rift basins formed during the early stages of Antarctica/Zealandia rifting. Extension is minor, as rifting jumped north of Thurston Island early in the rifting process. The Amundsen Sea Embayment continental shelf west of the rifted terrain is underlain by a deeper, more extensive sedimentary basin also formed during rifting between Antarctica and Zealandia. A well-defined boundary zone separates the mildly extended Abbot extensional terrain from the deeper Amundsen Embayment shelf basin. The shelf basin has an extension factor, β , of 1.5-1.7 with 80-100 km of extension occurring across an area now 250 km wide. Following this extension, rifting centered north of the present shelf edge and proceeded to continental rupture. Since then, the Amundsen Embayment continental shelf appears to have been tectonically quiescent and shaped by subsidence, sedimentation, and the advance and retreat of the West Antarctic Ice Sheet. The Bellingshausen Plate was located seaward of the Amundsen Sea margin prior to incorporation into the Antarctic Plate at about 62 Ma. During the latter part of its independent existence, Bellingshausen plate motion had a clockwise rotational component relative to Antarctica producing convergence across the north-south trending Bellingshausen Gravity Anomaly structure at 94°W and compressive deformation on the continental slope between 94°W and 102°W. Farther west, the relative motion was extensional along an east-west trending zone occupied by the Marie Byrd Seamounts. Abbot Ice Shelf is underlain by E-W rift basins created at ∼90 Ma Amundsen shelf shaped by subsidence, sedimentation, and passage of the ice sheet Bellingshausen plate boundary is located near the base of continental slope and rise.

  8. Abbot Ice Shelf, structure of the Amundsen Sea continental margin and the southern boundary of the Bellingshausen Plate seaward of West Antarctica

    PubMed Central

    Cochran, James R; Tinto, Kirsty J; Bell, Robin E

    2015-01-01

    Inversion of NASA Operation IceBridge airborne gravity over the Abbot Ice Shelf in West Antarctica for subice bathymetry defines an extensional terrain made up of east-west trending rift basins formed during the early stages of Antarctica/Zealandia rifting. Extension is minor, as rifting jumped north of Thurston Island early in the rifting process. The Amundsen Sea Embayment continental shelf west of the rifted terrain is underlain by a deeper, more extensive sedimentary basin also formed during rifting between Antarctica and Zealandia. A well-defined boundary zone separates the mildly extended Abbot extensional terrain from the deeper Amundsen Embayment shelf basin. The shelf basin has an extension factor, β, of 1.5–1.7 with 80–100 km of extension occurring across an area now 250 km wide. Following this extension, rifting centered north of the present shelf edge and proceeded to continental rupture. Since then, the Amundsen Embayment continental shelf appears to have been tectonically quiescent and shaped by subsidence, sedimentation, and the advance and retreat of the West Antarctic Ice Sheet. The Bellingshausen Plate was located seaward of the Amundsen Sea margin prior to incorporation into the Antarctic Plate at about 62 Ma. During the latter part of its independent existence, Bellingshausen plate motion had a clockwise rotational component relative to Antarctica producing convergence across the north-south trending Bellingshausen Gravity Anomaly structure at 94°W and compressive deformation on the continental slope between 94°W and 102°W. Farther west, the relative motion was extensional along an east-west trending zone occupied by the Marie Byrd Seamounts. Key Points: Abbot Ice Shelf is underlain by E-W rift basins created at ∼90 Ma Amundsen shelf shaped by subsidence, sedimentation, and passage of the ice sheet Bellingshausen plate boundary is located near the base of continental slope and rise PMID:26709352

  9. Compound prism design principles, I

    PubMed Central

    Hagen, Nathan; Tkaczyk, Tomasz S.

    2011-01-01

    Prisms have been needlessly neglected as components used in modern optical design. In optical throughput, stray light, flexibility, and in their ability to be used in direct-view geometry, they excel over gratings. Here we show that even their well-known weak dispersion relative to gratings has been overrated by designing doublet and double Amici direct-vision compound prisms that have 14° and 23° of dispersion across the visible spectrum, equivalent to 800 and 1300 lines/mm gratings. By taking advantage of the multiple degrees of freedom available in a compound prism design, we also show prisms whose angular dispersion shows improved linearity in wavelength. In order to achieve these designs, we exploit the well-behaved nature of prism design space to write customized algorithms that optimize directly in the nonlinear design space. Using these algorithms, we showcase a number of prism designs that illustrate a performance and flexibility that goes beyond what has often been considered possible with prisms. PMID:22423145

  10. Single-lens stereovision system using a prism: position estimation of a multi-ocular prism.

    PubMed

    Cui, Xiaoyu; Lim, Kah Bin; Zhao, Yue; Kee, Wei Loon

    2014-05-01

    In this paper, a position estimation method using a prism-based single-lens stereovision system is proposed. A multifaced prism was considered as a single optical system composed of few refractive planes. A transformation matrix which relates the coordinates of an object point to its coordinates on the image plane through the refraction of the prism was derived based on geometrical optics. A mathematical model which is able to denote the position of an arbitrary faces prism with only seven parameters is introduced. This model further extends the application of the single-lens stereovision system using a prism to other areas. Experimentation results are presented to prove the effectiveness and robustness of our proposed model.

  11. American Trypanosomiasis (Also Known as Chagas Disease) Detailed FAQs

    MedlinePlus

    ... have Chagas disease. In what parts of the world is Chagas disease found? People who have Chagas disease can be found anywhere in the world. However, vectorborne transmission is confined to the Americas, ...

  12. Chagas Disease and Breast-feeding

    PubMed Central

    López-Vélez, Rogelio

    2013-01-01

    Chagas disease (infection by the protozoan Trypanosoma cruzi) is a major parasitic disease of the Americas and one of the main neglected tropical diseases. Although various routes of transmission sre recognized, the risk for transmission of the infection through breast-feeding has not clearly been established. We reviewed the literature on transmission of T. cruzi through breast-feeding to provide breast-feeding mothers with Chagas disease with medical guidance. Although data from animal studies and human studies are scarce, we do not recommend that mothers with Chagas disease discontinue breast-feeding, unless they are experiencing the acute phase of the disease, reactivated disease resulting from immunosuppression, or bleeding nipples. In these cases, thermal treatment of milk before feeding the infant may be considered. PMID:24050257

  13. Chagas Disease

    MedlinePlus

    Chagas disease is caused by a parasite. It is common in Latin America but not in the United States. ... nose, the bite wound or a cut. The disease can also spread through contaminated food, a blood ...

  14. 21 CFR 886.1660 - Gonioscopic prism.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Gonioscopic prism. 886.1660 Section 886.1660 Food... DEVICES OPHTHALMIC DEVICES Diagnostic Devices § 886.1660 Gonioscopic prism. (a) Identification. A gonioscopic prism is a device that is a prism intended to be placed on the eye to study the anterior chamber...

  15. 21 CFR 886.1660 - Gonioscopic prism.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Gonioscopic prism. 886.1660 Section 886.1660 Food... DEVICES OPHTHALMIC DEVICES Diagnostic Devices § 886.1660 Gonioscopic prism. (a) Identification. A gonioscopic prism is a device that is a prism intended to be placed on the eye to study the anterior chamber...

  16. 21 CFR 886.1660 - Gonioscopic prism.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Gonioscopic prism. 886.1660 Section 886.1660 Food... DEVICES OPHTHALMIC DEVICES Diagnostic Devices § 886.1660 Gonioscopic prism. (a) Identification. A gonioscopic prism is a device that is a prism intended to be placed on the eye to study the anterior chamber...

  17. 21 CFR 886.1660 - Gonioscopic prism.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Gonioscopic prism. 886.1660 Section 886.1660 Food... DEVICES OPHTHALMIC DEVICES Diagnostic Devices § 886.1660 Gonioscopic prism. (a) Identification. A gonioscopic prism is a device that is a prism intended to be placed on the eye to study the anterior chamber...

  18. Usefulness of the ARCHITECT Chagas® assay as a single test for the diagnosis of chronic Chagas disease.

    PubMed

    Pérez-Ayala, Ana; Fradejas, Isabel; Rebollo, Lourdes; Lora-Pablos, David; Lizasoain, Manuel; Herrero-Martínez, Juan María

    2018-06-01

    Imported Chagas disease (CD) is an emerging health problem in Europe due to immigration from endemic countries. Although WHO currently recommends two different serological methods to establish diagnosis, new tools like the ARCHITECT Chagas assay have potential for use as a single diagnostic test. Our objective was to determine an optimal signal-to-cut-off (S/CO) value for the ARCHITECT Chagas assay to diagnose CD with a single test. A retrospective study conducted at the 12 de Octubre University Hospital (Madrid, Spain). All patients with requests for Chagas screening between January 2014 and August 2017 were consecutively included. All samples were routinely tested with the ARCHITECT assay. Negative samples (S/CO < 0.8) required no further testing. Immunochromatographic testing (ICT) and/or indirect immunofluorescence (IFI) was used to confirm samples with S/CO ≥ 0.8. Receiver operator characteristic (ROC) curve analysis determined the ARCHITECT S/CO value that yielded 100% specificity and positive predictive value. SPSS software, version 22.0 was used for data analysis. A total of 4153 samples were analysed; 361 (8.69%) gave a reactive ARCHITECT Chagas result. 261/361 (72.3%) were women; median age was 38 years old (2-79). 92.8% were Bolivian. A total of 307 (85.0%) were confirmed as cases of Chagas; 52 (14.4%) were not infected; two (0.6%) were not evaluable. Seroprevalence was 7.39%. An S/CO ≥ 3.80 yielded 100% specificity (95% confidence interval [CI], 0.93-1.00) and 100% positive predictive value (95% CI, 0.99-1.00). Using S/CO ≥ 3.80, the ARCHITECT Chagas could be used as a single test for diagnosis of chronic CD in Bolivian immigrants. Patients with S/CO between 0.80 and 3.80 would require additional testing. © 2018 John Wiley & Sons Ltd.

  19. Acoustic dispersive prism.

    PubMed

    Esfahlani, Hussein; Karkar, Sami; Lissek, Herve; Mosig, Juan R

    2016-01-07

    The optical dispersive prism is a well-studied element, which allows separating white light into its constituent spectral colors, and stands in nature as water droplets. In analogy to this definition, the acoustic dispersive prism should be an acoustic device with capability of splitting a broadband acoustic wave into its constituent Fourier components. However, due to the acoustical nature of materials as well as the design and fabrication difficulties, there is neither any natural acoustic counterpart of the optical prism, nor any artificial design reported so far exhibiting an equivalent acoustic behaviour. Here, based on exotic properties of the acoustic transmission-line metamaterials and exploiting unique physical behaviour of acoustic leaky-wave radiation, we report the first acoustic dispersive prism, effective within the audible frequency range 800 Hz-1300 Hz. The dispersive nature, and consequently the frequency-dependent refractive index of the metamaterial are exploited to split the sound waves towards different and frequency-dependent directions. Meanwhile, the leaky-wave nature of the structure facilitates the sound wave radiation into the ambient medium.

  20. Novel drug discovery for Chagas disease.

    PubMed

    Moraes, Carolina B; Franco, Caio H

    2016-01-01

    Chagas disease is a chronic infection associated with long-term morbidity. Increased funding and advocacy for drug discovery for neglected diseases have prompted the introduction of several important technological advances, and Chagas disease is among the neglected conditions that has mostly benefited from technological developments. A number of screening campaigns, and the development of new and improved in vitro and in vivo assays, has led to advances in the field of drug discovery. This review highlights the major advances in Chagas disease drug screening, and how these are being used not only to discover novel chemical entities and drug candidates, but also increase our knowledge about the disease and the parasite. Different methodologies used for compound screening and prioritization are discussed, as well as novel techniques for the investigation of these targets. The molecular mechanism of action is also discussed. Technological advances have been executed with scientific rigour for the development of new in vitro cell-based assays and in vivo animal models, to bring about novel and better drugs for Chagas disease, as well as to increase our understanding of what are the necessary properties for a compound to be successful in the clinic. The gained knowledge, combined with new exciting approaches toward target deconvolution, will help identifying new targets for Chagas disease chemotherapy in the future.

  1. Retroreflective Phase Retardation Prisms.

    DTIC Science & Technology

    1981-06-01

    resonant cavity of a 1.064 Mm laser. This report shows that it is possible to coat the reflecting surfaces of a porro prism so that incident plane...with controlled phase retardation can be made by coating each reflecting surface of a porro prism with a single dielectric film. The amount of phase...of angle of incidence (n, < n2) S. Phase change on reflection as a function of angle of incidence (n" n ) [RL-0202-’R 6. Porro prism 7. Phase change

  2. Contamination of disposable tonometer prisms during tonometry.

    PubMed

    Rajak, S N; Paul, J; Sharma, V; Vickers, S

    2006-03-01

    Due to the theoretical possibility of prion transmission in applanation tonometry, many ophthalmological units in the United Kingdom now use disposable tonometer prisms. We have investigated the potential for bacterial and viral transmission from the health practitioner to the patient via disposable prisms. All staff who perform applanation tonometry at the Sussex Eye Hospital (SEH) received a questionnaire to evaluate if the applanating face of the prism is touched during tonometry and the ease of use of the disposable prism compared to the reusable prisms that were previously used. We then cultured prisms handled by a random sample of staff members for common bacteria. Finally, we constructed a model to investigate the possibility of interpatient adenoviral transmission via disposable tonometer prisms. The questionnaire revealed that almost 50% of the staff admit to touching the applanating face of the tonometer prism prior to applanation. Cultures of the prisms grew a range of bacteria including Staphylococcus epidermidis, Staphylococcus aureus, and Bacillus species. The viral model suggested that adenovirus could be transmitted by applanation tonometry. The use of disposable prisms for applanation tonometry may reduce the risk of prion transmission but is not bacteriologically or virologically aseptic. This is a potential infection risk to patients.

  3. PRISM Spectrograph Optical Design

    NASA Technical Reports Server (NTRS)

    Chipman, Russell A.

    1995-01-01

    The objective of this contract is to explore optical design concepts for the PRISM spectrograph and produce a preliminary optical design. An exciting optical configuration has been developed which will allow both wavelength bands to be imaged onto the same detector array. At present the optical design is only partially complete because PRISM will require a fairly elaborate optical system to meet its specification for throughput (area*solid angle). The most complex part of the design, the spectrograph camera, is complete, providing proof of principle that a feasible design is attainable. This camera requires 3 aspheric mirrors to fit inside the 20x60 cm cross-section package. A complete design with reduced throughput (1/9th) has been prepared. The design documents the optical configuration concept. A suitable dispersing prism material, CdTe, has been identified for the prism spectrograph, after a comparison of many materials.

  4. Suicidality assessment with PRISM-S - simple, fast, and visual: a brief nonverbal method to assess suicidality in adolescent and adult patients.

    PubMed

    Harbauer, Gregor; Ring, Mariann; Schuetz, Christopher; Andreae, Andreas; Haas, Sebastian

    2013-01-01

    The PRISM-S task was developed at the Crisis Intervention Center (KIZ) Winterthur, Switzerland, to enable an assessment of the degree of suicidality in less than 5 minutes with a simple, visual instrument. Comparison of validity and clinical use of the new PRISM-S task with other instruments known as "gold standards". Quantitative pilot study enlisting 100 inpatients admitted to the KIZ, aged 15-42 years. Patients' suicidality was assessed by the PRISM-S task during the first clinical interview and compared to data obtained by standardized suicidality instruments. The patients completed the PRISM-S task in 2 to 5 minutes without difficulty. Data show significant positive correlations between the suicidality as assessed by PRISM-S and the gold standards, i.e., DSI-SS (r = 0.59, N = 65, p < .0001). There is no strong evidence that PRISM-S is useful for outpatients or in other settings. The experiences gained with outpatients/patients with other disorders are promising but have not been systematically evaluated. The results do not rely on a randomized design. The sample consists of persons coming to the crisis intervention center. PRISM-S offers a brief, easy-to-administer, and valid method to assess patients' suicidality. The simple instruction facilitates its use in other languages and other cultures as well. The acceptance by patients and health professionals was good, with no one refusing to complete the task.

  5. [Institutional insertion of Chagas' disease control].

    PubMed

    Silveira, Antônio Carlos; Pimenta, Fabiano

    2011-01-01

    After the starting of the Center for studies and prophylaxis of Chagas disease in 1943, with the help of Oswaldo Cruz Foundation, in the city of Bambuí, state of Minas Gerais, technological and methodological basis for the extensive control of the disease were conceived. A main step to achieve success was the introduction of a new insecticide (gammexane, P 530) and the demonstration of its efficacy in the vector control. A consequence of these improvements was the official inauguration of the first prophylactic campaign for Chagas disease in Brazil, held in Uberaba in May, 1950. Even with the knowledge of how to control the vectorial transmission, financial resources were not available by this time, at a necessary degree to make it both regularly and in all the affected area. The institutional allocation of these activities is useful to understand the low priority given to them at that time. Several national services were created in 1941, for diseases as malaria, pest, smallpox, among others, but Chagas was included in a group of diseases with lower importance, inside a Division of Sanitary Organization. In 1956, the National Department of Rural endemies (DNERu) allocate all the major endemic diseases in a single institution, however this was not translated in an implementation program for the control of Chagas disease. After profound changes at the Ministry of Health, in 1970, the Superintendência de Campanhas de Saúde Pública (SUCAM) was in charge of all rural endemies including Chagas disease, which now could compete with other diseases transmitted by vectors, formerly priorities, included in the National Division. With this new status, more funds were available, as well as redistribution of personnel and expenses from the malaria program to the vectorial control of Chagas disease. In 1991 the Health National foundation was created to substitute SUCAM in the control of endemic diseases and it included all the units of the Ministry of Health related to

  6. Chagas Heart Disease: An Update.

    PubMed

    Malik, Lindsey H; Singh, Gagan D; Amsterdam, Ezra A

    2015-11-01

    Chagas disease, also known as American trypanosomiasis, results from infection by the protozoan Trypanosoma cruzi, and is a major cause of cardiac disease worldwide. Until recently, Chagas disease was confined to those areas of South and Central America where Trypanosoma cruzi is endemic. With the migration of infected individuals, however, the disease has spread, and it is estimated that 6-7 million people worldwide are infected. In the US alone, more than 7 million people from Trypanosoma cruzi-endemic countries became legal US residents by the turn of the century, resulting in a surge of Chagas disease in this country. According to preliminary estimates, the US now ranks seventh in the Western Hemisphere in number of individuals infected with Trypanosoma cruzi, and the disease has become a major public health concern due to limited awareness in the medical community. Copyright © 2015 Elsevier Inc. All rights reserved.

  7. Prism Window for Optical Alignment

    NASA Technical Reports Server (NTRS)

    Tang, Hong

    2008-01-01

    A prism window has been devised for use, with an autocollimator, in aligning optical components that are (1) required to be oriented parallel to each other and/or at a specified angle of incidence with respect to a common optical path and (2) mounted at different positions along the common optical path. The prism window can also be used to align a single optical component at a specified angle of incidence. Prism windows could be generally useful for orienting optical components in manufacture of optical instruments. "Prism window" denotes an application-specific unit comprising two beam-splitter windows that are bonded together at an angle chosen to obtain the specified angle of incidence.

  8. Rotatable prism for pan and tilt

    NASA Technical Reports Server (NTRS)

    Ball, W. B.

    1980-01-01

    Compact, inexpensive, motor-driven prisms change field of view of TV camera. Camera and prism rotate about lens axis to produce pan effect. Rotating prism around axis parallel to lens produces tilt. Size of drive unit and required clearance are little more than size of camera.

  9. 21 CFR 886.1660 - Gonioscopic prism.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... DEVICES OPHTHALMIC DEVICES Diagnostic Devices § 886.1660 Gonioscopic prism. (a) Identification. A gonioscopic prism is a device that is a prism intended to be placed on the eye to study the anterior chamber. The device may have angled mirrors to facilitate visualization of anatomical features. (b...

  10. The PRISM project

    NASA Astrophysics Data System (ADS)

    Guilyardi, E.

    2003-04-01

    The European Union's PRISM infrastructure project (PRogram for Integrated earth System Modelling) aims at designing a flexible environment to easily assemble and run Earth System Models (http://prism.enes.org). Europe's widely distributed modelling expertise is both a strength and a challenge. Recognizing this, the PRISM project aims at developing an efficient shared modelling software infrastructure for climate scientists, providing them with an opportunity for greater focus on scientific issues, including the necessary scientific diversity (models and approaches). The proposed PRISM system includes 1) the use - or definition - and promotion of scientific and technical standards to increase component modularity, 2) an end-to-end software environment (coupler, user interface, diagnostics) to launch, monitor and analyze complex Earth System Models built around the existing and future community models, 3) testing and quality standards to ensure HPC performance on a variety of platforms and 4) community wide inputs and requirements capture in all stages of system specifications and design through user/developers meetings, workshops and thematic schools. This science driven project, led by 22 institutes* and started December 1st 2001, benefits from a unique gathering of scientific and technical expertise. More than 30 models (both global and regional) have expressed interest to be part of the PRISM system and 6 types of components have been identified: atmosphere, atmosphere chemistry, land surface, ocean, sea ice and ocean biochemistry. Progress and overall architecture design will be presented. * MPI-Met (Coordinator), KNMI (co-coordinator), MPI-M&D, Met Office, University of Reading, IPSL, Meteo-France, CERFACS, DMI, SMHI, NERSC, ETH Zurich, INGV, MPI-BGC, PIK, ECMWF, UCL-ASTR, NEC, FECIT, SGI, SUN, CCRLE

  11. TGF-β Polymorphisms Are a Risk Factor for Chagas Disease.

    PubMed

    Ferreira, Roberto Rodrigues; Madeira, Fabiana da Silva; Alves, Gabriel Farias; Chambela, Mayara da Costa; Curvo, Eduardo de Oliveira Vaz; Moreira, Aline Dos Santos; Almeida de Sá, Renata; Mendonça-Lima, Leila; Cabello, Pedro Hernan; Bailly, Sabine; Feige, Jean-Jacques; Araujo-Jorge, Tania Cremonini; Saraiva, Roberto Magalhães; Waghabi, Mariana Caldas

    2018-01-01

    Transforming growth factor β 1 (TGF- β 1) is an important mediator in Chagas disease. Furthermore, patients with higher TGF- β 1 serum levels show a worse clinical outcome. Gene polymorphism may account for differences in cytokine production during infectious diseases. We tested whether TGFB1 polymorphisms could be associated with Chagas disease susceptibility and severity in a Brazilian population. We investigated five single-nucleotide polymorphisms (-800 G>A, -509 C>T, +10 T>C, +25 G>C, and +263 C>T). 152 patients with Chagas disease (53 with the indeterminate form and 99 with the cardiac form) and 48 noninfected subjects were included. Genotypes CT and TT at position -509 of the TGFB1 gene were more frequent in Chagas disease patients than in noninfected subjects. Genotypes TC and CC at codon +10 of the TGFB1 gene were also more frequent in Chagas disease patients than in noninfected subjects. We found no significant differences in the distribution of the studied TGFB1 polymorphisms between patients with the indeterminate or cardiac form of Chagas disease. Therefore, -509 C>T and +10 T>C TGFB1 polymorphisms are associated with Chagas disease susceptibility in a Brazilian population.

  12. Stereoacuity as an indicator of prism adaptation.

    PubMed

    Momeni-Moghaddam, Hamed; Eperjesi, Frank; Kundart, James; Mostafavi-Nam, Kazem

    2014-08-01

    The purpose of this study was to determine whether stereoacuity can be used as an indicator of prism adaptation. In particular, we wanted to know whether the time required for stereoacuity to return to the initial level after viewing through a prism can be used to determine the degree of adaptation. Eighteen subjects participated in this study. Stereoacuity and dissociated phoria were determined using the TNO stereotest and the Maddox rod, respectively. Prism vergences were measured using a prism bar. For each participant, prism power equivalent to the blur point of base-in (BI) and base-out (BO) fusional vergence at 40 cm was divided and placed in front of both eyes. At 0, 3, 6, 9 and 12 min after prism introduction, the stereoacuity was measured, and at 0 and 12 min, the heterophoria was measured. The repeated measures ANOVA showed a significant difference between the mean stereoacuity for BI and BO prisms at the different measurement times (p < 0.05). For BO prism, the initial value was different between 0 and 3 min after the prism introduction, whereas for BI prism, a difference in stereoacuity was found between the pre-prism value and the value at 0, 3 and 6 min. The size of the heterophoria with BO and BI prisms was different from 0 to 12 min (p < 0.05). The time required for stereoacuity to return to baseline level was more than 3 min for BO, and more than 6 min for BI prism. In addition, the time required to return to baseline values was not similar for the stereoacuity and heterophoria. The recovery of stereoacuity is slower when adapting to divergence, as when looking from near to far. This implies that stereopsis responds faster to near targets than to distant one, and may precede complete phoria adaptation.

  13. Decreased cardiopulmonary baroreflex sensitivity in Chagas' heart disease.

    PubMed

    Consolim-Colombo, F M; Filho, J A; Lopes, H F; Sobrinho, C R; Otto, M E; Riccio, G M; Mady, C; Krieger, E M

    2000-12-01

    No study has been performed on reflexes originating from receptors in the heart that might be involved in the pathological lesions of Chagas' heart disease. Our study was undertaken to analyze the role of cardiopulmonary reflex on cardiovascular control in Chagas' disease. We studied 14 patients with Chagas' disease without heart failure and 12 healthy matched volunteers. Central venous pressure, arterial blood pressure, heart rate, forearm blood flow, and forearm vascular resistance were recorded during deactivation of cardiopulmonary receptors. By reducing central venous pressure by applying -10 and -15 mm Hg of negative pressure to the lower body, we observed (a) a similar decrease of central venous pressure in both groups; (b) a marked increase in forearm vascular resistance in the control group but a blunted increase in the Chagas' group; and (c) no significant changes in blood pressure and heart rate. To analyze cardiopulmonary and arterial receptors, we applied -40 mm Hg of lower-body negative pressure. As a consequence, (a) central venous pressure decreased similarly in both groups; (b) blood pressure was maintained in the control group, whereas in patients with Chagas' disease, a decrease in systolic and mean arterial pressure occurred; (c) heart rate increased in both groups; and (d) forearm vascular resistance increased significantly and similarly in both groups. Unloading of receptors with low levels of lower-body negative pressure did not increase forearm vascular resistance in patients with Chagas' disease, which suggests that the reflex mediated by cardiopulmonary receptors is impaired in patients with Chagas' disease without heart failure. Overall control of circulation appears to be compromised because patients did not maintain blood pressure under high levels of lower-body negative pressure.

  14. American Trypanosomiasis (Also Known as Chagas Disease) Diagnosis

    MedlinePlus

    ... Parasite That Causes Chagas Disease Among United States Blood Donors Information For: Adoption: Agencies & Parents Blood Banks Travelers ... Parasite That Causes Chagas Disease Among United States Blood Donors Information For: Adoption: Agencies & Parents Blood Banks Travelers ...

  15. American Trypanosomiasis (Also Known as Chagas Disease) Treatment

    MedlinePlus

    ... Parasite That Causes Chagas Disease Among United States Blood Donors Information For: Adoption: Agencies & Parents Blood Banks Travelers ... Parasite That Causes Chagas Disease Among United States Blood Donors Information For: Adoption: Agencies & Parents Blood Banks Travelers ...

  16. [The third and new face of Chagas disease].

    PubMed

    Pays, J-F

    2016-08-01

    After the publication of the results of the BENEFIT study concluding that the benznidazole (5 mg/kg/d/60 d) is ineffective to stop the progression of the established Chagas' cardiomyopathy in adults, the author evokes the new experiences and the new challenges of 2016 regarding Chagas disease while speculating on its future and by calling back some elements little known of his history, in particular the fact that it is Chagas who invented about it to some extent the concept of "neglected disease".

  17. Physician Knowledge of Chagas Disease in Hispanic Immigrants Living in Appalachian Ohio.

    PubMed

    Amstutz-Szalay, Shelley

    2017-06-01

    Studies have indicated that US physicians may not consider Chagas disease when diagnosing immigrant patients from Chagas-endemic areas. The purpose of this study was to evaluate physician knowledge of Chagas disease in six Appalachian Ohio counties. Physician knowledge was assessed by self-administrated survey (n = 105). Over 80 % of physicians reported that their current knowledge of Chagas disease was limited or very limited, and 50 % reported never considering Chagas disease diagnosis for their at-risk patients. Nearly 70 % of physicians were unaware of the percentage of chronic Chagas patients that develop clinical disease, and 36 % could not correctly identify the disease course. In addition, over 30 % of physicians reported that no services were available within their practice to assist Spanish-speaking patients with limited English proficiency. A lack of physician awareness of Chagas disease, coupled with a lack of translation services, may create a barrier to care by decreasing the likelihood of identification of patients at risk for Chagas disease. The results of this study support the need for interventions to ensure proper diagnosis and treatment of Chagas disease in Hispanic immigrants in rural Appalachian Ohio.

  18. Goldmann tonometer error correcting prism: clinical evaluation.

    PubMed

    McCafferty, Sean; Lim, Garrett; Duncan, William; Enikov, Eniko T; Schwiegerling, Jim; Levine, Jason; Kew, Corin

    2017-01-01

    Clinically evaluate a modified applanating surface Goldmann tonometer prism designed to substantially negate errors due to patient variability in biomechanics. A modified Goldmann prism with a correcting applanation tonometry surface (CATS) was mathematically optimized to minimize the intraocular pressure (IOP) measurement error due to patient variability in corneal thickness, stiffness, curvature, and tear film adhesion force. A comparative clinical study of 109 eyes measured IOP with CATS and Goldmann prisms. The IOP measurement differences between the CATS and Goldmann prisms were correlated to corneal thickness, hysteresis, and curvature. The CATS tonometer prism in correcting for Goldmann central corneal thickness (CCT) error demonstrated a reduction to <±2 mmHg in 97% of a standard CCT population. This compares to only 54% with CCT error <±2 mmHg using the Goldmann prism. Equal reductions of ~50% in errors due to corneal rigidity and curvature were also demonstrated. The results validate the CATS prism's improved accuracy and expected reduced sensitivity to Goldmann errors without IOP bias as predicted by mathematical modeling. The CATS replacement for the Goldmann prism does not change Goldmann measurement technique or interpretation.

  19. TGF-β Polymorphisms Are a Risk Factor for Chagas Disease

    PubMed Central

    Ferreira, Roberto Rodrigues; Madeira, Fabiana da Silva; Alves, Gabriel Farias; Chambela, Mayara da Costa; Curvo, Eduardo de Oliveira Vaz; Moreira, Aline dos Santos; Almeida de Sá, Renata; Cabello, Pedro Hernan; Bailly, Sabine; Araujo-Jorge, Tania Cremonini; Saraiva, Roberto Magalhães

    2018-01-01

    Transforming growth factor β1 (TGF-β1) is an important mediator in Chagas disease. Furthermore, patients with higher TGF-β1 serum levels show a worse clinical outcome. Gene polymorphism may account for differences in cytokine production during infectious diseases. We tested whether TGFB1 polymorphisms could be associated with Chagas disease susceptibility and severity in a Brazilian population. We investigated five single-nucleotide polymorphisms (−800 G>A, −509 C>T, +10 T>C, +25 G>C, and +263 C>T). 152 patients with Chagas disease (53 with the indeterminate form and 99 with the cardiac form) and 48 noninfected subjects were included. Genotypes CT and TT at position −509 of the TGFB1 gene were more frequent in Chagas disease patients than in noninfected subjects. Genotypes TC and CC at codon +10 of the TGFB1 gene were also more frequent in Chagas disease patients than in noninfected subjects. We found no significant differences in the distribution of the studied TGFB1 polymorphisms between patients with the indeterminate or cardiac form of Chagas disease. Therefore, −509 C>T and +10 T>C TGFB1 polymorphisms are associated with Chagas disease susceptibility in a Brazilian population. PMID:29670670

  20. High-Power Prismatic Devices for Oblique Peripheral Prisms

    PubMed Central

    Peli, Eli; Bowers, Alex R.; Keeney, Karen; Jung, Jae-Hyun

    2016-01-01

    ABSTRACT Purpose Horizontal peripheral prisms for hemianopia provide field expansion above and below the horizontal meridian; however, there is a vertical gap leaving the central area (important for driving) without expansion. In the oblique design, tilting the bases of both prism segments toward the horizontal meridian moves the field expansion area vertically and centrally (closing the central gap) while the prisms remain in the peripheral location. However, tilting the prisms results also in a reduction of the lateral field expansion. Higher prism powers are needed to counter this effect. Methods We developed, implemented, and tested a series of designs aimed at increasing the prism power to reduce the central gap while maintaining wide lateral expansion. The designs included inserting the peripheral prisms into carrier lenses that included yoked prism in the opposite direction, combination of two Fresnel segments attached at the base and angled to each other (bi-part prisms), and creating Fresnel prism–like segments from nonparallel periscopic mirror pairs (reflective prisms). Results A modest increase in lateral power was achieved with yoked-prism carriers. Bi-part combination of 36Δ Fresnel segments provided high power with some reduction in image quality. Fresnel reflective prism segments have potential for high power with superior optical quality but may be limited in field extent or by interruptions of the expanded field. Extended apical scotomas, even with unilateral fitting, may limit the utility of very high power prisms. The high-power bi-part and reflective prisms enable a wider effective eye scanning range (more than 15 degrees) into the blind hemifield. Conclusions Conventional prisms of powers higher than the available 57Δ are limited by the binocular impact of a wider apical scotoma and a reduced effective eye scanning range to the blind side. The various designs that we developed may overcome these limitations and find use in various other

  1. Barriers to Diagnosis Access for Chagas Disease in Colombia

    PubMed Central

    Toquica Gahona, Christian Camilo; Rodríguez Hernández, Jorge Martín

    2018-01-01

    Chagas disease is the leading cause of nonischemic cardiomyopathy in Latin America. Timely access to diagnosis and trypanocidal treatment and preventive tools for millions of infected people continues to be a challenge. The purpose of this study was to identify potential barriers for the diagnosis of Chagas disease in Colombia from the perspective of healthcare providers. Using a simultaneous mixed-methods study design, we analyzed trends in access to screening and diagnosis for Chagas disease in Colombia and assessed the national barriers to access. The main barriers to access at the national level included a limited governmental public health infrastructure for the diagnosis of Chagas disease and limited physician awareness and knowledge of the disease. Data indicate that 1.5% of total expected cases based on national prevalence estimates were reported. Few public health laboratories have the capacity to perform complementary tests for the diagnosis of Chagas disease and almost 6 months elapse between the requests of the tests and the confirmation of the disease. This study shows that infected people must overcome a number of barriers to achieve diagnosis. Reducing barriers to early diagnosis of Chagas disease is an important goal in the fight against the disease. PMID:29568648

  2. Bed Prism Spectacles

    NASA Astrophysics Data System (ADS)

    Ribeiro, Jair Lúcio Prados

    2018-01-01

    We only became aware of the existence of bed prism spectacles when a student brought them to the classroom and asked us about how they work. The device proved to be a fertile source of curiosity among the students, and, to be properly understood, it required us to develop a comparison between reflection in a typical mirror and total internal reflection in a prism. In this article we explain the physics behind this unfamiliar device, supported by geometrical optics principles.

  3. Prisms to Shift Pain Away: Pathophysiological and Therapeutic Exploration of CRPS with Prism Adaptation.

    PubMed

    Christophe, Laure; Chabanat, Eric; Delporte, Ludovic; Revol, Patrice; Volckmann, Pierre; Jacquin-Courtois, Sophie; Rossetti, Yves

    Complex Regional Pain Syndrome (CRPS) is an invalidating chronic condition subsequent to peripheral lesions. There is growing consensus for a central contribution to CRPS. However, the nature of this central body representation disorder is increasingly debated. Although it has been repeatedly argued that CRPS results in motor neglect of the affected side, visual egocentric reference frame was found to be deviated toward the pain, that is, neglect of the healthy side. Accordingly, prism adaptation has been successfully used to normalize this deviation. This study aimed at clarifying whether 7 CRPS patients exhibited neglect as well as exploring the pathophysiological mechanisms of this manifestation and of the therapeutic effects of prism adaptation. Pain and quality of life, egocentric reference frames (visual and proprioceptive straight-ahead), and neglect tests (line bisection, kinematic analyses of motor neglect and motor extinction) were repeatedly assessed prior to, during, and following a one-week intense prism adaptation intervention. First, our results provide no support for visual and motor neglect in CRPS. Second, reference frames for body representations were not systematically deviated. Third, intensive prism adaptation intervention durably ameliorated pain and quality of life. As for spatial neglect, understanding the therapeutic effects of prism adaptation deserves further investigations.

  4. Prisms to Shift Pain Away: Pathophysiological and Therapeutic Exploration of CRPS with Prism Adaptation

    PubMed Central

    Volckmann, Pierre; Jacquin-Courtois, Sophie

    2016-01-01

    Complex Regional Pain Syndrome (CRPS) is an invalidating chronic condition subsequent to peripheral lesions. There is growing consensus for a central contribution to CRPS. However, the nature of this central body representation disorder is increasingly debated. Although it has been repeatedly argued that CRPS results in motor neglect of the affected side, visual egocentric reference frame was found to be deviated toward the pain, that is, neglect of the healthy side. Accordingly, prism adaptation has been successfully used to normalize this deviation. This study aimed at clarifying whether 7 CRPS patients exhibited neglect as well as exploring the pathophysiological mechanisms of this manifestation and of the therapeutic effects of prism adaptation. Pain and quality of life, egocentric reference frames (visual and proprioceptive straight-ahead), and neglect tests (line bisection, kinematic analyses of motor neglect and motor extinction) were repeatedly assessed prior to, during, and following a one-week intense prism adaptation intervention. First, our results provide no support for visual and motor neglect in CRPS. Second, reference frames for body representations were not systematically deviated. Third, intensive prism adaptation intervention durably ameliorated pain and quality of life. As for spatial neglect, understanding the therapeutic effects of prism adaptation deserves further investigations. PMID:27668094

  5. A global systematic review of Chagas disease prevalence among migrants.

    PubMed

    Conners, Erin E; Vinetz, Joseph M; Weeks, John R; Brouwer, Kimberly C

    2016-04-01

    Human migration has been identified as a potential factor for increased Chagas disease risk and has transformed the disease from a Latin American problem to a global one. We conducted a systematic review of the scientific literature between 2004-2014 in order to: summarize recent seroprevalence estimates of Chagas disease among Latin American migrants, in both endemic and non-endemic settings; compare seroprevalence estimates in migrants to countrywide prevalence estimates; and identify risk factors for Chagas disease among migrants. A total of 320 studies were screened and 23 studies were included. We found evidence that the prevalence of Chagas disease is higher than expected in some migrant groups and that reliance on blood donor screening prevalence estimates underestimates the burden of disease. Overall there is a dearth of high quality epidemiologic studies on the prevalence of Chagas disease in migrants, especially among intra-regional migrants within Latin America. Given that this zoonotic disease cannot likely be eradicated, improved surveillance and reporting is vital to continuing control efforts. More accurate health surveillance of both Latin American migrants and the Chagas disease burden will help countries appropriately scale up their response to this chronic disease. Overall, improved estimates of Chagas disease among migrants would likely serve to highlight the real need for better screening, diagnostics, and treatment of individuals living with the disease. Copyright © 2016 Elsevier B.V. All rights reserved.

  6. Chagas disease and systemic autoimmune diseases among Bolivian patients in Switzerland.

    PubMed

    Jackson, Yves; Pula, Drenusha Vieira de Mello; Finckh, Axel; Chizzolini, Carlo; Chappuis, François

    2018-02-05

    Chronic cardiomyopathy occurs in 20-40% of the patients with Chagas disease. Autoimmune mechanisms may contribute to its pathogenesis. We diagnosed several cases of systemic autoimmune diseases among Bolivian migrants in Geneva with a high prevalence of Chagas disease. We tested the hypothesis of a clinical association between systemic autoimmune diseases and Chagas disease, particularly with the development of cardiomyopathy. We retrospectively searched the medical records of all Bolivian patients visiting Geneva University Hospitals between 2012 and 2015 for diagnosis of Chagas disease or systemic autoimmune diseases. Of the 2,189 eligible patients, 28 [1.3%; 95% confidence interval (CI) = 0.9-1.9%] presented with systemic autoimmune disease. The Chagas status was known in 903 (41.3%) patient, of whom 244 (27.0%; 95% CI = 24.2-30.0%) were positive. Eight (28.6%; 95% CI = 15.3-47.1%) of the 28 cases of systemic autoimmune disease had Chagas disease. We found no association between both entities (p = 1.000) or with Chagasic cardiomyopathy (p = 0.729). Moreover, there was no evidence of a temporal relationship between antiparasitic chemotherapy and the development of systemic autoimmune diseases. Our results do not support a clinical association between chronic Chagas disease and systemic autoimmune diseases. However, prospective studies in areas endemic for Chagas disease should better assess the prevalence of systemic autoimmune diseases and thus a possible relationship with this infection.

  7. Some Experiments with Thin Prisms.

    ERIC Educational Resources Information Center

    Fernando, P. C. B.

    1980-01-01

    Described are several experiments, for a course in geometrical optics or for a college physics laboratory, which have a bearing on ophthalmic optics. Experiments include the single thin prism, crossed prisms, and the prismatic power of a lens. (Author/DS)

  8. The PRISM3D paleoenvironmental reconstruction

    USGS Publications Warehouse

    Dowsett, H.; Robinson, M.; Haywood, A.M.; Salzmann, U.; Hill, Daniel; Sohl, L.E.; Chandler, M.; Williams, Mark; Foley, K.; Stoll, D.K.

    2010-01-01

    The Pliocene Research, Interpretation and Synoptic Mapping (PRISM) paleoenvironmental reconstruction is an internally consistent and comprehensive global synthesis of a past interval of relatively warm and stable climate. It is regularly used in model studies that aim to better understand Pliocene climate, to improve model performance in future climate scenarios, and to distinguish model-dependent climate effects. The PRISM reconstruction is constantly evolving in order to incorporate additional geographic sites and environmental parameters, and is continuously refined by independent research findings. The new PRISM three dimensional (3D) reconstruction differs from previous PRISM reconstructions in that it includes a subsurface ocean temperature reconstruction, integrates geochemical sea surface temperature proxies to supplement the faunal-based temperature estimates, and uses numerical models for the first time to augment fossil data. Here we describe the components of PRISM3D and describe new findings specific to the new reconstruction. Highlights of the new PRISM3D reconstruction include removal of Hudson Bay and the Great Lakes and creation of open waterways in locations where the current bedrock elevation is less than 25m above modern sea level, due to the removal of the West Antarctic Ice Sheet and the reduction of the East Antarctic Ice Sheet. The mid-Piacenzian oceans were characterized by a reduced east-west temperature gradient in the equatorial Pacific, but PRISM3D data do not imply permanent El Niño conditions. The reduced equator-to-pole temperature gradient that characterized previous PRISM reconstructions is supported by significant displacement of vegetation belts toward the poles, is extended into the Arctic Ocean, and is confirmed by multiple proxies in PRISM3D. Arctic warmth coupled with increased dryness suggests the formation of warm and salty paleo North Atlantic Deep Water (NADW) and a more vigorous thermohaline circulation system that may

  9. Survey of Obstetrician-Gynecologists in the United States About Chagas Disease

    PubMed Central

    Verani, Jennifer R.; Montgomery, Susan P.; Schulkin, Jay; Anderson, Britta; Jones, Jeffrey L.

    2010-01-01

    Chagas disease affects an estimated 300,000 people in the United States, and as many as 300 congenital infections are estimated to occur annually. The level of knowledge about Chagas disease among obstetricians-gynecologists in the United States has not been assessed. The American College of Obstetricians and Gynecologists surveyed a representative sample of 1,000 members about Chagas disease. Among 421 respondents, 68.2% (95% confidence interval [CI] = 63.5–72.6) described their knowledge level about Chagas disease as “very limited.” Only 8.8% (95% CI = 6.2–12.0) knew the risk of congenital infection, and 7.4% (95% CI = 5.1–10.4) were aware that both acute and chronic maternal infections can lead to congenital transmission. The majority of respondents (77.9%; 95% CI = 73.5–81.9) reported “never” considering a diagnosis of Chagas disease among their patients from endemic countries. Most of those who did consider the diagnosis did so “rarely.” Knowledge of Chagas disease among obstetricians-gynecologists in the United States is limited. Greater awareness may help to detect treatable congenital Chagas cases. PMID:20889886

  10. Cholinesterase inhibition reduces arrhythmias in asymptomatic Chagas disease.

    PubMed

    Castro, Renata R T; Porphirio, Graciema; Xavier, Sergio S; Moraes, Ruy S; Ferlin, Elton L; Ribeiro, Jorge P; da Nóbrega, Antonio C L

    2017-10-01

    Parasympathetic dysfunction may play a role in the genesis of arrhythmias in Chagas disease. This study evaluates the acute effects of pyridostigmine (PYR), a reversible cholinesterase inhibitor, on the occurrence of arrhythmias in patients with Chagas cardiac disease. Following a double-blind, randomized, placebo-controlled, cross-over protocol, 17 patients (age 50±2 years) with Chagas cardiac disease type B underwent 24-hour Holter recordings after oral administration of either pyridostigmine bromide (45 mg, 3 times/day) or placebo (PLA). Pyridostigmine reduced the 24-hours incidence (median [25%-75%]) of premature ventricular beats-PLA: 2998 (1920-4870), PYR: 2359 (940-3253), P=.044; ventricular couplets-PLA: 84 (15-159), PYR: 33 (6-94), P=.046. Although the total number of nonsustained ventricular tachycardia in the entire group was not different (P=.19) between PLA (1 [0-8]) and PYR (0 [0-4]), there were fewer episodes under PYR in 72% of the patients presenting this type of arrhythmia (P=.033). Acute administration of pyridostigmine reduced the incidence of nonsustained ventricular arrhythmias in patients with Chagas cardiac disease. Further studies that address the use of pyridostigmine by patients with Chagas cardiac disease under a more prolonged follow-up are warranted. © 2017 John Wiley & Sons Ltd.

  11. PRISM: Enmeshment of illness and self-schema.

    PubMed

    Denton, Fiona; Sharpe, Louise; Schrieber, Leslie

    2004-01-01

    The Pictorial Representation of Illness and Self Measure (PRISM) is a recently developed tool purported to assess burden of suffering due to illness. The nature of the PRISM task suggests a conceptual link to the illness self-schema construct hypothesised to be present in some individuals with chronic illness. This study investigates the relationship between PRISM and schema as measured by cognitive bias. 43 patients with systemic lupus erythematosus (SLE) completed an information-processing task involving endorsement of positive and negative illness words as descriptors of themselves, followed by free recall of the words. The outcome measures were endorsement and recall bias for negative illness words. Patients also completed the PRISM task and were assessed on other physical and psychological variables. PRISM did not correlate significantly with age, depression, functional impairment or disease activity. In a multiple regression analysis, only recall bias made an independent contribution to PRISM. Illness self-schema appears to play a significant role in determining the way in which SLE patients complete the PRISM task. This is discussed in light of a schema enmeshment model recently proposed in the cognitive bias literature. Copyright 2004 S. Karger AG, Basel

  12. 2 nd Brazilian Consensus on Chagas Disease, 2015.

    PubMed

    Dias, João Carlos Pinto; Ramos, Alberto Novaes; Gontijo, Eliane Dias; Luquetti, Alejandro; Shikanai-Yasuda, Maria Aparecida; Coura, José Rodrigues; Torres, Rosália Morais; Melo, José Renan da Cunha; Almeida, Eros Antonio de; Oliveira, Wilson de; Silveira, Antônio Carlos; Rezende, Joffre Marcondes de; Pinto, Fabiane Scalabrini; Ferreira, Antonio Walter; Rassi, Anis; Fragata, Abílio Augusto; Sousa, Andréa Silvestre de; Correia, Dalmo; Jansen, Ana Maria; Andrade, Glaucia Manzan Queiroz; Britto, Constança Felícia De Paoli de Carvalho; Pinto, Ana Yecê das Neves; Rassi, Anis; Campos, Dayse Elisabeth; Abad-Franch, Fernando; Santos, Silvana Eloi; Chiari, Egler; Hasslocher-Moreno, Alejandro Marcel; Moreira, Eliane Furtado; Marques, Divina Seila de Oliveira; Silva, Eliane Lages; Marin-Neto, José Antonio; Galvão, Lúcia Maria da Cunha; Xavier, Sergio Salles; Valente, Sebastião Aldo da Silva; Carvalho, Noêmia Barbosa; Cardoso, Alessandra Viana; Silva, Rafaella Albuquerque E; Costa, Veruska Maia da; Vivaldini, Simone Monzani; Oliveira, Suelene Mamede; Valente, Vera da Costa; Lima, Mayara Maia; Alves, Renato Vieira

    2016-12-01

    Chagas disease is a neglected chronic condition with a high burden of morbidity and mortality. It has considerable psychological, social, and economic impacts. The disease represents a significant public health issue in Brazil, with different regional patterns. This document presents the evidence that resulted in the Brazilian Consensus on Chagas Disease. The objective was to review and standardize strategies for diagnosis, treatment, prevention, and control of Chagas disease in the country, based on the available scientific evidence. The consensus is based on the articulation and strategic contribution of renowned Brazilian experts with knowledge and experience on various aspects of the disease. It is the result of a close collaboration between the Brazilian Society of Tropical Medicine and the Ministry of Health. It is hoped that this document will strengthen the development of integrated actions against Chagas disease in the country, focusing on epidemiology, management, comprehensive care (including families and communities), communication, information, education, and research .

  13. Acute Chagas Disease: New Global Challenges for an Old Neglected Disease

    PubMed Central

    Andrade, Daniela V.; Gollob, Kenneth J.; Dutra, Walderez O.

    2014-01-01

    Chagas disease is caused by infection with the protozoan Trypanosoma cruzi, and although over 100 years have passed since the discovery of Chagas disease, it still presents an increasing problem for global public health. A plethora of information concerning the chronic phase of human Chagas disease, particularly the severe cardiac form, is available in the literature. However, information concerning events during the acute phase of the disease is scarce. In this review, we will discuss (1) the current status of acute Chagas disease cases globally, (2) the immunological findings related to the acute phase and their possible influence in disease outcome, and (3) reactivation of Chagas disease in immunocompromised individuals, a key point for transplantation and HIV infection management. PMID:25077613

  14. Chagas disease and systemic autoimmune diseases among Bolivian patients in Switzerland

    PubMed Central

    Jackson, Yves; Pula, Drenusha Vieira de Mello; Finckh, Axel; Chizzolini, Carlo; Chappuis, François

    2018-01-01

    BACKGROUND Chronic cardiomyopathy occurs in 20-40% of the patients with Chagas disease. Autoimmune mechanisms may contribute to its pathogenesis. We diagnosed several cases of systemic autoimmune diseases among Bolivian migrants in Geneva with a high prevalence of Chagas disease. OBJECTIVES We tested the hypothesis of a clinical association between systemic autoimmune diseases and Chagas disease, particularly with the development of cardiomyopathy. METHODS We retrospectively searched the medical records of all Bolivian patients visiting Geneva University Hospitals between 2012 and 2015 for diagnosis of Chagas disease or systemic autoimmune diseases. FINDINGS Of the 2,189 eligible patients, 28 [1.3%; 95% confidence interval (CI) = 0.9-1.9%] presented with systemic autoimmune disease. The Chagas status was known in 903 (41.3%) patient, of whom 244 (27.0%; 95% CI = 24.2-30.0%) were positive. Eight (28.6%; 95% CI = 15.3-47.1%) of the 28 cases of systemic autoimmune disease had Chagas disease. We found no association between both entities (p = 1.000) or with Chagasic cardiomyopathy (p = 0.729). Moreover, there was no evidence of a temporal relationship between antiparasitic chemotherapy and the development of systemic autoimmune diseases. CONCLUSIONS Our results do not support a clinical association between chronic Chagas disease and systemic autoimmune diseases. However, prospective studies in areas endemic for Chagas disease should better assess the prevalence of systemic autoimmune diseases and thus a possible relationship with this infection. PMID:29412344

  15. 21 CFR 886.1655 - Ophthalmic Fresnel prism.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Ophthalmic Fresnel prism. 886.1655 Section 886...) MEDICAL DEVICES OPHTHALMIC DEVICES Diagnostic Devices § 886.1655 Ophthalmic Fresnel prism. (a) Identification. An ophthalmic Fresnel prism is a device that is a thin plastic sheet with embossed rulings which...

  16. 21 CFR 886.1655 - Ophthalmic Fresnel prism.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Ophthalmic Fresnel prism. 886.1655 Section 886...) MEDICAL DEVICES OPHTHALMIC DEVICES Diagnostic Devices § 886.1655 Ophthalmic Fresnel prism. (a) Identification. An ophthalmic Fresnel prism is a device that is a thin plastic sheet with embossed rulings which...

  17. 21 CFR 886.1655 - Ophthalmic Fresnel prism.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Ophthalmic Fresnel prism. 886.1655 Section 886...) MEDICAL DEVICES OPHTHALMIC DEVICES Diagnostic Devices § 886.1655 Ophthalmic Fresnel prism. (a) Identification. An ophthalmic Fresnel prism is a device that is a thin plastic sheet with embossed rulings which...

  18. 21 CFR 886.1655 - Ophthalmic Fresnel prism.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Ophthalmic Fresnel prism. 886.1655 Section 886...) MEDICAL DEVICES OPHTHALMIC DEVICES Diagnostic Devices § 886.1655 Ophthalmic Fresnel prism. (a) Identification. An ophthalmic Fresnel prism is a device that is a thin plastic sheet with embossed rulings which...

  19. 21 CFR 886.1655 - Ophthalmic Fresnel prism.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Ophthalmic Fresnel prism. 886.1655 Section 886...) MEDICAL DEVICES OPHTHALMIC DEVICES Diagnostic Devices § 886.1655 Ophthalmic Fresnel prism. (a) Identification. An ophthalmic Fresnel prism is a device that is a thin plastic sheet with embossed rulings which...

  20. Chagas Disease Awareness among Latin American Immigrants Living in Los Angeles, California

    PubMed Central

    Sanchez, Daniel R.; Traina, Mahmoud I.; Hernandez, Salvador; Smer, Aiman M.; Khamag, Haneen; Meymandi, Sheba K.

    2014-01-01

    Approximately 300,000 persons have Chagas disease in the United States, although almost all persons acquired the disease in Latin America. We examined awareness of Chagas disease among Latin American immigrants living in Los Angeles, California. We surveyed 2,677 persons (age range = 18–60 years) in Los Angeles who resided in Latin America for at least six months. A total of 62% of the participants recalled seeing triatomines in Latin America, and 27% of the participants reported triatomine bites at least once per year while living abroad. A total of 86% of the participants had never heard of Chagas disease. Of persons who had heard of Chagas disease, 81% believed that it was not serious. More than 95% of those who had heard of Chagas disease would want to be tested and treated. Most Latin American immigrants living in Los Angeles recalled exposure to vectors of Chagas disease. However, they have little knowledge of this disease. Increasing awareness of Chagas disease is needed in this high-risk population. PMID:25200261

  1. Occurrence of rhombic prisms in some structures

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Nyman, H.

    1976-02-01

    An ideal rhombic prism is defined as two regular trigonal prisms sharing a square face. In terms of such rhombic prisms, the structures of CrB and ..cap alpha..-PdCl/sub 2/, U/sub 3/Si/sub 2/ and Au/sub 3/Zn, and CoCa/sub 3/ and PdS are easily described. A network of rhombic prisms, with cubic symmetry, is also used to describe the structures of CoAs/sub 3/, Sc(OH)/sub 3/, WAl/sub 12/, and NaMn/sub 7/O/sub 12/.

  2. Dynamic changes in brain activity during prism adaptation.

    PubMed

    Luauté, Jacques; Schwartz, Sophie; Rossetti, Yves; Spiridon, Mona; Rode, Gilles; Boisson, Dominique; Vuilleumier, Patrik

    2009-01-07

    Prism adaptation does not only induce short-term sensorimotor plasticity, but also longer-term reorganization in the neural representation of space. We used event-related fMRI to study dynamic changes in brain activity during both early and prolonged exposure to visual prisms. Participants performed a pointing task before, during, and after prism exposure. Measures of trial-by-trial pointing errors and corrections allowed parametric analyses of brain activity as a function of performance. We show that during the earliest phase of prism exposure, anterior intraparietal sulcus was primarily implicated in error detection, whereas parieto-occipital sulcus was implicated in error correction. Cerebellum activity showed progressive increases during prism exposure, in accordance with a key role for spatial realignment. This time course further suggests that the cerebellum might promote neural changes in superior temporal cortex, which was selectively activated during the later phase of prism exposure and could mediate the effects of prism adaptation on cognitive spatial representations.

  3. 21 CFR 886.5810 - Ophthalmic prism reader.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Ophthalmic prism reader. 886.5810 Section 886.5810...) MEDICAL DEVICES OPHTHALMIC DEVICES Therapeutic Devices § 886.5810 Ophthalmic prism reader. (a) Identification. An ophthalmic prism reader is a device intended for use by a patient who is in a supine position...

  4. 21 CFR 886.5810 - Ophthalmic prism reader.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Ophthalmic prism reader. 886.5810 Section 886.5810...) MEDICAL DEVICES OPHTHALMIC DEVICES Therapeutic Devices § 886.5810 Ophthalmic prism reader. (a) Identification. An ophthalmic prism reader is a device intended for use by a patient who is in a supine position...

  5. 21 CFR 886.5810 - Ophthalmic prism reader.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Ophthalmic prism reader. 886.5810 Section 886.5810...) MEDICAL DEVICES OPHTHALMIC DEVICES Therapeutic Devices § 886.5810 Ophthalmic prism reader. (a) Identification. An ophthalmic prism reader is a device intended for use by a patient who is in a supine position...

  6. 21 CFR 886.5810 - Ophthalmic prism reader.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Ophthalmic prism reader. 886.5810 Section 886.5810...) MEDICAL DEVICES OPHTHALMIC DEVICES Therapeutic Devices § 886.5810 Ophthalmic prism reader. (a) Identification. An ophthalmic prism reader is a device intended for use by a patient who is in a supine position...

  7. Chronic Chagas disease: from basics to laboratory medicine.

    PubMed

    Haberland, Annekathrin; Saravia, Silvia Gilka Munoz; Wallukat, Gerd; Ziebig, Reinhard; Schimke, Ingolf

    2013-02-01

    Chagas disease, caused by Trypanosoma cruzi infection, is ranked as the most serious parasitic disease in Latin America and has huge potential to become a worldwide problem, due to increasing migration, and international tourism, as well as infectant transfer by blood contact and transfusion, intrauterine transfer, and organ transplantation. Nearly 30% of chronically-infected patients become symptomatic, often with a latency of 10-30 years, developing life-threatening complications. Of those, nearly 90% develop Chagas heart disease, while the others manifest gastrointestinal disease and neuronal disorders. Besides interrupting the infection cycle and chemo therapeutic infectant elimination, starting therapy early in symptomatic patients is important for counteracting the disease. This would be essentially supported by optimized patient management, involving risk assessment, early diagnosis and monitoring of the disease and its treatment. From economic and logistic viewpoints, the tools of laboratory medicine should be especially able to guarantee this. After summarizing the basics of chronic Chagas disease, such as the epidemiological data, the pathogenetic mechanisms thought to drive symptomatic Chagas disease and also treatment options, we present tools of laboratory medicine that address patient diagnosis, risk assessment for becoming symptomatic and guidance, focusing on autoantibody estimation for risk assessment and heart marker measurement for patient guidance. In addition, increases in levels of inflammation and oxidative stress markers in chronic Chagas disease are discussed.

  8. Resultant vertical prism in toric soft contact lenses.

    PubMed

    Sulley, Anna; Hawke, Ryan; Lorenz, Kathrine Osborn; Toubouti, Youssef; Olivares, Giovanna

    2015-08-01

    Rotational stability of toric soft contact lenses (TSCLs) is achieved using a range of designs. Designs utilising prism or peripheral ballast may result in residual prism in the optic zone. This study quantifies the vertical prism in the central 6mm present in TSCLs with various stabilisation methods. Vertical prism was computed using published refractive index and vertical thickness changes in the central optic zone on a full lens thickness map. Thickness maps were measured using scanning transmission microscopy. Designs tested were reusable, silicone hydrogel and hydrogel TSCLs: SofLens(®) Toric, PureVision(®)2 for Astigmatism, PureVision(®) Toric, Biofinity(®) Toric, Avaira(®) Toric, clariti(®) toric, AIR OPTIX(®) for ASTIGMATISM and ACUVUE OASYS(®) for ASTIGMATISM; with eight parameter combinations for each lens (-6.00DS to +3.00DS, -1.25DC, 90° and 180° axes). All TSCL designs evaluated had vertical prism in the optic zone except one which had virtually none (0.01Δ). Mean prism ranged from 0.52Δ to 1.15Δ, with three designs having prism that varied with sphere power. Vertical prism in ACUVUE OASYS(®) for ASTIGMATISM was significantly lower than all other TSCLs tested. TSCL designs utilising prism-ballast and peri-ballast for stabilisation have vertical prism in the central optic zone. In monocular astigmats fitted with a TSCL or those wearing a mix of toric designs, vertical prism imbalance could create or exacerbate disturbances in binocular vision function. Practitioners should be aware of this potential effect when selecting which TSCL designs to prescribe, particularly for monocular astigmats with pre-existing binocular vision anomalies, and when managing complaints of asthenopia in monocular astigmats. Copyright © 2015 British Contact Lens Association. Published by Elsevier Ltd. All rights reserved.

  9. The effect of prism on preferred retinal locus.

    PubMed

    Lewerenz, David; Blanco, Daniel; Ratzlaff, Chase; Zodrow, Ashley

    2018-03-01

    Whether prism, especially base-up prism, affects the area of the retina used for fixation in a patient with central scotoma has been a controversial subject for 35 years. Our pilot study employed microperimetry to evaluate the effect of base-up prism on the fixation locus, or preferred retinal locus (PRL), in subjects with central scotoma. We used a microperimeter to assess the PRL in 13 visually impaired subjects with central scotoma under four conditions: no lens, a lens with no prism (control lens), 6 Δ base-up, and 10 Δ base-up. The PRL was measured in degrees in horizontal and vertical co-ordinates from the centre of the optic disc using graphical analysis. The PRL with the control lens was not significantly different from the PRL with no lens. The preferred retinal loci with the two powers of prism were compared to the control lens and showed a superior shift in 22 of 26 cases (84.6 per cent). The amount of movement was significantly different from zero (p = 0.001 for 6 Δ and p = 0.004 for 10 Δ ). The vertical movement with the 10 Δ prism (1.73 ± 1.73 degrees) was not significantly greater (p = 0.562) than with the 6 Δ prism (1.37 ± 1.08 degrees). The shift was significantly less than the prism powers used (p < 0.001), and the amount of vertical relocation was not significantly different from the amount of horizontal movement. In our study, base-up prism appears to shift the PRL in the direction of the prism base most of the time, but our findings do not support the use of prism as a way of predictably relocating the PRL. More study is indicated to evaluate whether such a small shift is clinically or functionally significant. © 2017 Optometry Australia.

  10. Porro prism lasers: a new perspective

    NASA Astrophysics Data System (ADS)

    Burger, Liesl; Forbes, Andrew

    2008-08-01

    Porro prism lasers are insensitive to misalignment caused by, for example, shock and temperature variation, making them useful in field applications, for example in target designation and range-finding systems. This property is a result of the property of Porro prisms that they return a reflected beam parallel to the incident beam, regardless of any tilt on the prism. These lasers are generally used in a marginally stable or unstable configuration for low divergence, but in the stable configuration some interesting kaleidoscope modes can be modelled. In previous work on Porro prism resonators we formulated an analytical method of determining which Porro angles resonate and result in petal output modes, as well as the corresponding number of petals. This work has been verified using a numerical model as well as experimentally. We have developed this work further and have investigated the losses associated with a range of Porro angles as well as the effects of these losses on the resulting modes. We conclude by summarizing the design considerations for Porro prism lasers.

  11. Peripheral prism glasses: effects of moving and stationary backgrounds.

    PubMed

    Shen, Jieming; Peli, Eli; Bowers, Alex R

    2015-04-01

    Unilateral peripheral prisms for homonymous hemianopia (HH) expand the visual field through peripheral binocular visual confusion, a stimulus for binocular rivalry that could lead to reduced predominance and partial suppression of the prism image, thereby limiting device functionality. Using natural-scene images and motion videos, we evaluated whether detection was reduced in binocular compared with monocular viewing. Detection rates of nine participants with HH or quadranopia and normal binocularity wearing peripheral prisms were determined for static checkerboard perimetry targets briefly presented in the prism expansion area and the seeing hemifield. Perimetry was conducted under monocular and binocular viewing with targets presented over videos of real-world driving scenes and still frame images derived from those videos. With unilateral prisms, detection rates in the prism expansion area were significantly lower in binocular than in monocular (prism eye) viewing on the motion background (medians, 13 and 58%, respectively, p = 0.008) but not the still frame background (medians, 63 and 68%, p = 0.123). When the stimulus for binocular rivalry was reduced by fitting prisms bilaterally in one HH and one normally sighted subject with simulated HH, prism-area detection rates on the motion background were not significantly different (p > 0.6) in binocular and monocular viewing. Conflicting binocular motion appears to be a stimulus for reduced predominance of the prism image in binocular viewing when using unilateral peripheral prisms. However, the effect was only found for relatively small targets. Further testing is needed to determine the extent to which this phenomenon might affect the functionality of unilateral peripheral prisms in more real-world situations.

  12. Pure rotation of a prism on a ramp

    PubMed Central

    Zhao, Zhen; Liu, Caishan; Ma, Daolin

    2014-01-01

    In this work, we study a prism with a cross section in polygon rolling on a ramp inclined at a small angle. The prism under gravity rolls purely around each individual edge, intermittently interrupted by a sequence of face collisions between the side face of the prism and the ramp. By limiting the prism in a planar motion, we propose a mathematical model to deal with the events of the impacts. With a pair of laser-Doppler vibrometers, experiments are also conducted to measure the motions of various prisms made of different materials and with different edge number. Not only are good agreements achieved between our numerical and experimental results, but also an intriguing physical phenomenon is discovered: the purely rolling motion is nearly independent of the prism's materials, yet it is closely related to the prism's geometry. Imagine that an ideal circular section can be approximately equivalent to a polygon with a large enough edge number N, the finding presented in this paper may help discover the physical mechanism of rolling friction. PMID:25197242

  13. Pure rotation of a prism on a ramp.

    PubMed

    Zhao, Zhen; Liu, Caishan; Ma, Daolin

    2014-09-08

    In this work, we study a prism with a cross section in polygon rolling on a ramp inclined at a small angle. The prism under gravity rolls purely around each individual edge, intermittently interrupted by a sequence of face collisions between the side face of the prism and the ramp. By limiting the prism in a planar motion, we propose a mathematical model to deal with the events of the impacts. With a pair of laser-Doppler vibrometers, experiments are also conducted to measure the motions of various prisms made of different materials and with different edge number. Not only are good agreements achieved between our numerical and experimental results, but also an intriguing physical phenomenon is discovered: the purely rolling motion is nearly independent of the prism's materials, yet it is closely related to the prism's geometry. Imagine that an ideal circular section can be approximately equivalent to a polygon with a large enough edge number N , the finding presented in this paper may help discover the physical mechanism of rolling friction.

  14. An improved prism for use in laser resonators

    NASA Astrophysics Data System (ADS)

    Richards, J.

    1981-08-01

    The use of compound total internal reflection prisms rather than Porro prisms in polarisation coupled lasers is proposed. Performance advantages resulting from the use of these prisms include higher output without the need to bias the Pockels cell, ability to give a larger range of output coupling and independence of performance on the refractive index of the prism. In conventional Q-switched lasers the use of the prism at the Pockels cell end of the resonator instead of the usual 100% reflecting mirror also leads to some advantages including better hold-off, elimination of the need to bias the Pockels cell and insensitivity in one plane to angular misalignment.

  15. Peripheral Prism Glasses: Effects of Moving and Stationary Backgrounds

    PubMed Central

    Shen, Jieming; Peli, Eli; Bowers, Alex R.

    2015-01-01

    Purpose Unilateral peripheral prisms for homonymous hemianopia (HH) expand the visual field through peripheral binocular visual confusion, a stimulus for binocular rivalry that could lead to reduced predominance (partial local suppression) of the prism image and limit device functionality. Using natural-scene images and motion videos, we evaluated whether detection was reduced in binocular compared to monocular viewing. Methods Detection rates of nine participants with HH or quadranopia and normal binocularity wearing peripheral prisms were determined for static checkerboard perimetry targets briefly presented in the prism expansion area and the seeing hemifield. Perimetry was conducted under monocular and binocular viewing with targets presented over videos of real-world driving scenes and still frame images derived from those videos. Results With unilateral prisms, detection rates in the prism expansion area were significantly lower in binocular than monocular (prism eye) viewing on the motion background (medians 13% and 58%, respectively, p = 0.008), but not the still frame background (63% and 68%, p = 0.123). When the stimulus for binocular rivalry was reduced by fitting prisms bilaterally in 1 HH and 1 normally-sighted subject with simulated HH, prism-area detection rates on the motion background were not significantly different (p > 0.6) in binocular and monocular viewing. Conclusions Conflicting binocular motion appears to be a stimulus for reduced predominance of the prism image in binocular viewing when using unilateral peripheral prisms. However, the effect was only found for relatively small targets. Further testing is needed to determine the extent to which this phenomenon might affect the functionality of unilateral peripheral prisms in more real-world situations. PMID:25785533

  16. Duodenogastric reflux in Chagas' disease

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Troncon, L.E.; Rezende Filho, J.; Iazigi, N.

    1988-10-01

    Increased duodenogastric reflux has been recognized as a cause of gastric mucosa damage. The frequent finding of bile-stained gastric juice and a suggested higher frequency of lesions of the gastric mucosa in patients with Chagas' disease, which is characterized by a marked reduction of myenteric neurons, suggest that impairment of intrinsic innervation of the gut might be associated with increased duodenogastric reflux. Duodenogastric bile reflux was quantified after intravenous injection of 99mtechnetium-HIDA, in 18 patients with chronic Chagas' disease, 12 controls, and 7 patients with Billroth II gastrectomy. All but one of the chagasic patients were submitted to upper digestivemore » tract endoscopy. High reflux values (greater than or equal to 10%) were detected both in chagasic patients and in the controls, but the values for both groups were significantly lower (P less than 0.01) than those obtained for Billroth II patients (median: 55.79%; range: 12.58-87.22%). Reflux values tended to be higher in the Chagas' disease group (median: 8.20%; range: 0.0-29.40%) than in the control group (median: 3.20%; range: 0.0-30.64%), with no statistical difference between the two groups (P greater than 0.10). Chronic gastritis was detected by endoscopy in 12 chagasic patients, benign gastric ulcer in 2 patients, and a pool of bile in the stomach in 11 patients. However, neither the occurrence of gastric lesions nor the finding of bile-stained gastric juice was associated with high reflux values after (99mTc)HIDA injection. This study suggests that lesions of the intramural nervous system of the gut in Chagas' disease do not appear to be associated with abnormally increased duodenogastric reflux.« less

  17. An Improved Prism for Use in Laser Resonators

    DTIC Science & Technology

    1981-08-01

    reflection (TIR) prisms , will be shown to give significant advantages over the use of Porro prisms when used in polarisation coupled laser resonators . 2... resonator as shown in figure 2. As in the case of the crossed- Porro laser an in-line or folded configuration can be used. The compound TIR prism at the...thrashold, etc, rather than on refractive index, as in the case of Porro prisms . In conventional Q-switched Nd:YAG resonators , replacement of the 100

  18. Cerebellar inactivation impairs memory of learned prism gaze-reach calibrations.

    PubMed

    Norris, Scott A; Hathaway, Emily N; Taylor, Jordan A; Thach, W Thomas

    2011-05-01

    Three monkeys performed a visually guided reach-touch task with and without laterally displacing prisms. The prisms offset the normally aligned gaze/reach and subsequent touch. Naive monkeys showed adaptation, such that on repeated prism trials the gaze-reach angle widened and touches hit nearer the target. On the first subsequent no-prism trial the monkeys exhibited an aftereffect, such that the widened gaze-reach angle persisted and touches missed the target in the direction opposite that of initial prism-induced error. After 20-30 days of training, monkeys showed long-term learning and storage of the prism gaze-reach calibration: they switched between prism and no-prism and touched the target on the first trials without adaptation or aftereffect. Injections of lidocaine into posterolateral cerebellar cortex or muscimol or lidocaine into dentate nucleus temporarily inactivated these structures. Immediately after injections into cortex or dentate, reaches were displaced in the direction of prism-displaced gaze, but no-prism reaches were relatively unimpaired. There was little or no adaptation on the day of injection. On days after injection, there was no adaptation and both prism and no-prism reaches were horizontally, and often vertically, displaced. A single permanent lesion (kainic acid) in the lateral dentate nucleus of one monkey immediately impaired only the learned prism gaze-reach calibration and in subsequent days disrupted both learning and performance. This effect persisted for the 18 days of observation, with little or no adaptation.

  19. Cerebellar inactivation impairs memory of learned prism gaze-reach calibrations

    PubMed Central

    Hathaway, Emily N.; Taylor, Jordan A.; Thach, W. Thomas

    2011-01-01

    Three monkeys performed a visually guided reach-touch task with and without laterally displacing prisms. The prisms offset the normally aligned gaze/reach and subsequent touch. Naive monkeys showed adaptation, such that on repeated prism trials the gaze-reach angle widened and touches hit nearer the target. On the first subsequent no-prism trial the monkeys exhibited an aftereffect, such that the widened gaze-reach angle persisted and touches missed the target in the direction opposite that of initial prism-induced error. After 20–30 days of training, monkeys showed long-term learning and storage of the prism gaze-reach calibration: they switched between prism and no-prism and touched the target on the first trials without adaptation or aftereffect. Injections of lidocaine into posterolateral cerebellar cortex or muscimol or lidocaine into dentate nucleus temporarily inactivated these structures. Immediately after injections into cortex or dentate, reaches were displaced in the direction of prism-displaced gaze, but no-prism reaches were relatively unimpaired. There was little or no adaptation on the day of injection. On days after injection, there was no adaptation and both prism and no-prism reaches were horizontally, and often vertically, displaced. A single permanent lesion (kainic acid) in the lateral dentate nucleus of one monkey immediately impaired only the learned prism gaze-reach calibration and in subsequent days disrupted both learning and performance. This effect persisted for the 18 days of observation, with little or no adaptation. PMID:21389311

  20. Chagas disease risk in Texas.

    PubMed

    Sarkar, Sahotra; Strutz, Stavana E; Frank, David M; Rivaldi, Chissa-Louise; Sissel, Blake; Sánchez-Cordero, Victor

    2010-10-05

    Chagas disease, caused by Trypanosoma cruzi, remains a serious public health concern in many areas of Latin America, including México. It is also endemic in Texas with an autochthonous canine cycle, abundant vectors (Triatoma species) in many counties, and established domestic and peridomestic cycles which make competent reservoirs available throughout the state. Yet, Chagas disease is not reportable in Texas, blood donor screening is not mandatory, and the serological profiles of human and canine populations remain unknown. The purpose of this analysis was to provide a formal risk assessment, including risk maps, which recommends the removal of these lacunae. The spatial relative risk of the establishment of autochthonous Chagas disease cycles in Texas was assessed using a five-stage analysis. 1. Ecological risk for Chagas disease was established at a fine spatial resolution using a maximum entropy algorithm that takes as input occurrence points of vectors and environmental layers. The analysis was restricted to triatomine vector species for which new data were generated through field collection and through collation of post-1960 museum records in both México and the United States with sufficiently low georeferenced error to be admissible given the spatial resolution of the analysis (1 arc-minute). The new data extended the distribution of vector species to 10 new Texas counties. The models predicted that Triatoma gerstaeckeri has a large region of contiguous suitable habitat in the southern United States and México, T. lecticularia has a diffuse suitable habitat distribution along both coasts of the same region, and T. sanguisuga has a disjoint suitable habitat distribution along the coasts of the United States. The ecological risk is highest in south Texas. 2. Incidence-based relative risk was computed at the county level using the Bayesian Besag-York-Mollié model and post-1960 T. cruzi incidence data. This risk is concentrated in south Texas. 3. The

  1. Fresnel prisms and their effects on visual acuity and binocularity.

    PubMed Central

    Véronneau-Troutman, S

    1978-01-01

    1. The visual acuity with the Fresnel membrane prism is significantly less than that with the conventional prism of the same power for all prism powers from 12 delta through 30 delata at distance and from 15 delta through 30 delta at near. 2. The difference in the visual acuity between base up and base down, and between base in and base out, is not significantly different for either the Fresnel membrane prism or for the conventional prism. 3. For both Fresnel membrane prism and the conventional prism, the visual acuity when looking straight ahead. 4. Using Fresnel membrane prisms of the same power from different lots, the visual acuity varied significantly. The 30 delta prism caused the widest range in visual acuity. 5. When normal subjects are fitted with the higher powers of the Fresnel membrane prism, fusion and stereopsis are disrupted to such an extent that the use of this device to restore or to improve binocular vision in cases with large-angle deviations is seriously questioned. 6. Moreover, the disruption of fusion and stereopsis is abrupt and severe and does not parallel the decrease in visual acuity. The severely reduced ability to maintain fusion may be related to the optical aberrations, which, in turn, may be due to the molding process and the polyvinyl chloride molding material. 7. Through the flexibility of the membrane prism is a definite advantage, because of its proclivity to reduce visual acuity and increase aberrations its prescription for adults often must be limited to only one eye. 8. For the same reasons in the young child with binocular vision problems, the membrane prism presently available should be prescribed over both eyes only in powers less than 20 delta. When the membrane prism is to be used as a partial occluder (over one eye only), any power can be used. 9. The new Fresnel "hard" prism reduces visual acuity minimally and rarely disrupts binocularity, thus increasing the potential for prismotherapy to establish binocularity. This

  2. Developments in the management of Chagas cardiomyopathy

    PubMed Central

    Tanowitz, Herbert B; Machado, Fabiana S; Spray, David C; Friedman, Joel M; Weiss, Oren S; Lora, Jose N; Nagajyothi, Jyothi; Moraes, Diego N; Garg, Nisha Jain; Nunes, Maria Carmo P; Ribeiro, Antonio Luiz P

    2016-01-01

    Over 100 years have elapsed since the discovery of Chagas disease and there is still much to learn regarding pathogenesis and treatment. Although there are antiparasitic drugs available, such as benznidazole and nifurtimox, they are not totally reliable and often toxic. A recently released negative clinical trial with benznidazole in patients with chronic Chagas cardiomyopathy further reinforces the concerns regarding its effectiveness. New drugs and new delivery systems, including those based on nanotechnology, are being sought. Although vaccine development is still in its infancy, the reality of a therapeutic vaccine remains a challenge. New ECG methods may help to recognize patients prone to developing malignant ventricular arrhythmias. The management of heart failure, stroke and arrhythmias also remains a challenge. Although animal experiments have suggested that stem cell based therapy may be therapeutic in the management of heart failure in Chagas cardiomyopathy, clinical trials have not been promising. PMID:26496376

  3. Developments in the management of Chagas cardiomyopathy.

    PubMed

    Tanowitz, Herbert B; Machado, Fabiana S; Spray, David C; Friedman, Joel M; Weiss, Oren S; Lora, Jose N; Nagajyothi, Jyothi; Moraes, Diego N; Garg, Nisha Jain; Nunes, Maria Carmo P; Ribeiro, Antonio Luiz P

    2015-12-01

    Over 100 years have elapsed since the discovery of Chagas disease and there is still much to learn regarding pathogenesis and treatment. Although there are antiparasitic drugs available, such as benznidazole and nifurtimox, they are not totally reliable and often toxic. A recently released negative clinical trial with benznidazole in patients with chronic Chagas cardiomyopathy further reinforces the concerns regarding its effectiveness. New drugs and new delivery systems, including those based on nanotechnology, are being sought. Although vaccine development is still in its infancy, the reality of a therapeutic vaccine remains a challenge. New ECG methods may help to recognize patients prone to developing malignant ventricular arrhythmias. The management of heart failure, stroke and arrhythmias also remains a challenge. Although animal experiments have suggested that stem cell based therapy may be therapeutic in the management of heart failure in Chagas cardiomyopathy, clinical trials have not been promising.

  4. PRISM project optical instrument

    NASA Technical Reports Server (NTRS)

    Taylor, Charles R.

    1994-01-01

    The scientific goal of the Passively-cooled Reconnaissance of the InterStellar Medium (PRISM) project is to map the emission of molecular hydrogen at 17.035 micrometers and 28.221 micrometers. Since the atmosphere is opaque at these infrared wavelengths, an orbiting telescope is being studied. The availability of infrared focal plane arrays enables infrared imaging spectroscopy at the molecular hydrogen wavelengths. The array proposed for PRISM is 128 pixels square, with a pixel size of 75 micrometers. In order to map the sky in a period of six months, and to resolve the nearer molecular clouds, each pixel must cover 0.5 arcminutes. This sets the focal length at 51.6 cm. In order for the pixel size to be half the diameter of the central diffraction peak at 28 micrometers would require a telescope aperture of 24 cm; an aperture of 60 cm has been selected for the PRISM study for greater light gathering power.

  5. Calibration of the Wedge Prism

    Treesearch

    Charles B. Briscoe

    1957-01-01

    Since the introduction of plotless cruising in this country by Grosenbaugh and the later suggestion of using a wedge prism as an angle gauge by Bruce this method of determining basal area has been widely adopted in the South. One of the factors contributing to the occasionally unsatisfactory results obtained is failure to calibrate the prism used. As noted by Bruce the...

  6. Multibeam collimator uses prism stack

    NASA Technical Reports Server (NTRS)

    Minott, P. O.

    1981-01-01

    Optical instrument creates many divergent light beams for surveying and machine element alignment applications. Angles and refractive indices of stack of prisms are selected to divert incoming laser beam by small increments, different for each prism. Angles of emerging beams thus differ by small, precisely-controlled amounts. Instrument is nearly immune to vibration, changes in gravitational force, temperature variations, and mechanical distortion.

  7. An optofluidic prism tuned by two laminar flows.

    PubMed

    Xiong, S; Liu, A Q; Chin, L K; Yang, Y

    2011-06-07

    This paper presents a tunable optofluidic prism based on the configuration of two laminar flow streams with different refractive indices in a triangular chamber. The chambers with 70° and 90° apex angles are designed based on simulation results, which provide the optimum working range and avoid recirculating flows in the chambers. In addition, a hydrodynamic model has been developed to predict the tuning of the prisms by the variation in the flow rates. Prisms with different refractive indices are realized using benzyl alcohol and deionized (DI) water as the inner liquids, respectively. The mixture of ethylene glycol and DI water with an effective refractive index matched to that of the microchannel is used as the outer liquid. The apex angle of the prism is tuned from 75° to 135° by adjusting the ratio of the two flow rates. Subsequently, the deviation angle of the output light beam is tuned from -13.5° to 22°. One of the new features of this optofluidic prism is its capability to transform from a symmetric to an asymmetric prism with the assistance of a third flow. Two optical behaviours have been performed using the optofluidic prism. First, parallel light beam scanning is achieved with a constant deviation angle of 10° and a tuning range of 60 μm using the asymmetric prism. The detected output light intensity is increased by 65.7%. Second, light dispersion is experimentally demonstrated using 488-nm and 633-nm laser beams. The two laser beams become distinguishable with a deviation angle difference of 2.5° when the apex angle of the prism reaches 116°.

  8. Effects of Prism Eyeglasses on Objective and Subjective Fixation Disparity

    PubMed Central

    Schroth, Volkhard; Joos, Roland; Jaschinski, Wolfgang

    2015-01-01

    In optometry of binocular vision, the question may arise whether prisms should be included in eyeglasses to compensate an oculomotor and/or sensory imbalance between the two eyes. The corresponding measures of objective and subjective fixation disparity may be reduced by the prisms, or the adaptability of the binocular vergence system may diminish effects of the prisms over time. This study investigates effects of wearing prisms constantly for about 5 weeks in daily life. Two groups of 12 participants received eyeglasses with prisms having either a base-in direction or a base-out direction with an amount up to 8 prism diopters. Prisms were prescribed based on clinical fixation disparity test plates at 6 m. Two dependent variables were used: (1) subjective fixation disparity was indicated by a perceived offset of dichoptic nonius lines that were superimposed on the fusion stimuli and (2) objective fixation disparity was measured with a video based eye tracker relative to monocular calibration. Stimuli were presented at 6 m and included either central or more peripheral fusion stimuli. Repeated measurements were made without the prisms and with the prisms after about 5 weeks of wearing these prisms. Objective and subjective fixation disparity were correlated, but the type of fusion stimulus and the direction of the required prism may play a role. The prisms did not reduce the fixation disparity to zero, but induced significant changes in fixation disparity with large effect sizes. Participants receiving base-out prisms showed hypothesized effects, which were concurrent in both types of fixation disparity. In participants receiving base-in prisms, the individual effects of subjective and objective effects were negatively correlated: the larger the subjective (sensory) effect, the smaller the objective (motor) effect. This response pattern was related to the vergence adaptability, i.e. the individual fusional vergence reserves. PMID:26431525

  9. Challenges in the management of Chagas disease in Latin-American migrants in Europe.

    PubMed

    Monge-Maillo, B; López-Vélez, R

    2017-05-01

    Chagas disease is endemic in Latin America. Due to migration the infection has crossed borders and it is estimated that 68,000-120,000 people with Chagas disease are currently living in Europe and 30% of them may develop visceral involvement. However, up to 90% of Chagas disease cases in Europe remain undiagnosed. The challenges which have to be overcome in Chagas disease in non-endemic countries are focused on related downing barriers to health care access, and related to screening, diagnostic tools and therapeutic management. The aim of this review is to highlight how healthcare management for Latin American migrants with Chagas disease in Europe may be improved. Medical literature was searched using PubMed. No limits were placed with respect to the language or date of publication although most of the articles selected were articles published in the last five years. Chosen search terms were "Chagas disease" AND ("migrants" OR "screening" OR "transmission" OR "treatment"; OR "knowledge" OR "non-endemic countries"); migrants AND ("Public health" OR "Health Service Accessibility" OR "Delivery of Health care"); and "Congenital Chagas disease". Healthcare management of migrant populations with Chagas disease in Europe has to be improved: -Surveillance programmes are needed to measure the burden of the disease; -screening programmes are needed; -administrative and cultural barriers in the access to health care for migrants should be reduced; -education programmes on Chagas disease should be performed -research on new diagnostic tools and therapeutic options are required. This review highlights the needs of profound changes in the health care of Latin American migrants with Chagas disease in Europe. Copyright © 2017 European Society of Clinical Microbiology and Infectious Diseases. Published by Elsevier Ltd. All rights reserved.

  10. Risk factors for Chagas disease among pregnant women in El Salvador.

    PubMed

    Sasagawa, Emi; Aiga, Hirotsugu; Corado, Edith Y; Cuyuch, Blanca L; Hernández, Marta A; Guevara, Ana V; Romero, José E; Ramos, Hector M; Cedillos, Rafael A; Misago, Chizuru; Kita, Kiyoshi

    2015-03-01

    To determine the seroprevalence of Chagas disease among pregnant women and estimate the risk factors for Chagas disease during pregnancies. Community-based serological tests on Trypanosoma cruzi and structured interviews on socio-demographic and socio-economic status were conducted with pregnant women registered at three health centres in Sonsonate province, El Salvador. Of 797 pregnant women participating in the study, 29 (3.6%) were infected with Chagas disease. None had clinical symptoms. The results of bivariate analyses showed the significant association between seropositivity and maternal age ≥35 years, anaemia, illiteracy, having no formal school education and having knowledge on Chagas disease (P < 0.05). The results of multivariate analysis indicate that age ≥35 years and anaemia were significantly associated with being infected with Chagas disease among pregnant women (OR = 3.541 and 5.197, respectively). We recommend that the national Chagas disease control programme be better coordinated with the national maternal and child health programme to introduce blood screening for T. cruzi during antenatal visits. If financial constraint allows systematic blood screening to be only partially implemented, resources should be focused on pregnant women ≥35 years and women who have anaemia. © 2014 John Wiley & Sons Ltd.

  11. Serological Diagnosis of Chronic Chagas Disease: Is It Time for a Change?

    PubMed Central

    Abras, Alba; Gállego, Montserrat; Llovet, Teresa; Tebar, Silvia; Herrero, Mercedes; Berenguer, Pere; Ballart, Cristina; Martí, Carmen

    2016-01-01

    Chagas disease has spread to areas that are nonendemic for the disease with human migration. Since no single reference standard test is available, serological diagnosis of chronic Chagas disease requires at least two tests. New-generation techniques have significantly improved the accuracy of Chagas disease diagnosis by the use of a large mixture of recombinant antigens with different detection systems, such as chemiluminescence. The aim of the present study was to assess the overall accuracy of a new-generation kit, the Architect Chagas (cutoff, ≥1 sample relative light units/cutoff value [S/CO]), as a single technique for the diagnosis of chronic Chagas disease. The Architect Chagas showed a sensitivity of 100% (95% confidence interval [CI], 99.5 to 100%) and a specificity of 97.6% (95% CI, 95.2 to 99.9%). Five out of six false-positive serum samples were a consequence of cross-reactivity with Leishmania spp., and all of them achieved results of <5 S/CO. We propose the Architect Chagas as a single technique for screening in blood banks and for routine diagnosis in clinical laboratories. Only gray-zone and positive sera with a result of ≤6 S/CO would need to be confirmed by a second serological assay, thus avoiding false-positive sera and the problem of cross-reactivity with Leishmania species. The application of this proposal would result in important savings in the cost of Chagas disease diagnosis and therefore in the management and control of the disease. PMID:27053668

  12. Mechanism of Prism-Coupled Scanning Tunneling Microscope Light Emission

    NASA Astrophysics Data System (ADS)

    Iida, Wataru; Ahamed, Jamal U.; Katano, Satoshi; Uehara, Yoichi

    2011-09-01

    We have investigated the mechanism of scanning tunneling microscope light emission (STM-LE) in a prism-coupled configuration using finite difference time domain analysis. In this configuration, the sample is a metallic thin film evaporated on the bottom surface of a hemispherical glass prism. STM light emitted into the prism (prism-side emission) through the metallic film is measured. Since both localized surface plasmons (LSP) and surface plasmon polaritons (SPP) contribute to prism-side emission, this emission is stronger than that in conventional STM-LE measured from the sample surface side, which is radiated by LSP alone. We show that the spatial resolution of prism-side emission is determined not by the propagation length of SPP, but by the lateral size of LSP, similarly to conventional (i.e., tip side) STM-LE. Thus, we conclude that, by using the prism-coupled configuration, the signal level of STM-LE improves without the loss of spatial resolution attained in tip side emission.

  13. Symmetry Breaking Analysis of Prism Adaptation's Latent Aftereffect

    ERIC Educational Resources Information Center

    Frank, Till D.; Blau, Julia J. C.; Turvey, Michael T.

    2012-01-01

    The effect of prism adaptation on movement is typically reduced when the movement at test (prisms off) differs on some dimension from the movement at training (prisms on). Some adaptation is latent, however, and only revealed through further testing in which the movement at training is fully reinstated. Applying a nonlinear attractor dynamic model…

  14. Experimental Vaccines against Chagas Disease: A Journey through History.

    PubMed

    Rodríguez-Morales, Olivia; Monteón-Padilla, Víctor; Carrillo-Sánchez, Silvia C; Rios-Castro, Martha; Martínez-Cruz, Mariana; Carabarin-Lima, Alejandro; Arce-Fonseca, Minerva

    2015-01-01

    Chagas disease, or American trypanosomiasis, which is caused by the protozoan parasite Trypanosoma cruzi, is primarily a vector disease endemic in 21 Latin American countries, including Mexico. Although many vector control programs have been implemented, T. cruzi has not been eradicated. The development of an anti-T. cruzi vaccine for prophylactic and therapeutic purposes may significantly contribute to the transmission control of Chagas disease. Immune protection against experimental infection with T. cruzi has been studied since the second decade of the last century, and many types of immunogens have been used subsequently, such as killed or attenuated parasites and new DNA vaccines. This primary prevention strategy appears feasible, effective, safe, and inexpensive, although problems remain. The objective of this review is to summarize the research efforts about the development of vaccines against Chagas disease worldwide. A thorough literature review was conducted by searching PubMed with the terms "Chagas disease" and "American trypanosomiasis" together with "vaccines" or "immunization". In addition, reports and journals not cited in PubMed were identified. Publications in English, Spanish, and Portuguese were reviewed.

  15. [Research on improving spectrum resolution of optimized Wollaston prism array].

    PubMed

    Zhang, Peng; Wang, Jian-Rong; Zhang, Guo-Chen; Hou, Wen

    2011-11-01

    In order to not affect the image quality of interference fringes on the basis of the structure by increasing the structure angle of Wollaston prism to improve spectrum resolution, the authors optimized the structure of Wollaston prism. Calculating the function of the splitting angle and the structure angle, analysis indicated that taking the isosceles triangle prism with the same nature of the second wedge-shaped prism after the Wollaston prism, which makes the o and e light parallel to the optical axis, and alpha=0 degrees, the imaging interference fringes are no longer affected by changes in the splitting angle. Several optimized Wollaston prisms were made as an array to improve the spectral resolution. Experiments used traditional and optimized Wollaston prism array to detect the spectrum of the 980 nm laser. Experimental data showed that using optimized Wollaston prism array gets a clearer contrast of interference fringes, and the spectral data with Fourier transform are more accurate with DSP.

  16. [Seroepidemiology of Chagas disease in Mexico].

    PubMed

    Velasco-Castrejón, O; Valdespino, J L; Tapia-Conyer, R; Salvatierra, B; Guzmán-Bracho, C; Magos, C; Llausás, A; Gutiérrez, G; Sepúlveda, J

    1992-01-01

    The lack of information about Chagas disease in Mexico, as well as the controversy concerning its importance, was the basis for the seroprevalence study of Trypanosoma cruzi in the National Seroepidemiology Survey (NSS). This information was representative of the national situation with regard to disease prevalences and other factors related to the nation's health. Unfortunately the NSS was not a very good information source for the study of trypanosomiasis americana, because its coverage in the disperse rural areas was poor. Nevertheless, the results of the NSS indicated that Chagas disease has an irregular distribution in Mexico with seroprevalences of 1.6, 0.5 and 0.2 for the different dilution levels used in the evaluation. The survey data showed Chagas disease to be less important than that mentioned by other authors. The NSS data confirmed the areas of disease transmission already reported and identified some new ones in Hidalgo, Chiapas and Veracruz. The survey also detected migratory workers with Chagas antibodies in Baja California border cities, a situation which indicates a risk for blood transfusion in areas of the country presumed to be free of the disease. Three quarters (74.5%) of the seropositive population were less than 39 years old. Moreover, the fact that children of less than four years were infected suggests that natural transmission is still very important in some areas. Although the seroprevalences were greater in the lower socio-economic groups, some persons of the higher socio-economic level were also affected. This situation may be explained by the fact that many of these persons own vacation homes in tropical areas.

  17. From Lemongrass to Ivermectin: Ethnomedical Management of Chagas Disease in Tropical Bolivia.

    PubMed

    Forsyth, Colin

    2018-04-01

    Chagas disease is a neglected tropical disease; the only viable drugs are outdated and produce frequent side effects, and the overwhelming majority of cases are undiagnosed and untreated. Globally, people encounter numerous impediments to accessing biomedical treatment for Chagas disease. However, little is known about how people with Chagas disease manage their health outside the biomedical system. In this article, I discuss knowledge of ethnomedical treatments among marginalized patients in an endemic area of Bolivia. I interviewed 68 patients, 63 (93 percent) of whom had positive diagnoses for Chagas disease. Participants free listed 66 ethnomedical remedies either for Chagas disease (n = 39) or its cardiac symptoms. Participants stressed the accessibility of ethnomedical remedies in contrast to the multiple barriers to accessing biomedical treatment. Far from eroding in the face of globalization and sociopolitical marginalization, ethnomedical knowledge in the study area is dynamic and flexible, communicated through various channels.

  18. Modeling laser brightness from cross Porro prism resonators

    NASA Astrophysics Data System (ADS)

    Forbes, Andrew; Burger, Liesl; Litvin, Igor Anatolievich

    2006-08-01

    Laser brightness is a parameter often used to compare high power laser beam delivery from various sources, and incorporates both the power contained in the particular mode, as well as the propagation of that mode through the beam quality factor, M2. In this study a cross Porro prism resonator is considered; crossed Porro prism resonators have been known for some time, but until recently have not been modeled as a complete physical optics system that allows the modal output to be determined as a function of the rotation angle of the prisms. In this paper we consider the diffraction losses as a function of the prism rotation angle relative to one another, and combine this with the propagation of the specific modes to determine the laser output brightness as a function of the prism orientation.

  19. [Prism correction in heterophoria].

    PubMed

    Kommerell, G; Kromeier, M

    2002-01-01

    Unlike heterotropia (= manifest strabismus), heterophoria (= latent strabismus) is not a primarily existing condition but is a reaction to an interruption of the sensory-motor feedback control system. The reaction consists of a deviation from the orthovergence position. Binocular vision causes a continuous calibration of the vergence position. This "orthophorisation" explains that in most persons, heterophoria differs only slightly from zero. Nevertheless, a small heterophoria is common (70-80% of the population). The need to compensate for heterophoria by sensory-motor fusion can cause asthenopic complaints, such as headaches with prolonged reading. Since a variety of other defects can lead to similar symptoms, a causal relationship with heterophoria can be assumed only after a thorough differential diagnosis. Prism spectacles or eye muscle surgery for heterophoria should be recommended only after prism trials in free space, which include yoked prisms as a placebo control. Heterophoria should be distinguished from "Winkelfehlsichtigkeit", which is a deviation from orthoposition that results from the "measuring and correcting methodology after H.-J. Haase" (MKH) and is based on the idea that fixation disparity, a minute deviation from orthovergence position, indicates an inability to overcome a larger "vergence angle at rest". Objective recordings have, however, revealed that the subjective tests with stereo cues applied in the MKH can mislead to the assumption of a fixation disparity although both eyes are aligned exactly to the fixation point. A trial conducted in the Netherlands concerning the therapy of asthenopic complaints showed no statistically significant advantage of prism spectacles determined with the MKH over conventional spectacles.

  20. The effect of compliant prisms on subduction zone earthquakes and tsunamis

    NASA Astrophysics Data System (ADS)

    Lotto, Gabriel C.; Dunham, Eric M.; Jeppson, Tamara N.; Tobin, Harold J.

    2017-01-01

    Earthquakes generate tsunamis by coseismically deforming the seafloor, and that deformation is largely controlled by the shallow rupture process. Therefore, in order to better understand how earthquakes generate tsunamis, one must consider the material structure and frictional properties of the shallowest part of the subduction zone, where ruptures often encounter compliant sedimentary prisms. Compliant prisms have been associated with enhanced shallow slip, seafloor deformation, and tsunami heights, particularly in the context of tsunami earthquakes. To rigorously quantify the role compliant prisms play in generating tsunamis, we perform a series of numerical simulations that directly couple dynamic rupture on a dipping thrust fault to the elastodynamic response of the Earth and the acoustic response of the ocean. Gravity is included in our simulations in the context of a linearized Eulerian description of the ocean, which allows us to model tsunami generation and propagation, including dispersion and related nonhydrostatic effects. Our simulations span a three-dimensional parameter space of prism size, prism compliance, and sub-prism friction - specifically, the rate-and-state parameter b - a that determines velocity-weakening or velocity-strengthening behavior. We find that compliant prisms generally slow rupture velocity and, for larger prisms, generate tsunamis more efficiently than subduction zones without prisms. In most but not all cases, larger, more compliant prisms cause greater amounts of shallow slip and larger tsunamis. Furthermore, shallow friction is also quite important in determining overall slip; increasing sub-prism b - a enhances slip everywhere along the fault. Counterintuitively, we find that in simulations with large prisms and velocity-strengthening friction at the base of the prism, increasing prism compliance reduces rather than enhances shallow slip and tsunami wave height.

  1. Dobutamine Stress Echocardiography Safety in Chagas Disease Patients.

    PubMed

    Rassi, Daniela do Carmo; Vieira, Marcelo Luiz Campos; Furtado, Rogerio Gomes; Turco, Fabio de Paula; Melato, Luciano Henrique; Hotta, Viviane Tiemi; Nunes, Colandy Godoy de Oliveira; Rassi, Luiz; Rassi, Salvador

    2017-02-01

    A few decades ago, patients with Chagas disease were predominantly rural workers, with a low risk profile for obstructive coronary artery disease (CAD). As urbanization has increased, they became exposed to the same risk factors for CAD of uninfected individuals. Dobutamine stress echocardiography (DSE) has proven to be an important tool in CAD diagnosis. Despite being a potentially arrhythmogenic method, it is safe for coronary patients without Chagas disease. For Chagas disease patients, however, the indication of DSE in clinical practice is uncertain, because of the arrhythmogenic potential of that heart disease. To assess DSE safety in Chagas disease patients with clinical suspicion of CAD, as well as the incidence of arrhythmias and adverse events during the exam. Retrospective analysis of a database of patients referred for DSE from May/2012 to February/2015. This study assessed 205 consecutive patients with Chagas disease suspected of having CAD. All of them had their serology for Chagas disease confirmed. Their mean age was 64±10 years and most patients were females (65.4%). No patient had significant adverse events, such as acute myocardial infarction, ventricular fibrillation, asystole, stroke, cardiac rupture and death. Regarding arrhythmias, ventricular extrasystoles occurred in 48% of patients, and non-sustained ventricular tachycardia in 7.3%. DSE proved to be safe in this population of Chagas disease patients, in which no potentially life-threatening outcome was found. Até poucas décadas atrás, os pacientes chagásicos eram predominantemente trabalhadores rurais, com baixo perfil de risco para doença obstrutiva coronária. Com a crescente urbanização, passaram a ter os mesmos fatores de risco para doença aterosclerótica que indivíduos não infectados. O ecocardiograma sob estresse com dobutamina (EED) é uma importante ferramenta no diagnóstico de coronariopatia. É referido, porém, como um método potencialmente arritmogênico, mas

  2. Peripheral Prism Glasses: Effects of Dominance, Suppression and Background

    PubMed Central

    Ross, Nicole C.; Bowers, Alex R.; Optom, M.C.; Peli, Eli

    2012-01-01

    Purpose Unilateral peripheral prisms for homonymous hemianopia (HH) place different images on corresponding peripheral retinal points, a rivalrous situation in which local suppression of the prism image could occur and thus limit device functionality. Detection with peripheral prisms has primarily been evaluated using conventional perimetry where binocular rivalry is unlikely to occur. We quantified detection over more visually complex backgrounds and examined the effects of ocular dominance. Methods Detection rates of 8 participants with HH or quadranopia and normal binocularity wearing unilateral peripheral prism glasses were determined for static perimetry targets briefly presented in the prism expansion area (in the blind hemifield) and the seeing hemifield, under monocular and binocular viewing, over uniform gray and more complex patterned backgrounds. Results Participants with normal binocularity had mixed sensory ocular dominance, demonstrated no difference in detection rates when prisms were fitted on the side of the HH or the opposite side (p>0.2), and had detection rates in the expansion area that were not different for monocular and binocular viewing over both backgrounds (p>0.4). However, two participants with abnormal binocularity and strong ocular dominance demonstrated reduced detection in the expansion area when prisms were fitted in front of the non-dominant eye. Conclusions We found little evidence of local suppression of the peripheral prism image for HH patients with normal binocularity. However, in cases of strong ocular dominance, consideration should be given to fitting prisms before the dominant eye. Although these results are promising, further testing in more realistic conditions including image motion is needed. PMID:22885783

  3. PRISM: Priority Symptom Management Project phase I: assessment.

    PubMed

    Ropka, M E; Spencer-Cisek, P

    2001-01-01

    To provide an overview of the process, goals, and outcome recommendations from the assessment phase of the Oncology Nursing Society's Priority Symptom Management (PRISM) project and to provide the foundation for a series of evidence-based practice and qualitative systematic review articles generated from the first phase of PRISM. Published articles, abstracts, and books; computerized databases; nonpublished research; personal communications; and proceedings of the PRISM summit meeting. Symptom management is a key component in quality cancer care. The assessment phase of PRISM yielded systematic reviews with an evidence-based framework to evaluate key symptoms, developed a framework for teaching and evaluating other symptoms, and recommended future ONS initiatives. Outcome recommendations from the PRISM summit targeted practice; professional and public education; research; and health policy. These activities provide background for subsequent evidence-based practice and qualitative systematic review articles that will focus on cancer symptom management.

  4. PRISM Climate Group, Oregon State U

    Science.gov Websites

    FAQ PRISM Climate Data The PRISM Climate Group gathers climate observations from a wide range of monitoring networks, applies sophisticated quality control measures, and develops spatial climate datasets to reveal short- and long-term climate patterns. The resulting datasets incorporate a variety of modeling

  5. Dissecting slander and crying for justice: Carlos Chagas and the Nobel Prize of 1921.

    PubMed

    Bestetti, Reinaldo B; Cardinalli-Neto, Augusto

    2013-10-03

    Chagas disease was discovered by Carlos Chagas in 1909. Chagas worked at Oswaldo Cruz Institute, where the bases of experimental medicine were settled in Brazil, and that had no connection with the Faculty of Medicine of Rio de Janeiro. Chagas had several enemies at Oswaldo Cruz Institute mainly because of his election to Head of Service in 1910, and for the position of Oswaldo Cruz Directorship in 1917. Furthermore, Chagas gained enemies at Faculty of Medicine of Rio de Janeiro, which did not like to see the economical political autonomy of Oswaldo Cruz Institute. This allowed the Institute not only to perform top experimental research, but also to take the leadership of research in the country. Chagas was nominated to the Nobel Prize of 1921 in December, 1920. None was awarded the Nobel Prize in that year. He seems to have been evaluated by the Noble Committee of Karolinska Institute from March to May of 1921. At that time, his enemies were denying his discovery of Trypanosoma cruzi, a key point in Chagas' nomination by Karolinska Institute, and giving no epidemiological importance for the disease. By the same way, the obligation of small pox vaccination was tarnishing his public image. Having taken into account the epidemiologic importance of Chagas disease, the strong historical mistake in the process of Chagas evaluation, and the inequity behind all these facts, we insist on a posthumous Nobel Prize for the man who made the most complete medical-scientist discovery of all time. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

  6. Strongly-Refractive One-Dimensional Photonic Crystal Prisms

    NASA Technical Reports Server (NTRS)

    Ting, David Z. (Inventor)

    2004-01-01

    One-dimensional (1D) photonic crystal prisms can separate a beam of polychromatic electromagnetic waves into constituent wavelength components and can utilize unconventional refraction properties for wavelength dispersion over significant portions of an entire photonic band rather than just near the band edges outside the photonic band gaps. Using a ID photonic crystal simplifies the design and fabrication process and allows the use of larger feature sizes. The prism geometry broadens the useful wavelength range, enables better optical transmission, and exhibits angular dependence on wavelength with reduced non-linearity. The properties of the 1 D photonic crystal prism can be tuned by varying design parameters such as incidence angle, exit surface angle, and layer widths. The ID photonic crystal prism can be fabricated in a planar process, and can be used as optical integrated circuit elements.

  7. Evaluation of Right Ventricular Systolic Function in Chagas Disease Using Cardiac Magnetic Resonance Imaging.

    PubMed

    Moreira, Henrique T; Volpe, Gustavo J; Marin-Neto, José A; Ambale-Venkatesh, Bharath; Nwabuo, Chike C; Trad, Henrique S; Romano, Minna M D; Pazin-Filho, Antonio; Maciel, Benedito C; Lima, João A C; Schmidt, André

    2017-03-01

    Right ventricular (RV) impairment is postulated to be responsible for prominent systemic congestion in Chagas disease. However, occurrence of primary RV dysfunction in Chagas disease remains controversial. We aimed to study RV systolic function in patients with Chagas disease using cardiac magnetic resonance. This cross-sectional study included 158 individuals with chronic Chagas disease who underwent cardiac magnetic resonance. RV systolic dysfunction was defined as reduced RV ejection fraction based on predefined cutoffs accounting for age and sex. Multivariable logistic regression was used to verify the relationship of RV systolic dysfunction with age, sex, functional class, use of medications for heart failure, atrial fibrillation, and left ventricular systolic dysfunction. Mean age was 54±13 years, 51.2% men. RV systolic dysfunction was identified in 58 (37%) individuals. Although usually associated with reduced left ventricular ejection fraction, isolated RV systolic dysfunction was found in 7 (4.4%) patients, 2 of them in early stages of Chagas disease. Presence of RV dysfunction was not significantly different in patients with indeterminate/digestive form of Chagas disease (35.7%) compared with those with Chagas cardiomyopathy (36.8%) ( P =1.000). In chronic Chagas disease, RV systolic dysfunction is more commonly associated with left ventricular systolic dysfunction, although isolated and early RV dysfunction can also be identified. © 2017 American Heart Association, Inc.

  8. Chagas Disease Infection among Migrants at the Mexico/Guatemala Border.

    PubMed

    Conners, Erin E; Ordoñez, Teresa López; Cordon-Rosales, Celia; Casanueva, Carmen Fernández; Miranda, Sonia Morales; Brouwer, Kimberly C

    2017-10-01

    Chagas disease results in the largest burden, in terms of disability-adjusted-life-years, of any parasitic disease in the Americas. Monitoring Chagas disease among migrants is critical to controlling its spread and to serving the needs of the migrant community. Therefore, we determined the prevalence and correlates of Chagas disease in regional and international migrant populations at the Mexico/Guatemala border. Data were collected as part of a larger study of human immunodeficiency virus (HIV) and migration. Participants were a sample of recent regional and international migrants who used an illicit substance or had recent problem drinking. Trypanosoma cruzi infection was classified as testing positive on two different enzyme-linked immunosorbent assays (ELISAs). Interviewer-administered surveys captured sociodemographics, migration history, Chagas disease knowledge, and access to care. We enrolled 389 recent migrants, and the prevalence of Chagas disease was 3.1%. Only 19% of the participants reported having ever heard of the disease and less than 1% had been previously tested. Trypanosoma cruzi -positive participants were more likely to have been born in a rural area or town than a city (92% yes versus 59% no, P = 0.02) and have recently lived in a house with a makeshift roof (33% yes versus 8% no, P < 0.01), walls (42% yes versus 13% no, P < 0.01), or floor (50% yes versus 21% no, P < 0.02), or cinderblock walls (92% yes versus 63% no, P = 0.04). With migration rapidly changing the distribution of Chagas disease, more work needs to be done to create targeted surveillance programs and provide access to affordable treatment among Latin American migrants.

  9. A Pilot Study of Perceptual-Motor Training for Peripheral Prisms

    PubMed Central

    Houston, Kevin E.; Bowers, Alex R.; Fu, Xianping; Liu, Rui; Goldstein, Robert B.; Churchill, Jeff; Wiegand, Jean-Paul; Soo, Tim; Tang, Qu; Peli, Eli

    2016-01-01

    Purpose Peripheral prisms (p-prisms) shift peripheral portions of the visual field of one eye, providing visual field expansion for patients with hemianopia. However, patients rarely show adaption to the shift, incorrectly localizing objects viewed within the p-prisms. A pilot evaluation of a novel computerized perceptual-motor training program aiming to promote p-prism adaption was conducted. Methods Thirteen patients with hemianopia fitted with 57Δ oblique p-prisms completed the training protocol. They attended six 1-hour visits reaching and touching peripheral checkerboard stimuli presented over videos of driving scenes while fixating a central target. Performance was measured at each visit and after 3 months. Results There was a significant reduction in touch error (P = 0.01) for p-prism zone stimuli from pretraining median of 16.6° (IQR 12.1°–19.6°) to 2.7° ( IQR 1.0°–8.5°) at the end of training. P-prism zone reaction times did not change significantly with training (P > 0.05). P-prism zone detection improved significantly (P = 0.01) from a pretraining median 70% (IQR 50%–88%) to 95% at the end of training (IQR 73%–98%). Three months after training improvements had regressed but performance was still better than pretraining. Conclusions Improved pointing accuracy for stimuli detected in prism-expanded vision of patients with hemianopia wearing 57Δ oblique p-prisms is possible and training appears to further improve detection. Translational Relevance This is the first use of this novel software to train adaptation of visual direction in patients with hemianopia wearing peripheral prisms. PMID:26933522

  10. Simple Tidal Prism Models Revisited

    NASA Astrophysics Data System (ADS)

    Luketina, D.

    1998-01-01

    Simple tidal prism models for well-mixed estuaries have been in use for some time and are discussed in most text books on estuaries. The appeal of this model is its simplicity. However, there are several flaws in the logic behind the model. These flaws are pointed out and a more theoretically correct simple tidal prism model is derived. In doing so, it is made clear which effects can, in theory, be neglected and which can not.

  11. Blood Gene Signatures of Chagas Cardiomyopathy With or Without Ventricular Dysfunction.

    PubMed

    Ferreira, Ludmila Rodrigues Pinto; Ferreira, Frederico Moraes; Nakaya, Helder Imoto; Deng, Xutao; Cândido, Darlan da Silva; de Oliveira, Lea Campos; Billaud, Jean-Noel; Lanteri, Marion C; Rigaud, Vagner Oliveira-Carvalho; Seielstad, Mark; Kalil, Jorge; Fernandes, Fabio; Ribeiro, Antonio Luiz P; Sabino, Ester Cerdeira; Cunha-Neto, Edecio

    2017-02-01

    Chagas disease, caused by the protozoan parasite Trypanosoma cruzi, affects 7 million people in Latin American areas of endemicity. About 30% of infected patients will develop chronic Chagas cardiomyopathy (CCC), an inflammatory cardiomyopathy characterized by hypertrophy, fibrosis, and myocarditis. Further studies are necessary to understand the molecular mechanisms of disease progression. Transcriptome analysis has been increasingly used to identify molecular changes associated with disease outcomes. We thus assessed the whole-blood transcriptome of patients with Chagas disease. Microarray analysis was performed on blood samples from 150 subjects, of whom 30 were uninfected control patients and 120 had Chagas disease (1 group had asymptomatic disease, and 2 groups had CCC with either a preserved or reduced left ventricular ejection fraction [LVEF]). Each Chagas disease group displayed distinct gene expression and functional pathway profiles. The most different expression patterns were between CCC groups with a preserved or reduced LVEF. A more stringent analysis indicated that 27 differentially expressed genes, particularly those related to natural killer (NK)/CD8+ T-cell cytotoxicity, separated the 2 groups. NK/CD8+ T-cell cytotoxicity could play a role in determining Chagas disease progression. Understanding genes associated with disease may lead to improved insight into CCC pathogenesis and the identification of prognostic factors for CCC progression. © The Author 2016. Published by Oxford University Press for the Infectious Diseases Society of America. All rights reserved. For permissions, e-mail: journals.permissions@oup.com.

  12. Prism-based single-camera system for stereo display

    NASA Astrophysics Data System (ADS)

    Zhao, Yue; Cui, Xiaoyu; Wang, Zhiguo; Chen, Hongsheng; Fan, Heyu; Wu, Teresa

    2016-06-01

    This paper combines the prism and single camera and puts forward a method of stereo imaging with low cost. First of all, according to the principle of geometrical optics, we can deduce the relationship between the prism single-camera system and dual-camera system, and according to the principle of binocular vision we can deduce the relationship between binoculars and dual camera. Thus we can establish the relationship between the prism single-camera system and binoculars and get the positional relation of prism, camera, and object with the best effect of stereo display. Finally, using the active shutter stereo glasses of NVIDIA Company, we can realize the three-dimensional (3-D) display of the object. The experimental results show that the proposed approach can make use of the prism single-camera system to simulate the various observation manners of eyes. The stereo imaging system, which is designed by the method proposed by this paper, can restore the 3-D shape of the object being photographed factually.

  13. [Congenital ChagaśDisease: epidemiology, laboratorial diagnosis, prognosis and treatment].

    PubMed

    Reiche, E M; Inouye, M M; Bonametti, A M; Jankevicius, J V

    1996-01-01

    The authors review studies about epidemiology, clinical aspects and methods used in laboratorial diagnosis of congenital Chagas'disease, emphasizing the limitations in their specificity and sensibility, and suggest alternative methods to improve the accuracy and the quality of the laboratorial diagnosis of congenital Chagaśdisease, essential to an efficient treatment.

  14. Wollaston prism phase-stepping point diffraction interferometer and method

    DOEpatents

    Rushford, Michael C.

    2004-10-12

    A Wollaston prism phase-stepping point diffraction interferometer for testing a test optic. The Wollaston prism shears light into reference and signal beams, and provides phase stepping at increased accuracy by translating the Wollaston prism in a lateral direction with respect to the optical path. The reference beam produced by the Wollaston prism is directed through a pinhole of a diaphragm to produce a perfect spherical reference wave. The spherical reference wave is recombined with the signal beam to produce an interference fringe pattern of greater accuracy.

  15. Prism fingerprint sensor that uses a holographic optical element

    NASA Astrophysics Data System (ADS)

    Bahuguna, R. D.; Corboline, Tom

    1996-09-01

    A prism fingerprint sensor is described that uses a holographic grating glued to a right-angled prism. A light source normally illuminates the hypotenuse side of the prism with the finger pressed against the grating. The ridges and valleys of the finger are sensed on the basis of the principle of total internal reflection. The grating is used essentially to correct the distortion usually present with prism sensors. The quality of the fingerprint is very good: the pores on the ridges can be seen.

  16. Pathogenesis of Chagas' Disease: Parasite Persistence and Autoimmunity

    PubMed Central

    Teixeira, Antonio R. L.; Hecht, Mariana M.; Guimaro, Maria C.; Sousa, Alessandro O.; Nitz, Nadjar

    2011-01-01

    Summary: Acute Trypanosoma cruzi infections can be asymptomatic, but chronically infected individuals can die of Chagas' disease. The transfer of the parasite mitochondrial kinetoplast DNA (kDNA) minicircle to the genome of chagasic patients can explain the pathogenesis of the disease; in cases of Chagas' disease with evident cardiomyopathy, the kDNA minicircles integrate mainly into retrotransposons at several chromosomes, but the minicircles are also detected in coding regions of genes that regulate cell growth, differentiation, and immune responses. An accurate evaluation of the role played by the genotype alterations in the autoimmune rejection of self-tissues in Chagas' disease is achieved with the cross-kingdom chicken model system, which is refractory to T. cruzi infections. The inoculation of T. cruzi into embryonated eggs prior to incubation generates parasite-free chicks, which retain the kDNA minicircle sequence mainly in the macrochromosome coding genes. Crossbreeding transfers the kDNA mutations to the chicken progeny. The kDNA-mutated chickens develop severe cardiomyopathy in adult life and die of heart failure. The phenotyping of the lesions revealed that cytotoxic CD45, CD8+ γδ, and CD8α+ T lymphocytes carry out the rejection of the chicken heart. These results suggest that the inflammatory cardiomyopathy of Chagas' disease is a genetically driven autoimmune disease. PMID:21734249

  17. Advances and Progress in Chagas Disease Drug Discovery.

    PubMed

    Ferreira, Leonardo G; de Oliveira, Marcelo T; Andricopulo, Adriano D

    2016-01-01

    Chagas disease represents a serious burden for millions of people worldwide. Transmitted by the protozoan parasite Trypanosoma cruzi, this neglected tropical disease causes more than 10,000 deaths each year and is the main cause of heart failure in Latin America, where it is endemic. Although most cases are concentrated in Latin American countries, Chagas disease has been increasingly reported in non-endemic regions, where the low level of public awareness on the subject contributes to the growing prevalence of the disease. The available medicines are characterized by several safety and efficacy drawbacks that prevent millions of people, particularly those with advanced disease, from receiving adequate treatment. This urgent need has stimulated the emergence of diverse initiatives dedicated to the research and development (R&D) of novel therapeutic agents for Chagas disease. Public-private partnerships have been responsible for a significant increase in the investments in R&D programs and major advancements have been achieved over the past ten years. A number of collaborative projects have been leveraged by this organizational model, which privileges sharing of data, expertise, and resources between research institutions and pharmaceutical companies. Among the current strategies employed by these consortia, target-based and phenotypic screenings have achieved the most promising results. This article provides an overview on the current status and recent advances in Chagas disease drug discovery.

  18. The Program for Regional and International Shorebird Monitoring (PRISM)

    Treesearch

    Jonathan Bart; Brad Andres; Stephen Brown; Garry Donaldson; Brian Harrington; Vicky Johnston; Stephanie Jones; Guy Morrison; Susan Skagen

    2005-01-01

    This report describes the “Program for Regional and International Shorebird Monitoring” (PRISM). PRISM is being implemented by a Canada-United States Shorebird Monitoring and Assessment Committee formed in 2001 by the Canadian Shorebird Working Group and the U.S. Shorebird Council. PRISM provides a single blueprint for implementing the shorebird...

  19. Disposable versus non-disposable tonometer prisms: a UK national survey

    PubMed Central

    Jasani, Kirti M; Putri, Christine; Pearl, Amy; Sattar, Nayeem; Mercieca, Karl; Spaeth, George; Bhan-Bhargava, Archana

    2017-01-01

    Purpose To determine the prevalence of disposable tonometer versus non-disposable tonometer use in the UK and to determine methods of decontamination and frequency of replacement of prisms. A total of 137 ophthalmology departments were interviewed by telephone using a structured questionnaire. The main outcome measured were:types of tonometer prisms used in clinic (disposable, non-disposable and/or other)average disposable prisms used per clinic sessionaverage lifespan of non-disposable prismsprism preference by glaucoma and other teams within department. A cost and benefit analysis was then performed on the data acquired. Results One hundred and fifty-five departments were identified for the survey. Of these, 137 (88.3%) responded. Eighty-one departments (59.1%) used Tonosafe prisms alone, whereas 22 departments (16.1%) used Goldmann non-disposable prisms exclusively. Thirty-five departments (64%) on average have a change rate of 26.5% per year (range: 0–100, median: 20) attributed to damage, loss or theft. Sixteen departments (29%) reported that prisms were used until damaged or lost. Four departments (7%) were uncertain of their prism usage and could not provide further information. Conclusions Majority of eye departments in the UK opt for disposable prisms. This survey shows the perceived cost-effectiveness of disposable prisms is overestimated when the true cost of disinfection and damage is taken into account. Significant cost savings coupled with the low risk of infectivity (if decontaminated properly) should prompt clinicians and ophthalmic departments worldwide to reconsider the use of non-disposable prisms. PMID:29354698

  20. Chagas disease: control, elimination and eradication. Is it possible?

    PubMed Central

    Coura, José Rodrigues

    2013-01-01

    From an epidemiological point of view, Chagas disease and its reservoirs and vectors can present the following characteristics: (i) enzooty, maintained by wild animals and vectors, with broad occurrence from southern United States of America (USA) to southern Argentina and Chile (42ºN 49ºS), (ii) anthropozoonosis, when man invades the wild ecotope and becomes infected with Trypanosoma cruzi from wild animals or vectors or when the vectors and wild animals, especially marsupials, invade the human domicile and infect man, (iii) zoonosis-amphixenosis and exchanged infection between animals and humans by domestic vectors in endemic areas and (iv) zooanthroponosis, infection that is transmitted from man to animals, by means of domestic vectors, which is the rarest situation in areas endemic for Chagas disease. The characteristics of Chagas disease as an enzooty of wild animals and as an anthropozoonosis are seen most frequently in the Brazilian Amazon and in the Pan-Amazon region as a whole, where there are 33 species of six genera of wild animals: Marsupialia, Chiroptera, Rodentia, Edentata (Xenarthra), Carnivora and Primata and 27 species of triatomines, most of which infected with T. cruzi . These conditions place the resident populations of this area or its visitors - tourists, hunters, fishermen and especially the people whose livelihood involves plant extraction - at risk of being affected by Chagas disease. On the other hand, there has been an exponential increase in the acute cases of Chagas disease in that region through oral transmission of T. cruzi , causing outbreaks of the disease. In four seroepidemiological surveys that were carried out in areas of the microregion of the Negro River, state of Amazonas, in 1991, 1993, 1997 and 2010, we found large numbers of people who were serologically positive for T. cruzi infection. The majority of them and/or their relatives worked in piassava extraction and had come into contact with and were stung by wild

  1. On the tidal prism-channel area relations

    NASA Astrophysics Data System (ADS)

    D'Alpaos, Andrea; Lanzoni, Stefano; Marani, Marco; Rinaldo, Andrea

    2010-03-01

    We verify the broad applicability of tidal prism cross-sectional area relationships, originally proposed to relate the total water volume entering a lagoon during a characteristic tidal cycle (the tidal prism) to the size of its inlet, to arbitrary sheltered cross sections within a tidal network. We suggest, with reasonable approximation defining a statistical tendency rather than a pointwise equivalence, that the regime of tidal channels may be anywhere related to local landscape-forming prisms embedded in a characteristic spring tide oscillation. The importance of the proposed extension stems from its potential for quantitative predictions of the long-term morphological evolution of whole tidal landforms, in response to forcings affecting tidal prisms. This is the case, in particular, for alterations of relative mean sea levels possibly driven by climate change. Various 1-D and 2-D morphodynamic and hydrodynamic models are employed to evaluate peak flow rates, bottom shear stresses, and the ensuing local tidal prisms. One-dimensional morphodynamic models describing both the longitudinal and cross-sectional evolution of tidal channels are used to verify the validity of the relationship for sheltered sections. Relevant hydrodynamic features determined through accurate 2-D numerical models are compared with those obtained through time-invariant equivalents, defining a mean watershed by an energy landscape from averaged free surface gradients. Empirical evidence gathered within the lagoon of Venice (Italy) supports the proposed extension. We conclude that the geomorphic law relating tidal prisms to channel cross-sectional areas anywhere within a tidal landscape is a valuable tool for studies on long-term tidal geomorphology.

  2. Do dissociated or associated phoria predict the comfortable prism?

    PubMed Central

    Otto, Joanna M. N.; Kromeier, Miriam; Bach, Michael

    2008-01-01

    Background Dissociated and associated phoria are measures of latent strabismus under artificial viewing conditions. We examined to what extent dissociated and associated phoria predict the “comfortable prism”, i.e. the prism that appears most comfortable under natural viewing conditions. Methods For associated phoria, a configuration resembling the Mallett test was employed: both eyes were presented with a fixation cross, surrounded by fusionable objects. Nonius lines served as monocular markers. For dissociated phoria, the left eye was presented with all the Mallett elements, while only a white spot was presented to the right eye. To determine the comfortable prism, all the Mallett elements, including the Nonius lines, were shown to both eyes. In each of the three tests, the observer had to adjust a pair of counterrotating prisms. To avoid any (possibly prejudiced) influence of the experimenter, the prismatic power was recorded with a potentiometer. Twenty non-strabismic subjects with a visual acuity of ≥1.0 in each eye were examined. Results The range of the intertrial mean was for dissociated phoria from +9.3 eso to −5.9 cm/m exo, for associated phoria from +11.2 eso to −3.3 cm/m exo, and for the comfortable prism from +4.8 eso to −4.1 cm/m exo (cm/m = prism dioptre). In most observers, the phoria parameters differed greatly from the comfortable prism. On average, the phoria values were shifted about 2 cm/m towards the eso direction in relation to the comfortable prism (associated phoria not less than dissociated phoria). Conclusions The deviation of both, dissociated and associated phoria, from the comfortable prism suggests that the abnormal viewing conditions under which the phoria parameters are determined induce artefacts. Accordingly, the findings cast doubt on current textbook recommendations to use dissociated or associated phoria as a basis for therapeutic prisms. Rather, patients should be allowed to determine their comfortable prism

  3. Prism adaptation does not alter configural processing of faces

    PubMed Central

    Bultitude, Janet H.; Downing, Paul E.; Rafal, Robert D.

    2013-01-01

    Patients with hemispatial neglect (‘neglect’) following a brain lesion show difficulty responding or orienting to objects and events on the left side of space. Substantial evidence supports the use of a sensorimotor training technique called prism adaptation as a treatment for neglect. Reaching for visual targets viewed through prismatic lenses that induce a rightward shift in the visual image results in a leftward recalibration of reaching movements that is accompanied by a reduction of symptoms in patients with neglect. The understanding of prism adaptation has also been advanced through studies of healthy participants, in whom adaptation to leftward prismatic shifts results in temporary neglect-like performance. Interestingly, prism adaptation can also alter aspects of non-lateralised spatial attention. We previously demonstrated that prism adaptation alters the extent to which neglect patients and healthy participants process local features versus global configurations of visual stimuli. Since deficits in non-lateralised spatial attention are thought to contribute to the severity of neglect symptoms, it is possible that the effect of prism adaptation on these deficits contributes to its efficacy. This study examines the pervasiveness of the effects of prism adaptation on perception by examining the effect of prism adaptation on configural face processing using a composite face task. The composite face task is a persuasive demonstration of the automatic global-level processing of faces: the top and bottom halves of two familiar faces form a seemingly new, unknown face when viewed together. Participants identified the top or bottom halves of composite faces before and after prism adaptation. Sensorimotor adaptation was confirmed by significant pointing aftereffect, however there was no significant change in the extent to which the irrelevant face half interfered with processing. The results support the proposal that the therapeutic effects of prism adaptation

  4. Prism adaptation does not alter configural processing of faces.

    PubMed

    Bultitude, Janet H; Downing, Paul E; Rafal, Robert D

    2013-01-01

    Patients with hemispatial neglect ('neglect') following a brain lesion show difficulty responding or orienting to objects and events on the left side of space. Substantial evidence supports the use of a sensorimotor training technique called prism adaptation as a treatment for neglect. Reaching for visual targets viewed through prismatic lenses that induce a rightward shift in the visual image results in a leftward recalibration of reaching movements that is accompanied by a reduction of symptoms in patients with neglect. The understanding of prism adaptation has also been advanced through studies of healthy participants, in whom adaptation to leftward prismatic shifts results in temporary neglect-like performance. Interestingly, prism adaptation can also alter aspects of non-lateralised spatial attention. We previously demonstrated that prism adaptation alters the extent to which neglect patients and healthy participants process local features versus global configurations of visual stimuli. Since deficits in non-lateralised spatial attention are thought to contribute to the severity of neglect symptoms, it is possible that the effect of prism adaptation on these deficits contributes to its efficacy. This study examines the pervasiveness of the effects of prism adaptation on perception by examining the effect of prism adaptation on configural face processing using a composite face task. The composite face task is a persuasive demonstration of the automatic global-level processing of faces: the top and bottom halves of two familiar faces form a seemingly new, unknown face when viewed together. Participants identified the top or bottom halves of composite faces before and after prism adaptation. Sensorimotor adaptation was confirmed by significant pointing aftereffect, however there was no significant change in the extent to which the irrelevant face half interfered with processing. The results support the proposal that the therapeutic effects of prism adaptation are

  5. When a misperception favors a tragedy: Carlos Chagas and the Nobel Prize of 1921.

    PubMed

    Bestetti, Reinaldo B; Couto, Lucélio B; Cardinalli-Neto, Augusto

    2013-11-20

    Carlos Chagas, the discoverer of Chagas' disease was nominated to the Nobel Prize in 1921, but none did win the prize in that year. As a leader of a young scientist team, he discovered all aspects of the new disease from 1909 to 1920. It is still obscure why he did not win the Nobel Prize in 1921. Chagas was discarded by Gunnar Hedrèn on April 16, 1921. Hedrèn should have made a written report about the details of his evaluation to the Nobel Committee. However, such a document has not been found in the Nobel Committee Archives. No evidence of detractions made by Brazilian scientists on Chagas was found. Since Chagas nomination was consistent with the Nobel Committee requirements, as seen in the presentation letter by until now unknown Cypriano de Freitas, it become clear that Chagas did not win the Nobel Prize exclusively because the Nobel Committee did not perceive the importance of his discovery. Thus, it would be fair a posthumous Nobel Prize of 1921 to Carlos Chagas. A diploma of the Nobel Prize, as precedent with Dogmack in 1947, would recognize the merit of the scientist who made the most complete medical discovery of all times. © 2013 Elsevier Ireland Ltd. All rights reserved.

  6. A Critical Assessment of Officially Reported Chagas Disease Surveillance Data in Mexico

    PubMed Central

    Shelly, Ellen M.; Acuna-Soto, Rodolfo; Ernst, Kacey C.; Sterling, Charles R.

    2016-01-01

    Objective Chagas disease, a disease caused by Trypanosoma cruzi, disproportionately affects poor people throughout Latin America. In Mexico, assessments of officially reported burden have not been previously reported. To evaluate discontinuity between surveillance data and data from other sources, we used data from the Mexican Ministry of Health to describe the distribution of reported Chagas disease over time in Mexico and compare it with estimates from the literature. Methods We summarized age and sex differences for Chagas cases and mortality for 1995–2013 and 1982–2010, respectively. We examined the spatial distribution of Chagas disease over time with respect to disease burden. We further compared officially reported figures with estimates from the literature. Results Among 6,494 officially reported cases, rates of Chagas disease were highest in adults aged 25–44 years (47.3%). Mortality was highest in adults aged ≥45 years (423/495, 85.5%). The data indicated increasing temporal trends for incidence and mortality. The greatest burden occurred in southern states, with increasing spatial distribution over time. Fewer than 900 cases and 40 deaths were officially reported annually, in contrast to estimates from the literature of approximately 69,000 new cases and 25,000 deaths annually. Conclusion While increasing trends in officially reported data have been observed, large discrepancies in case estimates compromise our understanding of Chagas disease epidemiology. Reported cases based on current practices are not enough to correctly assess the Chagas disease burden and spatial distribution in Mexico. Understanding the true epidemiology of this disease will lead to more focused and successful control and prevention strategies to decrease disease burden. PMID:26843671

  7. Tc-99m pyrophosphate myocardial scanning in Chagas' disease

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    da Rocha, A.F.; Meguerian, B.A.; Harbert, J.C.

    1981-04-01

    Chagas' disease is a serious protozoan infection affecting up to 20% of populations in some endemic areas. Myocarditis and cardiomyopathy occur in 50% of patients who go on to develop chronic Chagas' disease. We have studied a patient with no overt cardiac symptoms who revealed intense myocardial uptake of Tc-99m pyrophosphate. The significance of this finding in relation to early detection and progress of therapy is explored.

  8. Tc-99m pyrophosphate myocardial scanning in Chagas' disease

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Goncalves da Rocha, A.F.; Meguerian, B.A.; Harbert, J.C.

    1981-04-01

    Chagas' disease is a serious protozoan infection affecting up to 20% of populations in some endemic areas. Myocarditis and cardiomyopathy occur in 50% of patients who go on to develop chronic Chagas's disease. We have studied a patient with no overt cardiac symptoms who revealed intense myocardial uptake of Tc-99m pyrophosphate. The significance of this finding in relation to early detection and progress of therapy is explored.

  9. 21 CFR 886.5810 - Ophthalmic prism reader.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Ophthalmic prism reader. 886.5810 Section 886.5810 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES OPHTHALMIC DEVICES Therapeutic Devices § 886.5810 Ophthalmic prism reader. (a...

  10. Molecular Epidemiologic Source Tracking of Orally Transmitted Chagas Disease, Venezuela

    PubMed Central

    Segovia, Maikell; Martínez, Clara E.; Messenger, Louisa A.; Nessi, Anaibeth; Londoño, Juan C.; Espinosa, Raul; Martínez, Cinda; Alfredo, Mijares; Bonfante-Cabarcas, Rafael; Lewis, Michael D.; de Noya, Belkisyolé A.; Miles, Michael A.; Llewellyn, Martin S.

    2013-01-01

    Oral outbreaks of Chagas disease are increasingly reported in Latin America. The transitory presence of Trypanosoma cruzi parasites within contaminated foods, and the rapid consumption of those foods, precludes precise identification of outbreak origin. We report source attribution for 2 peri-urban oral outbreaks of Chagas disease in Venezuela via high resolution microsatellite typing. PMID:23768982

  11. What Do We Know About Chagas Disease in the United States?

    PubMed

    Montgomery, Susan P; Parise, Monica E; Dotson, Ellen M; Bialek, Stephanie R

    2016-12-07

    Chagas disease, caused by the parasite Trypanosoma cruzi, affects more than 5 million people worldwide leading to serious heart and gastrointestinal disease in a proportion of chronically infected patients. Important modes of transmission include vector-borne, congenital, and via blood transfusion or organ transplant from an infected donor. Vector-borne transmission of Chagas disease occurs in the Americas, including the southern half of North America, where the specific vector insects (triatomines), T. cruzi, and infected reservoir mammalian hosts are found. In the United States, there are estimated to be at least 300,000 cases of chronic Chagas disease among people originally from countries of Latin America where Chagas disease is endemic. Fewer than 30 cases of locally acquired infection have been documented in the United States, although a sylvatic transmission cycle has been known to exist in this country for at least a century. Studies defining risks for locally acquired infection and effective prevention strategies are needed to help prevent domestic transmission of T. cruzi To help address Chagas disease in the United States, improved health-care provider awareness and knowledge, better tools for screening and diagnosing patients, and wider availability of treatment drugs are needed. © The American Society of Tropical Medicine and Hygiene.

  12. Increased mortality attributed to Chagas disease: a systematic review and meta-analysis.

    PubMed

    Cucunubá, Zulma M; Okuwoga, Omolade; Basáñez, María-Gloria; Nouvellet, Pierre

    2016-01-27

    The clinical outcomes associated with Chagas disease remain poorly understood. In addition to the burden of morbidity, the burden of mortality due to Trypanosoma cruzi infection can be substantial, yet its quantification has eluded rigorous scrutiny. This is partly due to considerable heterogeneity between studies, which can influence the resulting estimates. There is a pressing need for accurate estimates of mortality due to Chagas disease that can be used to improve mathematical modelling, burden of disease evaluations, and cost-effectiveness studies. A systematic literature review was conducted to select observational studies comparing mortality in populations with and without a diagnosis of Chagas disease using the PubMed, MEDLINE, EMBASE, Web of Science and LILACS databases, without restrictions on language or date of publication. The primary outcome of interest was mortality (as all-cause mortality, sudden cardiac death, heart transplant or cardiovascular deaths). Data were analysed using a random-effects model to obtain the relative risk (RR) of mortality, the attributable risk percent (ARP), and the annual mortality rates (AMR). The statistic I(2) (proportion of variance in the meta-analysis due to study heterogeneity) was calculated. Sensitivity analyses and publication bias test were also conducted. Twenty five studies were selected for quantitative analysis, providing data on 10,638 patients, 53,346 patient-years of follow-up, and 2739 events. Pooled estimates revealed that Chagas disease patients have significantly higher AMR compared with non-Chagas disease patients (0.18 versus 0.10; RR = 1.74, 95% CI 1.49-2.03). Substantial heterogeneity was found among studies (I(2) = 67.3%). The ARP above background mortality was 42.5%. Through a sub-analysis patients were classified by clinical group (severe, moderate, asymptomatic). While RR did not differ significantly between clinical groups, important differences in AMR were found: AMR = 0.43 in

  13. Influence of Visual Prism Adaptation on Auditory Space Representation.

    PubMed

    Pochopien, Klaudia; Fahle, Manfred

    2017-01-01

    Prisms shifting the visual input sideways produce a mismatch between the visual versus felt position of one's hand. Prism adaptation eliminates this mismatch, realigning hand proprioception with visual input. Whether this realignment concerns exclusively the visuo-(hand)motor system or it generalizes to acoustic inputs is controversial. We here show that there is indeed a slight influence of visual adaptation on the perceived direction of acoustic sources. However, this shift in perceived auditory direction can be fully explained by a subconscious head rotation during prism exposure and by changes in arm proprioception. Hence, prism adaptation does only indirectly generalize to auditory space perception.

  14. Forward and inverse solutions for three-element Risley prism beam scanners.

    PubMed

    Li, Anhu; Liu, Xingsheng; Sun, Wansong

    2017-04-03

    Scan blind zone and control singularity are two adverse issues for the beam scanning performance in double-prism Risley systems. In this paper, a theoretical model which introduces a third prism is developed. The critical condition for a fully eliminated scan blind zone is determined through a geometric derivation, providing several useful formulae for three-Risley-prism system design. Moreover, inverse solutions for a three-prism system are established, based on the damped least-squares iterative refinement by a forward ray tracing method. It is shown that the efficiency of this iterative calculation of the inverse solutions can be greatly enhanced by a numerical differentiation method. In order to overcome the control singularity problem, the motion law of any one prism in a three-prism system needs to be conditioned, resulting in continuous and steady motion profiles for the other two prisms.

  15. Experimental Chagas disease-induced perturbations of the fecal microbiome and metabolome.

    PubMed

    McCall, Laura-Isobel; Tripathi, Anupriya; Vargas, Fernando; Knight, Rob; Dorrestein, Pieter C; Siqueira-Neto, Jair L

    2018-03-01

    Trypanosoma cruzi parasites are the causative agents of Chagas disease. These parasites infect cardiac and gastrointestinal tissues, leading to local inflammation and tissue damage. Digestive Chagas disease is associated with perturbations in food absorption, intestinal traffic and defecation. However, the impact of T. cruzi infection on the gut microbiota and metabolome have yet to be characterized. In this study, we applied mass spectrometry-based metabolomics and 16S rRNA sequencing to profile infection-associated alterations in fecal bacterial composition and fecal metabolome through the acute-stage and into the chronic stage of infection, in a murine model of Chagas disease. We observed joint microbial and chemical perturbations associated with T. cruzi infection. These included alterations in conjugated linoleic acid (CLA) derivatives and in specific members of families Ruminococcaceae and Lachnospiraceae, as well as alterations in secondary bile acids and members of order Clostridiales. These results highlight the importance of multi-'omics' and poly-microbial studies in understanding parasitic diseases in general, and Chagas disease in particular.

  16. Ultradispersive adaptive prism based on a coherently prepared atomic medium

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Sautenkov, Vladimir A.; P. N. Lebedev Institute of Physics, Moscow 119991; Li Hebin

    2010-06-15

    We have experimentally demonstrated an ultra-dispersive optical prism made from a coherently driven Rb atomic vapor. The prism possesses spectral angular dispersion that is 6 orders of magnitude higher than that of a prism made of optical glass; such angular dispersion allows one to spatially resolve light beams with different frequencies separated by a few kilohertz. The prism operates near the resonant frequency of atomic vapor and its dispersion is optically controlled by a coherent driving field.

  17. PRogram In Support of Moms (PRISM): Development and Beta Testing.

    PubMed

    Byatt, Nancy; Pbert, Lori; Hosein, Safiyah; Swartz, Holly A; Weinreb, Linda; Allison, Jeroan; Ziedonis, Douglas

    2016-08-01

    Most women with perinatal depression do not receive depression treatment. The authors describe the development and beta testing of a new program, PRogram In Support of Moms (PRISM), to improve treatment of perinatal depression in obstetric practices. A multidisciplinary work group of seven perinatal and behavioral health professionals was convened to design, refine, and beta-test PRISM in an obstetric practice. Iterative feedback and problem solving facilitated development of PRISM components, which include provider training and a toolkit, screening procedures, implementation assistance, and access to immediate psychiatric consultation. Beta testing with 50 patients over two months demonstrated feasibility and suggested that PRISM may improve provider screening rates and self-efficacy to address depression. On the basis of lessons learned, PRISM will be enhanced to integrate proactive patient engagement and monitoring into obstetric practices. PRISM may help overcome patient-, provider-, and system-level barriers to managing perinatal depression in obstetric settings.

  18. Prevalence of Chagas Disease among Solid Organ-Transplanted Patients in a Nonendemic Country.

    PubMed

    Salvador, Fernando; Sánchez-Montalvá, Adrián; Sulleiro, Elena; Moreso, Francesc; Berastegui, Cristina; Caralt, Mireia; Pinazo, María-Jesús; Moure, Zaira; Los-Arcos, Ibai; Len, Oscar; Gavaldà, Joan; Molina, Israel

    2018-03-01

    Reactivation of Chagas disease in the chronic phase may occur after solid organ transplantation, which may result in high parasitemia and severe clinical manifestations such as myocarditis and meningoencephalitis. The aim of the present study is to describe the prevalence of Chagas disease among solid organ-transplanted patients in a tertiary hospital from a nonendemic country. A cross-sectional study was performed at Vall d'Hebron University Hospital (Barcelona, Spain) from April to September 2016. Chagas disease screening was performed through serological tests in adult patients coming from endemic areas that had received solid organ transplantation and were being controlled in our hospital during the study period. Overall, 42 patients were included, 20 (47.6%) were male and median age was 50.5 (23-73) years. Transplanted organs were as follows: 18 kidneys, 17 lungs, and 7 livers. Three patients had Chagas disease, corresponding to a prevalence among this group of solid organ-transplanted patients of 7.1%. All three patients were born in Bolivia, had been diagnosed with Chagas disease and received specific treatment before the organ transplantation. We highly recommend providing screening tests for Chagas disease in patients with or candidates for solid organ transplantation coming from endemic areas, early treatment with benznidazole, and close follow-up to prevent clinical reactivations.

  19. Considering Apical Scotomas, Confusion, and Diplopia When Prescribing Prisms for Homonymous Hemianopia

    PubMed Central

    Apfelbaum, Henry L.; Ross, Nicole C.; Bowers, Alex R.; Peli, Eli

    2013-01-01

    Purpose: While prisms are commonly prescribed for homonymous hemianopia to extend or expand the visual field, they cause potentially troubling visual side effects, including nonveridical location of perceived images, diplopia, and visual confusion. In addition, the field behind a prism at its apex is lost to an apical scotoma equal in magnitude to the amount of prism shift. The perceptual consequences of apical scotomas and the other effects of various designs were examined to consider parameters and designs that can mitigate the impact of these effects. Methods: Various configurations of sector and peripheral prisms were analyzed, in various directions of gaze, and their visual effects were illustrated using simulated perimetry. A novel “percept” diagram was developed that yielded insights into the patient's view through the prisms. The predictions were verified perimetrically with patients. Results: The diagrams distinguish between potentially beneficial field expansion via visual confusion and the pericentrally disturbing and useless effect of diplopia, and their relationship to prism power and gaze direction. They also illustrate the nonexpanding substitution of field segments of some popular prism designs. Conclusions: Yoked sector prisms have no effect at primary gaze or when gaze is directed toward the seeing hemifield, and they introduce pericentral field loss when gaze is shifted into them. When fitted unilaterally, sector prisms also have an effect only when the gaze is directed into the prism and may cause a pericentral scotoma and/or central diplopia. Peripheral prisms are effective at essentially all gaze angles. Since gaze is not directed into them, they avoid problematic pericentral effects. We derive useful recommendations for prism power and position parameters, including novel ways of fitting prisms asymmetrically. Translational Relevance: Clinicians will find these novel diagrams, diagramming techniques, and analyses valuable when prescribing

  20. Abbot Ice Shelf, structure of the Amundsen Sea continental margin and the southern boundary of the Bellingshausen Plate seaward of West Antarctica

    NASA Astrophysics Data System (ADS)

    Cochran, James R.; Tinto, Kirsty J.; Bell, Robin E.

    2015-05-01

    Inversion of NASA Operation IceBridge airborne gravity over the Abbot Ice Shelf in West Antarctica for subice bathymetry defines an extensional terrain made up of east-west trending rift basins formed during the early stages of Antarctica/Zealandia rifting. Extension is minor, as rifting jumped north of Thurston Island early in the rifting process. The Amundsen Sea Embayment continental shelf west of the rifted terrain is underlain by a deeper, more extensive sedimentary basin also formed during rifting between Antarctica and Zealandia. A well-defined boundary zone separates the mildly extended Abbot extensional terrain from the deeper Amundsen Embayment shelf basin. The shelf basin has an extension factor, β, of 1.5-1.7 with 80-100 km of extension occurring across an area now 250 km wide. Following this extension, rifting centered north of the present shelf edge and proceeded to continental rupture. Since then, the Amundsen Embayment continental shelf appears to have been tectonically quiescent and shaped by subsidence, sedimentation, and the advance and retreat of the West Antarctic Ice Sheet. The Bellingshausen Plate was located seaward of the Amundsen Sea margin prior to incorporation into the Antarctic Plate at about 62 Ma. During the latter part of its independent existence, Bellingshausen plate motion had a clockwise rotational component relative to Antarctica producing convergence across the north-south trending Bellingshausen Gravity Anomaly structure at 94°W and compressive deformation on the continental slope between 94°W and 102°W. Farther west, the relative motion was extensional along an east-west trending zone occupied by the Marie Byrd Seamounts. The copyright line for this article was changed on 5 JUN 2015 after original online publication.

  1. Boolean Operations with Prism Algebraic Patches

    PubMed Central

    Bajaj, Chandrajit; Paoluzzi, Alberto; Portuesi, Simone; Lei, Na; Zhao, Wenqi

    2009-01-01

    In this paper we discuss a symbolic-numeric algorithm for Boolean operations, closed in the algebra of curved polyhedra whose boundary is triangulated with algebraic patches (A-patches). This approach uses a linear polyhedron as a first approximation of both the arguments and the result. On each triangle of a boundary representation of such linear approximation, a piecewise cubic algebraic interpolant is built, using a C1-continuous prism algebraic patch (prism A-patch) that interpolates the three triangle vertices, with given normal vectors. The boundary representation only stores the vertices of the initial triangulation and their external vertex normals. In order to represent also flat and/or sharp local features, the corresponding normal-per-face and/or normal-per-edge may be also given, respectively. The topology is described by storing, for each curved triangle, the two triples of pointers to incident vertices and to adjacent triangles. For each triangle, a scaffolding prism is built, produced by its extreme vertices and normals, which provides a containment volume for the curved interpolating A-patch. When looking for the result of a regularized Boolean operation, the 0-set of a tri-variate polynomial within each such prism is generated, and intersected with the analogous 0-sets of the other curved polyhedron, when two prisms have non-empty intersection. The intersection curves of the boundaries are traced and used to decompose each boundary into the 3 standard classes of subpatches, denoted in, out and on. While tracing the intersection curves, the locally refined triangulation of intersecting patches is produced, and added to the boundary representation. PMID:21516262

  2. Prevention of congenital Chagas disease by Benznidazole treatment in reproductive-age women. An observational study.

    PubMed

    Álvarez, María G; Vigliano, Carlos; Lococo, Bruno; Bertocchi, Graciela; Viotti, Rodolfo

    2017-10-01

    Since the decline in new cases of infection by insect/vector, congenital Chagas disease has become more relevant in the transmission of Chagas disease. Treatment with benznidazole significantly reduces the parasitemia, which constitutes an important factor linked to vertical transmission. The objective of this study was to evaluate whether treatment with benznidazole previously administered to women of childbearing age can prevent or reduce the incidence of new cases of congenital Chagas disease. An historical cohort study that included all women in reproductive age (15-45 years) assisted in our center was designed. We included 67 mothers with chronic Chagas disease; 35 women had not been treated prior to pregnancy, 15 had been treated prior to pregnancy and 17 gave birth prior and after treatment with benznidazole. Eight mothers gave birth to 16 children with congenital Chagas disease (8/67, 12%). The prevalence of congenital Chagas was 16/114 (14%) children born to untreated mothers and 0/42 (0%) children born to benznidazole- treated mothers, p=0.01. No significant differences were observed in clinical, serologic, epidemiological or socioeconomic baseline variables between mothers with and without children born with congenital Chagas. A 32% conversion rate to negative serology was observed in benznidazole-treated women after long-term follow up. Antiparasitic treatment administered to women in reproductive age can prevent the occurrence of congenital Chagas disease. Copyright © 2017 Elsevier B.V. All rights reserved.

  3. Mapping of Chagas disease research: analysis of publications in the period between 1940 and 2009.

    PubMed

    Ramos, José Manuel; González-Alcaide, Gregorio; Gascón, Joaquín; Gutiérrez, Félix

    2011-01-01

    Publications are often used as a measure of success in research work. Chagas disease occurs in Central and Southern America. However, during the past years, the disease has been occurring outside Latin America due to migration from endemic zones. This article describes a bibliometric review of the literature on Chagas disease research indexed in PubMed during a 70-year period. Medline was used via the PubMed online service of the U.S. National Library of Medicine from 1940 to 2009. The search strategy was: Chagas disease [MeSH] OR Trypanosoma cruzi [MeSH]. A total of 13,989 references were retrieved. The number of publications increased steadily over time from 1,361 (1940-1969) to 5,430 (2000-2009) (coefficient of determination for linear fit, R²=0.910). Eight journals contained 25% of the Chagas disease literature. Of the publications, 64.2% came from endemic countries. Brazil was the predominant country (37%), followed by the United States (17.6%) and Argentina (14%). The ranking in production changed when the number of publications was normalized by estimated cases of Chagas disease (Panama and Uruguay), population (Argentina and Uruguay), and gross domestic product (Bolivia and Brazil). Several Latin American countries, where the prevalence of T. cruzi infection was not very high, were the main producers of the Chagas disease literature, after adjusting for economic and population indexes. The countries with more estimated cases of Chagas disease produced less research on Chagas disease than some developed countries.

  4. Pointing error analysis of Risley-prism-based beam steering system.

    PubMed

    Zhou, Yuan; Lu, Yafei; Hei, Mo; Liu, Guangcan; Fan, Dapeng

    2014-09-01

    Based on the vector form Snell's law, ray tracing is performed to quantify the pointing errors of Risley-prism-based beam steering systems, induced by component errors, prism orientation errors, and assembly errors. Case examples are given to elucidate the pointing error distributions in the field of regard and evaluate the allowances of the error sources for a given pointing accuracy. It is found that the assembly errors of the second prism will result in more remarkable pointing errors in contrast with the first one. The pointing errors induced by prism tilt depend on the tilt direction. The allowances of bearing tilt and prism tilt are almost identical if the same pointing accuracy is planned. All conclusions can provide a theoretical foundation for practical works.

  5. Chagas disease in a Texan horse with neurologic deficits.

    PubMed

    Bryan, Laura K; Hamer, Sarah A; Shaw, Sarah; Curtis-Robles, Rachel; Auckland, Lisa D; Hodo, Carolyn L; Chaffin, Keith; Rech, Raquel R

    2016-01-30

    A 10-year-old Quarter Horse gelding presented to the Texas A&M University Veterinary Teaching Hospital with a six month-history of ataxia and lameness in the hind limbs. The horse was treated presumptively for equine protozoal myeloencephalitis (EPM) based on clinical signs but was ultimately euthanized after its condition worsened. Gross lesions were limited to a small area of reddening in the gray matter of the thoracic spinal cord. Histologically, trypanosome amastigotes morphologically similar to Trypanosoma cruzi, the agent of Chagas disease in humans and dogs, were sporadically detected within segments of the thoracic spinal cord surrounded by mild lymphoplasmacytic inflammation. Ancillary testing for Sarcocystis neurona, Neospora spp., Toxoplasma gondii and Leishmania spp. was negative. Conventional and real time polymerase chain reaction (PCR) of affected paraffin embedded spinal cord were positive for T. cruzi, and sequencing of the amplified T. cruzi satellite DNA PCR fragment from the horse was homologous with various clones of T. cruzi in GenBank. While canine Chagas disease cases have been widely reported in southern Texas, this is the first report of clinical T. cruzi infection in an equid with demonstrable amastigotes in the spinal cord. In contrast to previous instances of Chagas disease in the central nervous system (CNS) of dogs and humans, no inflammation or T. cruzi amastigotes were detected in the heart of the horse. Based on clinical signs, there is a potential for misdiagnosis of Chagas disease with other infectious diseases that affect the equine CNS. T. cruzi should be considered as a differential diagnosis in horses with neurologic clinical signs and histologic evidence of meningomyelitis that originate in areas where Chagas disease is present. The prevalence of T. cruzi in horses and the role of equids in the parasite life cycle require further study. Copyright © 2015 Elsevier B.V. All rights reserved.

  6. Current drug therapy and pharmaceutical challenges for Chagas disease.

    PubMed

    Bermudez, José; Davies, Carolina; Simonazzi, Analía; Real, Juan Pablo; Palma, Santiago

    2016-04-01

    One of the most significant health problems in the American continent in terms of human health, and socioeconomic impact is Chagas disease, caused by the protozoan parasite Trypanosoma cruzi. Infection was originally transmitted by reduviid insects, congenitally from mother to fetus, and by oral ingestion in sylvatic/rural environments, but blood transfusions, organ transplants, laboratory accidents, and sharing of contaminated syringes also contribute to modern day transmission. Likewise, Chagas disease used to be endemic from Northern Mexico to Argentina, but migrations have earned it global. The parasite has a complex life cycle, infecting different species, and invading a variety of cells - including muscle and nerve cells of the heart and gastrointestinal tract - in the mammalian host. Human infection outcome is a potentially fatal cardiomyopathy, and gastrointestinal tract lesions. In absence of a vaccine, vector control and treatment of patients are the only tools to control the disease. Unfortunately, the only drugs now available for Chagas' disease, Nifurtimox and Benznidazole, are relatively toxic for adult patients, and require prolonged administration. Benznidazole is the first choice for Chagas disease treatment due to its lower side effects than Nifurtimox. However, different strategies are being sought to overcome Benznidazole's toxicity including shorter or intermittent administration schedules-either alone or in combination with other drugs. In addition, a long list of compounds has shown trypanocidal activity, ranging from natural products to specially designed molecules, re-purposing drugs commercialized to treat other maladies, and homeopathy. In the present review, we will briefly summarize the upturns of current treatment of Chagas disease, discuss the increment on research and scientific publications about this topic, and give an overview of the state-of-the-art research aiming to produce an alternative medication to treat T. cruzi infection

  7. Chagas disease: 100 years after its discovery. A systemic review.

    PubMed

    Coura, José Rodrigues; Borges-Pereira, José

    2010-01-01

    Although Chagas disease was only discovered in 1909, it began millions of years ago as an enzootic disease among wild animals. Its transmission to man began accidentally as an anthropozoonosis when mankind invaded wild ecotopes. Endemic Chagas disease became established as a zoonosis over the last 200-300 years through deforestation for agriculture and livestock rearing and adaptation of triatomines to dwellings and to humans and domestic animals as food sources. When T. cruzi is transmitted to man, it invades the bloodstream and lymphatic system and lodges in muscle and heart tissue, the digestive system and phagocytic cells. Through this, it causes inflammatory lesions and an immune response, particularly mediated by CD4(+), CD8(+), IL2 and IL4, with cell and neuron destruction and fibrosis. These processes lead to blockage of the heart's conductive system, arrhythmias, heart failure, aperistalsis and dilatation of hollow viscera, especially the esophagus and colons. Chagas disease is characterized by an acute phase with or without symptoms, with (or more often without) T. cruzi penetration signs (inoculation chagoma or Romaña's sign), fever, adenomegaly, hepatosplenomegaly and patent parasitemia; and a chronic phase: indeterminate (asymptomatic, with normal electrocardiogram and heart, esophagus and colon X-rays) or cardiac, digestive or cardiac/digestive forms. There is great regional variation in the morbidity caused by Chagas disease: severe cardiac or digestive forms may occur in 10-50%, and indeterminate forms in the remaining, asymptomatic cases. The epidemiological and control characteristics of Chagas disease vary according to each country's ecological conditions and health policies. 2010. Published by Elsevier B.V.

  8. [Globalization, inequity and Chagas disease].

    PubMed

    Dias, João Carlos Pinto

    2007-01-01

    Chagas disease (American trypanosomiasis) bears a close relationship to multiple social and political aspects involving issues of globalization and inequity. Such relations concern the process of disease production and control in parallel with medical management. Despite the poverty in Latin America and various problems related to inequities and globalization, Chagas disease has been controlled in several areas, a fact that reinforces the countries' self-reliance. Several problems and challenges related to the disease can be expected in the future, mainly concerning medical care for already infected individuals and the sustainability of effective epidemiological surveillance. Both points depend heavily on improved performance by the national health systems, principally in terms of their efficiency and their capacity to overcome inequity. A particularly important role has been attributed to the Latin American scientific and academic community in the implementation and sustainability of efficient control policies. Control activities have now evolved towards internationally shared initiatives, a major new stride forward in the region's political context.

  9. Chagas Disease Knowledge and Risk Behaviors of the Homeless Population in Houston, TX.

    PubMed

    Ingber, Alexandra; Garcia, Melissa N; Leon, Juan; Murray, Kristy O

    2018-04-01

    Chagas disease is a parasitic infection, caused by Trypanosoma cruzi, endemic in Latin America. Sylvatic T. cruzi-infected triatomine vectors are present in rural and urban areas in the southern USA and may transmit T. cruzi infection to at-risk populations, such as homeless individuals. Our study aimed to evaluate Chagas disease knowledge and behaviors potentially associated with transmission risk of Chagas disease among Houston, Texas' homeless population by performing interviews with 212 homeless individuals. The majority of the 212 surveyed homeless individuals were male (79%), African-American (43%), American-born individuals (96%). About 30% of the individuals reported having seen triatomines in Houston, and 25% had evidence of blood-borne transmission risk (IV drug use and/or unregulated tattoos). The median total time homeless was significantly associated with recognition of the triatomine vector. Our survey responses indicate that the homeless populations may exhibit potential risks for Chagas disease, due to increased vector exposure, and participation in blood-borne pathogen risk behaviors. Our findings warrant additional research to quantify the prevalence of Chagas disease among homeless populations.

  10. Prism adaptation magnitude has differential influences on perceptual versus manual responses.

    PubMed

    Striemer, Christopher L; Russell, Karyn; Nath, Priya

    2016-10-01

    Previous research has indicated that rightward prism adaptation can reduce symptoms of spatial neglect following right brain damage. In addition, leftward prism adaptation can create "neglect-like" patterns of performance in healthy adults on tasks that measure attention and spatial biases. Although a great deal of research has focused on which behaviors are influenced by prism adaptation, very few studies have focused directly on how the magnitude of visual shift induced by prisms might be related to the observed aftereffects, or the effects of prisms on measures of attentional and spatial biases. In the current study, we examined these questions by having groups of healthy adult participants complete manual line bisection and landmark tasks prior to and following adaptation to either 8.5° (15 diopter; n = 22) or 17° (30 diopter; n = 25) leftward shifting prisms. Our results demonstrated a significantly larger rightward shift in straight-ahead pointing (a measure of prism aftereffect) following adaptation to 17°, compared to 8.5° leftward shifting prisms. In addition, only 17° leftward shifting prisms resulted in a significant rightward shift in line bisection following adaptation. However, there was a significant change in performance on the landmark task pre- versus post-adaptation in both the 8.5° and 17° leftward shifting prism groups. Interestingly, correlation analyses indicated that changes in straight-ahead pointing pre- versus post-adaptation were positively correlated with changes in performance on the manual line bisection task, but not the landmark task. These data suggest that larger magnitudes of prism adaptation seem to have a greater influence on tasks that require a response with the adapted hand (i.e., line bisection), compared to tasks that only require a perceptual judgment (i.e., the landmark task). In addition, these data provide further evidence that the effects of prisms on manual and perceptual responses are not related to one

  11. The Costs of Preventing and Treating Chagas Disease in Colombia

    PubMed Central

    Castillo-Riquelme, Marianela; Guhl, Felipe; Turriago, Brenda; Pinto, Nestor; Rosas, Fernando; Martínez, Mónica Flórez; Fox-Rushby, Julia; Davies, Clive; Campbell-Lendrum, Diarmid

    2008-01-01

    Background The objective of this study is to report the costs of Chagas disease in Colombia, in terms of vector disease control programmes and the costs of providing care to chronic Chagas disease patients with cardiomyopathy. Methods Data were collected from Colombia in 2004. A retrospective review of costs for vector control programmes carried out in rural areas included 3,084 houses surveyed for infestation with triatomine bugs and 3,305 houses sprayed with insecticide. A total of 63 patient records from 3 different hospitals were selected for a retrospective review of resource use. Consensus methodology with local experts was used to estimate care seeking behaviour and to complement observed data on utilisation. Findings The mean cost per house per entomological survey was $4.4 (in US$ of 2004), whereas the mean cost of spraying a house with insecticide was $27. The main cost driver of spraying was the price of the insecticide, which varied greatly. Treatment of a chronic Chagas disease patient costs between $46.4 and $7,981 per year in Colombia, depending on severity and the level of care used. Combining cost and utilisation estimates the expected cost of treatment per patient-year is $1,028, whereas lifetime costs averaged $11,619 per patient. Chronic Chagas disease patients have limited access to healthcare, with an estimated 22% of patients never seeking care. Conclusion Chagas disease is a preventable condition that affects mostly poor populations living in rural areas. The mean costs of surveying houses for infestation and spraying infested houses were low in comparison to other studies and in line with treatment costs. Care seeking behaviour and the type of insurance affiliation seem to play a role in the facilities and type of care that patients use, thus raising concerns about equitable access to care. Preventing Chagas disease in Colombia would be cost-effective and could contribute to prevent inequalities in health and healthcare. PMID:19015725

  12. Chagas Disease, Migration and Community Settlement Patterns in Arequipa, Peru

    PubMed Central

    Gilman, Robert H.; Cornejo del Carpio, Juan G.; Naquira, Cesar; Bern, Caryn; Levy, Michael Z.

    2009-01-01

    Background Chagas disease is one of the most important neglected tropical diseases in the Americas. Vectorborne transmission of Chagas disease has been historically rare in urban settings. However, in marginal communities near the city of Arequipa, Peru, urban transmission cycles have become established. We examined the history of migration and settlement patterns in these communities, and their connections to Chagas disease transmission. Methodology/Principal Findings This was a qualitative study that employed focus group discussions and in-depth interviews. Five focus groups and 50 in-depth interviews were carried out with 94 community members from three shantytowns and two traditional towns near Arequipa, Peru. Focus groups utilized participatory methodologies to explore the community's mobility patterns and the historical and current presence of triatomine vectors. In-depth interviews based on event history calendars explored participants' migration patterns and experience with Chagas disease and vectors. Focus group data were analyzed using participatory analysis methodologies, and interview data were coded and analyzed using a grounded theory approach. Entomologic data were provided by an ongoing vector control campaign. We found that migrants to shantytowns in Arequipa were unlikely to have brought triatomines to the city upon arrival. Frequent seasonal moves, however, took shantytown residents to valleys surrounding Arequipa where vectors are prevalent. In addition, the pattern of settlement of shantytowns and the practice of raising domestic animals by residents creates a favorable environment for vector proliferation and dispersal. Finally, we uncovered a phenomenon of population loss and replacement by low-income migrants in one traditional town, which created the human settlement pattern of a new shantytown within this traditional community. Conclusions/Significance The pattern of human migration is therefore an important underlying determinant of

  13. Global economic burden of Chagas disease: a computational simulation model.

    PubMed

    Lee, Bruce Y; Bacon, Kristina M; Bottazzi, Maria Elena; Hotez, Peter J

    2013-04-01

    As Chagas disease continues to expand beyond tropical and subtropical zones, a growing need exists to better understand its resulting economic burden to help guide stakeholders such as policy makers, funders, and product developers. We developed a Markov simulation model to estimate the global and regional health and economic burden of Chagas disease from the societal perspective. Our Markov model structure had a 1 year cycle length and consisted of five states: acute disease, indeterminate disease, cardiomyopathy with or without congestive heart failure, megaviscera, and death. Major model parameter inputs, including the annual probabilities of transitioning from one state to another, and present case estimates for Chagas disease came from various sources, including WHO and other epidemiological and disease-surveillance-based reports. We calculated annual and lifetime health-care costs and disability-adjusted life-years (DALYs) for individuals, countries, and regions. We used a discount rate of 3% to adjust all costs and DALYs to present-day values. On average, an infected individual incurs US$474 in health-care costs and 0·51 DALYs annually. Over his or her lifetime, an infected individual accrues an average net present value of $3456 and 3·57 DALYs. Globally, the annual burden is $627·46 million in health-care costs and 806,170 DALYs. The global net present value of currently infected individuals is $24·73 billion in health-care costs and 29,385,250 DALYs. Conversion of this burden into costs results in annual per-person costs of $4660 and lifetime per-person costs of $27,684. Global costs are $7·19 billion per year and $188·80 billion per lifetime. More than 10% of these costs emanate from the USA and Canada, where Chagas disease has not been traditionally endemic. A substantial proportion of the burden emerges from lost productivity from cardiovascular disease-induced early mortality. The economic burden of Chagas disease is similar to or exceeds those

  14. Goldmann Tonometer Prism with an Optimized Error Correcting Applanation Surface.

    PubMed

    McCafferty, Sean; Lim, Garrett; Duncan, William; Enikov, Eniko; Schwiegerling, Jim

    2016-09-01

    We evaluate solutions for an applanating surface modification to the Goldmann tonometer prism, which substantially negates the errors due to patient variability in biomechanics. A modified Goldmann or correcting applanation tonometry surface (CATS) prism is presented which was optimized to minimize the intraocular pressure (IOP) error due to corneal thickness, stiffness, curvature, and tear film. Mathematical modeling with finite element analysis (FEA) and manometric IOP referenced cadaver eyes were used to optimize and validate the design. Mathematical modeling of the optimized CATS prism indicates an approximate 50% reduction in each of the corneal biomechanical and tear film errors. Manometric IOP referenced pressure in cadaveric eyes demonstrates substantial equivalence to GAT in nominal eyes with the CATS prism as predicted by modeling theory. A CATS modified Goldmann prism is theoretically able to significantly improve the accuracy of IOP measurement without changing Goldmann measurement technique or interpretation. Clinical validation is needed but the analysis indicates a reduction in CCT error alone to less than ±2 mm Hg using the CATS prism in 100% of a standard population compared to only 54% less than ±2 mm Hg error with the present Goldmann prism. This article presents an easily adopted novel approach and critical design parameters to improve the accuracy of a Goldmann applanating tonometer.

  15. Accuracy assessment of ALOS optical instruments: PRISM and AVNIR-2

    NASA Astrophysics Data System (ADS)

    Tadono, Takeo; Shimada, Masanobu; Iwata, Takanori; Takaku, Junichi; Kawamoto, Sachi

    2017-11-01

    This paper describes the updated results of calibration and validation to assess the accuracies for optical instruments onboard the Advanced Land Observing Satellite (ALOS, nicknamed "Daichi"), which was successfully launched on January 24th, 2006 and it is continuously operating very well. ALOS has an L-band Synthetic Aperture Radar called PALSAR and two optical instruments i.e. the Panchromatic Remotesensing Instrument for Stereo Mapping (PRISM) and the Advanced Visible and Near Infrared Radiometer type-2 (AVNIR-2). PRISM consists of three radiometers and is used to derive a digital surface model (DSM) with high spatial resolution that is an objective of the ALOS mission. Therefore, geometric calibration is important in generating a precise DSM with stereo pair images of PRISM. AVNIR-2 has four radiometric bands from blue to near infrared and uses for regional environment and disaster monitoring etc. The radiometric calibration and image quality evaluation are also important for AVNIR-2 as well as PRISM. This paper describes updated results of geometric calibration including geolocation determination accuracy evaluations of PRISM and AVNIR-2, image quality evaluation of PRISM, and validation of generated PRISM DSM. These works will be done during the ALOS mission life as an operational calibration to keep absolute accuracies of the standard products.

  16. Molecular mechanisms of cardiac electromechanical remodeling during Chagas disease: Role of TNF and TGF-β.

    PubMed

    Cruz, Jader Santos; Machado, Fabiana Simão; Ropert, Catherine; Roman-Campos, Danilo

    2017-02-01

    Chagas disease is caused by the trypanosomatid Trypanosoma cruzi, which chronically causes heart problems in up to 30% of infected patients. Chagas disease was initially restricted to Latin America. However, due to migratory events, this disease may become a serious worldwide health problem. During Chagas disease, many patients die of cardiac arrhythmia despite the apparent benefits of anti-arrhythmic therapy (e.g., amiodarone). Here, we assimilate the cardiac form of Chagas disease to an inflammatory cardiac disease. Evidence from the literature, mostly provided using experimental models, supports this view and argues in favor of new strategies for treating cardiac arrhythmias in Chagas disease by modulating cytokine production and/or action. But the complex nature of myocardial inflammation underlies the need to better understand the molecular mechanisms of the inflammatory response during Chagas disease. Here, particular attention has been paid to tumor necrosis factor alpha (TNF) and transforming growth factor beta (TGF-β) although other cytokines may be involved in the chagasic cardiomyopathy. Copyright © 2016 Elsevier Inc. All rights reserved.

  17. A mathematical model of Chagas disease transmission

    NASA Astrophysics Data System (ADS)

    Hidayat, Dayat; Nugraha, Edwin Setiawan; Nuraini, Nuning

    2018-03-01

    Chagas disease is a parasitic infection caused by protozoan Trypanosoma cruzi which is transmitted to human by insects of the subfamily Triatominae, including Rhodnius prolixus. This disease is a major problem in several countries of Latin America. A mathematical model of Chagas disease with separate vector reservoir and a neighboring human resident is constructed. The basic reproductive ratio is obtained and stability analysis of the equilibria is shown. We also performed sensitivity populations dynamics of infected humans and infected insects based on migration rate, carrying capacity, and infection rate parameters. Our findings showed that the dynamics of the infected human and insect is mostly affected by carrying capacity insect in the settlement.

  18. Survey of Pediatric Infectious Diseases Society Members About Congenital Chagas Disease.

    PubMed

    Edwards, Morven S; Abanyie, Francisca A; Montgomery, Susan P

    2018-01-01

    Participants in a survey about congenital Chagas disease, distributed electronically to Pediatric Infectious Diseases Society members, perceived having limited knowledge about congenital Trypanosoma cruzi infection. Most rarely or never consider the diagnosis in infants born to parents from Latin America. Improved awareness of congenital Chagas disease and assessment of at-risk infants is needed.

  19. Modeling Chagas Disease at Population Level to Explain Venezuela's Real Data

    PubMed Central

    González-Parra, Gilberto; Chen-Charpentier, Benito M.; Bermúdez, Moises

    2015-01-01

    Objectives In this paper we present an age-structured epidemiological model for Chagas disease. This model includes the interactions between human and vector populations that transmit Chagas disease. Methods The human population is divided into age groups since the proportion of infected individuals in this population changes with age as shown by real prevalence data. Moreover, the age-structured model allows more accurate information regarding the prevalence, which can help to design more specific control programs. We apply this proposed model to data from the country of Venezuela for two periods, 1961–1971, and 1961–1991 taking into account real demographic data for these periods. Results Numerical computer simulations are presented to show the suitability of the age-structured model to explain the real data regarding prevalence of Chagas disease in each of the age groups. In addition, a numerical simulation varying the death rate of the vector is done to illustrate prevention and control strategies against Chagas disease. Conclusion The proposed model can be used to determine the effect of control strategies in different age groups. PMID:26929912

  20. Negative index effects from a homogeneous positive index prism

    NASA Astrophysics Data System (ADS)

    Marcus, Sherman W.; Epstein, Ariel

    2017-12-01

    Cellular structured negative index metamaterials in the form of a right triangular prism have often been tested by observing the refraction of a beam across the prism hypotenuse which is serrated in order to conform to the cell walls. We show that not only can this negative index effect be obtained from a homogeneous dielectric prism having a positive index of refraction, but in addition, for sampling at the walls of the cellular structure, the phase in the material has the illusory appearance of moving in a negative direction. Although many previous reports relied on refraction direction and phase velocity of prism structures to verify negative index design, our investigation indicates that to unambiguously demonstrate material negativity additional empirical evidence is required.

  1. [Do prisms according to Hans-Joachim Haase improve stereoacuity?].

    PubMed

    Kromeier, Miriam; Schmitt, Christina; Bach, Michael; Kommerell, Guntram

    2002-06-01

    The "Measuring and Correcting Methodology" after H.-J. Haase (MKH) aims at converting "fixation disparity" into bicentral fixation, using prismatic spectacles. In the context of the MKH, fixation disparity is diagnosed by a series of subjective tests. According to H.-J. Haase, a long-standing fixation disparity can lead to "disparate correspondence" between the central areas of both retinae, which consolidates the fixation disparity and gradually converts a "young" into an "old fixation disparity". In "old fixation disparity" it is thought that bicentral fixation does not occur anymore, so that stereoacuity is impaired. However, prismatic spectacles can, according to H.-J. Haase, restitute bicentral fixation and consequently improve stereoacuity, even in some cases of "old fixation disparity". Ten non-strabismic subjects with a visual acuity of >/= 1.0 in both eyes were examined. It turned out that all ten had, according to MKH, a "disparate correspondence", 5 subjects with a "young" and 5 with an "old fixation disparity". According to the MKH, a correcting prism was determined. All 10 subjects underwent the automatic Freiburg Stereoacuity Test, without and with the MKH-prism. Without the MKH-prism, the stereoscopic threshold ranged between 1.5 and 14.5 arcsec. With the MKH-prism, the values were not significantly different. Stereoacuity ranged between good and excellent in the 5 subjects with "young" as well as in the 5 subjects with "old fixation disparity". The MKH-prism did not improve the stereoacuity in any of the subjects. These results cast doubt on Haase's assertion that an "old fixation disparity" implies a reduced stereoacuity. Hence, the premise for a benefit of the MKH-prism with respect of stereoacuity is not substantiated. In the 5 subjects with a "young fixation disparity", the good stereoacuity is consistent with Haase's theory, so that a benefit of the MKH-prism for stereoacuity was not expected. In previous studies, stereoacuity was found to be

  2. Chagas disease in European countries: the challenge of a surveillance system.

    PubMed

    Basile, L; Jansa, J M; Carlier, Y; Salamanca, D D; Angheben, A; Bartoloni, A; Seixas, J; Van Gool, T; Canavate, C; Flores-Chavez, M; Jackson, Y; Chiodini, P L; Albajar-Vinas, P

    2011-09-15

    A study of aggregate data collected from the literature and official sources was undertaken to estimate expected and observed prevalence of Trypanosoma cruzi infection, annual incidence of congenital transmission and rate of underdiagnosis of Chagas disease among Latin American migrants in the nine European countries with the highest prevalence of Chagas disease. Formal and informal data sources were used to estimate the population from endemic countries resident in Europe in 2009, diagnosed cases of Chagas disease and births from mothers originating from endemic countries. By 2009, 4,290 cases had been diagnosed in Europe, compared with an estimated 68,000 to 122,000 expected cases. The expected prevalence was very high in undocumented migrants (on average 45% of total expected cases) while the observed prevalence rate was 1.3 cases per 1,000 resident migrants from endemic countries. An estimated 20 to 183 babies with congenital Chagas disease are born annually in the study countries. The annual incidence rate of congenital transmission per 1,000 pregnancies in women from endemic countries was between none and three cases. The index of under diagnosis of T. cruzi infection was between 94% and 96%. Chagas disease is a public health challenge in the studied European countries. Urgent measures need to be taken to detect new cases of congenital transmission and take care of the existing cases with a focus on migrants without legal residency permit and potential difficulty accessing care.

  3. Asymmetric transmission in prisms using structures and materials with isotropic-type dispersion.

    PubMed

    Gundogdu, Funda Tamara; Serebryannikov, Andriy E; Cakmak, A Ozgur; Ozbay, Ekmel

    2015-09-21

    It is demonstrated that strong asymmetry in transmission can be obtained at the Gaussian beam illumination for a single prism based on a photonic crystal (PhC) with isotropic-type dispersion, as well as for its analog made of a homogeneous material. Asymmetric transmission can be realized with the aid of refraction at a proper orientation of the interfaces and wedges of the prism, whereas neither contribution of higher diffraction orders nor anisotropic-type dispersion is required. Furthermore, incidence toward a prism wedge can be used for one of two opposite directions in order to obtain asymmetry. Thus, asymmetric transmission is a general property of the prism configurations, which can be obtained by using simple geometries and quite conventional materials. The obtained results show that strong asymmetry can be achieved in PhC prisms with (nearly) circular shape of equifrequency dispersion contours, in both cases associated with the index of refraction 01. For the comparison purposes, results are also presented for solid uniform non-magnetic prisms made of a material with the same value of n. It is shown in zero-loss approximation that the PhC prism and the ultralow-index material prism (0prism and the solid dielectric prism can show the same scenario at n>1. Possible contributions of scattering on the individual rods and diffraction on the wedge to the resulting mechanism are discussed. Analogs of unidirectional splitting and unidirectional deflection regimes, which are known from the studies of PhC gratings, are obtained in PhC prisms and solid uniform prisms, i.e. without higher diffraction orders.

  4. Three timescales in prism adaptation.

    PubMed

    Inoue, Masato; Uchimura, Motoaki; Karibe, Ayaka; O'Shea, Jacinta; Rossetti, Yves; Kitazawa, Shigeru

    2015-01-01

    It has been proposed that motor adaptation depends on at least two learning systems, one that learns fast but with poor retention and another that learns slowly but with better retention (Smith MA, Ghazizadeh A, Shadmehr R. PLoS Biol 4: e179, 2006). This two-state model has been shown to account for a range of behavior in the force field adaptation task. In the present study, we examined whether such a two-state model could also account for behavior arising from adaptation to a prismatic displacement of the visual field. We first confirmed that an "adaptation rebound," a critical prediction of the two-state model, occurred when visual feedback was deprived after an adaptation-extinction episode. We then examined the speed of decay of the prism aftereffect (without any visual feedback) after repetitions of 30, 150, and 500 trials of prism exposure. The speed of decay decreased with the number of exposure trials, a phenomenon that was best explained by assuming an "ultraslow" system, in addition to the fast and slow systems. Finally, we compared retention of aftereffects 24 h after 150 or 500 trials of exposure: retention was significantly greater after 500 than 150 trials. This difference in retention could not be explained by the two-state model but was well explained by the three-state model as arising from the difference in the amount of adaptation of the "ultraslow process." These results suggest that there are not only fast and slow systems but also an ultraslow learning system in prism adaptation that is activated by prolonged prism exposure of 150-500 trials. Copyright © 2015 the American Physiological Society.

  5. DSM Generation from ALSO/PRISM Images Using SAT-PP

    NASA Astrophysics Data System (ADS)

    Wolff, Kirsten; Gruen, Armin

    2008-11-01

    One of the most important products of ALOS/PRISM image data are accurate DSMs. To exploit the full potential of the full resolution of PRISM for DSM generation, a highly developed image matcher is needed. As a member of the validation and calibration team for PRISM we published earlier results of DSM generation using PRISM image triplets in combination with our software package SAT-PP. The overall accuracy across all object and image features for all tests lies between 1-5 pixels in matching, depending primarily on surface roughness, vegetation, image texture and image quality. Here we will discuss some new results. We focus on four different topics: the use of two different evaluation methods, the difference between a 5m and a 10m GSD for the final PRISM DSM, the influence of the level of initial information and the comparison of the quality of different combinations of the three different views forward, nadir and backward. All tests have been conducted with our testfield Bern/Thun, Switzerland.

  6. The Program for Regional and International Shorebird Monitoring (PRISM)

    USGS Publications Warehouse

    Bart, J.; Andres, B.; Brown, S.; Donaldson, G.; Harrington, B.; Johnston, V.; Jones, S.; Morrison, R.I.G.; Skagen, S.K.

    2005-01-01

    This report describes the "Program for Regional and International Shorebird Monitoring" (PRISM). PRISM is being implemented by a Canada-United States Shorebird Monitoring and Assessment Committee formed in 2001 by the Canadian Shorebird Working Group and the U.S. Shorebird Council. PRISM provides a single blueprint for implementing the shorebird conservation plans recently completed in Canada and the United States. The goals of PRISM are to (1) estimate the size of breeding population of 74 shorebird taxa in North America; (2) describe the distribution, abundance, and habitat relationships for each of these taxa; (3) monitor trends in shorebird population size; (4) monitor shorebird numbers at stopover locations, and; (5) assist local managers in meeting their shorebird conservation goals. PRISM has four main components: arctic and boreal breeding surveys, temperate breeding surveys, temperate non-breeding surveys, and neotropical surveys. Progress on, and action items for, each major component are described. The more important major tasks for immediate action are carrying out the northern surveys, conducting regional analyses to design the program of migration counts, and evaluating aerial photographic surveys for migration and winter counts.

  7. PRISM3/GISS Topographic Reconstruction

    USGS Publications Warehouse

    Sohl, Linda E.; Chandler, Mark A.; Schmunk, Robert B.; Mankoff, Ken; Jonas, Jeffrey A.; Foley, Kevin M.; Dowsett, Harry J.

    2009-01-01

    The PRISM3/GISS topographic reconstruction is one of the global data sets incorporated into a new reconstruction for the mid-Piacenzian warm interval of the Pliocene, at about 3.3 to 3.0 Ma. The PRISM3/GISS topography-gridded data set is a digitization of a graphical reconstruction, provided at 2 deg x 2 deg resolution and based on updated paleoaltimetry data and a refined land/ocean mask. Mid-Piacenzian topography as shown in this data set is generally quite similar to modern topography, with three notable differences: (1) the coastline as shown is 25 meters higher than modern sea level, reflecting the hypothesized reduction in ice sheet volume; (2) Hudson Bay is filled in to low elevation, in the absence of evidence for submergence at that time; and (3) the West Antarctic ice sheet is absent, permitting open seaways to exist in Ellsworth and Marie Byrd Lands. Two alternate ice sheet configurations with corresponding vegetation schemes are available; one is a minor modification of the PRISM2 ice reconstruction, and one is derived from the British Antarctic Survey Ice Sheet Model (BAS ISM).

  8. Kinematic markers dissociate error correction from sensorimotor realignment during prism adaptation.

    PubMed

    O'Shea, Jacinta; Gaveau, Valérie; Kandel, Matthieu; Koga, Kazuo; Susami, Kenji; Prablanc, Claude; Rossetti, Yves

    2014-03-01

    This study investigated the motor control mechanisms that enable healthy individuals to adapt their pointing movements during prism exposure to a rightward optical shift. In the prism adaptation literature, two processes are typically distinguished. Strategic motor adjustments are thought to drive the pattern of rapid endpoint error correction typically observed during the early stage of prism exposure. This is distinguished from so-called 'true sensorimotor realignment', normally measured with a different pointing task, at the end of prism exposure, which reveals a compensatory leftward 'prism after-effect'. Here, we tested whether each mode of motor compensation - strategic adjustments versus 'true sensorimotor realignment' - could be distinguished, by analyzing patterns of kinematic change during prism exposure. We hypothesized that fast feedforward versus slower feedback error corrective processes would map onto two distinct phases of the reach trajectory. Specifically, we predicted that feedforward adjustments would drive rapid compensation of the initial (acceleration) phase of the reach, resulting in the rapid reduction of endpoint errors typically observed early during prism exposure. By contrast, we expected visual-proprioceptive realignment to unfold more slowly and to reflect feedback influences during the terminal (deceleration) phase of the reach. The results confirmed these hypotheses. Rapid error reduction during the early stage of prism exposure was achieved by trial-by-trial adjustments of the motor plan, which were proportional to the endpoint error feedback from the previous trial. By contrast, compensation of the terminal reach phase unfolded slowly across the duration of prism exposure. Even after 100 trials of pointing through prisms, adaptation was incomplete, with participants continuing to exhibit a small rightward shift in both the reach endpoints and in the terminal phase of reach trajectories. Individual differences in the degree of

  9. First-order approximation error analysis of Risley-prism-based beam directing system.

    PubMed

    Zhao, Yanyan; Yuan, Yan

    2014-12-01

    To improve the performance of a Risley-prism system for optical detection and measuring applications, it is necessary to be able to determine the direction of the outgoing beam with high accuracy. In previous works, error sources and their impact on the performance of the Risley-prism system have been analyzed, but their numerical approximation accuracy was not high. Besides, pointing error analysis of the Risley-prism system has provided results for the case when the component errors, prism orientation errors, and assembly errors are certain. In this work, the prototype of a Risley-prism system was designed. The first-order approximations of the error analysis were derived and compared with the exact results. The directing errors of a Risley-prism system associated with wedge-angle errors, prism mounting errors, and bearing assembly errors were analyzed based on the exact formula and the first-order approximation. The comparisons indicated that our first-order approximation is accurate. In addition, the combined errors produced by the wedge-angle errors and mounting errors of the two prisms together were derived and in both cases were proved to be the sum of errors caused by the first and the second prism separately. Based on these results, the system error of our prototype was estimated. The derived formulas can be implemented to evaluate beam directing errors of any Risley-prism beam directing system with a similar configuration.

  10. Development of salt production technology using prism greenhouse method

    NASA Astrophysics Data System (ADS)

    Guntur, G.; Jaziri, A. A.; Prihanto, A. A.; Arisandi, D. M.; Kurniawan, A.

    2018-01-01

    The main problem of salt production in Indonesia is low productivity and quality because the technology used commonly by Indonesian salt farmers is traditional method. This research aims to increase production of salt by using the prism greenhouse method. The prism greenhouse method is a salt production system with a combination of several salt production technologies, including geomembrane, threaded filter, and prism greenhouse technology. This research method used descriptive method. The results of this study were the productivity increased threefold, and the quality of salt produced also increased in terms of the content of NaCl from 85% to 95%. In addition, salt production with the prism greenhouse method has several advantages, such as faster harvest time, weather resistance, easy to use, and higher profit than traditional methods.

  11. Socio-Cultural Aspects of Chagas Disease: A Systematic Review of Qualitative Research

    PubMed Central

    Ventura-Garcia, Laia; Roura, Maria; Pell, Christopher; Posada, Elisabeth; Gascón, Joaquim; Aldasoro, Edelweis; Muñoz, Jose; Pool, Robert

    2013-01-01

    Background Globally, more than 10 million people are infected with Trypanosoma cruzi, which causes about 20 000 annual deaths. Although Chagas disease is endemic to certain regions of Latin America, migratory flows have enabled its expansion into areas where it was previously unknown. Economic, social and cultural factors play a significant role in its presence and perpetuation. This systematic review aims to provide a comprehensive overview of qualitative research on Chagas disease, both in endemic and non-endemic countries. Methodology/Principal Findings Searches were carried out in ten databases, and the bibliographies of retrieved studies were examined. Data from thirty-three identified studies were extracted, and findings were analyzed and synthesized along key themes. Themes identified for endemic countries included: socio-structural determinants of Chagas disease; health practices; biomedical conceptions of Chagas disease; patient's experience; and institutional strategies adopted. Concerning non-endemic countries, identified issues related to access to health services and health seeking. Conclusions The emergence and perpetuation of Chagas disease depends largely on socio-cultural aspects influencing health. As most interventions do not address the clinical, environmental, social and cultural aspects jointly, an explicitly multidimensional approach, incorporating the experiences of those affected is a potential tool for the development of long-term successful programs. Further research is needed to evaluate this approach. PMID:24069473

  12. Successful treatment of diplopia with prism improves health-related quality of life.

    PubMed

    Hatt, Sarah R; Leske, David A; Liebermann, Laura; Holmes, Jonathan M

    2014-06-01

    To report change in strabismus-specific health-related quality of life (HRQOL) following treatment with prism. Retrospective cross-sectional study. Thirty-four patients with diplopia (median age 63, range 14-84 years) completed the Adult Strabismus-20 questionnaire (100-0, best to worst HRQOL) and a diplopia questionnaire in a clinical practice before prism and in prism correction. Before prism, diplopia was "sometimes" or worse for reading and/or straight-ahead distance. Prism treatment success was defined as diplopia rated "never" or "rarely" on the diplopia questionnaire for reading and straight-ahead distance. Failure was defined as worsening or no change in diplopia. For both successes and failures, mean Adult Strabismus-20 scores were compared before prism and in prism correction. Each of the 4 Adult Strabismus-20 domains (self-perception, interactions, reading function, and general function) was analyzed separately. Twenty-three of 34 (68%) were successes and 11 (32%) were failures. For successes, reading function improved from 57 ± 27 (SD) before prism to 69 ± 27 in-prism correction (difference 12 ± 20, 95% CI 3.2-20.8, P = .02) and general function improved from 66 ± 25 to 80 ± 18 (difference 14 ± 22, 95% CI 5.0-23.6, P = .003). Self-perception and interaction domains remained unchanged (P > .2). For failures there was no significant change in Adult Strabismus-20 score on any domain (P > .4). Successful correction of diplopia with prism is associated with improvement in strabismus-specific HRQOL, specifically reading function and general function. Copyright © 2014 Elsevier Inc. All rights reserved.

  13. The anatomy of a hydrothermal (explosion ) breccia, Abbot Village, central Maine

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Roy, D.C.

    1993-03-01

    An apparently intrusive hydrothermal breccia is exposed in a large outcrop along Kingsbury Stream downstream from the Route 6 bridge in Abbot Village. The breccia intrudes the Siluro-Devonian Madrid Formation which is comprised of thick-bedded metasandstone interbedded with less fine-grained schist and phyllite at regional biotite grade. In the vicinity of the breccia, the bedding attitude in the Madrid is N60E 70SE and the section faces SE. The breccia is a concordant body with respect to bedding and the exposure shows what appears to the SW terminus of the intrusion which extends an unknown distance NE. The main phase ofmore » the breccia consists of randomly oriented and angular clasts'' of Madrid metasandstone and schist that are cemented by a quartz-dominated matrix. The random orientation of the clasts is present this phase were it is in contact with the country rock. The matrix comprises about 15% of the volume of the breccia and, in addition to quartz, contains biotite, galena, chalcopyrite ( ), pyrite, and an iron-carbonate. In some interstitial matrix, apparently late iron-carbonate fills post-quartz vugs that contain quartz-crystal terminations. The wall phase contains a higher proportion of biotite schist clasts that in places are bent around each other and metasandstone clasts. Quartz veins extending into the country rock near the breccia follow prominent regional joint directions and suggest hydrofracturing of the Madrid was the principal mechanism for breccia formation. The breccia is interpreted to be of explosive origin with the main phase of the body representing clasts that fell down within the vent'' following upward transport. The wall phase is taken to have formed due to adhesion to the wall of breccia clasts during the eruptive stage.« less

  14. Accuracy of a Rapid Diagnostic Test (Cypress Chagas Quick Test®) for the Diagnosis of Chronic Chagas Disease in a Nonendemic Area: A Retrospective Longitudinal Study.

    PubMed

    Angheben, Andrea; Staffolani, Silvia; Anselmi, Mariella; Tais, Stefano; Degani, Monica; Gobbi, Federico; Buonfrate, Dora; Gobbo, Maria; Bisoffi, Zeno

    2017-11-01

    We analyzed the accuracy of Chagas Quick Test ® , a rapid diagnostic test, for the diagnosis of chronic Chagas disease through a retrospective study on a cohort of 669 patients consecutively examined at a single reference center in Italy, during a 7-year period. We observed high concordance with serological reference standard but low accuracy for screening purposes (sensitivity/specificity: 82.8%/98.7%) at least in our nonendemic context.

  15. 49 CFR 390.203 - PRISM State registration/biennial updates.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... the Performance and Registration Information Systems Management (PRISM) program (authorized under... FEDERAL MOTOR CARRIER SAFETY REGULATIONS; GENERAL Unified Registration System § 390.203 PRISM State... procedures, provided the State has integrated the USDOT registration/update capability into its vehicle...

  16. 49 CFR 390.203 - PRISM State registration/biennial updates.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... the Performance and Registration Information Systems Management (PRISM) program (authorized under... FEDERAL MOTOR CARRIER SAFETY REGULATIONS; GENERAL Unified Registration System § 390.203 PRISM State... procedures, provided the State has integrated the USDOT registration/update capability into its vehicle...

  17. Dietary intake and nutritional status of patients with Chagas disease.

    PubMed

    Compagnucci, Agustina Bertola; Ddvila, Ariana; Beloscar, Juan; Pezzotto, Stella Maris; Davila, Hector

    2016-09-01

    Chagas disease is a parasitic infection that affects 17 million people in Latin America. The real influence of nutritional status and food intake effect over the course of the disease to chronic Chagas Cardiomyopathy is still unknown. Furthermore, some cardiovascular risk factors might influence the evolution of the disease. A cross-sectional study of a sample of patients with Chagas disease attending the Cardiology Section of the Hospital Centenario of Rosario was carried out in order to characterize their food intake and nutritional status. Data on the general characteristics of the sample was collected; anthropometric measurements were performed and food consumption was investigated using a food frequency questionnaire and a n photographic atlas. One hundred and thirteen patients were enrolled; 70% of men and 90% of women were overweight or obese. In addition 78.9% of women and 27% of men presented a waist-hip ratio according to cardiovascular risk. When analyzing macronutrient intake, it was observed that lipid intake recommendations were exceeded. When the food intake groups were analyzed separately, it was found that men consume more lean beef, cold cuts, pork and alcoholic drinks, while women eat more whole dairy products and sugary drinks. This patients´ urban sample with Chagas disease, he presents a nutritional profile similar to that of the general population, and the food consumption is influenced by life in big cities.

  18. Epidemiology, genetics, and subtyping of preserved ratio impaired spirometry (PRISm) in COPDGene.

    PubMed

    Wan, Emily S; Castaldi, Peter J; Cho, Michael H; Hokanson, John E; Regan, Elizabeth A; Make, Barry J; Beaty, Terri H; Han, MeiLan K; Curtis, Jeffrey L; Curran-Everett, Douglas; Lynch, David A; DeMeo, Dawn L; Crapo, James D; Silverman, Edwin K

    2014-08-06

    Preserved Ratio Impaired Spirometry (PRISm), defined as a reduced FEV1 in the setting of a preserved FEV1/FVC ratio, is highly prevalent and is associated with increased respiratory symptoms, systemic inflammation, and mortality. Studies investigating quantitative chest tomographic features, genetic associations, and subtypes in PRISm subjects have not been reported. Data from current and former smokers enrolled in COPDGene (n = 10,192), an observational, cross-sectional study which recruited subjects aged 45-80 with ≥10 pack years of smoking, were analyzed. To identify epidemiological and radiographic predictors of PRISm, we performed univariate and multivariate analyses comparing PRISm subjects both to control subjects with normal spirometry and to subjects with COPD. To investigate common genetic predictors of PRISm, we performed a genome-wide association study (GWAS). To explore potential subgroups within PRISm, we performed unsupervised k-means clustering. The prevalence of PRISm in COPDGene is 12.3%. Increased dyspnea, reduced 6-minute walk distance, increased percent emphysema and decreased total lung capacity, as well as increased segmental bronchial wall area percentage were significant predictors (p-value <0.05) of PRISm status when compared to control subjects in multivariate models. Although no common genetic variants were identified on GWAS testing, a significant association with Klinefelter's syndrome (47XXY) was observed (p-value < 0.001). Subgroups identified through k-means clustering include a putative "COPD-subtype", "Restrictive-subtype", and a highly symptomatic "Metabolic-subtype". PRISm subjects are clinically and genetically heterogeneous. Future investigations into the pathophysiological mechanisms behind and potential treatment options for subgroups within PRISm are warranted. Clinicaltrials.gov Identifier: NCT000608764.

  19. Successful treatment of diplopia with prism improves health-related quality of life

    PubMed Central

    Hatt, Sarah R.; Leske, David A.; Liebermann, Laura; Holmes, Jonathan M.

    2014-01-01

    Purpose To report change in strabismus-specific health-related quality of life (HRQOL) following treatment with prism. Design Retrospective cross-sectional study Methods Thirty-four patients with diplopia (median age 63, range 14 to 84 years) completed the Adult Strabismus-20 questionnaire (100 to 0, best to worst HRQOL) and a diplopia questionnaire in a clinical practice before prism and in prism correction. Before prism, diplopia was “sometimes” or worse for reading and/or straight ahead distance. Prism treatment success was defined as diplopia rated “never” or “rarely” on the Diplopia Questionnaire for reading and straight ahead distance. Failure was defined as worsening or no change in diplopia. For both successes and failures, mean Adult Strabismus -20 scores were compared pre-prism and in prism correction. Each of the four Adult Strabismus -20 domains (Self-perception, Interactions, Reading function and General function) were analyzed separately. Results Twenty-three (68%) of 34 were successes and 11 (32%) were failures. For successes, Reading Function improved from 57 ± 27 (SD) before prism to 69 ± 27 in-prism correction (difference 12 ± 20, 95% CI 3.2 to 20.8, P=0.02) and General Function improved from 66 ± 25 to 80 ± 18 (difference 14 ± 22, 95% CI 5.0 to 23.6, P=0.003). Self-perception and Interaction domains remained unchanged (P>0.2). For failures there was no significant change in Adult Strabismus -20 score on any domain (P>0.4). Conclusions Successful correction of diplopia with prism is associated with improvement in strabismus-specific HRQOL, specifically reading function and general function. PMID:24561171

  20. PRISM 3: expanded prediction of natural product chemical structures from microbial genomes

    PubMed Central

    Skinnider, Michael A.; Merwin, Nishanth J.; Johnston, Chad W.

    2017-01-01

    Abstract Microbial natural products represent a rich resource of pharmaceutically and industrially important compounds. Genome sequencing has revealed that the majority of natural products remain undiscovered, and computational methods to connect biosynthetic gene clusters to their corresponding natural products therefore have the potential to revitalize natural product discovery. Previously, we described PRediction Informatics for Secondary Metabolomes (PRISM), a combinatorial approach to chemical structure prediction for genetically encoded nonribosomal peptides and type I and II polyketides. Here, we present a ground-up rewrite of the PRISM structure prediction algorithm to derive prediction of natural products arising from non-modular biosynthetic paradigms. Within this new version, PRISM 3, natural product scaffolds are modeled as chemical graphs, permitting structure prediction for aminocoumarins, antimetabolites, bisindoles and phosphonate natural products, and building upon the addition of ribosomally synthesized and post-translationally modified peptides. Further, with the addition of cluster detection for 11 new cluster types, PRISM 3 expands to detect 22 distinct natural product cluster types. Other major modifications to PRISM include improved sequence input and ORF detection, user-friendliness and output. Distribution of PRISM 3 over a 300-core server grid improves the speed and capacity of the web application. PRISM 3 is available at http://magarveylab.ca/prism/. PMID:28460067

  1. Economic evaluation of Chagas disease screening in Spain.

    PubMed

    Imaz-Iglesia, Iñaki; Miguel, Lucía García-San; Ayala-Morillas, L Eduardo; García-Pérez, Lidia; González-Enríquez, Jesús; Blasco-Hernández, Teresa; Martín-Águeda, María Belén; Sarría-Santamera, Antonio

    2015-08-01

    Although Spain is the European country with the highest Chagas disease burden, the country does not have a national control program of the disease. The purpose of this study is to evaluate the efficiency of several strategies for Chagas disease screening among Latin American residents living in Spain. The following screening strategies were evaluated: (1) non-screening; (2) screening of the Latin American pregnant women and their newborns; (3) screening also the relatives of the positive pregnant women; (4) screening also the relatives of the negative pregnant women. A cost-utility analysis was carried out to compare the four strategies from two perspectives, the societal and the Spanish National Health System (SNHS). A decision tree representing the clinical evolution of Chagas disease throughout patient's life was built. The strategies were compared through the incremental cost-utility ratio, using euros as cost measurement and quality-adjusted life years as utility measurement. A sensitivity analysis was performed to test the model parameters and their influence on the results. We found the "Non-screening" as the most expensive and less effective of the evaluated strategies, from both the societal and the SNHS perspectives. Among the screening evaluated strategies the most efficient was, from both perspectives, to extent the antenatal screening of the Latin American pregnant women and their newborns up to the relatives of the positive women. Several parameters influenced significantly on the sensitivity analyses, particularly the chronic treatment efficacy or the prevalence of Chagas disease. In conclusion, for the general Latin American immigrants living in Spain the most efficient would be to screen the Latin American mothers, their newborns and the close relatives of the mothers with a positive serology. However for higher prevalence immigrant population the most efficient intervention would be to extend the program to the close relatives of the negative

  2. Antioxidant effect of Morus nigra on Chagas disease progression.

    PubMed

    Montenote, Michelly Cristina; Wajsman, Vithor Zuccaro; Konno, Yoichi Takaki; Ferreira, Paulo César; Silva, Regildo Márcio Gonçalves; Therezo, Altino Luiz Silva; Silva, Luciana Pereira; Martins, Luciamáre Perinetti Alves

    2017-11-06

    Considering the widespread popular use of Morus nigra and the amount of scientific information on its antioxidant and anti-inflammatory activity, the effectiveness of this phytotherapeutic compound in the parasitemia progression during the acute phase of Chagas disease and its role in the development of the inflammatory process as well as its effects on the oxidative damage in the chronic phase of infection were evaluated. Thus, 96 male Swiss mice were randomly divided into eight groups, four groups were uninfected controls, and four groups were intraperitoneally infected with 5.0 x 104 blood trypomastigotes forms of T. cruzi QM2 strain. Four batches composed of one uninfected and one infected group were respectively treated with 70% alcohol solution and 25 μL, 50 μL and 75 μL of the phytotherapeutic compound. Levels of antioxidant elements (TBARS, FRAP, GSH and Sulfhydryl groups) were measured in plasma samples. The phytotherapeutic compound's antioxidant activity was measured by polyphenol and total flavonoid quantification, DPPH, NO, and FRAP method. Our results showed that the vehicle influenced some of the results that may have physiological relevance in Chagas disease. However, an important action of M. nigra tincture was observed in the progression of Chagas disease, since our results demonstrated a reduction in parasitemia of treated groups when compared to controls, especially in the group receiving 25 µL. However, in the chronic phase, the 50-µL dosage presented a better activity on some antioxidant defenses and minimized the tissue inflammatory process. Results indicated an important action of M. nigra tincture on the Chagas disease progression.

  3. Rhomboid prism pair for rotating the plane of parallel light beams

    NASA Technical Reports Server (NTRS)

    Orloff, K. L. (Inventor); Yanagita, H.

    1982-01-01

    An optical system is described for rotating the plane defined by a pair of parallel light beams. In one embodiment a single pair of rhomboid prisms have their respective input faces disposed to receive the respective input beams. Each prism is rotated about an axis of revolution coaxial with each of the respective input beams by means of a suitable motor and gear arrangement to cause the plane of the parallel output beams to be rotated relative to the plane of the input beams. In a second embodiment, two pairs of rhomboid prisms are provided. In a first angular orientation of the output beams, the prisms merely decrease the lateral displacement of the output beams in order to keep in the same plane as the input beams. In a second angular orientation of the prisms, the input faces of the second pair of prisms are brought into coincidence with the input beams for rotating the plane of the output beams by a substantial angle such as 90 deg.

  4. Angiotensin-Converting Enzyme ID Polymorphism in Patients with Heart Failure Secondary to Chagas Disease

    PubMed Central

    da Silva, Silene Jacinto; Rassi, Salvador; Pereira, Alexandre da Costa

    2017-01-01

    Background Changes in the angiotensin-converting enzyme (ACE) gene may contribute to the increase in blood pressure and consequently to the onset of heart failure (HF). The role of polymorphism is very controversial, and its identification in patients with HF secondary to Chagas disease in the Brazilian population is required. Objective To determine ACE polymorphism in patients with HF secondary to Chagas disease and patients with Chagas disease without systolic dysfunction, and to evaluate the relationship of the ACE polymorphism with different clinical variables. Methods This was a comparative clinical study with 193 participants, 103 of them with HF secondary to Chagas disease and 90 with Chagas disease without systolic dysfunction. All patients attended the outpatient department of the General Hospital of the Federal University of Goias general hospital. Alleles I and D of ACE polymorphism were identified by polymerase chain reaction of the respective intron 16 fragments in the ACE gene and visualized by electrophoresis. Results In the group of HF patients, 63% were male, whereas 53.6% of patients with Chagas disease without systolic dysfunction were female (p = 0,001). The time from diagnosis varied from 1 to 50 years. Distribution of DD, ID and II genotypes was similar between the two groups, without statistical significance (p = 0,692). There was no difference in clinical characteristics or I/D genotypes between the groups. Age was significantly different between the groups (p = 0,001), and mean age of patients with HF was 62.5 years. Conclusion No differences were observed in the distribution of (Insertion/Deletion) genotype frequencies of ACE polymorphism between the studied groups. The use of this genetic biomarker was not useful in detecting a possible relationship between ACE polymorphism and clinical manifestations in HF secondary to Chagas disease. PMID:28977050

  5. Angiotensin-Converting Enzyme ID Polymorphism in Patients with Heart Failure Secondary to Chagas Disease.

    PubMed

    Silva, Silene Jacinto da; Rassi, Salvador; Pereira, Alexandre da Costa

    2017-10-01

    Changes in the angiotensin-converting enzyme (ACE) gene may contribute to the increase in blood pressure and consequently to the onset of heart failure (HF). The role of polymorphism is very controversial, and its identification in patients with HF secondary to Chagas disease in the Brazilian population is required. To determine ACE polymorphism in patients with HF secondary to Chagas disease and patients with Chagas disease without systolic dysfunction, and to evaluate the relationship of the ACE polymorphism with different clinical variables. This was a comparative clinical study with 193 participants, 103 of them with HF secondary to Chagas disease and 90 with Chagas disease without systolic dysfunction. All patients attended the outpatient department of the General Hospital of the Federal University of Goias general hospital. Alleles I and D of ACE polymorphism were identified by polymerase chain reaction of the respective intron 16 fragments in the ACE gene and visualized by electrophoresis. In the group of HF patients, 63% were male, whereas 53.6% of patients with Chagas disease without systolic dysfunction were female (p = 0,001). The time from diagnosis varied from 1 to 50 years. Distribution of DD, ID and II genotypes was similar between the two groups, without statistical significance (p = 0,692). There was no difference in clinical characteristics or I/D genotypes between the groups. Age was significantly different between the groups (p = 0,001), and mean age of patients with HF was 62.5 years. No differences were observed in the distribution of (Insertion/Deletion) genotype frequencies of ACE polymorphism between the studied groups. The use of this genetic biomarker was not useful in detecting a possible relationship between ACE polymorphism and clinical manifestations in HF secondary to Chagas disease.

  6. Towards a neuro-computational account of prism adaptation.

    PubMed

    Petitet, Pierre; O'Reilly, Jill X; O'Shea, Jacinta

    2017-12-14

    Prism adaptation has a long history as an experimental paradigm used to investigate the functional and neural processes that underlie sensorimotor control. In the neuropsychology literature, prism adaptation behaviour is typically explained by reference to a traditional cognitive psychology framework that distinguishes putative functions, such as 'strategic control' versus 'spatial realignment'. This theoretical framework lacks conceptual clarity, quantitative precision and explanatory power. Here, we advocate for an alternative computational framework that offers several advantages: 1) an algorithmic explanatory account of the computations and operations that drive behaviour; 2) expressed in quantitative mathematical terms; 3) embedded within a principled theoretical framework (Bayesian decision theory, state-space modelling); 4) that offers a means to generate and test quantitative behavioural predictions. This computational framework offers a route towards mechanistic neurocognitive explanations of prism adaptation behaviour. Thus it constitutes a conceptual advance compared to the traditional theoretical framework. In this paper, we illustrate how Bayesian decision theory and state-space models offer principled explanations for a range of behavioural phenomena in the field of prism adaptation (e.g. visual capture, magnitude of visual versus proprioceptive realignment, spontaneous recovery and dynamics of adaptation memory). We argue that this explanatory framework can advance understanding of the functional and neural mechanisms that implement prism adaptation behaviour, by enabling quantitative tests of hypotheses that go beyond merely descriptive mapping claims that 'brain area X is (somehow) involved in psychological process Y'. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

  7. Ecologic Niche Modeling and Potential Reservoirs for Chagas Disease, Mexico.

    PubMed Central

    Sánchez-Cordero, Victor; Ben Beard, C.; Ramsey, Janine M.

    2002-01-01

    Ecologic niche modeling may improve our understanding of epidemiologically relevant vector and parasite-reservoir distributions. We used this tool to identify host relationships of Triatoma species implicated in transmission of Chagas disease. Associations have been documented between the protracta complex (Triatoma: Triatominae: Reduviidae) with packrat species (Neotoma spp.), providing an excellent case study for the broader challenge of developing hypotheses of association. Species pairs that were identified coincided exactly with those in previous studies, suggesting that local interactions between Triatoma and Neotoma species and subspecies have implications at a geographic level. Nothing is known about sylvatic associates of T. barberi, which are considered the primary Chagas vector in Mexico; its geographic distribution coincided closely with that of N. mexicana, suggesting interaction. The presence of the species was confirmed in two regions where it had been predicted but not previously collected. This approach may help in identifying Chagas disease risk areas, planning vector-control strategies, and exploring parasite-reservoir associations for other emerging diseases. PMID:12095431

  8. Device for magneto-optic signal detection with a small crystal prism.

    PubMed

    Saito, K; Sato, S; Shino, K; Taniguchi, T

    2000-03-10

    A device made of a birefringent crystal for signal detection of magneto-optic (MO) disks is presented. The light beam from a MO disk is separated into two orthogonally polarized components at the surface of a birefringent prism. After these two components are reflected by the top and the bottom surfaces of the prism inside, at the detector they become sufficiently separated from each other for discrete detection, even though the prism is small. A method for calculating the light intensities and the positions of focused beams in a birefringent prism and the results of a fundamental experiment are presented.

  9. Morphologic and morphometric evaluation of pancreatic islets in chronic Chagas' disease.

    PubMed

    Saldanha, J C; dos Santos, V M; dos Reis, M A; da Cunha, D F; Antunes Teixeira, V P

    2001-01-01

    Hyperglycemia and abnormal glucose tolerance tests observed in some patients with chronic Chagas' disease suggest the possibility of morphological changes in pancreatic islets and/or denervation. The purpose of this study was to describe the morphology and morphometry of pancreatic islets in chronic Chagas' disease. Morphologic and computerized morphometric studies were performed in fragments of the head, body, and tail regions of the pancreas obtained at necropsies of 8 normal controls and 17 patients with chronic Chagas' disease: 8 with the digestive form (Megas) and 9 with the congestive heart failure form. The Megas group had a larger (p < 0.05) pancreatic islet area in the tail of the pancreas (10649.3 +/- 4408.8 micrometer2) than the normal control (9481.8 +/- 3242.4 micrometer2) and congestive heart failure (9475.1 +/- 2104.9 micrometer2) groups; likewise, the density of the pancreatic islets (PI) was greater (1.2 +/- 0.7 vs. 0.9 +/- 0.6 vs. 1.9 +/- 1.0 PI/mm2, respectively). In the tail region of the pancreas of patients with the Megas form, there was a significant and positive correlation (r = +0.73) between the area and density of pancreatic islets. Discrete fibrosis and leukocytic infiltrates were found in pancreatic ganglia and pancreatic islets of the patients with Chagas' disease. Trypanosoma cruzi nests were not observed in the examined sections. Individuals with the Megas form of Chagas' disease showed increased area and density of pancreatic islets in the tail of the pancreas. The observed morphometric and morphologic alterations are consistent with functional changes in the pancreas, including glycemia and insulin disturbances.

  10. Chagas disease drug discovery: toward a new era.

    PubMed

    Chatelain, Eric

    2015-01-01

    American trypanosomiasis, or Chagas disease, is the result of infection by the Trypanosoma cruzi parasite. Endemic in Latin America where it is the major cause of death from cardiomyopathy, the impact of the disease is reaching global proportions through migrating populations. New drugs that are safe, efficacious, low cost, and adapted to the field are critically needed. Over the past five years, there has been increased interest in the disease and a surge in activities within various organizations. However, recent clinical trials with azoles, specifically posaconazole and the ravuconazole prodrug E1224, were disappointing, with treatment failure in Chagas patients reaching 70% to 90%, as opposed to 6% to 30% failure for benznidazole-treated patients. The lack of translation from in vitro and in vivo models to the clinic observed for the azoles raises several questions. There is a scientific requirement to review and challenge whether we are indeed using the right tools and decision-making processes to progress compounds forward for the treatment of this disease. New developments in the Chagas field, including new technologies and tools now available, will be discussed, and a redesign of the current screening strategy during the discovery process is proposed. © 2014 Society for Laboratory Automation and Screening.

  11. The PRISM4 (mid-Piacenzian) Palaeoenvironmental Reconstruction

    NASA Technical Reports Server (NTRS)

    Dowsett, Harry; Dolan, Aisling; Rowley, David; Moucha, Robert; Forte, Alessandro M.; Mitrovica, Jerry X.; Pound, Matthew; Salzmann, Ulrich; Robinson, Marci; Chandler, Mark; hide

    2016-01-01

    The mid-Piacenzian is known as a period of relative warmth when compared to the present day. A comprehensive understanding of conditions during the Piacenzian serves as both a conceptual model and a source for boundary conditions as well as means of verification of global climate model experiments. In this paper we present the PRISM4 reconstruction, a paleoenvironmental reconstruction of the mid-Piacenzian (approximately 3 Ma) containing data for paleogeography, land and sea ice, sea-surface temperature, vegetation, soils, and lakes. Our retrodicted paleogeography takes into account glacial isostatic adjustments and changes in dynamic topography. Soils and lakes, both significant as land surface features, are introduced to the PRISM reconstruction for the first time. Sea-surface temperature and vegetation reconstructions are unchanged but now have confidence assessments. The PRISM4 reconstruction is being used as boundary condition data for the Pliocene Model Intercomparison Project Phase 2 (PlioMIP2) experiments.

  12. A bi-prism interferometer for hard x-ray photons

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Isakovic, A.F.; Siddons, D.; Stein, A.

    2010-04-06

    Micro-fabricated bi-prisms have been used to create an interference pattern from an incident hard X-ray beam, and the intensity of the pattern probed with fluorescence from a 30 nm-thick metal film. Maximum fringe visibility exceeded 0.9 owing to the nano-sized probe and the choice of single-crystal prism material. A full near-field analysis is necessary to describe the fringe field intensities, and the transverse coherence lengths were extracted at APS beamline 8-ID-I. It is also shown that the maximum number of fringes is dependent only on the complex refractive index of the prism material.

  13. Bed Prism Spectacles

    ERIC Educational Resources Information Center

    Ribeiro, Jair Lúcio Prados

    2018-01-01

    We only became aware of the existence of bed prism spectacles when a student brought them to the classroom and asked us about how they work. The device proved to be a fertile source of curiosity among the students, and, to be properly understood, it required us to develop a comparison between reflection in a typical mirror and total internal…

  14. Generalization of Prism Adaptation

    ERIC Educational Resources Information Center

    Redding, Gordon M.; Wallace, Benjamin

    2006-01-01

    Prism exposure produces 2 kinds of adaptive response. Recalibration is ordinary strategic remapping of spatially coded movement commands to rapidly reduce performance error. Realignment is the extraordinary process of transforming spatial maps to bring the origins of coordinate systems into correspondence. Realignment occurs when spatial…

  15. Two-photon laser scanning microscopy with electrowetting-based prism scanning

    PubMed Central

    Supekar, Omkar D.; Ozbay, Baris N.; Zohrabi, Mo; Nystrom, Philip D.; Futia, Gregory L.; Restrepo, Diego; Gibson, Emily A.; Gopinath, Juliet T.; Bright, Victor M.

    2017-01-01

    Laser scanners are an integral part of high resolution biomedical imaging systems such as confocal or 2-photon excitation (2PE) microscopes. In this work, we demonstrate the utility of electrowetting on dielectric (EWOD) prisms as a lateral laser-scanning element integrated in a conventional 2PE microscope. To the best of our knowledge, this is the first such demonstration for EWOD prisms. EWOD devices provide a transmissive, low power consuming, and compact alternative to conventional adaptive optics, and hence this technology has tremendous potential. We demonstrate 2PE microscope imaging of cultured mouse hippocampal neurons with a FOV of 130 × 130 μm2 using EWOD prism scanning. In addition, we show simulations of the optical system with the EWOD prism, to evaluate the effect of propagating a Gaussian beam through the EWOD prism on the imaging quality. Based on the simulation results a beam size of 0.91 mm full width half max was chosen to conduct the imaging experiments, resulting in a numerical aperture of 0.17 of the imaging system. PMID:29296477

  16. Genomes to natural products PRediction Informatics for Secondary Metabolomes (PRISM)

    PubMed Central

    Skinnider, Michael A.; Dejong, Chris A.; Rees, Philip N.; Johnston, Chad W.; Li, Haoxin; Webster, Andrew L. H.; Wyatt, Morgan A.; Magarvey, Nathan A.

    2015-01-01

    Microbial natural products are an invaluable source of evolved bioactive small molecules and pharmaceutical agents. Next-generation and metagenomic sequencing indicates untapped genomic potential, yet high rediscovery rates of known metabolites increasingly frustrate conventional natural product screening programs. New methods to connect biosynthetic gene clusters to novel chemical scaffolds are therefore critical to enable the targeted discovery of genetically encoded natural products. Here, we present PRISM, a computational resource for the identification of biosynthetic gene clusters, prediction of genetically encoded nonribosomal peptides and type I and II polyketides, and bio- and cheminformatic dereplication of known natural products. PRISM implements novel algorithms which render it uniquely capable of predicting type II polyketides, deoxygenated sugars, and starter units, making it a comprehensive genome-guided chemical structure prediction engine. A library of 57 tailoring reactions is leveraged for combinatorial scaffold library generation when multiple potential substrates are consistent with biosynthetic logic. We compare the accuracy of PRISM to existing genomic analysis platforms. PRISM is an open-source, user-friendly web application available at http://magarveylab.ca/prism/. PMID:26442528

  17. PRISM 3: expanded prediction of natural product chemical structures from microbial genomes.

    PubMed

    Skinnider, Michael A; Merwin, Nishanth J; Johnston, Chad W; Magarvey, Nathan A

    2017-07-03

    Microbial natural products represent a rich resource of pharmaceutically and industrially important compounds. Genome sequencing has revealed that the majority of natural products remain undiscovered, and computational methods to connect biosynthetic gene clusters to their corresponding natural products therefore have the potential to revitalize natural product discovery. Previously, we described PRediction Informatics for Secondary Metabolomes (PRISM), a combinatorial approach to chemical structure prediction for genetically encoded nonribosomal peptides and type I and II polyketides. Here, we present a ground-up rewrite of the PRISM structure prediction algorithm to derive prediction of natural products arising from non-modular biosynthetic paradigms. Within this new version, PRISM 3, natural product scaffolds are modeled as chemical graphs, permitting structure prediction for aminocoumarins, antimetabolites, bisindoles and phosphonate natural products, and building upon the addition of ribosomally synthesized and post-translationally modified peptides. Further, with the addition of cluster detection for 11 new cluster types, PRISM 3 expands to detect 22 distinct natural product cluster types. Other major modifications to PRISM include improved sequence input and ORF detection, user-friendliness and output. Distribution of PRISM 3 over a 300-core server grid improves the speed and capacity of the web application. PRISM 3 is available at http://magarveylab.ca/prism/. © The Author(s) 2017. Published by Oxford University Press on behalf of Nucleic Acids Research.

  18. PRISM Software: Processing and Review Interface for Strong‐Motion Data

    USGS Publications Warehouse

    Jones, Jeanne M.; Kalkan, Erol; Stephens, Christopher D.; Ng, Peter

    2017-01-01

    A continually increasing number of high‐quality digital strong‐motion records from stations of the National Strong Motion Project (NSMP) of the U.S. Geological Survey, as well as data from regional seismic networks within the United States, calls for automated processing of strong‐motion records with human review limited to selected significant or flagged records. The NSMP has developed the Processing and Review Interface for Strong Motion data (PRISM) software to meet this need. In combination with the Advanced National Seismic System Quake Monitoring System (AQMS), PRISM automates the processing of strong‐motion records. When used without AQMS, PRISM provides batch‐processing capabilities. The PRISM software is platform independent (coded in Java), open source, and does not depend on any closed‐source or proprietary software. The software consists of two major components: a record processing engine composed of modules for each processing step, and a review tool, which is a graphical user interface for manual review, edit, and processing. To facilitate use by non‐NSMP earthquake engineers and scientists, PRISM (both its processing engine and review tool) is easy to install and run as a stand‐alone system on common operating systems such as Linux, OS X, and Windows. PRISM was designed to be flexible and extensible to accommodate implementation of new processing techniques. All the computing features have been thoroughly tested.

  19. Comment on Schuster's Technique for Focusing the Prism Spectrometer.

    ERIC Educational Resources Information Center

    Beynon, John

    1991-01-01

    Discussed is the physics that underpins Schuster's technique for obtaining a parallel light beam for use in various prism and grating experiments. Basic physics concepts using geometrical optics of prism, together with elementary differential calculus are explained as well as the mechanics of Schuster's technique. (KR)

  20. The infrared bands Pechan prism axis parallel detection method

    NASA Astrophysics Data System (ADS)

    Qiang, Hua; Ji, Ming; He, Yu-lan; Wang, Nan-xi; Chang, Wei-jun; Wang, Ling; Liu, Li

    2017-02-01

    In this paper, we put forward a new method to adjust the air gap of the total reflection air gap of the infrared Pechan prism. The adjustment of the air gap in the air gap of the Pechan prism directly affects the parallelism of the optical axis, so as to affect the consistency of the optical axis of the infrared system. The method solves the contradiction between the total reflection and the high transmission of the infrared wave band, and promotes the engineering of the infrared wave band. This paper puts forward the method of adjusting and controlling, which can ensure the full reflection and high penetration of the light, and also can accurately measure the optical axis of the optical axis of the different Pechan prism, and can achieve the precision of the level of the sec. For Pechan prism used in the infrared band image de rotation, make the product to realize miniaturization, lightweight plays an important significance.

  1. Salt-induced square prism Pd microtubes and their ethanol electrocatalysis properties

    NASA Astrophysics Data System (ADS)

    Jiang, Kunpeng; Ma, Shenghua; Wang, Yinan; Zhang, Ying; Han, Xiaojun

    2017-05-01

    The synthesis of square prism tubes are always challenging due to their thermo and dynamical instability. We demonstrated a simple method using Pd2+ doped PoPD oligomers as building blocks to assemble into 1D square prism metal-organic microtubes, which consists of cataphracted nanosheets on the surfaces. After high temperature treatment, the microtubes became square prism Pd tubes with a cross section size of 3 μm. The pure Pd microtubes showed excellent catalyzing activity towards the electro oxidation of ethanol. Their electrochemically active surface area is 48.2 m2 g-1, which indicates the square prism Pd tubes have great potential in the field of fuel cell.

  2. Randomized crossover clinical trial of real and sham peripheral prism glasses for hemianopia.

    PubMed

    Bowers, Alex R; Keeney, Karen; Peli, Eli

    2014-02-01

    There is a major lack of randomized controlled clinical trials evaluating the efficacy of prismatic treatments for hemianopia. Evidence for their effectiveness is mostly based on anecdotal case reports and open-label evaluations without a control condition. To evaluate the efficacy of real relative to sham peripheral prism glasses for patients with complete homonymous hemianopia. Double-masked, randomized crossover trial at 13 study sites, including the Peli laboratory at Schepens Eye Research Institute, 11 vision rehabilitation clinics in the United States, and 1 in the United Kingdom. Patients were 18 years or older with complete homonymous hemianopia for at least 3 months and without visual neglect or significant cognitive decline. Patients were allocated by minimization into 2 groups. One group received real (57-prism diopter) oblique and sham (<5-prism diopter) horizontal prisms; the other received real horizontal and sham oblique, in counterbalanced order. Each crossover period was 4 weeks. The primary outcome was the overall difference, across the 2 periods of the crossover, between the proportion of participants who wanted to continue with (said yes to) real prisms and the proportion who said yes to sham prisms. The secondary outcome was the difference in perceived mobility improvement between real and sham prisms. Of 73 patients randomized, 61 completed the crossover. A significantly higher proportion said yes to real than sham prisms (64% vs 36%; odds ratio, 5.3; 95% CI, 1.8-21.0). Participants who continued wear after 6 months reported greater improvement in mobility with real than sham prisms at crossover end (P = .002); participants who discontinued wear reported no difference. Real peripheral prism glasses were more helpful for obstacle avoidance when walking than sham glasses, with no differences between the horizontal and oblique designs. Peripheral prism glasses provide a simple and inexpensive mobility rehabilitation intervention for hemianopia

  3. The PRISM4 (mid-Piacenzian) paleoenvironmental reconstruction

    USGS Publications Warehouse

    Dowsett, Harry J.; Dolan, Aisling M.; Rowley, David; Moucha, Robert; Forte, Alessandro; Mitrovica, Jerry X.; Pound, Matthew; Salzmann, Ulrich; Robinson, Marci M.; Chandler, Mark; Foley, Kevin M.; Haywood, Alan M.

    2016-01-01

    The mid-Piacenzian is known as a period of relative warmth when compared to the present day. A comprehensive understanding of conditions during the Piacenzian serves as both a conceptual model and a source for boundary conditions as well as means of verification of global climate model experiments. In this paper we present the PRISM4 reconstruction, a paleoenvironmental reconstruction of the mid-Piacenzian ( ∼ 3 Ma) containing data for paleogeography, land and sea ice, sea-surface temperature, vegetation, soils, and lakes. Our retrodicted paleogeography takes into account glacial isostatic adjustments and changes in dynamic topography. Soils and lakes, both significant as land surface features, are introduced to the PRISM reconstruction for the first time. Sea-surface temperature and vegetation reconstructions are unchanged but now have confidence assessments. The PRISM4 reconstruction is being used as boundary condition data for the Pliocene Model Intercomparison Project Phase 2 (PlioMIP2) experiments.

  4. Prism Adaptation in Schizophrenia

    ERIC Educational Resources Information Center

    Bigelow, Nirav O.; Turner, Beth M.; Andreasen, Nancy C.; Paulsen, Jane S.; O'Leary, Daniel S.; Ho, Beng-Choon

    2006-01-01

    The prism adaptation test examines procedural learning (PL) in which performance facilitation occurs with practice on tasks without the need for conscious awareness. Dynamic interactions between frontostriatal cortices, basal ganglia, and the cerebellum have been shown to play key roles in PL. Disruptions within these neural networks have also…

  5. Genomes to natural products PRediction Informatics for Secondary Metabolomes (PRISM).

    PubMed

    Skinnider, Michael A; Dejong, Chris A; Rees, Philip N; Johnston, Chad W; Li, Haoxin; Webster, Andrew L H; Wyatt, Morgan A; Magarvey, Nathan A

    2015-11-16

    Microbial natural products are an invaluable source of evolved bioactive small molecules and pharmaceutical agents. Next-generation and metagenomic sequencing indicates untapped genomic potential, yet high rediscovery rates of known metabolites increasingly frustrate conventional natural product screening programs. New methods to connect biosynthetic gene clusters to novel chemical scaffolds are therefore critical to enable the targeted discovery of genetically encoded natural products. Here, we present PRISM, a computational resource for the identification of biosynthetic gene clusters, prediction of genetically encoded nonribosomal peptides and type I and II polyketides, and bio- and cheminformatic dereplication of known natural products. PRISM implements novel algorithms which render it uniquely capable of predicting type II polyketides, deoxygenated sugars, and starter units, making it a comprehensive genome-guided chemical structure prediction engine. A library of 57 tailoring reactions is leveraged for combinatorial scaffold library generation when multiple potential substrates are consistent with biosynthetic logic. We compare the accuracy of PRISM to existing genomic analysis platforms. PRISM is an open-source, user-friendly web application available at http://magarveylab.ca/prism/. © The Author(s) 2015. Published by Oxford University Press on behalf of Nucleic Acids Research.

  6. Randomized crossover clinical trial of real and sham peripheral prism glasses for hemianopia

    PubMed Central

    Bowers, Alex R.; Keeney, Karen; Peli, Eli

    2013-01-01

    Objective To evaluate the efficacy of real relative to sham peripheral prism glasses for patients with complete homonymous hemianopia and without visual neglect. Methods Patients recruited at 13 clinics were allocated by minimization into a double-masked, crossover trial with two groups. One group received real (57Δ) oblique and sham (≤ 5Δ) horizontal prisms; the other received real horizontal and sham oblique, in counterbalanced order. A masked data collector at each clinic administered questionnaires after each 4-week crossover period. Main outcome measure The primary outcome was the overall difference, across the two periods of the crossover, between the proportion of participants who wanted to continue with (said “yes” to) real prisms and the proportion who said yes to sham prisms. The secondary outcome was the difference in perceived mobility improvement between real and sham prisms. Results Of 73 patients randomized, 61 completed the crossover. A significantly higher proportion said yes to real than sham prisms (64% vs. 36%; odds ratio 5.3, 95% CI 1.8 to 21.0). Participants who continued wear after 6 months reported greater improvement in mobility with real than sham prisms at crossover end (p=0.002); participants who discontinued wear reported no difference. Conclusion Real peripheral prism glasses were more helpful for obstacle avoidance when walking than sham glasses, with no differences between the horizontal and oblique designs. Applications to clinical practice Peripheral prism glasses provide a simple and inexpensive mobility rehabilitation intervention for hemianopia. PMID:24201760

  7. Standardization of motion sickness induced by left-right and up-down reversing prisms

    NASA Technical Reports Server (NTRS)

    Reschke, M. F.; Vanderploeg, J. M.; Brumley, E. A.; Kolafa, J. J.; Wood, S. J.

    1990-01-01

    Reversing prisms are known to produce symptoms of motion sickness, and have been used to provide a chronic stimulus for training subjects on symptom recognition and regulation. However, testing procedures with reversing prisms have not been standardized. A set of procedures were evaluated which could be standardized using prisms for provocation and to compare the results between Right/Left Reversing Prisms (R/L-RP) and Up/Down Reversing Prisms (U/D-RP). Fifteen subjects were tested with both types of prisms using a self paced walking course throughout the laboratory with work stations established at specified intervals. The work stations provided tasks requiring eye-hand-foot coordination and various head movements. Comparisons were also made between these prism tests and two other standardized susceptibility tests, the KC-135 parabolic static chair test and the Staircase Velocity Motion Test (SVMT). Two different types of subjective symptom reports were compared. The R/L-RP were significantly more provocative than the U/D-RP. The incidence of motion sickness symptoms for the R/L-RP was similar to the KC-135 parabolic static chair test. Poor correlations were found between the prism tests and the other standardized susceptibility tests, which might indicate that different mechanisms are involved in provoking motion sickness for these different tests.

  8. Technological innovation strategies for the specific treatment of Chagas disease based on Benznidazole.

    PubMed

    Ferraz, Leslie Raphael de Moura; Alves, Alinne Élida Gonçalves; Nascimento, Débora Dolores Souza da Silva; Amariz, Isabela Araújo E; Ferreira, Aline Silva; Costa, Salvana Priscylla Manso; Rolim, Larissa Araújo; Lima, Ádley Antonini Neves de; Rolim Neto, Pedro José

    2018-02-13

    Caused by Trypanosoma cruzi, Chagas disease is responsible for public health problems greater in magnitude than those attributed to malaria, schistosomiasis, or leishmaniasis. A factor in the socioeconomic development of poor countries, Chagas disease can cause death due to a high parasitic burden during its acute phase due and irreversible damage in organs such as the heart, esophagus, and colon during its chronic phase, even when the number of parasites is minimal. For treating Chagas disease, benznidazole (BNZ) remains the drug of choice and, in Latin America, the only drug on the market for treating the disease. However, BNZ has exhibited insufficient activity in the chronic phase of Chagas disease, required administration in large doses, prolonged treatment, and shown a high incidence of adverse reactions (vomiting, rash, peripheral neuropathy, and spinal cord depression), toxicity, and low solubility in water. As an antidote, pharmaceutical technologies have been introduced that can improve BNZ's solubility and dissolution, as well as reduce side effects in light of its bioavailability, all of which can enhance therapy for Chagas disease. In response to that trend, by conducting a literature review, we sought to identify current pharmaceutical technologies used in tandem with BNZ to improve therapy for Chagas disease. Documented techniques include emulsion and microemulsion formation, solutions, parenteral formulas, micronization, and drug delivery systems supported by the development of nanoparticles and cyclodextrins, solid dispersions, and the use of metal-organic frameworks as innovative excipients. Such technologies increase the water solubility of BNZ by 4-25-fold on dissolution and an 85% release with efficacy in only a few minutes, as recorded during a viability experiment with nanoparticle suspensions. That experiment demonstrated the need for a lower concentration of BNZ to kill 50% of trypomastigote forms of T. cruzi, described in terms of the

  9. [Costs of Chagas' disease screening test in blood donors in two Colombian blood banks, 2015].

    PubMed

    Alvis, Nelson José; Díaz, Diana Patricia; Castillo, Liliana; Alvis, Nelson Rafael; Bermúdez, María Isabel; Berrío, Olga Maritza; Beltrán, Mauricio; Castañeda-Orjuela, Carlos Andrés

    2018-03-15

    Transfusion is a mechanism of transmission of Chagas' disease. There are no studies on the costs of the screening test in Colombian blood banks. To estimate the costs of the screening test for Chagas' disease among blood donors in two Colombian blood banks, 2015. We conducted a micro-costing study from the perspective of the health care provider to estimate the cost of Chagas' disease testing in two blood banks, Banco de Sangre de la Cruz Roja, Seccional Bolívar, and Banco de Sangre del Hospital de Yopal, Casanare, taking into account four cost categories: 1) Administrative costs: public services and insurance costs were calculated based on the blood bank area in square meters; 2) capital costs: building and equipment costs that were annualized using a 3% discount rate and a lifespan of 20 years for building and five for equipment; 3) costs of Chagas' disease test materials and reagents adjusted by blood bank production level, and 4) costs of staff in charge of Chagas' disease test processing. The costs of transfusion bagsand immunohematology tests are also reported. The cost of Chagas' disease test in the blood bank of Seccional Bolívar was COP$ 37,804 (USD$ 12), and the blood bag and immunohematology test costs were COP$ 25,941 (USD$ 8.2) and COP$ 6,800 (USD$ 2.2), respectively. In the blood bank of Yopal, Casanare, the costs were COP$ 77,384 (USD$ 24.6), COP$ 30,141 (USD$ 9.6) and COP$ 12,627 (USD$ 4), respectively. Personnel cost accounted for the highest percentage of the total cost for both blood banks (47.5% in Seccional Bolívar, and 55.7% in Yopal, Casanare). Our results are an important input for the planning of services and cost-effectiveness studies for screening tests for Chagas' disease in Colombian blood banks.

  10. Rapid diagnostic tests duo as alternative to conventional serological assays for conclusive Chagas disease diagnosis.

    PubMed

    Egüez, Karina E; Alonso-Padilla, Julio; Terán, Carolina; Chipana, Zenobia; García, Wilson; Torrico, Faustino; Gascon, Joaquim; Lozano-Beltran, Daniel-Franz; Pinazo, María-Jesús

    2017-04-01

    Chagas disease is caused by the parasite Trypanosoma cruzi. It affects several million people, mainly in Latin America, and severe cardiac and/or digestive complications occur in ~30% of the chronically infected patients. Disease acute stage is mostly asymptomatic and infection goes undiagnosed. In the chronic phase direct parasite detection is hampered due to its concealed presence and diagnosis is achieved by serological methods, like ELISA or indirect hemagglutination assays. Agreement in at least two tests must be obtained due to parasite wide antigenic variability. These techniques require equipped labs and trained personnel and are not available in distant regions. As a result, many infected people often remain undiagnosed until it is too late, as the two available chemotherapies show diminished efficacy in the advanced chronic stage. Easy-to-use rapid diagnostic tests have been developed to be implemented in remote areas as an alternative to conventional tests. They do not need electricity, nor cold chain, they can return results within an hour and some even work with whole blood as sample, like Chagas Stat-Pak (ChemBio Inc.) and Chagas Detect Plus (InBIOS Inc.). Nonetheless, in order to qualify a rapidly diagnosed positive patient for treatment, conventional serological confirmation is obligatory, which might risk its start. In this study two rapid tests based on distinct antigen sets were used in parallel as a way to obtain a fast and conclusive Chagas disease diagnosis using whole blood samples. Chagas Stat-Pak and Chagas Detect Plus were validated by comparison with three conventional tests yielding 100% sensitivity and 99.3% specificity over 342 patients seeking Chagas disease diagnosis in a reference centre in Sucre (Bolivia). Combined used of RDTs in distant regions could substitute laborious conventional serology, allowing immediate treatment and favouring better adhesion to it.

  11. Controlled but not cured: Structural processes and explanatory models of Chagas disease in tropical Bolivia.

    PubMed

    Forsyth, Colin

    2015-11-01

    Dressler (2001:456) characterizes medical anthropology as divided between two poles: the constructivist, which focuses on the "meaning and significance that events have for people," and the structuralist, which emphasizes socioeconomic processes and relationships. This study synthesizes structuralist and constructivist perspectives by investigating how structural processes impact explanatory models of Chagas disease in a highly endemic area. The research took place from March-June 2013 through the Centro Medico Humberto Parra, a non-profit clinic servicing low income populations in Palacios, Bolivia and surrounding communities. Semistructured interviews (n = 68) and consensus analysis questionnaires (n = 48) were administered to people dealing with Chagas disease. In the interview narratives, respondents link Chagas disease with experiences of marginalization and rural poverty, and describe multilayered impediments to accessing treatment. They often view the disease as incurable, but this reflects inconsistent messages from the biomedical system. The consensus analysis results show strong agreement on knowledge of the vector, ethnomedical treatment, and structural factors related to Chagas disease. In interpreting Chagas disease, respondents account for the structural factors which place them at risk and impede access to care. Copyright © 2015 Elsevier Ltd. All rights reserved.

  12. Chagas Cardiomyopathy in the Context of the Chronic Disease Transition

    PubMed Central

    Hidron, Alicia I.; Gilman, Robert H.; Justiniano, Juan; Blackstock, Anna J.; LaFuente, Carlos; Selum, Walter; Calderon, Martiza; Verastegui, Manuela; Ferrufino, Lisbeth; Valencia, Eduardo; Tornheim, Jeffrey A.; O'Neal, Seth; Comer, Robert; Galdos-Cardenas, Gerson; Bern, Caryn

    2010-01-01

    Background Patients with Chagas disease have migrated to cities, where obesity, hypertension and other cardiac risk factors are common. Methodology/Principal Findings The study included adult patients evaluated by the cardiology service in a public hospital in Santa Cruz, Bolivia. Data included risk factors for T. cruzi infection, medical history, physical examination, electrocardiogram, echocardiogram, and contact 9 months after initial data collection to ascertain mortality. Serology and PCR for Trypanosoma cruzi were performed. Of 394 participants, 251 (64%) had confirmed T. cruzi infection by serology. Among seropositive participants, 109 (43%) had positive results by conventional PCR; of these, 89 (82%) also had positive results by real time PCR. There was a high prevalence of hypertension (64%) and overweight (body mass index [BMI] >25; 67%), with no difference by T. cruzi infection status. Nearly 60% of symptomatic congestive heart failure was attributed to Chagas cardiomyopathy; mortality was also higher for seropositive than seronegative patients (p = 0.05). In multivariable models, longer residence in an endemic province, residence in a rural area and poor housing conditions were associated with T. cruzi infection. Male sex, increasing age and poor housing were independent predictors of Chagas cardiomyopathy severity. Males and participants with BMI ≤25 had significantly higher likelihood of positive PCR results compared to females or overweight participants. Conclusions Chagas cardiomyopathy remains an important cause of congestive heart failure in this hospital population, and should be evaluated in the context of the epidemiological transition that has increased risk of obesity, hypertension and chronic cardiovascular disease. PMID:20502520

  13. [What is not searched, it is difficult to find: Chagas' disease].

    PubMed

    Briceno, Luis; Mosca, Walter

    2016-05-01

    A conservative estimation indicates that more than 400 000 Latin American immigrants are living in Italy. Several studies have shown that among these, the prevalence of Chagas disease is between 3.9% and 17%, so it is not unlikely to find a patient with this disease during a cardiology visit. How many patients from Latin America are diagnosed with heart failure in Italy and no one has ever thought about a possible Chagas disease? This brief review describes the situation of the disease in Italy, its characteristics, the etiology of this disease and its treatment. The latter aspect will be discussed considering the recent published results of the BENEFIT study, where it was found that treatment with benznidazole in patients with Chagas' cardiomyopathy is able to reduce significantly the detection of parasites in the blood, but it is not able to prevent clinical deterioration during 5 years of follow-up. The possible implications of these results will be discussed.

  14. The impact of Chagas disease control in Latin America: a review.

    PubMed

    Dias, J C P; Silveira, A C; Schofield, C J

    2002-07-01

    Discovered in 1909, Chagas disease was progressively shown to be widespread throughout Latin America, affecting millions of rural people with a high impact on morbidity and mortality. With no vaccine or specific treatment available for large-scale public health interventions, the main control strategy relies on prevention of transmission, principally by eliminating the domestic insect vectors and control of transmission by blood transfusion. Vector control activities began in the 1940s, initially by means of housing improvement and then through insecticide spraying following successful field trials in Brazil (Bambui Research Centre), with similar results soon reproduced in São Paulo, Argentina, Venezuela and Chile. But national control programmes only began to be implemented after the 1970s, when technical questions were overcome and the scientific demonstration of the high social impact of Chagas disease was used to encourage political determination in favour of national campaigns (mainly in Brazil). Similarly, large-scale screening of infected blood donors in Latin America only began in the 1980s following the emergence of AIDS. By the end of the last century it became clear that continuous control in contiguous endemic areas could lead to the elimination of the most highly domestic vector populations - especially Triatoma infestans and Rhodnius prolixus - as well as substantial reductions of other widespread species such as T. brasiliensis, T. sordida, and T. dimidiata, leading in turn to interruption of disease transmission to rural people. The social impact of Chagas disease control can now be readily demonstrated by the disappearance of acute cases and of new infections in younger age groups, as well as progressive reductions of mortality and morbidity rates in controlled areas. In economic terms, the cost-benefit relationship between intervention (insecticide spraying, serology in blood banks) and the reduction of Chagas disease (in terms of medical and

  15. Cell therapies for Chagas disease.

    PubMed

    Carvalho, Adriana Bastos; Goldenberg, Regina Coeli Dos Santos; Campos de Carvalho, Antonio Carlos

    2017-11-01

    In this review of cell therapies in Chagas disease, we cover aspects related to the disease, its treatment and world demographics, before proceeding to describe the preclinical and clinical trials performed using cell therapies in the search for an alternative therapy for the most severe and lethal form of this disease, chronic chagasic cardiomyopathy. Copyright © 2017 International Society for Cellular Therapy. Published by Elsevier Inc. All rights reserved.

  16. Reflection by Porro Prisms

    NASA Astrophysics Data System (ADS)

    Greenslade, Thomas B.

    2010-04-01

    Students all know that reflection from a plane mirror produces an image that is reversed right to left and so cannot be read by anyone but Leonardo da Vinci, who kept his notes in mirror writing. A useful counter-example is the Porro prism, which produces an image that is not reversed.

  17. Behavioural alterations are independent of sickness behaviour in chronic experimental Chagas disease.

    PubMed

    Vilar-Pereira, Glaucia; Ruivo, Leonardo Alexandre de Souza; Lannes-Vieira, Joseli

    2015-12-01

    The existence of the nervous form of Chagas disease is a matter of discussion since Carlos Chagas described neurological disorders, learning and behavioural alterations in Trypanosoma cruzi-infected individuals. In most patients, the clinical manifestations of the acute phase, including neurological abnormalities, resolve spontaneously without apparent consequence in the chronic phase of infection. However, chronic Chagas disease patients have behavioural changes such as psychomotor alterations, attention and memory deficits, and depression. In the present study, we tested whether or not behavioural alterations are reproducible in experimental models. We show that C57BL/6 mice chronically infected with the Colombian strain of T. cruzi (150 days post-infection) exhibit behavioural changes as (i) depression in the tail suspension and forced swim tests, (ii) anxiety analysed by elevated plus maze and open field test sand and (iii) motor coordination in the rotarod test. These alterations are neither associated with neuromuscular disorders assessed by the grip strength test nor with sickness behaviour analysed by temperature variation sand weight loss. Therefore, chronically T. cruzi-infected mice replicate behavioural alterations (depression and anxiety) detected in Chagas disease patients opening an opportunity to study the interconnection and the physiopathology of these two biological processes in an infectious scenario.

  18. [Control of Chagas disease in pregnant Latin-American women and her children].

    PubMed

    Merino, Francisco J; Martínez-Ruiz, Rocío; Olabarrieta, Iciar; Merino, Paloma; García-Bujalance, Silvia; Gastañaga, Teresa; Flores-Chavez, María

    2013-09-01

    Chagas disease is a chronic and systemic infection caused by Trypanosoma cruzi. According to estimates from WHO, 10 million people are affected by this parasite. In the last years, birthrate among the immigrant women from Latin America settled in the Comunidad Autónoma de Madrid has been increasing, and as T. cruzi can be transmitted from mother to child, in fact 11 cases of congenital Chagas disease have been confirmed. Therefore, the aim of this paper is encouraging improvements in the coverage of the anti-T. cruzi antibodies detection in pregnant women from endemic areas. By this strategy, an active search for infected pregnant women and early detection of her infected newborns could be conducted, and then an early specific treatment could be administrated. Thus, there could be an important contribution to the control of Chagas disease in non-endemic area.

  19. Epidemiology, control and surveillance of Chagas disease: 100 years after its discovery.

    PubMed

    Coura, José Rodrigues; Dias, João Carlos Pinto

    2009-07-01

    Chagas disease originated millions of years ago as an enzootic infection of wild animals and began to be transmitted to humans as an anthropozoonosis when man invaded wild ecotopes. While evidence of human infection has been found in mummies up to 9,000 years old, endemic Chagas disease became established as a zoonosis only in the last 200-300 years, as triatomines adapted to domestic environments. It is estimated that 15-16 million people are infected with Trypanosoma cruzi in Latin America, and 75-90 million are exposed to infection. Control of Chagas disease must be undertaken by interrupting its transmission by vectors and blood transfusions, improving housing and areas surrounding dwellings, providing sanitation education for exposed populations and treating acute and recently infected chronic cases. These measures should be complemented by surveillance and primary, secondary and tertiary care.

  20. PRISM Polarimetry of Massive Stars

    NASA Astrophysics Data System (ADS)

    Kerkstra, Brennan; Lomax, Jamie R.; Bjorkman, Karen S.; Bjorkman, Jon Eric; Skiff, Brian; Covey, Kevin R.; Wisniewski, John P.

    2016-01-01

    We present the early results from our long-term, multi-epoch filter polarization survey of massive stars in and around young Galactic clusters. These BVRI polarization data were obtained using the PRISM instrument mounted on the 1.8m Perkins Telescope at Lowell Observatory. We first detail the creation of our new semi-automated polarization data reduction pipeline that we developed to process these data. Next, we present our analysis of the instrumental polarization properties of the PRISM instrument, via observations of polarized and unpolarized standard stars. Finally, we present early results on the total and intrinsic polarization behavior of several isolated, previously suggested classical Be stars, and discuss these results in the context of the larger project.BK acknowledges support from a NSF/REU at the University of Oklahoma. This program was also supported by NSF-AST 11411563, 1412110, and 1412135.

  1. Cardiomyocyte dysfunction during the chronic phase of Chagas disease.

    PubMed

    Roman-Campos, Danilo; Sales-Júnior, Policarpo; Duarte, Hugo Leonardo; Gomes, Eneas Ricardo; Guatimosim, Silvia; Ropert, Catherine; Gazzinelli, Ricardo Tostes; Cruz, Jader Santos

    2013-04-01

    Chagas disease, which is caused by the parasite Trypanosoma cruzi, is an important cause of heart failure. We investigated modifications in the cellular electrophysiological and calcium-handling characteristics of an infected mouse heart during the chronic phase of the disease. The patch-clamp technique was used to record action potentials (APs) and L-type Ca2+ and transient outward K+ currents. [Ca2+]i changes were determined using confocal microscopy. Infected ventricular cells showed prolonged APs, reduced transient outward K+ and L-type Ca2+ currents and reduced Ca2+ release from the sarcoplasmic reticulum. Thus, the chronic phase of Chagas disease is characterised by cardiomyocyte dysfunction, which could lead to heart failure.

  2. Cardiomyocyte dysfunction during the chronic phase of Chagas disease

    PubMed Central

    Roman-Campos, Danilo; Sales-Júnior, Policarpo; Duarte, Hugo Leonardo; Gomes, Eneas Ricardo; Guatimosim, Silvia; Ropert, Catherine; Gazzinelli, Ricardo Tostes; Cruz, Jader Santos

    2013-01-01

    Chagas disease, which is caused by the parasite Trypanosoma cruzi, is an important cause of heart failure. We investigated modifications in the cellular electrophysiological and calcium-handling characteristics of an infected mouse heart during the chronic phase of the disease. The patch-clamp technique was used to record action potentials (APs) and L-type Ca2+ and transient outward K+ currents. [Ca2+]i changes were determined using confocal microscopy. Infected ventricular cells showed prolonged APs, reduced transient outward K+ and L-type Ca2+ currents and reduced Ca2+ release from the sarcoplasmic reticulum. Thus, the chronic phase of Chagas disease is characterised by cardiomyocyte dysfunction, which could lead to heart failure. PMID:23579807

  3. Left-Deviating Prism Adaptation in Left Neglect Patient: Reflexions on a Negative Result

    PubMed Central

    Luauté, Jacques; Jacquin-Courtois, Sophie; O'Shea, Jacinta; Christophe, Laure; Rode, Gilles; Boisson, Dominique; Rossetti, Yves

    2012-01-01

    Adaptation to right-deviating prisms is a promising intervention for the rehabilitation of patients with left spatial neglect. In order to test the lateral specificity of prism adaptation on left neglect, the present study evaluated the effect of left-deviating prism on straight-ahead pointing movements and on several classical neuropsychological tests in a group of five right brain-damaged patients with left spatial neglect. A group of healthy subjects was also included for comparison purposes. After a single session of exposing simple manual pointing to left-deviating prisms, contrary to healthy controls, none of the patients showed a reliable change of the straight-ahead pointing movement in the dark. No significant modification of attentional paper-and-pencil tasks was either observed immediately or 2 hours after prism adaptation. These results suggest that the therapeutic effect of prism adaptation on left spatial neglect relies on a specific lateralized mechanism. Evidence for a directional effect for prism adaptation both in terms of the side of the visuomanual adaptation and therefore possibly in terms of the side of brain affected by the stimulation is discussed. PMID:23050168

  4. Local Seismicity Recorded by ChilePEPPER: Implications for Dynamic Accretionary Prism Response and Long-term Prism Evolution

    NASA Astrophysics Data System (ADS)

    de Moor, A.; Trehu, A. M.; Tryon, M. D.

    2015-12-01

    To investigate the dynamic response of the outer accretionary wedge updip from the patch of greatest slip during the Mw8.8 2010 Maule earthquake, 10 Ocean Bottom Seismometers (OBS) were deployed from May 2012 to March 2013 in a small array with an inter-instrument spacing of ~12 km . Nine instruments were recovered, with 4 recording data on 3 intermediate-band 3-component seismometers and a differential pressure gauge and 5 recording data from absolute pressure gauges. [note: All instruments were also equipped with a fluid flow meter sensitive to flow rates as low as 0.0001 cm/yr in or out of the sediments. However, no flow signal was detected.] Here we present hypocenters for 569 local events that have S-P times less than 17 seconds (i.e. within ~125 km of the array) using hand-picked arrival times and a 1D velocity model derived from a 2D seismic refraction profile through the region (Moscoso et al 2011, EPSL). We analyze the distribution of seismicity in the context of published slip models, ChilePEPPER high-resolution seismic reflection data, critical taper analysis done by Cubas et al 2013 (EPSL), and offshore gravity data. The data show distinct segmentation within the outer prism. The northern section of the study area is characterized by a lack of seismicity, accretion of nearly all incoming sediment and a prism at critical taper. In contrast, abundant seismicity, significant sediment underthrusting at the deformation front and a prism below critical taper angle characterize the southern part of the study area. Both coseismic slip and post-rupture local seismicity can be related to density anomalies within the upper plate as revealed by free air gravity data corrected for the effects of bathymetry and the subducting plate. [ChilePEPPER - Project Evaluating Prism Post-Earthquake Response

  5. Impact of high power and angle of incidence on prism corrections for visual field loss.

    PubMed

    Jung, Jae-Hyun; Peli, Eli

    2014-01-17

    Prism distortions and spurious reflections are not usually considered when prescribing prisms to compensate for visual field loss due to homonymous hemianopia. Distortions and reflections in the high power Fresnel prisms used in peripheral prism placement can be considerable, and the simplifying assumption that prism deflection power is independent of angle of incidence into the prisms results in substantial errors. We analyze the effects of high prism power and incidence angle on the field expansion, size of the apical scotomas, and image compression/expansion. We analyze and illustrate the effects of reflections within the Fresnel prisms, primarily due to reflections at the bases, and secondarily due to surface reflections. The strength and location of these effects differs materially depending on whether the serrated prismatic surface is placed toward or away from the eye, and this affects the contribution of the reflections to visual confusion, diplopia, false alarms, and loss of contrast. We conclude with suggestions for controlling and mitigating these effects in clinical practice.

  6. Impact of high power and angle of incidence on prism corrections for visual field loss

    PubMed Central

    Jung, Jae-Hyun; Peli, Eli

    2014-01-01

    Prism distortions and spurious reflections are not usually considered when prescribing prisms to compensate for visual field loss due to homonymous hemianopia. Distortions and reflections in the high power Fresnel prisms used in peripheral prism placement can be considerable, and the simplifying assumption that prism deflection power is independent of angle of incidence into the prisms results in substantial errors. We analyze the effects of high prism power and incidence angle on the field expansion, size of the apical scotomas, and image compression/expansion. We analyze and illustrate the effects of reflections within the Fresnel prisms, primarily due to reflections at the bases, and secondarily due to surface reflections. The strength and location of these effects differs materially depending on whether the serrated prismatic surface is placed toward or away from the eye, and this affects the contribution of the reflections to visual confusion, diplopia, false alarms, and loss of contrast. We conclude with suggestions for controlling and mitigating these effects in clinical practice. PMID:24497649

  7. Trypanosoma cruzi and Chagas' Disease in the United States

    PubMed Central

    Bern, Caryn; Kjos, Sonia; Yabsley, Michael J.; Montgomery, Susan P.

    2011-01-01

    Summary: Chagas' disease is caused by the protozoan parasite Trypanosoma cruzi and causes potentially life-threatening disease of the heart and gastrointestinal tract. The southern half of the United States contains enzootic cycles of T. cruzi, involving 11 recognized triatomine vector species. The greatest vector diversity and density occur in the western United States, where woodrats are the most common reservoir; other rodents, raccoons, skunks, and coyotes are also infected with T. cruzi. In the eastern United States, the prevalence of T. cruzi is highest in raccoons, opossums, armadillos, and skunks. A total of 7 autochthonous vector-borne human infections have been reported in Texas, California, Tennessee, and Louisiana; many others are thought to go unrecognized. Nevertheless, most T. cruzi-infected individuals in the United States are immigrants from areas of endemicity in Latin America. Seven transfusion-associated and 6 organ donor-derived T. cruzi infections have been documented in the United States and Canada. As improved control of vector- and blood-borne T. cruzi transmission decreases the burden in countries where the disease is historically endemic and imported Chagas' disease is increasingly recognized outside Latin America, the United States can play an important role in addressing the altered epidemiology of Chagas' disease in the 21st century. PMID:21976603

  8. Chagas disease and human migration.

    PubMed

    Guhl, F; Jaramillo, C; Vallejo, G A; Cárdenas A-Arroyo, F; Aufderheide, A

    2000-01-01

    Human Chagas disease is a purely accidental occurrence. As humans came into contact with the natural foci of infection might then have become infected as a single addition to the already extensive host range of Trypanosoma cruzi that includes other primates. Thus began a process of adaptation and domiciliation to human habitations through which the vectors had direct access to abundant food as well as protection from climatic changes and predators. Our work deals with the extraction and specific amplification by polymerase chain reaction of T. cruzi DNA obtained from mummified human tissues and the positive diagnosis of Chagas disease in a series of 4, 000-year-old Pre-Hispanic human mummies from the northern coast of Chile. The area has been inhabited at least for 7,000 years, first by hunters, fishers and gatherers, and then gradually by more permanent settlements. The studied specimens belonged to the Chinchorro culture, a people inhabiting the area now occupied by the modern city of Arica. These were essentially fishers with a complex religious ideology, which accounts for the preservation of their dead in the way of mummified bodies, further enhanced by the extremely dry conditions of the desert. Chinchorro mummies are, perhaps, the oldest preserved bodies known to date.

  9. Matrix Metalloproteinases 2 and 9 Are Differentially Expressed in Patients with Indeterminate and Cardiac Clinical Forms of Chagas Disease

    PubMed Central

    Fares, Rafaelle Christine Gomes; Gomes, Juliana de Assis Silva; Garzoni, Luciana Ribeiro; Waghabi, Mariana Caldas; Saraiva, Roberto Magalhães; Medeiros, Nayara Ingrid; Oliveira-Prado, Roberta; Sangenis, Luiz Henrique Conde; Chambela, Mayara da Costa; de Araújo, Fernanda Fortes; Teixeira-Carvalho, Andréa; Damásio, Marcos Paulo; Valente, Vanessa Azevedo; Ferreira, Karine Silvestre; Sousa, Giovane Rodrigo; Rocha, Manoel Otávio da Costa

    2013-01-01

    Dilated chronic cardiomyopathy (DCC) from Chagas disease is associated with myocardial remodeling and interstitial fibrosis, resulting in extracellular matrix (ECM) changes. In this study, we characterized for the first time the serum matrix metalloproteinase 2 (MMP-2) and MMP-9 levels, as well as their main cell sources in peripheral blood mononuclear cells from patients presenting with the indeterminate (IND) or cardiac (CARD) clinical form of Chagas disease. Our results showed that serum levels of MMP-9 are associated with the severity of Chagas disease. The analysis of MMP production by T lymphocytes showed that CD8+ T cells are the main mononuclear leukocyte source of both MMP-2 and MMP-9 molecules. Using a new 3-dimensional model of fibrosis, we observed that sera from patients with Chagas disease induced an increase in the extracellular matrix components in cardiac spheroids. Furthermore, MMP-2 and MMP-9 showed different correlations with matrix proteins and inflammatory cytokines in patients with Chagas disease. Our results suggest that MMP-2 and MMP-9 show distinct activities in Chagas disease pathogenesis. While MMP-9 seems to be involved in the inflammation and cardiac remodeling of Chagas disease, MMP-2 does not correlate with inflammatory molecules. PMID:23856618

  10. Full-wave simulation of a three-dimensional metamaterial prism

    DOE PAGES

    Basilio, Lorena I.; Langston, William L.; Warne, Larry K.; ...

    2015-01-23

    In our article, a negative-index metamaterial prism based on a composite unit cell containing a split-ring resonator and a z-dipole is designed and simulated. The design approach combines simulations of a single unit cell to identify the appropriate cell design (yielding the desired negative-index behavior) together with subcell modeling (which simplifies the mesh representation of the resonator geometry and allows for a larger number of resonator cells to be handled). Furthermore, to describe the methodology used in designing a n = -1 refractive index prism, our results include the effective-medium parameters, the far-field scattered patterns, and the near-zone field distributionsmore » corresponding to a normally incident plane-wave excitation of the prism.« less

  11. Quartz-Enhanced Photoacoustic Spectroscopy with Right-Angle Prism.

    PubMed

    Liu, Yongning; Chang, Jun; Lian, Jie; Liu, Zhaojun; Wang, Qiang; Qin, Zengguang

    2016-02-06

    A right-angle prism was used to enhance the acoustic signal of a quartz-enhanced photoacoustic spectroscopy (QEPAS) system. The incident laser beam was parallelly inverted by the right-angle prism and passed through the gap between two tuning fork prongs again to produce another acoustic excitation. Correspondingly, two pairs of rigid metal tubes were used as acoustic resonators with resonance enhancement factors of 16 and 12, respectively. The QEPAS signal was enhanced by a factor of 22.4 compared with the original signal, which was acquired without resonators or a prism. In addition, the system noise was reduced a little with double resonators due to the Q factor decrease. The signal-to-noise ratio (SNR) was greatly improved. Additionally, a normalized noise equivalent absorption coefficient (NNEA) of 5.8 × 10(-8) W·cm(-1)·Hz(-1/2) was achieved for water vapor detection in the atmosphere.

  12. Comprehensive analysis of three TYK2 gene variants in the susceptibility to Chagas disease infection and cardiomyopathy.

    PubMed

    Leon Rodriguez, Daniel A; Acosta-Herrera, Marialbert; Carmona, F David; Dolade, Nuria; Vargas, Sofia; Echeverría, Luis Eduardo; González, Clara Isabel; Martin, Javier

    2018-01-01

    Tyrosine kinase 2 (TYK2) is a member of the Janus kinases family implicated in the signal transduction of type I interferons and several interleukins. It has been described that genetic mutations within TYK2 lead to multiple deleterious effects in the immune response. In this work, we have analyzed three functional independent variants from the frequency spectrum on the TYK2 gene (common and low-frequency variants) suggested to reduce the function of the gene in mediating cytokine signaling and the susceptibility to infections by Trypanosoma cruzi and/or the development of Chagas cardiomyopathy in the Colombian population. A total of 1,323 individuals from a Colombian endemic region for Chagas disease were enrolled in the study. They were classified as seronegative (n = 445), seropositive asymptomatic (n = 336), and chronic Chagas Cardiomyopathy subjects (n = 542). DNA samples were genotyped using TaqMan probes. Our results showed no statistically significant differences between the allelic frequencies of the three analyzed variants when seropositive and seronegative individuals were compared, therefore these variants were not associated with susceptibility to Chagas disease. Moreover, when Chagas cardiomyopathy patients were compared to asymptomatic patients, no significant associations were found. Previous reports highlighted the association of this gene in immune-related disorders under an autoimmunity context, but not predisposing patients to infectious diseases, which is consistent with our findings. Therefore, according to our results, TYK2 gene variants do not seem to play an important role in Chagas disease susceptibility and/or chronic Chagas cardiomyopathy.

  13. Compact cross-dispersion device based on a prism and a plane transmission grating

    NASA Astrophysics Data System (ADS)

    Yang, Qinghua; Wang, Weiqiang

    2018-05-01

    This paper presents a cross-dispersion prism-grating device using a plane transmission grating attached directly to a prism, which is different from traditional cross-dispersion grating-prism systems that are based on the reflection grating. Unlike conventional direct-vision grism or constant-dispersion grism in which both the prism and grating have the same dispersion direction, for this device the dispersion directions of the prism and grating are different. The analytical expressions for the cross-dispersion of this device are derived in detail and the formulas of the footprint of the dispersed spectra are given. The numerical results and ray-tracing simulations by ZEMAX are shown. The device provides a compact, small-sized and broadband cross-dispersion device used for the medium resolution spectrometer.

  14. Superconducting magnetic Wollaston prism for neutron spin encoding

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Li, F., E-mail: fankli@indiana.edu; Parnell, S. R.; Wang, T.

    2014-05-15

    A magnetic Wollaston prism can spatially split a polarized neutron beam into two beams with different neutron spin states, in a manner analogous to an optical Wollaston prism. Such a Wollaston prism can be used to encode the trajectory of neutrons into the Larmor phase associated with their spin degree of freedom. This encoding can be used for neutron phase-contrast radiography and in spin echo scattering angle measurement (SESAME). In this paper, we show that magnetic Wollaston prisms with highly uniform magnetic fields and low Larmor phase aberration can be constructed to preserve neutron polarization using high temperature superconducting (HTS)more » materials. The Meissner effect of HTS films is used to confine magnetic fields produced electromagnetically by current-carrying HTS tape wound on suitably shaped soft iron pole pieces. The device is cooled to ∼30 K by a closed cycle refrigerator, eliminating the need to replenish liquid cryogens and greatly simplifying operation and maintenance. A HTS film ensures that the magnetic field transition within the prism is sharp, well-defined, and planar due to the Meissner effect. The spin transport efficiency across the device was measured to be ∼98.5% independent of neutron wavelength and energizing current. The position-dependent Larmor phase of neutron spins was measured at the NIST Center for Neutron Research facility and found to agree well with detailed simulations. The phase varies linearly with horizontal position, as required, and the neutron beam shows little depolarization. Consequently, the device has advantages over existing devices with similar functionality and provides the capability for a large neutron beam (20 mm × 30 mm) and an increase in length scales accessible to SESAME to beyond 10 μm. With further improvements of the external coupling guide field in the prototype device, a larger neutron beam could be employed.« less

  15. Superconducting magnetic Wollaston prism for neutron spin encoding

    NASA Astrophysics Data System (ADS)

    Li, F.; Parnell, S. R.; Hamilton, W. A.; Maranville, B. B.; Wang, T.; Semerad, R.; Baxter, D. V.; Cremer, J. T.; Pynn, R.

    2014-05-01

    A magnetic Wollaston prism can spatially split a polarized neutron beam into two beams with different neutron spin states, in a manner analogous to an optical Wollaston prism. Such a Wollaston prism can be used to encode the trajectory of neutrons into the Larmor phase associated with their spin degree of freedom. This encoding can be used for neutron phase-contrast radiography and in spin echo scattering angle measurement (SESAME). In this paper, we show that magnetic Wollaston prisms with highly uniform magnetic fields and low Larmor phase aberration can be constructed to preserve neutron polarization using high temperature superconducting (HTS) materials. The Meissner effect of HTS films is used to confine magnetic fields produced electromagnetically by current-carrying HTS tape wound on suitably shaped soft iron pole pieces. The device is cooled to ˜30 K by a closed cycle refrigerator, eliminating the need to replenish liquid cryogens and greatly simplifying operation and maintenance. A HTS film ensures that the magnetic field transition within the prism is sharp, well-defined, and planar due to the Meissner effect. The spin transport efficiency across the device was measured to be ˜98.5% independent of neutron wavelength and energizing current. The position-dependent Larmor phase of neutron spins was measured at the NIST Center for Neutron Research facility and found to agree well with detailed simulations. The phase varies linearly with horizontal position, as required, and the neutron beam shows little depolarization. Consequently, the device has advantages over existing devices with similar functionality and provides the capability for a large neutron beam (20 mm × 30 mm) and an increase in length scales accessible to SESAME to beyond 10 μm. With further improvements of the external coupling guide field in the prototype device, a larger neutron beam could be employed.

  16. Superconducting magnetic Wollaston prism for neutron spin encoding.

    PubMed

    Li, F; Parnell, S R; Hamilton, W A; Maranville, B B; Wang, T; Semerad, R; Baxter, D V; Cremer, J T; Pynn, R

    2014-05-01

    A magnetic Wollaston prism can spatially split a polarized neutron beam into two beams with different neutron spin states, in a manner analogous to an optical Wollaston prism. Such a Wollaston prism can be used to encode the trajectory of neutrons into the Larmor phase associated with their spin degree of freedom. This encoding can be used for neutron phase-contrast radiography and in spin echo scattering angle measurement (SESAME). In this paper, we show that magnetic Wollaston prisms with highly uniform magnetic fields and low Larmor phase aberration can be constructed to preserve neutron polarization using high temperature superconducting (HTS) materials. The Meissner effect of HTS films is used to confine magnetic fields produced electromagnetically by current-carrying HTS tape wound on suitably shaped soft iron pole pieces. The device is cooled to ~30 K by a closed cycle refrigerator, eliminating the need to replenish liquid cryogens and greatly simplifying operation and maintenance. A HTS film ensures that the magnetic field transition within the prism is sharp, well-defined, and planar due to the Meissner effect. The spin transport efficiency across the device was measured to be ~98.5% independent of neutron wavelength and energizing current. The position-dependent Larmor phase of neutron spins was measured at the NIST Center for Neutron Research facility and found to agree well with detailed simulations. The phase varies linearly with horizontal position, as required, and the neutron beam shows little depolarization. Consequently, the device has advantages over existing devices with similar functionality and provides the capability for a large neutron beam (20 mm × 30 mm) and an increase in length scales accessible to SESAME to beyond 10 μm. With further improvements of the external coupling guide field in the prototype device, a larger neutron beam could be employed.

  17. A metasurface-based prism analogue for terahertz rainbow spectrum manipulation

    NASA Astrophysics Data System (ADS)

    Zheng, Shen; Li, Chao; Li, Shichao; Zhang, Xiaojuan; Fang, Guangyou

    2017-06-01

    Optical prisms can spread compound light spatially into a rainbow and have widespread applications in spectroscopy and imaging. Limited by the natural materials as well as technologies, there has been no natural counterpart of the optical prism that works in the Terahertz (THz) band so far. In this letter, a THz prism analogue based on metasurfaces working in the transmission diffraction mechanism is first proposed to generate the THz rainbow spectrum. The physics of different modes excited by the interaction between the incident wave and the metasurface is investigated in theory and simulation. A coherent enhancement method was developed to improve the mode competition of the rainbow spectrum over other unwanted leaky modes to guarantee the high transfer efficiency of the wavelength dependent transmission diffraction. The experimental results show that the prism analogue can spread the incident spectrum from 0.15 to 0.22 THz in an angular scope of about 30.8° with comparatively high transferring efficiency.

  18. Optimization of SPR signals: Monitoring the physical structures and refractive indices of prisms

    NASA Astrophysics Data System (ADS)

    Maisarah Mukhtar, Wan; Halim, Razman Mohd; Hassan, Hazirah

    2017-11-01

    Surface plasmon resonance (SPR) can only be achieved if sufficient energy is provided at the boundary between metal and dielectric. An employment of prism as a light coupler by using Kretschmann configuration is one of the alternative for the production of adequate energy to be generated as surface plasmon polaritons (SPP). This work is carried out to investigate the effect of physical structure of the prism and its refractive index to the excitation of SPPs. A 50nm gold thin metal film with dielectric constant of ɛ=-12.45i+1.3 was deposited on the hypotenuse surface of the prisms. The physical structures of the prisms were varied such as triangular, conical, hemispherical and half cylindrical. These prisms were classified into two types of refractive indices (RI), namely n=1.51(type BK7) and n=1.77(type SF11). Based on SPR curve analyses, we discovered that strong SPR signals which consist of 82.98% photons were excited as SPPs can be obtained by using type-BK7 prism with physical structures of hemispherical or half cylindrical. From the view of selectivity ability as sensors, the usage of type-SF11 prisms (half cylindrical and hemispherical) able to enhance this impressive feature in which sharp SPR curves with small FWHM values were obtained. In conclusion, apart from properties of thin film materials, the physical structure of prisms and their RI values play crucial roles to obtain optimum SPR signal. High sensitivity SPR sensor can be established with the appointment of type-BK7 prisms (hemispherical or half cylindrical shape) as light couplers.

  19. PRISM, Processing and Review Interface for Strong Motion Data Software

    NASA Astrophysics Data System (ADS)

    Kalkan, E.; Jones, J. M.; Stephens, C. D.; Ng, P.

    2016-12-01

    A continually increasing number of high-quality digital strong-motion records from stations of the National Strong Motion Project (NSMP) of the U.S. Geological Survey (USGS), as well as data from regional seismic networks within the U.S., calls for automated processing of strong-motion records with human review limited to selected significant or flagged records. The NSMP has developed the Processing and Review Interface for Strong Motion data (PRISM) software to meet this need. PRISM automates the processing of strong-motion records by providing batch-processing capabilities. The PRISM software is platform-independent (coded in Java), open-source, and does not depend on any closed-source or proprietary software. The software consists of two major components: a record processing engine composed of modules for each processing step, and a graphical user interface (GUI) for manual review and processing. To facilitate the use by non-NSMP earthquake engineers and scientists, PRISM (both its processing engine and GUI components) is easy to install and run as a stand-alone system on common operating systems such as Linux, OS X and Windows. PRISM was designed to be flexible and extensible in order to accommodate implementation of new processing techniques. Input to PRISM currently is limited to data files in the Consortium of Organizations for Strong-Motion Observation Systems (COSMOS) V0 format, so that all retrieved acceleration time series need to be converted to this format. Output products include COSMOS V1, V2 and V3 files as: (i) raw acceleration time series in physical units with mean removed (V1), (ii) baseline-corrected and filtered acceleration, velocity, and displacement time series (V2), and (iii) response spectra, Fourier amplitude spectra and common earthquake-engineering intensity measures (V3). A thorough description of the record processing features supported by PRISM is presented with examples and validation results. All computing features have been

  20. Interleukin-10 and tumour necrosis factor-alpha serum levels in chronic Chagas disease patients.

    PubMed

    Vasconcelos, R H T; Azevedo, E de A N; Diniz, G T N; Cavalcanti, M da G A de M; de Oliveira, W; de Morais, C N L; Gomes, Y de M

    2015-07-01

    In Chagas disease, chronically infected individuals may be asymptomatic or may present cardiac or digestive complications, and it is well known that the human immune response is related to different clinical manifestations. Different patterns of cytokine levels have been previously described in different clinical forms of this disease, but contradictory results are reported. Our aim was to evaluate the serum levels of interleukin-10 and tumour necrosis factor-alpha in patients with asymptomatic and cardiac Chagas disease. The serum interleukin-10 levels in patients with cardiomyopathy were higher than those in asymptomatic patients, mainly in those without heart enlargement. Although no significant difference was observed in serum tumour necrosis factor-alpha levels among the patients, we found that cardiac patients also present high levels of this cytokine, largely those with heart dilatation. Therefore, these cytokines play an important role in chronic Chagas disease cardiomyopathy. Follow-up investigations of these and other cytokines in patients with chronic Chagas disease need to be conducted to improve the understanding of the immunopathology of this disease. © 2015 John Wiley & Sons Ltd.

  1. Use of prism adaptation in children with unilateral brain lesion: Is it feasible?

    PubMed

    Riquelme, Inmaculada; Henne, Camille; Flament, Benoit; Legrain, Valéry; Bleyenheuft, Yannick; Hatem, Samar M

    2015-01-01

    Unilateral visuospatial deficits have been observed in children with brain damage. While the effectiveness of prism adaptation for treating unilateral neglect in adult stroke patients has been demonstrated previously, the usefulness of prism adaptation in a pediatric population is still unknown. The present study aims at evaluating the feasibility of prism adaptation in children with unilateral brain lesion and comparing the validity of a game procedure designed for child-friendly paediatric intervention, with the ecological task used for prism adaptation in adult patients. Twenty-one children with unilateral brain lesion randomly were assigned to a prism group wearing prismatic glasses, or a control group wearing neutral glasses during a bimanual task intervention. All children performed two different bimanual tasks on randomly assigned consecutive days: ecological tasks or game tasks. The efficacy of prism adaptation was measured by assessing its after-effects with visual open loop pointing (visuoproprioceptive test) and subjective straight-ahead pointing (proprioceptive test). Game tasks and ecological tasks produced similar after-effects. Prismatic glasses elicited a significant shift of visuospatial coordinates which was not observed in the control group. Prism adaptation performed with game tasks seems an effective procedure to obtain after-effects in children with unilateral brain lesion. The usefulness of repetitive prism adaptation sessions as a therapeutic intervention in children with visuospatial deficits and/or neglect, should be investigated in future studies. Copyright © 2015 Elsevier Ltd. All rights reserved.

  2. Does my patient have chronic Chagas disease? Development and temporal validation of a diagnostic risk score.

    PubMed

    Brasil, Pedro Emmanuel Alvarenga Americano do; Xavier, Sergio Salles; Holanda, Marcelo Teixeira; Hasslocher-Moreno, Alejandro Marcel; Braga, José Ueleres

    2016-01-01

    With the globalization of Chagas disease, unexperienced health care providers may have difficulties in identifying which patients should be examined for this condition. This study aimed to develop and validate a diagnostic clinical prediction model for chronic Chagas disease. This diagnostic cohort study included consecutive volunteers suspected to have chronic Chagas disease. The clinical information was blindly compared to serological tests results, and a logistic regression model was fit and validated. The development cohort included 602 patients, and the validation cohort included 138 patients. The Chagas disease prevalence was 19.9%. Sex, age, referral from blood bank, history of living in a rural area, recognizing the kissing bug, systemic hypertension, number of siblings with Chagas disease, number of relatives with a history of stroke, ECG with low voltage, anterosuperior divisional block, pathologic Q wave, right bundle branch block, and any kind of extrasystole were included in the final model. Calibration and discrimination in the development and validation cohorts (ROC AUC 0.904 and 0.912, respectively) were good. Sensitivity and specificity analyses showed that specificity reaches at least 95% above the predicted 43% risk, while sensitivity is at least 95% below the predicted 7% risk. Net benefit decision curves favor the model across all thresholds. A nomogram and an online calculator (available at http://shiny.ipec.fiocruz.br:3838/pedrobrasil/chronic_chagas_disease_prediction/) were developed to aid in individual risk estimation.

  3. Overcoming research barriers in Chagas disease-designing effective implementation science.

    PubMed

    Henao-Martínez, Andrés F; Colborn, Kathryn; Parra-Henao, Gabriel

    2017-01-01

    Chagas disease is a complex tropical parasitic infection. It affects a significant portion of the population in Latin America, especially in areas of poverty and poor access to health care. It also affects immigrants in high-income countries who lack access to health care due to their legal status. Millions of people are at risk of contracting the disease, and approximately 30 % of chronically infected patients will develop cardiomyopathy. The cost of caring for patients that have been infected is substantial. Basic science research has introduced new concepts and knowledge for the parasite and vector biology as well as better understanding of the pathophysiology of the disease. These research findings nevertheless require effective and timely translation into clinical practice. Likewise, the design of new research projects should account for the multiple system-based barriers. Implementation science facilitates the applicability of research findings and identifies barriers to its execution. Creation of implementation science measures to reach and sustain research programs with greater potential to impact Chagas disease are lacking. This point of view proposes opportunities for implementation science in Chagas disease and strategies for researching effective interventions for preventing and treating the disease.

  4. Is the aligning prism measured with the Mallett unit correlated with fusional vergence reserves?

    PubMed

    Conway, Miriam L; Thomas, Jennifer; Subramanian, Ahalya

    2012-01-01

    The Mallett Unit is a clinical test designed to detect the fixation disparity that is most likely to occur in the presence of a decompensated heterophoria. It measures the associated phoria, which is the "aligning prism" needed to nullify the subjective disparity. The technique has gained widespread acceptance within professions such as optometry, for investigating suspected cases of decompensating heterophoria; it is, however, rarely used by orthoptists and ophthalmologists. The aim of this study was to investigate whether fusional vergence reserves, measured routinely by both orthoptists and ophthalmologists to detect heterophoria decompensation, were correlated with aligning prism (associated phoria) in a normal clinical population. Aligning prism (using the Mallett Unit) and fusional vergence reserves (using a prism bar) were measured in 500 participants (mean 41.63 years; standard deviation 11.86 years) at 40 cm and 6 m. At 40 cm a strong correlation (p<0.001) between base in aligning prism (Exo FD) and positive fusional reserves was found. Of the participants with zero aligning prism 30% had reduced fusional reserves. At 6 m a weak correlation between base out aligning prism (Eso FD) and negative fusional reserves was found to break (p = 0.01) and to recovery (p = 0.048). Of the participants with zero aligning prism 12% reported reduced fusional reserves. For near vision testing, the strong inverse correlation between base in aligning prism (Exo FD) and fusional vergence reserves supports the notion that both measures are indicators of decompensation of heterophoria. For distance vision testing and for those patients reporting zero aligning prism further research is required to determine why the relationship appears to be weak/non-existent?

  5. Stabilization of a self-referenced, prism-based, Cr:forsterite laser frequency comb using an intracavity prism

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Tillman, Karl A.; Thapa, Rajesh; Knabe, Kevin

    2009-12-20

    The frequency comb from a prism-based Cr:forsterite laser has been frequency stabilized using intracavity prism insertion and pump power modulation. Absolute frequency measurements of a CW fiber laser stabilized to the P(13) transition of acetylene demonstrate a fractional instability of {approx}2x10{sup -11} at a 1 s gate time, limited by a commercial Global Positioning System (GPS)-disciplined rubidium oscillator. Additionally, absolute frequency measurements made simultaneously using a second frequency comb indicate relative instabilities of 3x10{sup -12} for both combs for a 1 s gate time. Estimations of the carrier-envelope offset frequency linewidth based on relative intensity noise and the response dynamicsmore » of the carrier-envelope offset to pump power changes confirm the observed linewidths.« less

  6. Effects of aspirin-triggered resolvin D1 on peripheral blood mononuclear cells from patients with Chagas' heart disease.

    PubMed

    Ogata, Haline; Teixeira, Maxelle Martins; Sousa, Rodrigo Cunha de; Silva, Marcos Vinícius da; Correia, Dalmo; Rodrigues Junior, Virmondes; Levy, Bruce David; Rogério, Alexandre de Paula

    2016-04-15

    Chagas disease is caused by Trypanosoma cruzi (T. cruzi). In some patients with Chagas disease, symptoms progress to chronic chagasic cardiomyopathy. Endogenously, inflammation is resolved in the presence of lipid mediators such as aspirin-triggered RvD1 (AT-RvD1) which has anti-inflammatory and pro-resolution effects. Here, we demonstrated, for the first time, the effects of AT-RvD1 on T. cruzi antigen-stimulated peripheral blood mononuclear cells (PBMCs) from patients with Chagas heart disease. The levels of IFN-γ, TNF-α, IL-10, and IL-13 increased in PBMCs from cardiac-form Chagas patients in stage B1 (patients with fewer heart abnormalities) stimulated with T. cruzi antigen compared to those in non-stimulated PBMCs. AT-RvD1 reduced the IFN-γ concentrations in PBMCs from patients with Chagas disease stimulated with T. cruzi antigen compared to stimulated with T. cruzi antigen cells. AT-RvD1 treatment resulted in no observable changes in TNF-α, IL-10, and IL-13 levels. AT-RvD1 significantly decreased the percentage of necrotic cells and caused a significant reduction in the proliferation rate of T. cruzi antigen-stimulated PBMCs from patients with Chagas disease. These findings demonstrate that AT-RvD1 modulates the immune response in Chagas disease patients and might have potential to be used as an alternative approach for slowing the development of further heart damage. Copyright © 2016 Elsevier B.V. All rights reserved.

  7. Community resilience and Chagas disease in a rural region of Mexico.

    PubMed

    Rangel, José Antonio Santana; Monreal, Luz Arenas; Ramsey, Janine M

    2016-08-04

    To explore the pillars of community resilience in a region where Chagas disease is endemic, with the aim of promoting participatory processes to deal with this condition from the resilience of the population. Qualitative study using ethnographic record and six interviews of focus groups with young people, women and men. The research was carried out in a rural area of the state of Morelos, Mexico, between 2006 and 2007. We carried out educational sessions with the population in general, so that residents could identify the relationship between the vector Triatoma pallidipennis, the parasite (Trypanosoma cruzi), symptoms, and preventive actions for Chagas disease. The ethnographic record and groups were analyzed based on Taylor and Bogdan's modification, and the focus was to understand the socio-cultural meanings that guide the speeches and activities of residents in relation to the pillars of community resilience. The population felt proud of belonging to that location and three pillars of community resilience were clearly identified: collective self-esteem, cultural identity, and social honesty. Having these pillars as bases, we promoted the participation of the population concerning Chagas disease, and a Community Action Group was formed with young people, adult men and women, and social leaders. This Group initiated actions of epidemiological and entomological surveillance in the community to deal with this problem. It is necessary to create more experiences that deepen the understanding of the pillars of community resilience, and how they contribute to enhance participation in health to deal with Chagas disease. Explorar los pilares de la resiliencia comunitaria en una región en la que la enfermedad de Chagas es endémica, con la finalidad de partir de la resiliencia de la población para impulsar procesos participativos para enfrentar este padecimiento. Estudio cualitativo que utilizó registro etnográfico y seis entrevistas de grupos focales con j

  8. Post-mortem diagnosis of chronic Chagas's disease comparative evaluation of three serological tests on pericardial fluid.

    PubMed

    Lopes, E R; Chapadeiro, E; Batista, S M; Cunha, J G; Rocha, A; Miziara, L; Ribeiro, J U; Patto, R J

    1978-01-01

    In an attempt to improve the post-mortem diagnosis of Chagas's disease the authors performed haemagglutination tests (HAT), fluorescent Trypanosoma cruzi antibody tests (FAT), and complement fixation tests (CFT) on the pericardial fluid obtained at autopsy of 50 individuals with Chagas's heart disease, and 93 patients in whom this disease was not thought to be present. The results demonstrate that all three tests are efficient for the post-mortem diagnosis of Chagas's disease but suggest that their combined use would detect more cases than would one isolated reaction only.

  9. Experimental static aerodynamics of a regular hexagonal prism in a low density hypervelocity flow

    NASA Technical Reports Server (NTRS)

    Guy, R. W.; Mueller, J. N.; Lee, L. P.

    1972-01-01

    A regular hexagonal prism, having a fineness ratio of 1.67, has been tested in a wind tunnel to determine its static aerodynamic characteristics in a low-density hypervelocity flow. The prism tested was a 1/4-scale model of the graphite heat shield which houses the radioactive fuel for the Viking spacecraft auxiliary power supply. The basic hexagonal prism was also modified to simulate a prism on which ablation of one of the six side flats had occurred. This modified hexagonal prism was tested to determine the effects on the aerodynamic characteristics of a shape change caused by ablation during a possible side-on stable reentry.

  10. Single-Frequency Nd:YAG Ring Lasers with Corner Cube Prism

    NASA Astrophysics Data System (ADS)

    Wu, Ke-Ying; Yang, Su-Hui; Zhao, Chang-Ming; Wei, Guang-Hui

    2000-10-01

    We put forward another form of the non-planar ring lasers, in which the corner cube prism is the key element and the Nd:YAG crystal is used as a Porro prism to enclose the ring resonator. The phase shift due to the total internal reflections of the three differently orientated reflection planes of the corner cube prism, Faraday rotation in the Nd:YAG crystal placed in a magnetic field and the different output coupling in S and P polarization form an optical diode and enforce the single-frequency generating power. A round trip analysis of the polarization properties of the resonator is made by the evaluation of Jones matrix.

  11. PRISM software—Processing and review interface for strong-motion data

    USGS Publications Warehouse

    Jones, Jeanne M.; Kalkan, Erol; Stephens, Christopher D.; Ng, Peter

    2017-11-28

    Rapidly available and accurate ground-motion acceleration time series (seismic recordings) and derived data products are essential to quickly providing scientific and engineering analysis and advice after an earthquake. To meet this need, the U.S. Geological Survey National Strong Motion Project has developed a software package called PRISM (Processing and Review Interface for Strong-Motion data). PRISM automatically processes strong-motion acceleration records, producing compatible acceleration, velocity, and displacement time series; acceleration, velocity, and displacement response spectra; Fourier amplitude spectra; and standard earthquake-intensity measures. PRISM is intended to be used by strong-motion seismic networks, as well as by earthquake engineers and seismologists.

  12. Driving With Hemianopia VI: Peripheral Prisms and Perceptual-Motor Training Improve Detection in a Driving Simulator

    PubMed Central

    Houston, Kevin E.; Peli, Eli; Goldstein, Robert B.; Bowers, Alex R.

    2018-01-01

    Purpose Drivers with homonymous hemianopia (HH) were previously found to have impaired detection of blind-side hazards, yet in many jurisdictions they may obtain a license. We evaluated whether oblique 57Δ peripheral prisms (p-prisms) and perceptual-motor training improved blind-side detection rates. Methods Patients with HH (n = 11) wore p-prisms for 2 weeks and then received perceptual-motor training (six visits) detecting and touching stimuli in the prism-expanded vision. In a driving simulator, patients drove and pressed the horn upon detection of pedestrians who ran toward the roadway (26 from each side): (1) without p-prisms at baseline; (2) with p-prisms after 2 weeks acclimation but before training; (3) with p-prisms after training; and (4) 3 months later. Results P-prisms improved blind-side detection from 42% to 56%, which further improved after training to 72% (all P < 0.001). Blind-side timely responses (adequate time to have stopped) improved from 31% without to 44% with p-prisms (P < 0.001) and further improved with training to 55% (P = 0.02). At the 3-month follow-up, improvements from training were maintained for detection (65%; P = 0.02) but not timely responses (P = 0.725). There was wide between-subject variability in baseline detection performance and response to p-prisms. There were no negative effects of p-prisms on vehicle control or seeing-side performance. Conclusions P-prisms improved detection with no negative effects, and training may provide additional benefit. Translational Relevance In jurisdictions where people with HH are legally driving, these data aid in clinical decision making by providing evidence that p-prisms improve performance without negative effects. PMID:29359111

  13. Challenges and opportunities for primary, secondary, and tertiary prevention of Chagas' disease.

    PubMed

    Rassi, A; Dias, J C P; Marin-Neto, J A; Rassi, A

    2009-04-01

    A century after its discovery, Chagas' disease still represents a major public health challenge in Latin America. Moreover, because of growing population movements, an increasing number of cases of imported Chagas' disease have now been detected in non-endemic areas, such as North America and some European countries. This parasitic zoonosis, caused by Trypanosoma cruzi, is transmitted to humans by infected Triatominae insects, or occasionally by non-vectorial mechanisms, such as blood transfusion, mother to fetus, or oral ingestion of materials contaminated with parasites. Following the acute phase of the infection, untreated individuals enter a chronic phase that is initially asymptomatic or clinically unapparent. Usually, a few decades later, 40-50% of patients develop progressive cardiomyopathy and/or motility disturbances of the oesophagus and colon. In the last decades several interventions targeting primary, secondary and tertiary prevention of Chagas' disease have been attempted. While control of both vectorial and blood transfusion transmission of T cruzi (primary prevention) has been successful in many regions of Latin America, early detection and aetiological treatment of asymptomatic subjects with Chagas' disease (secondary prevention) have been largely underutilised. At the same time, in patients with established chronic disease, several pharmacological and non-pharmacological interventions are currently available and have been increasingly used with the intention of preventing or delaying complications of the disease (tertiary prevention). In this review we discuss in detail each of these issues.

  14. Studying the neural bases of prism adaptation using fMRI: A technical and design challenge.

    PubMed

    Bultitude, Janet H; Farnè, Alessandro; Salemme, Romeo; Ibarrola, Danielle; Urquizar, Christian; O'Shea, Jacinta; Luauté, Jacques

    2017-12-01

    Prism adaptation induces rapid recalibration of visuomotor coordination. The neural mechanisms of prism adaptation have come under scrutiny since the observations that the technique can alleviate hemispatial neglect following stroke, and can alter spatial cognition in healthy controls. Relative to non-imaging behavioral studies, fMRI investigations of prism adaptation face several challenges arising from the confined physical environment of the scanner and the supine position of the participants. Any researcher who wishes to administer prism adaptation in an fMRI environment must adjust their procedures enough to enable the experiment to be performed, but not so much that the behavioral task departs too much from true prism adaptation. Furthermore, the specific temporal dynamics of behavioral components of prism adaptation present additional challenges for measuring their neural correlates. We developed a system for measuring the key features of prism adaptation behavior within an fMRI environment. To validate our configuration, we present behavioral (pointing) and head movement data from 11 right-hemisphere lesioned patients and 17 older controls who underwent sham and real prism adaptation in an MRI scanner. Most participants could adapt to prismatic displacement with minimal head movements, and the procedure was well tolerated. We propose recommendations for fMRI studies of prism adaptation based on the design-specific constraints and our results.

  15. Association of caspase-1 polymorphisms with Chagas cardiomyopathy among individuals in Santa Cruz, Bolivia.

    PubMed

    Fu, Katherine Yih-Jia; Zamudio, Roxana; Henderson-Frost, Jo; Almuedo, Alex; Steinberg, Hannah; Clipman, Steven Joseph; Duran, Gustavo; Marcus, Rachel; Crawford, Thomas; Alyesh, Daniel; Colanzi, Rony; Flores, Jorge; Gilman, Robert Hugh; Bern, Caryn

    2017-01-01

    Trypanosoma cruzi (Tc) infection is usually acquired in childhood in endemic areas, leading to Chagas disease, which progresses to Chagas cardiomyopathy in 20-30% of infected individuals over decades. The pathogenesis of Chagas cardiomyopathy involves the host inflammatory response to T. cruzi, in which upstream caspase-1 activation prompts the cascade of inflammatory chemokines/cytokines, cardiac remodeling, and myocardial dysfunction. The aim of the present study was to examine the association of two caspase-1 single nucleotide polymorphisms (SNPs) with cardiomyopathy. We recruited infected (Tc+, n = 149) and uninfected (Tc-, n = 87) participants in a hospital in Santa Cruz, Bolivia. Cardiac status was classified (I, II, III, IV) based on Chagas cardiomyopathy-associated electrocardiogram findings and ejection fractions on echocardiogram. Genotypes were determined using Taqman probes via reverse transcription-polymerase chain reaction of peripheral blood DNA. Genotype frequencies were analyzed according to three inheritance patterns (dominant, recessive, additive) using logistic regression adjusted for age and sex. The AA allele for the caspase-1 SNP rs501192 was more frequent in Tc+ cardiomyopathy (classes II, III, IV) patients compared to those with a normal cardiac status (class I) [odds ratio (OR) = -2.18, p = 0.117]. This trend approached statistical significant considering only Tc+ patients in class I and II (OR = -2.64, p = 0.064). Caspase-1 polymorphisms may play a role in Chagas cardiomyopathy development and could serve as markers to identify individuals at higher risk for priority treatment.

  16. Pacemaker Implants in Children and Adolescents with Chagas Disease in Brazil: 18-Year Incidence

    PubMed Central

    Mizzaci, Carolina Christianini; Souza, Thiago Gonçalves Schroder e; Targueta, Gabriel Pelegrineti; Tótora, Ana Paula Frederico; Mateos, Juan Carlos Pachón; Mateos, José Carlos Pachon

    2017-01-01

    Background: Chagas disease continues to be a serious public health problem, and accounts for 25-30% of the indications for cardiac stimulation in Brazil. Objective: To assess clinical and epidemiological characteristics of patients with Chagas disease, younger than 18 years, who had undergone pacemaker implantation in Brazil between 1994 and 2011, and its temporal trend. Methods: This was a cross-sectional analysis of data from the Brazilian Pacemaker Registry database. The following variables were analyzed: year when pacemaker was implanted, location, age, sex, ethnic group, functional class and the main electrocardiographic findings at baseline. Results: In a total of 183,123 implants performed between 1994 and 2011, 214 implants of cardiac stimulation device in Chagas disease patients aged younger than 18 years were identified. Mean age at implantation was 5.6 ± 6.2 years. Second- and third-degree atrioventricular blocks corresponded to 71% of indications for pacemaker implantation. Fifty-six percent of the procedures were performed in the southeast region. Regarding the total number of pacemaker implants per year, there was a remarkable increase in the implants for all causes. However, time series analysis of the implants in Chagas disease patients younger than 18 years revealed a significant reduction in the annual number of implants. Conclusion: There has been an important reduction in the number of pacemaker implantations among children and adolescents with Chagas disease, suggesting a reduction in the vertical transmission of the parasite. PMID:28699977

  17. Prism adaptation does not alter object-based attention in healthy participants.

    PubMed

    Bultitude, Janet H; List, Alexandra; Aimola Davies, Anne M

    2013-01-01

    Hemispatial neglect ('neglect') is a disabling condition that can follow damage to the right side of the brain, in which patients show difficulty in responding to or orienting towards objects and events that occur on the left side of space. Symptoms of neglect can manifest in both space- and object-based frames of reference. Although patients can show a combination of these two forms of neglect, they are considered separable and have distinct neurological bases. In recent years considerable evidence has emerged to demonstrate that spatial symptoms of neglect can be reduced by an intervention called prism adaptation. Patients point towards objects viewed through prismatic lenses that shift the visual image to the right. Approximately five minutes of repeated pointing results in a leftward recalibration of pointing and improved performance on standard clinical tests for neglect. The understanding of prism adaptation has also been advanced through studies of healthy participants, in whom adaptation to leftward prismatic shifts results in temporary neglect-like performance. Here we examined the effect of prism adaptation on the performance of healthy participants who completed a computerised test of space- and object-based attention. Participants underwent adaptation to leftward- or rightward-shifting prisms, or performed neutral pointing according to a between-groups design. Significant pointing after-effects were found for both prism groups, indicating successful adaptation. In addition, the results of the computerised test revealed larger reaction-time costs associated with shifts of attention between two objects compared to shifts of attention within the same object, replicating previous work. However there were no differences in the performance of the three groups, indicating that prism adaptation did not influence space- or object-based attention for this task. When combined with existing literature, the results are consistent with the proposal that prism

  18. Prism adaptation does not alter object-based attention in healthy participants

    PubMed Central

    Bultitude, Janet H.

    2013-01-01

    Hemispatial neglect (‘neglect’) is a disabling condition that can follow damage to the right side of the brain, in which patients show difficulty in responding to or orienting towards objects and events that occur on the left side of space. Symptoms of neglect can manifest in both space- and object-based frames of reference. Although patients can show a combination of these two forms of neglect, they are considered separable and have distinct neurological bases. In recent years considerable evidence has emerged to demonstrate that spatial symptoms of neglect can be reduced by an intervention called prism adaptation. Patients point towards objects viewed through prismatic lenses that shift the visual image to the right. Approximately five minutes of repeated pointing results in a leftward recalibration of pointing and improved performance on standard clinical tests for neglect. The understanding of prism adaptation has also been advanced through studies of healthy participants, in whom adaptation to leftward prismatic shifts results in temporary neglect-like performance. Here we examined the effect of prism adaptation on the performance of healthy participants who completed a computerised test of space- and object-based attention. Participants underwent adaptation to leftward- or rightward-shifting prisms, or performed neutral pointing according to a between-groups design. Significant pointing after-effects were found for both prism groups, indicating successful adaptation. In addition, the results of the computerised test revealed larger reaction-time costs associated with shifts of attention between two objects compared to shifts of attention within the same object, replicating previous work. However there were no differences in the performance of the three groups, indicating that prism adaptation did not influence space- or object-based attention for this task. When combined with existing literature, the results are consistent with the proposal that prism

  19. Accurate geometrical optics model for single-lens stereovision system using a prism.

    PubMed

    Cui, Xiaoyu; Lim, Kah Bin; Guo, Qiyong; Wang, DaoLei

    2012-09-01

    In this paper, we proposed a new method for analyzing the image formation of a prism. The prism was considered as a single optical system composed of some planes. By analyzing each plane individually and then combining them together, we derived a transformation matrix which can express the relationship between an object point and its image by the refraction of a prism. We also explained how to use this matrix for epipolar geometry and three-dimensional point reconstruction. Our method is based on optical geometry and could be used in a multiocular prism. Experimentation results are presented to prove the accuracy of our method is better than former researchers' and is comparable with that of the multicamera stereovision system.

  20. Does prism width from the shell prismatic layer have a random distribution?

    NASA Astrophysics Data System (ADS)

    Vancolen, Séverine; Verrecchia, Eric

    2008-10-01

    A study of the distribution of the prism width inside the prismatic layer of Unio tumidus (Philipsson 1788, Diss Hist-Nat, Berling, Lundæ) from Lake Neuchâtel, Switzerland, has been conducted in order to determine whether or not this distribution is random. Measurements of 954 to 1,343 prism widths (depending on shell sample) have been made using a scanning electron microscope in backscattered electron mode. A white noise test has been applied to the distribution of prism sizes (i.e. width). It shows that there is no temporal cycle that could potentially influence their formation and growth. These results suggest that prism widths are randomly distributed, and related neither to external rings nor to environmental constraints.

  1. Electrocardiographic and echocardiographic abnormalities in Chagas disease: findings in residents of rural Bolivian communities hyperendemic for Chagas disease.

    PubMed

    Fernandez, Antonio B; Nunes, Maria Carmo P; Clark, Eva H; Samuels, Aaron; Menacho, Silvio; Gomez, Jesus; Bozo Gutierrez, Ricardo W; Crawford, Thomas C; Gilman, Robert H; Bern, Caryn

    2015-09-01

    Chagas disease is a neglected and preventable tropical disease that causes significant cardiac morbidity and mortality in Latin America. This study sought to describe cardiac findings among inhabitants of rural communities of the Bolivian Chaco. The cardiac study drew participants from an epidemiologic study in 7 indigenous Guarani communities. All infected participants 10 years or older were asked to undergo a brief physical examination and 12-lead electrocardiogram (ECG). A subset had echocardiograms. ECG and echocardiograms were read by 1 or more cardiologists. Of 1,137 residents 10 years or older, 753 (66.2%) had Trypanosoma cruzi infection. Cardiac evaluations were performed for 398 infected participants 10 years or older. Fifty-five participants (13.8%) had 1 or more ECG abnormalities suggestive of Chagas cardiomyopathy. The most frequent abnormalities were bundle branch blocks in 42 (11.3%), followed by rhythm disturbances or ventricular ectopy in 13 (3.3%), and atrioventricular blocks (AVB) in 10 participants (2.6%). The prevalence of any abnormality rose from 1.1% among those 10 to 19 years old to 14.2%, 17.3%, and 26.4% among those 20 to 39, 40 to 59, and older than 60 years, respectively. First-degree AVB was seen most frequently in participants 60 years or older, but the 4 patients with third-degree AVB were all under 50 years old. Eighteen and 2 participants had a left ventricular ejection fraction of 40% to 54% and <40%, respectively. An increasing number of ECG abnormalities was associated with progressively larger left ventricular end-diastolic dimensions and lower left ventricular ejection fraction. We found a high prevalence of ECG abnormalities and substantial evidence of Chagas cardiomyopathy. Programs to improve access to basic cardiac care (annual ECG, antiarrhythmics, pacemakers) could have an immediate impact on morbidity and mortality in these highly endemic communities. Copyright © 2015 World Heart Federation (Geneva). All rights reserved.

  2. Evolution of the clinical and epidemiological knowledge about Chagas disease 90 years after its discovery.

    PubMed

    Prata, A

    1999-01-01

    Three different periods may be considered in the evolution of knowledge about the clinical and epidemiological aspects of Chagas disease since its discovery: (a) early period concerning the studies carried out by Carlos Chagas in Lassance with the collaboration of other investigators of the Manguinhos School. At that time the disease was described and the parasite, transmitters and reservoirs were studied. The coexistence of endemic goiter in the same region generated some confusion about the clinical forms of the disease; (b) second period involving uncertainty and the description of isolated cases, which lasted until the 1940 decade. Many acute cases were described during this period and the disease was recognized in many Latin American countries. Particularly important were the studies of the Argentine Mission of Regional Pathology Studies, which culminated with the description of the Romaña sign in the 1930 decade, facilitating the diagnosis of the early phase of the disease. However, the chronic phase, which was the most important, continued to be difficult to recognize; (c) period of consolidation of knowledge and recognition of the importance of Chagas disease. Studies conducted by Laranja, Dias and Nóbrega in Bambuí updated the description of Chagas heart disease made by Carlos Chagas and Eurico Villela. From then on, the disease was more easily recognized, especially with the emphasis on the use of a serologic diagnosis; (d) period of enlargement of knowledges on the disease. The studies on denervation conducted in Ribeirão Preto by Fritz Köberle starting in the 1950 decade led to a better understanding of the relations between Chagas disease and megaesophagus and other visceral megas detected in endemic areas.

  3. A study on suppressing transmittance fluctuations for air-gapped Glan-type polarizing prisms

    NASA Astrophysics Data System (ADS)

    Zhang, Chuanfa; Li, Dailin; Zhu, Huafeng; Li, Chuanzhi; Jiao, Zhiyong; Wang, Ning; Xu, Zhaopeng; Wang, Xiumin; Song, Lianke

    2018-05-01

    Light intensity transmittance is a key parameter for the design of polarizing prisms, while sometimes its experimental curves based on spatial incident angle presents periodical fluctuations. Here, we propose a novel method for completely suppressing these fluctuations via setting a glued error angle in the air gap of Glan-Taylor prisms. The proposal consists of: an accurate formula of the intensity transmittance for Glan-Taylor prisms, a numerical simulation and a contrast experiment of Glan-Taylor prisms for analyzing the causes of the fluctuations, and a simple method for accurately measuring the glued error angle. The result indicates that when the setting glued error angle is larger than the critical angle for a certain polarizing prism, the fluctuations can be completely suppressed, and a smooth intensity transmittance curve can be obtained. Besides, the critical angle in the air gap for suppressing the fluctuations is decreased with the increase of beam spot size. This method has the advantage of having less demand for the prism position in optical systems.

  4. Heterologous Infection During Chagas' Disease

    NASA Astrophysics Data System (ADS)

    Sibona, G. J.; Condat, C. A.; Cossi Isasi, S.

    2007-05-01

    Human populations are often infected with more than one parasite strain. This is frequently the case with ChagasŠ disease, which is endemic to large regions of Latin America. In the present work we study the dynamics of the heterologous infection for this disease, using a model for the interaction between the trypanosoma cruzi parasite and the immune system. We find the dependence of the nature of the post-acute stage on the parameters characterizing the inoculated infectious strains.

  5. Chagas disease as a cause of heart failure and ventricular arrhythmias in patients long removed from endemic areas: an emerging problem in Europe.

    PubMed

    Vannucchi, Vieri; Tomberli, Benedetta; Zammarchi, Lorenzo; Fornaro, Alessandra; Castelli, Gabriele; Pieralli, Filippo; Berni, Andrea; Yacoub, Sophie; Bartoloni, Alessandro; Olivotto, Iacopo

    2015-12-01

    Chagas disease is a parasitic disease caused by the protozoan Trypanosoma cruzi. In endemic areas (South and Central America), Chagas disease represents a relevant public health issue, and is the most frequent cause of cardiomyopathy. In nonendemic areas, such as Europe, Chagas disease represents an emerging problem following the establishment of sizeable communities from Brazil and Bolivia. Chagas cardiomyopathy represents the most frequent and serious complication of chronic Chagas disease, affecting about 20-30% of patients, potentially leading to heart failure, arrhythmias, thromboembolism, stroke and sudden death. Because late complications of Chagas disease may develop several years or even decades after the acute infection, it may be extremely challenging to reach the correct diagnosis in patients long removed from the countries of origin. We report two examples of Chagas cardiomyopathy in South American women permanently residing in Italy for more than 20 years, presenting with cardiac manifestations ranging from left ventricular dysfunction and heart failure to isolated ventricular arrhythmias. The present review emphasizes that Chagas disease should be considered as a potential diagnosis in patients from endemic areas presenting with 'idiopathic' cardiac manifestations, even when long removed from their country of origin, with potential implications for treatment and control of Chagas disease transmission.

  6. Design of direct-vision cyclo-olefin-polymer double Amici prism for spectral imaging.

    PubMed

    Wang, Lei; Shao, Zhengzheng; Tang, Wusheng; Liu, Jiying; Nie, Qianwen; Jia, Hui; Dai, Suian; Zhu, Jubo; Li, Xiujian

    2017-10-20

    A direct-vision Amici prism is a desired dispersion element in the value of spectrometers and spectral imaging systems. In this paper, we focus on designing a direct-vision cyclo-olefin-polymer double Amici prism for spectral imaging systems. We illustrate a designed structure: E48R/N-SF4/E48R, from which we obtain 13 deg dispersion across the visible spectrum, which is equivalent to 700 line pairs/mm grating. We construct a simulative spectral imaging system with the designed direct-vision cyclo-olefin-polymer double Amici prism in optical design software and compare its imaging performance to a glass double Amici prism in the same system. The results of spot-size RMS demonstrate that the plastic prism can serve as well as their glass competitors and have better spectral resolution.

  7. Community resilience and Chagas disease in a rural region of Mexico

    PubMed Central

    Rangel, José Antonio Santana; Monreal, Luz Arenas; Ramsey, Janine M

    2016-01-01

    ABSTRACT OBJECTIVE To explore the pillars of community resilience in a region where Chagas disease is endemic, with the aim of promoting participatory processes to deal with this condition from the resilience of the population. METHODS Qualitative study using ethnographic record and six interviews of focus groups with young people, women and men. The research was carried out in a rural area of the state of Morelos, Mexico, between 2006 and 2007. We carried out educational sessions with the population in general, so that residents could identify the relationship between the vector Triatoma pallidipennis, the parasite (Trypanosoma cruzi), symptoms, and preventive actions for Chagas disease. The ethnographic record and groups were analyzed based on Taylor and Bogdan’s modification, and the focus was to understand the socio-cultural meanings that guide the speeches and activities of residents in relation to the pillars of community resilience. RESULTS The population felt proud of belonging to that location and three pillars of community resilience were clearly identified: collective self-esteem, cultural identity, and social honesty. Having these pillars as bases, we promoted the participation of the population concerning Chagas disease, and a Community Action Group was formed with young people, adult men and women, and social leaders. This Group initiated actions of epidemiological and entomological surveillance in the community to deal with this problem. CONCLUSIONS It is necessary to create more experiences that deepen the understanding of the pillars of community resilience, and how they contribute to enhance participation in health to deal with Chagas disease. PMID:27509012

  8. Clinical and Laboratory Evaluation of Peripheral Prism Glasses for Hemianopia

    PubMed Central

    Giorgi, Robert G.; Woods, Russell L.; Peli, Eli

    2008-01-01

    Purpose Homonymous hemianopia (the loss of vision on the same side in each eye) impairs the ability to navigate and walk safely. We evaluated peripheral prism glasses as a low vision optical device for hemianopia in an extended wearing trial. Methods Twenty-three patients with complete hemianopia (13 right) with neither visual neglect nor cognitive deficit enrolled in the 5-visit study. To expand the horizontal visual field, patients’ spectacles were fitted with both upper and lower Press-On™ Fresnel prism segments (each 40 prism diopters) across the upper and lower portions of the lens on the hemianopic (“blind”) side. Patients were asked to wear these spectacles as much as possible for the duration of the study, which averaged 9 (range: 5 to 13) weeks. Clinical success (continued wear, indicating perceived overall benefit), visual field expansion, perceived direction and perceived quality of life were measured. Results Clinical Success: 14 of 21 (67%) patients chose to continue to wear the peripheral prism glasses at the end of the study (2 patients did not complete the study for non-vision reasons). At long-term follow-up (8 to 51 months), 5 of 12 (42%) patients reported still wearing the device. Visual Field Expansion: Expansion of about 22 degrees in both the upper and lower quadrants was demonstrated for all patients (binocular perimetry, Goldmann V4e). Perceived Direction: Two patients demonstrated a transient adaptation to the change in visual direction produced by the peripheral prism glasses. Quality of Life: At study end, reduced difficulty noticing obstacles on the hemianopic side was reported. Conclusions The peripheral prism glasses provided reported benefits (usually in obstacle avoidance) to 2/3 of the patients completing the study, a very good success rate for a vision rehabilitation device. Possible reasons for long-term discontinuation and limited adaptation of perceived direction are discussed. PMID:19357552

  9. Prism adaptation for spatial neglect after stroke: translational practice gaps.

    PubMed

    Barrett, A M; Goedert, Kelly M; Basso, Julia C

    2012-10-01

    Spatial neglect increases hospital morbidity and costs in around 50% of the 795,000 people per year in the USA who survive stroke, and an urgent need exists to reduce the care burden of this condition. However, effective acute treatment for neglect has been elusive. In this article, we review 48 studies of a treatment of intense neuroscience interest: prism adaptation training. Due to its effects on spatial motor 'aiming', prism adaptation training may act to reduce neglect-related disability. However, research failed, first, to suggest methods to identify the 50-75% of patients who respond to treatment; second, to measure short-term and long-term outcomes in both mechanism-specific and functionally valid ways; third, to confirm treatment utility during the critical first 8 weeks poststroke; and last, to base treatment protocols on systematic dose-response data. Thus, considerable investment in prism adaptation research has not yet touched the fundamentals needed for clinical implementation. We suggest improved standards and better spatial motor models for further research, so as to clarify when, how and for whom prism adaptation should be applied.

  10. Multi-tip nano-prisms: Controlled growth and emission enhancement properties

    NASA Astrophysics Data System (ADS)

    Liu, Ming; Meng, Cong; Xue, Zheng-Hong; Xiong, Xiang; Shu, Da-Jun; Peng, Ru-Wen; Wu, Qiang; Hu, Zheng; Wang, Mu

    2013-10-01

    We report here the experimental observations that the tip topography of ZnO nano-prisms sensitively depends on the percentage of oxygen in the flux of the carrying gas in vapor growth. At a relatively high oxygen concentration, a number of thin filaments can be nucleated atop nano-prisms, forming a unique fish-spear-like multi-tip morphology. The length and density of the “spear tines” depend on the flux of the carrying gas. The field emission properties of the nanorod array with different tip morphology are investigated. The structures with longer and denser spear tines possess lower turn-on electric field and higher electric current density. The cathodoluminescence properties of the ZnO nano-prisms have also been studied. The luminescence related to defects in multi-tip nano-prisms possesses the strongest intensity, and the nanorod without any tine structure possesses the lowest defect luminescence intensity. The intrinsic luminescence of ZnO around 385 nm, however, has the opposite tendency. We suggest that our observation is inspiring in optimizing the emission properties of the nanowire devices.

  11. Adaptation to Laterally Displacing Prisms in Anisometropic Amblyopia.

    PubMed

    Sklar, Jaime C; Goltz, Herbert C; Gane, Luke; Wong, Agnes M F

    2015-06-01

    Using visual feedback to modify sensorimotor output in response to changes in the external environment is essential for daily function. Prism adaptation is a well-established experimental paradigm to quantify sensorimotor adaptation; that is, how the sensorimotor system adapts to an optically-altered visuospatial environment. Amblyopia is a neurodevelopmental disorder characterized by spatiotemporal deficits in vision that impacts manual and oculomotor function. This study explored the effects of anisometropic amblyopia on prism adaptation. Eight participants with anisometropic amblyopia and 11 visually-normal adults, all right-handed, were tested. Participants pointed to visual targets and were presented with feedback of hand position near the terminus of limb movement in three blocks: baseline, adaptation, and deadaptation. Adaptation was induced by viewing with binocular 11.4° (20 prism diopter [PD]) left-shifting prisms. All tasks were performed during binocular viewing. Participants with anisometropic amblyopia required significantly more trials (i.e., increased time constant) to adapt to prismatic optical displacement than visually-normal controls. During the rapid error correction phase of adaptation, people with anisometropic amblyopia also exhibited greater variance in motor output than visually-normal controls. Amblyopia impacts on the ability to adapt the sensorimotor system to an optically-displaced visual environment. The increased time constant and greater variance in motor output during the rapid error correction phase of adaptation may indicate deficits in processing of visual information as a result of degraded spatiotemporal vision in amblyopia.

  12. [Chagas's disease and deep ecology: the anti-vectorial fight in question].

    PubMed

    Siqueira-Batista, Rodrigo; Gomes, Andréia Patrícia; Rôças, Giselle; Cotta, Rosângela Minardi Mitre; Rubião, Eduardo Cárdenas Nogueira; Pissinatti, Alcides

    2011-02-01

    The inter-relations between man and the environment are among the main themes currently debated by the Brazilian public health. On such horizon, the questions concerning Chagas's disease are found to remain specially in the scope of the directed actions of control to the triatomine, the anti-vectorial fight , though already a century since its first description by Carlos Chagas, a major epidemiological problem in Latin America. Based on these considerations the present article will seek to discuss the main ecological aspects related to the American trypanosomiasis, emphasizing the control of the vectorial transmission in the context of the deep ecology.

  13. Design of airborne imaging spectrometer based on curved prism

    NASA Astrophysics Data System (ADS)

    Nie, Yunfeng; Xiangli, Bin; Zhou, Jinsong; Wei, Xiaoxiao

    2011-11-01

    A novel moderate-resolution imaging spectrometer spreading from visible wavelength to near infrared wavelength range with a spectral resolution of 10 nm, which combines curved prisms with the Offner configuration, is introduced. Compared to conventional imaging spectrometers based on dispersive prism or diffractive grating, this design possesses characteristics of small size, compact structure, low mass as well as little spectral line curve (smile) and spectral band curve (keystone or frown). Besides, the usage of compound curved prisms with two or more different materials can greatly reduce the nonlinearity inevitably brought by prismatic dispersion. The utilization ratio of light radiation is much higher than imaging spectrometer of the same type based on combination of diffractive grating and concentric optics. In this paper, the Seidel aberration theory of curved prism and the optical principles of Offner configuration are illuminated firstly. Then the optical design layout of the spectrometer is presented, and the performance evaluation of this design, including spot diagram and MTF, is analyzed. To step further, several types of telescope matching this system are provided. This work provides an innovational perspective upon optical system design of airborne spectral imagers; therefore, it can offer theoretic guide for imaging spectrometer of the same kind.

  14. Integrated control of Chagas disease for its elimination as public health problem - A Review

    PubMed Central

    Sosa-Estani, Sergio; Segura, Elsa Leonor

    2015-01-01

    Chagas disease or American trypanosomiasis is, together with geohelminths, the neglected disease that causes more loss of years of healthy life due to disability in Latin America. Chagas disease, as determined by the factors and determinants, shows that different contexts require different actions, preventing new cases or reducing the burden of disease. Control strategies must combine two general courses of action including prevention of transmission to prevent the occurrence of new cases (these measures are cost effective), as well as opportune diagnosis and treatment of infected individuals in order to prevent the clinical evolution of the disease and to allow them to recuperate their health. All actions should be implemented as fully as possible and with an integrated way, to maximise the impact. Chagas disease cannot be eradicated due because of the demonstrated existence of infected wild triatomines in permanent contact with domestic cycles and it contributes to the occurrence of at least few new cases. However, it is possible to interrupt the transmission of Trypanosoma cruzi in a large territory and to eliminate Chagas disease as a public health problem with a dramatic reduction of burden of the disease. PMID:25993503

  15. Integrated control of Chagas disease for its elimination as public health problem--a review.

    PubMed

    Sosa-Estani, Sergio; Segura, Elsa Leonor

    2015-05-01

    Chagas disease or American trypanosomiasis is, together with geohelminths, the neglected disease that causes more loss of years of healthy life due to disability in Latin America. Chagas disease, as determined by the factors and determinants, shows that different contexts require different actions, preventing new cases or reducing the burden of disease. Control strategies must combine two general courses of action including prevention of transmission to prevent the occurrence of new cases (these measures are cost effective), as well as opportune diagnosis and treatment of infected individuals in order to prevent the clinical evolution of the disease and to allow them to recuperate their health. All actions should be implemented as fully as possible and with an integrated way, to maximise the impact. Chagas disease cannot be eradicated due because of the demonstrated existence of infected wild triatomines in permanent contact with domestic cycles and it contributes to the occurrence of at least few new cases. However, it is possible to interrupt the transmission of Trypanosoma cruzi in a large territory and to eliminate Chagas disease as a public health problem with a dramatic reduction of burden of the disease.

  16. Porous Ni-Co-Mn oxides prisms for high performance electrochemical energy storage

    NASA Astrophysics Data System (ADS)

    Zhao, Jianbo; Li, Man; Li, Junru; Wei, Chengzhen; He, Yuyue; Huang, Yixuan; Li, Qiaoling

    2017-12-01

    Porous Ni-Co-Mn oxides prisms have been successfully synthesized via a facile route. The process involves the preparation of nickel-cobalt-manganese acetate hydroxide by a simple co-precipitation method and subsequently the thermal treatment. The as-synthesized Ni-Co-Mn oxides prisms had a large surface area (96.53 m2 g-1) and porous structure. As electrode materials for supercapacitors, porous Ni-Co-Mn oxides prisms showed a high specific capacitance of 1623.5 F g-1 at 1.0 A g-1. Moreover, the porous Ni-Co-Mn oxides prisms were also employed as positive electrode materials to assemble flexible solid-state asymmetric supercapacitors. The resulting flexible device had a maximum volumetric energy density (0.885 mW h cm-3) and power density (48.9 mW cm-3). Encouragingly, the flexible device exhibited good cycling stability with only about 2.2% loss after 5000 charge-discharge cycles and excellent mechanical stability. These results indicate that porous Ni-Co-Mn oxides prisms have the promising application in high performance electrochemical energy storage.

  17. Role of T. cruzi exposure in the pattern of T cell cytokines among chronically infected HIV and Chagas disease patients.

    PubMed

    Tozetto-Mendoza, Tania Regina; Vasconcelos, Dewton de Moraes; Ibrahim, Karim Yaqub; Sartori, Ana Marli Christovam; Bezerra, Rita C; Freitas, Vera Lúcia Teixeira de; Shikanai-Yasuda, Maria Aparecida

    2017-11-01

    The impact of Chagas disease (CD) in HIV-infected patients is relevant throughout the world. In fact, the characterization of the adaptive immune response in the context of co-infection is important for predicting the need for interventions in areas in which HIV and Chagas disease co-exist. We described and compared the frequency of cytokine-producing T cells stimulated with soluble antigen of Trypanosoma cruzi (T. cruzi) using a cytometric assay for the following groups: individuals with chronic Chagas disease (CHR, n=10), those with Chagas disease and HIV infection (CO, n=11), those with only HIV (HIV, n=14) and healthy individuals (C, n=15). We found 1) a constitutively lower frequency of IL-2+ and IFN-γ+ T cells in the CHR group compared with the HIV, CO and healthy groups; 2) a suppressive activity of soluble T. cruzi antigen, which down-regulated IL-2+CD4+ and IFN-γ+CD4+ phenotypes, notably in the healthy group; 3) a down-regulation of inflammatory cytokines on CD8+ T cells in the indeterminate form of Chagas disease; and 4) a significant increase in IL-10+CD8+ cells distinguishing the indeterminate form from the cardiac/digestive form of Chagas disease, even in the presence of HIV infection. Taken together, our data suggest the presence of an immunoregulatory response in chronic Chagas disease, which seems to be driven by T. cruzi antigens. Our findings provide new insights into immunotherapeutic strategies for people living with HIV/AIDS and Chagas disease.

  18. Analysis of transverse field distributions in Porro prism resonators

    NASA Astrophysics Data System (ADS)

    Litvin, Igor A.; Burger, Liesl; Forbes, Andrew

    2007-05-01

    A model to describe the transverse field distribution of the output beam from porro prism resonators is proposed. The model allows the prediction of the output transverse field distribution by assuming that the main areas of loss are located at the apexes of the porro prisms. Experimental work on a particular system showed some interested correlations between the time domain behavior of the resonator and the transverse field output. These findings are presented and discussed.

  19. Chagas disease in Switzerland: history and challenges.

    PubMed

    Jackson, Y; Chappuis, F

    2011-09-15

    Chagas disease, endemic in Latin America, is an emerging health problem in Europe affecting an estimated 80,000 persons. Around 60,000 Latin American migrants live in Switzerland, and cases of Chagas disease have been reported since 1979. As of June 2011, 258 cases have been diagnosed, mostly adults in the indeterminate phase of the chronic stage of the disease. Vertical transmission has been identified and there is a high potential for blood- and organ-borne transmission in the absence of systematic screening. Major challenges include (i) raising awareness among migrants and healthcare professionals, (ii) developing national protocols for screening and treatment targeting high-risk groups such as pregnant woman, newborns, migrants from highly endemic areas (e.g. Bolivia), and immunocompromised migrants, (iii) preventing blood- and organ-borne transmission by appropriate screening strategies, (iv) taking into account the social vulnerability of individuals at risk in the design and implementation of public health programmes, and (v) facilitating contacts with the communities at risk through outreach programmes, for example in churches and cultural groups.

  20. Towards Chagas disease elimination: Neonatal screening for congenital transmission in rural communities.

    PubMed

    Pennington, Pamela Marie; Juárez, José Guillermo; Arrivillaga, Margarita Rivera; De Urioste-Stone, Sandra María; Doktor, Katherine; Bryan, Joe P; Escobar, Clara Yaseli; Cordón-Rosales, Celia

    2017-09-01

    Chagas disease is a neglected tropical disease that continues to affect populations living in extreme poverty in Latin America. After successful vector control programs, congenital transmission remains as a challenge to disease elimination. We used the PRECEDE-PROCEED planning model to develop strategies for neonatal screening of congenital Chagas disease in rural communities of Guatemala. These communities have persistent high triatomine infestations and low access to healthcare. We used mixed methods with multiple stakeholders to identify and address maternal-infant health behaviors through semi-structured interviews, participatory group meetings, archival reviews and a cross-sectional survey in high risk communities. From December 2015 to April 2016, we jointly developed a strategy to illustratively advertise newborn screening at the Health Center. The strategy included socioculturally appropriate promotional and educational material, in collaboration with midwives, nurses and nongovernmental organizations. By March 2016, eight of 228 (3.9%) pregnant women had been diagnosed with T. cruzi at the Health Center. Up to this date, no neonatal screening had been performed. By August 2016, seven of eight newborns born to Chagas seropositive women had been parasitologically screened at the Health Center, according to international standards. Thus, we implemented a successful community-based neonatal screening strategy to promote congenital Chagas disease healthcare in a rural setting. The success of the health promotion strategies developed will depend on local access to maternal-infant services, integration with detection of other congenital diseases and reliance on community participation in problem and solution definition.

  1. Towards Chagas disease elimination: Neonatal screening for congenital transmission in rural communities

    PubMed Central

    Juárez, José Guillermo; Arrivillaga, Margarita Rivera; De Urioste-Stone, Sandra María; Doktor, Katherine; Bryan, Joe P.; Escobar, Clara Yaseli; Cordón-Rosales, Celia

    2017-01-01

    Chagas disease is a neglected tropical disease that continues to affect populations living in extreme poverty in Latin America. After successful vector control programs, congenital transmission remains as a challenge to disease elimination. We used the PRECEDE-PROCEED planning model to develop strategies for neonatal screening of congenital Chagas disease in rural communities of Guatemala. These communities have persistent high triatomine infestations and low access to healthcare. We used mixed methods with multiple stakeholders to identify and address maternal-infant health behaviors through semi-structured interviews, participatory group meetings, archival reviews and a cross-sectional survey in high risk communities. From December 2015 to April 2016, we jointly developed a strategy to illustratively advertise newborn screening at the Health Center. The strategy included socioculturally appropriate promotional and educational material, in collaboration with midwives, nurses and nongovernmental organizations. By March 2016, eight of 228 (3.9%) pregnant women had been diagnosed with T. cruzi at the Health Center. Up to this date, no neonatal screening had been performed. By August 2016, seven of eight newborns born to Chagas seropositive women had been parasitologically screened at the Health Center, according to international standards. Thus, we implemented a successful community-based neonatal screening strategy to promote congenital Chagas disease healthcare in a rural setting. The success of the health promotion strategies developed will depend on local access to maternal-infant services, integration with detection of other congenital diseases and reliance on community participation in problem and solution definition. PMID:28892479

  2. 3D Printed Prisms with Tunable Dispersion for the THz Frequency Range

    NASA Astrophysics Data System (ADS)

    Busch, Stefan F.; Castro-Camus, Enrique; Beltran-Mejia, Felipe; Balzer, Jan C.; Koch, Martin

    2018-04-01

    Here, we present a 3D printed prism for THz waves made out of an artificial dielectric material in which the dispersion can be tuned by external compression. The artificial material consists of thin dielectric layers with variable air spacings which has been produced using a fused deposition molding process. The material properties are carefully characterized and the functionality of the prisms is in a good agreement with the underlying theory. These prisms are durable, lightweight, inexpensive, and easy to produce.

  3. 3D Printed Prisms with Tunable Dispersion for the THz Frequency Range

    NASA Astrophysics Data System (ADS)

    Busch, Stefan F.; Castro-Camus, Enrique; Beltran-Mejia, Felipe; Balzer, Jan C.; Koch, Martin

    2018-06-01

    Here, we present a 3D printed prism for THz waves made out of an artificial dielectric material in which the dispersion can be tuned by external compression. The artificial material consists of thin dielectric layers with variable air spacings which has been produced using a fused deposition molding process. The material properties are carefully characterized and the functionality of the prisms is in a good agreement with the underlying theory. These prisms are durable, lightweight, inexpensive, and easy to produce.

  4. Mortality among blood donors seropositive and seronegative for Chagas disease (1996-2000) in São Paulo, Brazil: A death certificate linkage study.

    PubMed

    Capuani, Ligia; Bierrenbach, Ana Luiza; Pereira Alencar, Airlane; Mendrone, Alfredo; Ferreira, João Eduardo; Custer, Brian; P Ribeiro, Antonio Luiz; Cerdeira Sabino, Ester

    2017-05-01

    Individuals in the indeterminate phase of Chagas disease are considered to have mortality rates similar to those of the overall population. This study compares mortality rates among blood donors seropositive for Chagas disease and negative controls in the city of São Paulo, Brazil. This is a retrospective cohort study of blood donors from 1996 to 2000: 2842 seropositive and 5684 seronegative for Chagas disease. Death status was ascertained by performing probabilistic record linkage (RL) with the Brazil national mortality information system (SIM). RL was assessed in a previous validation study. Cox Regression was used to derive hazard ratios (HR), adjusting for confounders. RL identified 159 deaths among the 2842 seropositive blood donors (5.6%) and 103 deaths among the 5684 seronegative (1.8%). Out of the 159 deaths among seropositive donors, 26 had the 10th International Statistical Classification of Diseases and Related Health Problems (ICD-10) indicating Chagas disease as the underlying cause of death (B57.0/B57.5), 23 had ICD-10 codes (I42.0/I42.2/I47.0/I47.2/I49.0/I50.0/I50.1/ I50.9/I51.7) indicating cardiac abnormalities possibly related to Chagas disease listed as an underlying or associated cause of death, with the others having no mention of Chagas disease in part I of the death certificate. Donors seropositive for Chagas disease had a 2.3 times higher risk of death due to all causes (95% Confidence Interval (95% CI), 1.8-3.0) than seronegative donors. When considering deaths due to Chagas disease or those that had underlying causes of cardiac abnormalities related to Chagas disease, seropositive donors had a risk of death 17.9 (95% CI, 6.3-50.8) times greater than seronegative donors. There is an excess risk of death in donors seropositive blood for Chagas disease compared to seronegative donors. Chagas disease is an under-reported cause of death in the Brazilian mortality database.

  5. Multi-energy CT based on a prior rank, intensity and sparsity model (PRISM).

    PubMed

    Gao, Hao; Yu, Hengyong; Osher, Stanley; Wang, Ge

    2011-11-01

    We propose a compressive sensing approach for multi-energy computed tomography (CT), namely the prior rank, intensity and sparsity model (PRISM). To further compress the multi-energy image for allowing the reconstruction with fewer CT data and less radiation dose, the PRISM models a multi-energy image as the superposition of a low-rank matrix and a sparse matrix (with row dimension in space and column dimension in energy), where the low-rank matrix corresponds to the stationary background over energy that has a low matrix rank, and the sparse matrix represents the rest of distinct spectral features that are often sparse. Distinct from previous methods, the PRISM utilizes the generalized rank, e.g., the matrix rank of tight-frame transform of a multi-energy image, which offers a way to characterize the multi-level and multi-filtered image coherence across the energy spectrum. Besides, the energy-dependent intensity information can be incorporated into the PRISM in terms of the spectral curves for base materials, with which the restoration of the multi-energy image becomes the reconstruction of the energy-independent material composition matrix. In other words, the PRISM utilizes prior knowledge on the generalized rank and sparsity of a multi-energy image, and intensity/spectral characteristics of base materials. Furthermore, we develop an accurate and fast split Bregman method for the PRISM and demonstrate the superior performance of the PRISM relative to several competing methods in simulations.

  6. Early polymerase chain reaction detection of Chagas disease reactivation in heart transplant patients.

    PubMed

    da Costa, Priscilla Almeida; Segatto, Marcela; Durso, Danielle Fernandes; de Carvalho Moreira, Wagson José; Junqueira, Lucas Lodi; de Castilho, Fábio Morato; de Andrade, Silvio Amadeu; Gelape, Cláudio Léo; Chiari, Egler; Teixeira-Carvalho, Andréa; Junho Pena, Sergio Danilo; Machado, Carlos Renato; Franco, Gloria Regina; Filho, Geraldo Brasileiro; Vieira Moreira, Maria da Consolação; Mara Macedo, Andréa

    2017-07-01

    Heart transplantation is a valuable therapeutic option for Chagas disease patients with severe cardiomyopathy. During patient follow-up, the differential diagnosis between cardiac transplant rejection and Chagas disease infection reactivation remains a challenging task, which hinders rapid implementation of the appropriate treatment. Herein we investigate whether polymerase chain reaction (PCR) strategies could facilitate early detection of Trypanosoma cruzi (T cruzi) in transplanted endomyocardial biopsies (EMBs). In this study we analyzed 500 EMB specimens obtained from 58 chagasic cardiac transplant patients, using PCR approaches targeted to nuclear (rDNA 24Sα) and kinetoplastid (kDNA) markers, and compared the efficiency of these approaches with that of other tests routinely used. T cruzi DNA was detected in 112 EMB specimens derived from 39 patients (67.2%). The first positive result occurred at a median 1.0 month post-transplant. Conventional histopathologic, blood smear and hemoculture analyses showed lower sensitivity and higher median time to the first positive result. Patient follow-up revealed that 31 of 39 PCR-positive cases presented clinical reactivation of Chagas disease at different time-points after transplantation. PCR techniques showed considerable sensitivity (0.82) and specificity (0.60), with area under the receiver operating characteristic (ROC) curves of 0.708 (p = 0.001). Moreover, PCR techniques anticipated the clinical signs of Chagas disease reactivation by up to 36 months, with a median time of 6 months and an average of 9.1 months. We found a good association between the PCR diagnosis and the clinical signs of the disease, indicating that the PCR approaches used herein are suitable for early diagnosis of Chagas disease reactivation, with high potential to assist physicians in treatment decisions. For this purpose, an algorithm is proposed for surveillance based on the molecular tests. Copyright © 2017 International Society for the

  7. Postural stability changes during large vertical diplopia induced by prism wear in normal subjects.

    PubMed

    Matsuo, Toshihiko; Yamasaki, Hanako; Yasuhara, Hirotaka; Hasebe, Kayoko

    2013-01-01

    To test the effect of double vision on postural stability, we measured postural stability by electric stabilometry before prism-wearing and immediately, 15, 30, and 60min after continuous prism-wearing with 6 prism diopters in total (a 3-prism-diopter prism placed with the base up in front of one eye and with the base down in front of the other eye) in 20 normal adult individuals with their eyes open or closed. Changes in stabilometric parameters in the time course of 60min were analyzed statistically by repeated-measure analysis of variance. When subjectsセ eyes were closed, the total linear length (cm) and the unit-time length (cm/sec) of the sway path were significantly shortened during the 60-minute prism-wearing (p<0.05). No significant change was noted in any stabilometric parameters obtained with the eyes open during the time course. In conclusion, postural stability did not change with the eyes open in the condition of large vertical diplopia, induced by prism-wearing for 60min, while the stability became better when measured with the eyes closed. A postural control mechanism other than that derived from visual input might be reinforced under abnormal visual input such as non-fusionable diplopia.

  8. ePRISM: A case study in multiple proxy and mixed temporal resolution integration

    USGS Publications Warehouse

    Robinson, Marci M.; Dowsett, Harry J.

    2010-01-01

    As part of the Pliocene Research, Interpretation and Synoptic Mapping (PRISM) Project, we present the ePRISM experiment designed I) to provide climate modelers with a reconstruction of an early Pliocene warm period that was warmer than the PRISM interval (similar to 3.3 to 3.0 Ma), yet still similar in many ways to modern conditions and 2) to provide an example of how best to integrate multiple-proxy sea surface temperature (SST) data from time series with varying degrees of temporal resolution and age control as we begin to build the next generation of PRISM, the PRISM4 reconstruction, spanning a constricted time interval. While it is possible to tie individual SST estimates to a single light (warm) oxygen isotope event, we find that the warm peak average of SST estimates over a narrowed time interval is preferential for paleoclimate reconstruction as it allows for the inclusion of more records of multiple paleotemperature proxies.

  9. Chagas disease vector blood meal sources identified by protein mass spectrometry

    PubMed Central

    Keller, Judith I.; Ballif, Bryan A.; St. Clair, Riley M.; Vincent, James J.; Monroy, M. Carlota

    2017-01-01

    Chagas disease is a complex vector borne parasitic disease involving blood feeding Triatominae (Hemiptera: Reduviidae) insects, also known as kissing bugs, and the vertebrates they feed on. This disease has tremendous impacts on millions of people and is a global health problem. The etiological agent of Chagas disease, Trypanosoma cruzi (Kinetoplastea: Trypanosomatida: Trypanosomatidae), is deposited on the mammalian host in the insect’s feces during a blood meal, and enters the host’s blood stream through mucous membranes or a break in the skin. Identifying the blood meal sources of triatomine vectors is critical in understanding Chagas disease transmission dynamics, can lead to identification of other vertebrates important in the transmission cycle, and aids management decisions. The latter is particularly important as there is little in the way of effective therapeutics for Chagas disease. Several techniques, mostly DNA-based, are available for blood meal identification. However, further methods are needed, particularly when sample conditions lead to low-quality DNA or to assess the risk of human cross-contamination. We demonstrate a proteomics-based approach, using liquid chromatography tandem mass spectrometry (LC-MS/MS) to identify host-specific hemoglobin peptides for blood meal identification in mouse blood control samples and apply LC-MS/MS for the first time to Triatoma dimidiata insect vectors, tracing blood sources to species. In contrast to most proteins, hemoglobin, stabilized by iron, is incredibly stable even being preserved through geologic time. We compared blood stored with and without an anticoagulant and examined field-collected insect specimens stored in suboptimal conditions such as at room temperature for long periods of time. To our knowledge, this is the first study using LC-MS/MS on field-collected arthropod disease vectors to identify blood meal composition, and where blood meal identification was confirmed with more traditional DNA

  10. The Role of Gender in Chagas Disease Prevention and Control in Honduras: An Analysis of Communication and Collaboration Networks.

    PubMed

    Triana, Diana Rocío Rodríguez; Mertens, Frédéric; Zúniga, Concepción Valeriano; Mendoza, Yolanda; Nakano, Eduardo Yoshio; Monroy, Maria Carlota

    2016-09-01

    In Honduras, where Chagas disease is a serious health and environmental concern, prevention measures face the challenge of achieving widespread and long-term sustainable adoption by communities. The article integrates social network analysis and a gender-sensitive approach to understand the role of men and women in the implementation of a community-level intervention, based on the adoption of housing improvements to reduce the presence of the insect vector. A total of 108 people in the community of El Salitre were interviewed. Data were collected on socio-demographic characteristics, participation in project activities, communication and collaboration networks related to Chagas disease prevention, knowledge of Chagas disease, and adoption of housing improvements techniques. Communication mostly occurred between the same gender individuals and was associated with knowledge of Chagas disease. Socioeconomic status, Chagas disease knowledge, and collaboration with men were associated with women adopting housing improvements. For men, however, participation in project activities, formal education, and collaboration with women were associated with adoption. These findings suggest that men and women were driven by distinct concerns, interests, and motivations when adopting new Chagas disease prevention strategies. Participatory community interventions that seek to generate health knowledge and foster collaborations to reduce health risk should address gender differences.

  11. Is the Aligning Prism Measured with the Mallett Unit Correlated with Fusional Vergence Reserves?

    PubMed Central

    Conway, Miriam L.; Thomas, Jennifer; Subramanian, Ahalya

    2012-01-01

    Background The Mallett Unit is a clinical test designed to detect the fixation disparity that is most likely to occur in the presence of a decompensated heterophoria. It measures the associated phoria, which is the “aligning prism” needed to nullify the subjective disparity. The technique has gained widespread acceptance within professions such as optometry, for investigating suspected cases of decompensating heterophoria; it is, however, rarely used by orthoptists and ophthalmologists. The aim of this study was to investigate whether fusional vergence reserves, measured routinely by both orthoptists and ophthalmologists to detect heterophoria decompensation, were correlated with aligning prism (associated phoria) in a normal clinical population. Methodology/Principal Findings Aligning prism (using the Mallett Unit) and fusional vergence reserves (using a prism bar) were measured in 500 participants (mean 41.63 years; standard deviation 11.86 years) at 40 cm and 6 m. At 40 cm a strong correlation (p<0.001) between base in aligning prism (Exo FD) and positive fusional reserves was found. Of the participants with zero aligning prism 30% had reduced fusional reserves. At 6 m a weak correlation between base out aligning prism (Eso FD) and negative fusional reserves was found to break (p = 0.01) and to recovery (p = 0.048). Of the participants with zero aligning prism 12% reported reduced fusional reserves. Conclusions/Significance For near vision testing, the strong inverse correlation between base in aligning prism (Exo FD) and fusional vergence reserves supports the notion that both measures are indicators of decompensation of heterophoria. For distance vision testing and for those patients reporting zero aligning prism further research is required to determine why the relationship appears to be weak/non-existent? PMID:22905174

  12. Update on oral Chagas disease outbreaks in Venezuela: epidemiological, clinical and diagnostic approaches

    PubMed Central

    de Noya, Belkisyolé Alarcón; Díaz-Bello, Zoraida; Colmenares, Cecilia; Ruiz-Guevara, Raiza; Mauriello, Luciano; Muñoz-Calderón, Arturo; Noya, Oscar

    2015-01-01

    Orally transmitted Chagas disease has become a matter of concern due to outbreaks reported in four Latin American countries. Although several mechanisms for orally transmitted Chagas disease transmission have been proposed, food and beverages contaminated with whole infected triatomines or their faeces, which contain metacyclic trypomastigotes of Trypanosoma cruzi, seems to be the primary vehicle. In 2007, the first recognised outbreak of orally transmitted Chagas disease occurred in Venezuela and largest recorded outbreak at that time. Since then, 10 outbreaks (four in Caracas) with 249 cases (73.5% children) and 4% mortality have occurred. The absence of contact with the vector and of traditional cutaneous and Romana’s signs, together with a florid spectrum of clinical manifestations during the acute phase, confuse the diagnosis of orally transmitted Chagas disease with other infectious diseases. The simultaneous detection of IgG and IgM by ELISA and the search for parasites in all individuals at risk have been valuable diagnostic tools for detecting acute cases. Follow-up studies regarding the microepidemics primarily affecting children has resulted in 70% infection persistence six years after anti-parasitic treatment. Panstrongylus geniculatus has been the incriminating vector in most cases. As a food-borne disease, this entity requires epidemiological, clinical, diagnostic and therapeutic approaches that differ from those approaches used for traditional direct or cutaneous vector transmission. PMID:25946155

  13. Chagas' heart disease: gender differences in myocardial damage assessed by cardiovascular magnetic resonance.

    PubMed

    Assunção, Antonildes N; Jerosch-Herold, Michael; Melo, Rodrigo L; Mauricio, Alejandra V; Rocha, Liliane; Torreão, Jorge A; Fernandes, Fabio; Ianni, Barbara M; Mady, Charles; Ramires, José A F; Kalil-Filho, Roberto; Rochitte, Carlos E

    2016-11-28

    Since a male-related higher cardiovascular morbidity and mortality in patients with Chagas' heart disease has been reported, we aimed to investigate gender differences in myocardial damage assessed by cardiovascular magnetic resonance (CMR). Retrospectively, 62 seropositive Chagas' heart disease patients referred to CMR (1.5 T) and with low probability of having significant coronary artery disease were included in this analysis. Amongst both sexes, there was a strong negative correlation between LV ejection fraction and myocardial fibrosis (male r = 0.64, female r = 0.73, both P < 0.001), with males showing significantly greater myocardial fibrosis (P = 0.002) and lower LV ejection fraction (P < 0.001) than females. After adjustment for potential confounders, gender remained associated with myocardial dysfunction, and 53% of the effect was mediated by myocardial fibrosis (P for mediation = 0.004). Also, the transmural pattern was more prevalent among male patients (23.7 vs. 9.9%, P < 0.001) as well as the myocardial heterogeneity or gray zone (2.2 vs. 1.3 g, P = 0.003). We observed gender-related differences in myocardial damage assessed by CMR in patients with Chagas' heart disease. As myocardial fibrosis and myocardial dysfunction are associated to cardiovascular outcomes, our findings might help to understand the poorer prognosis observed in males in Chagas' disease.

  14. Prism adaptation for spatial neglect after stroke: translational practice gaps

    PubMed Central

    Barrett, A. M.; Goedert, Kelly M.; Basso, Julia C.

    2012-01-01

    Spatial neglect increases hospital morbidity and costs in around 50% of the 795,000 people per year in the USA who survive stroke, and an urgent need exists to reduce the care burden of this condition. However, effective acute treatment for neglect has been elusive. In this article, we review 48 studies of a treatment of intense neuroscience interest: prism adaptation training. Due to its effects on spatial motor ‘aiming’, prism adaptation training may act to reduce neglect-related disability. However, research failed, first, to suggest methods to identify the 50–75% of patients who respond to treatment; second, to measure short-term and long-term outcomes in both mechanism-specific and functionally valid ways; third, to confirm treatment utility during the critical first 8 weeks poststroke; and last, to base treatment protocols on systematic dose–response data. Thus, considerable investment in prism adaptation research has not yet touched the fundamentals needed for clinical implementation. We suggest improved standards and better spatial motor models for further research, so as to clarify when, how and for whom prism adaptation should be applied. PMID:22926312

  15. Investigating First Year Elementary Mathematics Teacher Education Students' Knowledge of Prism

    ERIC Educational Resources Information Center

    Bozkurt, Ali; Koc, Yusuf

    2012-01-01

    The purpose of this study was to investigate first year elementary mathematics teacher education students' knowledge of prism. For this goal, the participants were asked to define the geometric concept of prism. The participants were 158 first year elementary mathematics teacher education students from a public university in Southern Turkey. The…

  16. Circulating Plasma MicroRNA-208a as Potential Biomarker of Chronic Indeterminate Phase of Chagas Disease.

    PubMed

    Linhares-Lacerda, Leandra; Granato, Alessandra; Gomes-Neto, João Francisco; Conde, Luciana; Freire-de-Lima, Leonardo; de Freitas, Elisangela O; Freire-de-Lima, Celio G; Coutinho Barroso, Shana P; Jorge de Alcântara Guerra, Rodrigo; Pedrosa, Roberto C; Savino, Wilson; Morrot, Alexandre

    2018-01-01

    Chagas cardiomyopathy is the most severe clinical manifestation of chronic Chagas disease. The disease affects most of the Latin American countries, being considered one of the leading causes of morbidity and death in the continent. The pathogenesis of Chagas cardiomyopathy is very complex, with mechanisms involving parasite-dependent cytopathy, immune-mediated myocardial damage and neurogenic disturbances. These pathological changes eventually result in cardiac myocyte hypertrophy, arrhythmias, congestive heart failure and stroke during chronic infection phase. Herein, we show that miR-208a, a microRNA that is a key factor in promoting cardiovascular dysfunction during cardiac hypertrophy processes of heart failure, has its circulating levels increased during chronic indeterminate phase when compared to cardiac (CARD) clinical forms in patients with Chagas disease. In contrast, we have not found altered serum levels of miR-34a, a microRNA known to promote pro-apoptotic role in myocardial infarction during degenerative process of cardiac injuries thus indicating intrinsic differences in the nature of the mechanisms underlying the heart failure triggered by Trypanosoma cruzi infection. Our findings support that the chronic indeterminate phase is a progressive phase involved in the genesis of chagasic cardiopathy and point out the use of plasma levels of miR-208a as candidate biomarker in risk-prediction score for the clinical prognosis of Chagas disease.

  17. Analytical models for the groundwater tidal prism and associated benthic water flux

    USGS Publications Warehouse

    King, Jeffrey N.; Mehta, Ashish J.; Dean, Robert G.

    2010-01-01

    The groundwater tidal prism is defined as the volume of water that inundates a porous medium, forced by one tidal oscillation in surface water. The pressure gradient that generates the prism acts on the subterranean estuary. Analytical models for the groundwater tidal prism and associated benthic flux are presented. The prism and flux are shown to be directly proportional to porosity, tidal amplitude, and the length of the groundwater wave; flux is inversely proportional to tidal period. The duration of discharge flux exceeds the duration of recharge flux over one tidal period; and discharge flux continues for some time following low tide. Models compare favorably with laboratory observations and are applied to a South Atlantic Bight study area, where tide generates an 11-m3 groundwater tidal prism per m of shoreline, and drives 81 m3 s −1 to the study area, which describes 23% of an observational estimate. In a marine water body, the discharge component of any oscillatory benthic water flux is submarine groundwater discharge. Benthic flux transports constituents between groundwater and surface water, and is a process by which pollutant loading and saltwater intrusion may occur in coastal areas.

  18. Study of dose calculation on breast brachytherapy using prism TPS

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Fendriani, Yoza; Haryanto, Freddy

    2015-09-30

    PRISM is one of non-commercial Treatment Planning System (TPS) and is developed at the University of Washington. In Indonesia, many cancer hospitals use expensive commercial TPS. This study aims to investigate Prism TPS which been applied to the dose distribution of brachytherapy by taking into account the effect of source position and inhomogeneities. The results will be applicable for clinical Treatment Planning System. Dose calculation has been implemented for water phantom and CT scan images of breast cancer using point source and line source. This study used point source and line source and divided into two cases. On the firstmore » case, Ir-192 seed source is located at the center of treatment volume. On the second case, the source position is gradually changed. The dose calculation of every case performed on a homogeneous and inhomogeneous phantom with dimension 20 × 20 × 20 cm{sup 3}. The inhomogeneous phantom has inhomogeneities volume 2 × 2 × 2 cm{sup 3}. The results of dose calculations using PRISM TPS were compared to literature data. From the calculation of PRISM TPS, dose rates show good agreement with Plato TPS and other study as published by Ramdhani. No deviations greater than ±4% for all case. Dose calculation in inhomogeneous and homogenous cases show similar result. This results indicate that Prism TPS is good in dose calculation of brachytherapy but not sensitive for inhomogeneities. Thus, the dose calculation parameters developed in this study were found to be applicable for clinical treatment planning of brachytherapy.« less

  19. Prion-like Nanofibrils of Small Molecules (PriSM) Selectively Inhibit Cancer Cells by Impeding Cytoskeleton Dynamics*

    PubMed Central

    Kuang, Yi; Long, Marcus J. C.; Zhou, Jie; Shi, Junfeng; Gao, Yuan; Xu, Chen; Hedstrom, Lizbeth; Xu, Bing

    2014-01-01

    Emerging evidence reveals that prion-like structures play important roles to maintain the well-being of cells. Although self-assembly of small molecules also affords prion-like nanofibrils (PriSM), little is known about the functions and mechanisms of PriSM. Previous works demonstrated that PriSM formed by a dipeptide derivative selectively inhibiting the growth of glioblastoma cells over neuronal cells and effectively inhibiting xenograft tumor in animal models. Here we examine the protein targets, the internalization, and the cytotoxicity pathway of the PriSM. The results show that the PriSM selectively accumulate in cancer cells via macropinocytosis to impede the dynamics of cytoskeletal filaments via promiscuous interactions with cytoskeletal proteins, thus inducing apoptosis. Intriguingly, Tau proteins are able to alleviate the effect of the PriSM, thus protecting neuronal cells. This work illustrates PriSM as a new paradigm for developing polypharmacological agents that promiscuously interact with multiple proteins yet result in a primary phenotype, such as cancer inhibition PMID:25157102

  20. Protective Human Leucocyte Antigen Haplotype, HLA-DRB1*01-B*14, against Chronic Chagas Disease in Bolivia

    PubMed Central

    del Puerto, Florencia; Nishizawa, Juan Eiki; Kikuchi, Mihoko; Roca, Yelin; Avilas, Cinthia; Gianella, Alberto; Lora, Javier; Velarde, Freddy Udalrico Gutierrez; Miura, Sachio; Komiya, Norihiro; Maemura, Koji; Hirayama, Kenji

    2012-01-01

    Background Chagas disease, caused by the flagellate parasite Trypanosoma cruzi affects 8–10 million people in Latin America. The mechanisms that underlie the development of complications of chronic Chagas disease, characterized primarily by pathology of the heart and digestive system, are not currently understood. To identify possible host genetic factors that may influence the clinical course of Chagas disease, Human Leucocyte Antigen (HLA) regional gene polymorphism was analyzed in patients presenting with differing clinical symptoms. Methodology Two hundred and twenty nine chronic Chagas disease patients in Santa Cruz, Bolivia, were examined by serological tests, electrocardiogram (ECG), and Barium enema colon X-ray. 31.4% of the examinees showed ECG alterations, 15.7% megacolon and 58.1% showed neither of them. A further 62 seropositive megacolon patients who had undergone colonectomy due to acute abdomen were recruited. We analyzed their HLA genetic polymorphisms (HLA-A, HLA-B, MICA, MICB, DRB1 and TNF-alpha promoter region) mainly through Sequence based and LABType SSO typing test using LUMINEX Technology. Principal Findings The frequencies of HLA-DRB1*01 and HLA-B*14:02 were significantly lower in patients suffering from megacolon as well as in those with ECG alteration and/or megacolon compared with a group of patients with indeterminate symptoms. The DRB1*0102, B*1402 and MICA*011 alleles were in strong Linkage Disequilibrium (LD), and the HLA-DRB1*01-B*14-MICA*011haplotype was associated with resistance against chronic Chagas disease. Conclusions This is the first report of HLA haplotype association with resistance to chronic Chagas disease. PMID:22448298

  1. Radionuclide evaluation of left-ventricular function in chronic Chagas' cardiomyopathy

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Arreaza, N.; Puigbo, J.J.; Acquatella, H. Casal, H.

    1983-07-01

    Left-ventricular ejection fraction (LVEF) and abnormalities of regional wall motion (WMA) were studied by means of radionuclide ventriculography in 41 patients prospectively diagnosed as having chronic Chagas' disease. Thirteen patients were asymptomatic (ASY), 16 were arrhythmic (ARR), and 12 had congestive heart failure (CHF). Mean LVEF was normal in ASY but markedly depressed in CHF. Regional WMAs were minimal in ASY and their severity increased in ARR. Most CHFs (75%) had diffuse hypokinesia of the left ventricle. Seven patients had a distinct apical aneurysm. Correlation between radionuclide and contrast ventriculography data was good in 17 patients. Selective coronary arteriography showedmore » normal arteries in all patients. Therefore, chronic Chagas' heart disease joins ischemic heart disease as a cause of regional WMA.« less

  2. Is endothelial microvascular function equally impaired among patients with chronic Chagas and ischemic cardiomyopathy?

    PubMed

    Borges, Juliana Pereira; Mendes, Fernanda de Souza Nogueira Sardinha; Lopes, Gabriella de Oliveira; Sousa, Andréa Silvestre de; Mediano, Mauro Felippe Felix; Tibiriçá, Eduardo

    2018-08-15

    Chronic Chagas cardiomyopathy (CCC) and cardiomyopathies due to other etiologies involve differences in pathophysiological pathways that are still unclear. Systemic microvascular abnormalities are associated with the pathogenesis of ischemic heart disease. However, systemic microvascular endothelial function in CCC remains to be elucidated. Thus, we compared the microvascular endothelial function of patients presenting with CCC to those with ischemic cardiomyopathy disease. Microvascular reactivity was assessed in 21 patients with cardiomyopathy secondary to Chagas disease, 21 patients with cardiomyopathy secondary to ischemic disease and 21 healthy controls. Microvascular blood flow was assessed in the skin of the forearm using laser speckle contrast imaging coupled with iontophoresis of acetylcholine (ACh). Peak increase in forearm blood flow with ACh iontophoresis in relation to baseline was greater in healthy controls than in patients with heart disease (controls: 162.7 ± 58.4% vs. ischemic heart disease: 74.1 ± 48.3% and Chagas: 85.1 ± 68.1%; p < 0.0001). Patients with Chagas and ischemic cardiomyopathy presented similar ACh-induced changes from baseline in skin blood flow (p = 0.55). Endothelial microvascular function was equally impaired among patients with CCC and ischemic cardiomyopathy. Copyright © 2018 Elsevier B.V. All rights reserved.

  3. Frontal lesions predict response to prism adaptation treatment in spatial neglect: A randomised controlled study.

    PubMed

    Goedert, Kelly M; Chen, Peii; Foundas, Anne L; Barrett, A M

    2018-03-20

    Spatial neglect commonly follows right hemisphere stroke. It is defined as impaired contralesional stimulus detection, response, or action, causing functional disability. While prism adaptation treatment is highly promising to promote functional recovery of spatial neglect, not all individuals respond. Consistent with a primary effect of prism adaptation on spatial movements, we previously demonstrated that functional improvement after prism adaptation treatment is linked to frontal lobe lesions. However, that study was a treatment-only study with no randomised control group. The current study randomised individuals with spatial neglect to receive 10 days of prism adaptation treatment or to receive only standard care (control group). Replicating our earlier results, we found that the presence of frontal lesions moderated response to prism adaptation treatment: among prism-treated patients, only those with frontal lesions demonstrated functional improvements in their neglect symptoms. Conversely, among individuals in the standard care control group, the presence of frontal lesions did not modify recovery. These results suggest that further research is needed on how frontal lesions may predict response to prism adaptation treatment. Additionally, the results help elucidate the neural network involved in spatial movement and could be used to aid decisions about treatment.

  4. Assessing the risk zones of Chagas' disease in Chile, in a world marked by global climatic change

    PubMed Central

    Tapia-Garay, Valentina; Figueroa, Daniela P; Maldonado, Ana; Frías-Laserre, Daniel; Gonzalez, Christian R; Parra, Alonso; Canals, Lucia; Apt, Werner; Alvarado, Sergio; Cáceres, Dante; Canals, Mauricio

    2018-01-01

    BACKGROUND Vector transmission of Trypanosoma cruzi appears to be interrupted in Chile; however, data show increasing incidence of Chagas' disease, raising concerns that there may be a reemerging problem. OBJECTIVE To estimate the actual risk in a changing world it is necessary to consider the historical vector distribution and correlate this distribution with the presence of cases and climate change. METHODS Potential distribution models of Triatoma infestans and Chagas disease were performed using Maxent, a machine-learning method. FINDINGS Climate change appears to play a major role in the reemergence of Chagas' disease and T. infestans in Chile. The distribution of both T. infestans and Chagas' disease correlated with maximum temperature, and the precipitation during the driest month. The overlap of Chagas' disease and T. infestans distribution areas was high. The distribution of T. infestans, under two global change scenarios, showed a minimal reduction tendency in suitable areas. MAIN CONCLUSION The impact of temperature and precipitation on the distribution of T. infestans, as shown by the models, indicates the need for aggressive control efforts; the current control measures, including T. infestans control campaigns, should be maintained with the same intensity as they have at present, avoiding sylvatic foci, intrusions, and recolonisation of human dwellings. PMID:29211105

  5. Mortality among blood donors seropositive and seronegative for Chagas disease (1996–2000) in São Paulo, Brazil: A death certificate linkage study

    PubMed Central

    Bierrenbach, Ana Luiza; Pereira Alencar, Airlane; Mendrone, Alfredo; Ferreira, João Eduardo; Custer, Brian; P. Ribeiro, Antonio Luiz; Cerdeira Sabino, Ester

    2017-01-01

    Background Individuals in the indeterminate phase of Chagas disease are considered to have mortality rates similar to those of the overall population. This study compares mortality rates among blood donors seropositive for Chagas disease and negative controls in the city of São Paulo, Brazil. Methodology/principal findings This is a retrospective cohort study of blood donors from 1996 to 2000: 2842 seropositive and 5684 seronegative for Chagas disease. Death status was ascertained by performing probabilistic record linkage (RL) with the Brazil national mortality information system (SIM). RL was assessed in a previous validation study. Cox Regression was used to derive hazard ratios (HR), adjusting for confounders. RL identified 159 deaths among the 2842 seropositive blood donors (5.6%) and 103 deaths among the 5684 seronegative (1.8%). Out of the 159 deaths among seropositive donors, 26 had the 10th International Statistical Classification of Diseases and Related Health Problems (ICD-10) indicating Chagas disease as the underlying cause of death (B57.0/B57.5), 23 had ICD-10 codes (I42.0/I42.2/I47.0/I47.2/I49.0/I50.0/I50.1/ I50.9/I51.7) indicating cardiac abnormalities possibly related to Chagas disease listed as an underlying or associated cause of death, with the others having no mention of Chagas disease in part I of the death certificate. Donors seropositive for Chagas disease had a 2.3 times higher risk of death due to all causes (95% Confidence Interval (95% CI), 1.8–3.0) than seronegative donors. When considering deaths due to Chagas disease or those that had underlying causes of cardiac abnormalities related to Chagas disease, seropositive donors had a risk of death 17.9 (95% CI, 6.3–50.8) times greater than seronegative donors. Conclusions/significance There is an excess risk of death in donors seropositive blood for Chagas disease compared to seronegative donors. Chagas disease is an under-reported cause of death in the Brazilian mortality database

  6. Cavity Enhanced Absorption Spectroscopy Using a Broadband Prism Cavity and a Supercontinuum Source

    NASA Astrophysics Data System (ADS)

    Johnston, Paul S.; Lehmann, Kevin K.

    2009-06-01

    The multiplex advantage of current cavity enhanced spectrometers is limited by the high reflectivity bandwidth of the mirrors used to construct the high finesse cavity. Previously, we reported the design and construction of a new spectrometer that circumvents this limitation by utilizing Brewster^{,}s angle prism retroreflectors. The prisms, made from fused silica and combined with a supercontinuum source generated by pumping a highly nonlinear photonic crystal fiber, yields a spectral window ranging from 500 nm to 1750 nm. Recent progress in the instruments development will be discussed, including work on modeling the prism cavity losses, alternative prism material for use in the UV and mid-IR spectral regions, and a new high power supercontinuum source based on mode-locked picosecond laser.

  7. Cardiac troponin T measured with a highly sensitive assay for diagnosis and monitoring of heart injury in chronic Chagas disease.

    PubMed

    Saravia, Silvia Gilka Muñoz; Haberland, Annekathrin; Bartel, Sabine; Araujo, Raul; Valda, Gregorio; Reynaga, Diana Duchen; Ramirez, Ivan Diaz; Borges, Adrian C; Wallukat, Gerd; Schimke, Ingolf

    2011-02-01

    Chronic Chagas disease (15 million patients; annual incidence, 40, 000 patients; annual mortality, 12 ,500 patients) is the most serious parasitic disease in Latin America. Between 10 and 30 years after infection, 30% of patients with Chagas disease develop heart injury, which is the main reason for its high mortality. Consequently, frequent cardiac diagnostics are required for patients with Chagas disease. To minimize time-intensive and cost-intensive diagnostics, such as electrocardiography, echocardiography, and radiologic imaging, we tested the effect of measuring serum cardiac troponin T (cTnT) with a highly sensitive assay. To indicate the pathophysiologic background for cTnT release in Chagas heart injury, inflammation markers, such as C-reactive protein and interleukin 6, were measured in parallel. Serum cTnT was measured in 26 healthy subjects and in 179 patients with chronic Chagas disease who were asymptomatic (indeterminate stage, n  =  86), who were suffering from cardiomyopathy with or without megacolon (n  =  71), or who were suffering from megacolon exclusively (n  =  22). Serum cTnT was significantly higher in patients with cardiomyopathy with or without megacolon than in healthy subjects, asymptomatic subjects, and patients with megacolon, and the cTnT value was correlated with the severity of the cardiomyopathy. The lower limit of detection for the highly sensitive assay (3 ng/L) was best at distinguishing patients with, and without, heart injury. C-reactive protein and interleukin 6 were found to parallel cTnT changes in both the different Chagas groups and the cardiomyopathy groups separated by disease severity. Highly sensitive cTnT measurement has the potential to contribute to diagnosis and monitoring of heart injury in patients with chronic Chagas disease. The highly sensitive assay of cTnT release seems to be related to Chagas heart disease-specific inflammation.

  8. Use of a Chagas Urine Nanoparticle Test (Chunap) to Correlate with Parasitemia Levels in T. cruzi/HIV Co-infected Patients.

    PubMed

    Castro-Sesquen, Yagahira E; Gilman, Robert H; Mejia, Carolina; Clark, Daniel E; Choi, Jeong; Reimer-McAtee, Melissa J; Castro, Rosario; Valencia-Ayala, Edward; Flores, Jorge; Bowman, Natalie; Castillo-Neyra, Ricardo; Torrico, Faustino; Liotta, Lance; Bern, Caryn; Luchini, Alessandra

    2016-02-01

    Early diagnosis of reactivated Chagas disease in HIV patients could be lifesaving. In Latin America, the diagnosis is made by microscopical detection of the T. cruzi parasite in the blood; a diagnostic test that lacks sensitivity. This study evaluates if levels of T. cruzi antigens in urine, determined by Chunap (Chagas urine nanoparticle test), are correlated with parasitemia levels in T. cruzi/HIV co-infected patients. T. cruzi antigens in urine of HIV patients (N = 55: 31 T. cruzi infected and 24 T. cruzi serology negative) were concentrated using hydrogel particles and quantified by Western Blot and a calibration curve. Reactivation of Chagas disease was defined by the observation of parasites in blood by microscopy. Parasitemia levels in patients with serology positive for Chagas disease were classified as follows: High parasitemia or reactivation of Chagas disease (detectable parasitemia by microscopy), moderate parasitemia (undetectable by microscopy but detectable by qPCR), and negative parasitemia (undetectable by microscopy and qPCR). The percentage of positive results detected by Chunap was: 100% (7/7) in cases of reactivation, 91.7% (11/12) in cases of moderate parasitemia, and 41.7% (5/12) in cases of negative parasitemia. Chunap specificity was found to be 91.7%. Linear regression analysis demonstrated a direct relationship between parasitemia levels and urine T. cruzi antigen concentrations (p<0.001). A cut-off of > 105 pg was chosen to determine patients with reactivation of Chagas disease (7/7). Antigenuria levels were 36.08 times (95% CI: 7.28 to 64.88) higher in patients with CD4+ lymphocyte counts below 200/mL (p = 0.016). No significant differences were found in HIV loads and CD8+ lymphocyte counts. Chunap shows potential for early detection of Chagas reactivation. With appropriate adaptation, this diagnostic test can be used to monitor Chagas disease status in T. cruzi/HIV co-infected patients.

  9. Pacemaker Implants in Children and Adolescents with Chagas Disease in Brazil: 18-Year Incidence.

    PubMed

    Mizzaci, Carolina Christianini; Souza, Thiago Gonçalves Schroder E; Targueta, Gabriel Pelegrineti; Tótora, Ana Paula Frederico; Mateos, Juan Carlos Pachón; Mateos, José Carlos Pachon

    2017-06-01

    Chagas disease continues to be a serious public health problem, and accounts for 25-30% of the indications for cardiac stimulation in Brazil. To assess clinical and epidemiological characteristics of patients with Chagas disease, younger than 18 years, who had undergone pacemaker implantation in Brazil between 1994 and 2011, and its temporal trend. This was a cross-sectional analysis of data from the Brazilian Pacemaker Registry database. The following variables were analyzed: year when pacemaker was implanted, location, age, sex, ethnic group, functional class and the main electrocardiographic findings at baseline. In a total of 183,123 implants performed between 1994 and 2011, 214 implants of cardiac stimulation device in Chagas disease patients aged younger than 18 years were identified. Mean age at implantation was 5.6 ± 6.2 years. Second- and third-degree atrioventricular blocks corresponded to 71% of indications for pacemaker implantation. Fifty-six percent of the procedures were performed in the southeast region. Regarding the total number of pacemaker implants per year, there was a remarkable increase in the implants for all causes. However, time series analysis of the implants in Chagas disease patients younger than 18 years revealed a significant reduction in the annual number of implants. There has been an important reduction in the number of pacemaker implantations among children and adolescents with Chagas disease, suggesting a reduction in the vertical transmission of the parasite. A doença de Chagas mantém-se como sério problema de saúde pública e tem sido responsável por aproximadamente 25% a 30% das indicações de estimulação cardíaca no Brasil. Estudar as características clínicas e epidemiológicas dos pacientes menores de 18 anos portadores de doença de Chagas submetidos a implante de marca-passo no território brasileiro entre 1994 e 2011, e sua tendência temporal. Trata-se de um estudo retrospectivo que utilizou informa

  10. Preserving with Prisms: Producing Nets

    ERIC Educational Resources Information Center

    Prummer, Kathy E.; Amador, Julie M.; Wallin, Abraham J.

    2016-01-01

    Two mathematics teachers in a small rural school decided to create a task that would engage seventh graders. The goal of the real-world activity was to help students develop geometric and spatial reasoning and to support their understanding of volume of rectangular prisms. The impetus for the task came from the teachers' desire to engage students…

  11. Beam pointing direction changes in a misaligned Porro prism resonator

    NASA Astrophysics Data System (ADS)

    Lee, Jyh-Fa; Leung, Chung-Yee

    1988-07-01

    The relative change of the beam pointing direction for a misaligned Porro prism resonator has been analyzed, using an oscillation axis concept for the Porro prism resonator to find the beam direction. Expressions for the beam tilting angles are presented which show that the angular misalignment in the horizontal direction will result in beam tilting in both the horizontal and vertical directions. Good agreement between experimental and theoretical results is found.

  12. Opportunity cost for early treatment of Chagas disease in Mexico.

    PubMed

    Ramsey, Janine M; Elizondo-Cano, Miguel; Sanchez-González, Gilberto; Peña-Nieves, Adriana; Figueroa-Lara, Alejandro

    2014-04-01

    Given current neglect for Chagas disease in public health programs in Mexico, future healthcare and economic development policies will need a more robust model to analyze costs and impacts of timely clinical attention of infected populations. A Markov decision model was constructed to simulate the natural history of a Chagas disease cohort in Mexico and to project the associated short and long-term clinical outcomes and corresponding costs. The lifetime cost for a timely diagnosed and treated Chagas disease patient is US$ 10,160, while the cost for an undiagnosed individual is US$ 11,877. The cost of a diagnosed and treated case increases 24-fold from early acute to indeterminate stage. The major cost component for lifetime cost was working days lost, between 44% and 75%, depending on the program scenario for timely diagnosis and treatment. In the long term, it is cheaper to diagnose and treat chagasic patients early, instead of doing nothing. This finding by itself argues for the need to shift current policy, in order to prioritize and attend this neglected disease for the benefit of social and economic development, which implies including treatment drugs in the national formularies. Present results are even more relevant, if one considers that timely diagnosis and treatment can arrest clinical progression and enhance a chronic patient's quality of life.

  13. Opportunity Cost for Early Treatment of Chagas Disease in Mexico

    PubMed Central

    Ramsey, Janine M.; Elizondo-Cano, Miguel; Sanchez-González, Gilberto; Peña-Nieves, Adriana; Figueroa-Lara, Alejandro

    2014-01-01

    Background Given current neglect for Chagas disease in public health programs in Mexico, future healthcare and economic development policies will need a more robust model to analyze costs and impacts of timely clinical attention of infected populations. Methodology/Principal Findings A Markov decision model was constructed to simulate the natural history of a Chagas disease cohort in Mexico and to project the associated short and long-term clinical outcomes and corresponding costs. The lifetime cost for a timely diagnosed and treated Chagas disease patient is US$ 10,160, while the cost for an undiagnosed individual is US$ 11,877. The cost of a diagnosed and treated case increases 24-fold from early acute to indeterminate stage. The major cost component for lifetime cost was working days lost, between 44% and 75%, depending on the program scenario for timely diagnosis and treatment. Conclusions/Significance In the long term, it is cheaper to diagnose and treat chagasic patients early, instead of doing nothing. This finding by itself argues for the need to shift current policy, in order to prioritize and attend this neglected disease for the benefit of social and economic development, which implies including treatment drugs in the national formularies. Present results are even more relevant, if one considers that timely diagnosis and treatment can arrest clinical progression and enhance a chronic patient's quality of life. PMID:24743112

  14. Longitudinal study of patients with chronic Chagas cardiomyopathy in Brazil (SaMi-Trop project): a cohort profile

    PubMed Central

    Cardoso, Clareci Silva; Sabino, Ester Cerdeira; Oliveira, Claudia Di Lorenzo; de Oliveira, Lea Campos; Ferreira, Ariela Mota; Cunha-Neto, Edécio; Bierrenbach, Ana Luiza; Ferreira, João Eduardo; Haikal, Desirée Sant'Ana; Reingold, Arthur L; Ribeiro, Antonio Luiz P

    2016-01-01

    Purpose We have established a prospective cohort of 1959 patients with chronic Chagas cardiomyopathy to evaluate if a clinical prediction rule based on ECG, brain natriuretic peptide (BNP) levels, and other biomarkers can be useful in clinical practice. This paper outlines the study and baseline characteristics of the participants. Participants The study is being conducted in 21 municipalities of the northern part of Minas Gerais State in Brazil, and includes a follow-up of 2 years. The baseline evaluation included collection of sociodemographic information, social determinants of health, health-related behaviours, comorbidities, medicines in use, history of previous treatment for Chagas disease, functional class, quality of life, blood sample collection, and ECG. Patients were mostly female, aged 50–74 years, with low family income and educational level, with known Chagas disease for >10 years; 46% presented with functional class >II. Previous use of benznidazole was reported by 25.2% and permanent use of pacemaker by 6.2%. Almost half of the patients presented with high blood cholesterol and hypertension, and one-third of them had diabetes mellitus. N-terminal of the prohormone BNP (NT-ProBNP) level was >300 pg/mL in 30% of the sample. Findings to date Clinical and laboratory markers predictive of severe and progressive Chagas disease were identified as high NT-ProBNP levels, as well as symptoms of advanced heart failure. These results confirm the important residual morbidity of Chagas disease in the remote areas, thus supporting political decisions that should prioritise in addition to epidemiological surveillance the medical treatment of chronic Chagas cardiomyopathy in the coming years. The São Paulo-Minas Gerais Tropical Medicine Research Center (SaMi-Trop) represents a major challenge for focused research in neglected diseases, with knowledge that can be applied in primary healthcare. Future plans We will continue following this patients’ cohort

  15. Digital Beam Steering Device Based on Decoupled Birefringent Prism Deflector and Polarization Rotator

    NASA Technical Reports Server (NTRS)

    Pishnyak, Oleg; Kreminska, Lyubov; Laventovich, Oleg D.; Pouch, John J.; Miranda, Felix A.; Winker, Bruce K.

    2004-01-01

    We describe digital beam deflectors (DBDs) based on liquid crystals. Each stage of the device comprises a polarization rotator and a birefringent prism deflector. The birefringent prism deflects the beam by an angle that depends on polarization of the incident beam. The prism can be made of the uniaxial smectic A (SmA) liquid crystal (LC) or a solid crystal such as yttrium orthovanadate (YVO4). SmA prisms have high birefringence and can be constructed in a variety of shapes, including single prisms and prismatic blazed gratings of different angles and profiles. We address the challenges of uniform alignment of SmA, such as elimination of focal conic domains. Rotation of linear polarization is achieved by an electrically switched twisted nematic (TN) cell. A DBD composed of N rotator-deflector pairs steers the beam into 2(sup N) directions. As an example, we describe a four-stage DBD deflecting normally incident laser beam within the range of +/- 56 mrad with 8 mrad steps. Redirection of the beam is achieved by switching the TN cells.

  16. Fault structure, properties and activity of the Makran Accretionary Prism and implications for seismogenic potential

    NASA Astrophysics Data System (ADS)

    Smith, G. L.; McNeill, L. C.; Henstock, T.; Bull, J. M.

    2011-12-01

    The Makran subduction zone is the widest accretionary prism in the world (~400km), generated by convergence between the Arabian and Eurasian tectonic plates. It represents a global end-member, with a 7km thick incoming sediment section. Accretionary prisms have traditionally been thought to be aseismic due to the presence of unconsolidated sediment and elevated basal pore pressures. The seismogenic potential of the Makran subduction zone is unclear, despite a Mw 8.1 earthquake in 1945 that may have been located on the plate boundary beneath the prism. In this study, a series of imbricate landward dipping (seaward verging) thrust faults have been interpreted across the submarine prism (outer 70 km) using over 6000km of industry multichannel seismic data and bathymetric data. A strong BSR (bottom simulating reflector) is present throughout the prism (excluding the far east). An unreflective décollement is interpreted from the geometry of the prism thrusts. Two major sedimentary units are identified in the input section, the lower of which contains the extension of the unreflective décollement surface. Between 60%-100% of the input section is currently being accreted. The geometry of piggy-back basin stratigraphy shows that the majority of thrusts, including those over 50km from the trench, are recently active. Landward thrusts show evidence for reactivation after periods of quiescence. Negative polarity fault plane reflectors are common in the frontal thrusts and in the eastern prism, where they may be related to increased fault activity and fluid expulsion, and are rarer in older landward thrusts. Significant NE-SW trending basement structures (The Murray Ridge and Little Murray Ridge) on the Arabian plate intersect the deformation front and affect sediment input to the subduction zone. Prism taper and structure are apparently primarily controlled by sediment supply and the secondary influence of subducting basement ridges. The thick, likely distal, sediment

  17. Lower richness of small wild mammal species and chagas disease risk.

    PubMed

    Xavier, Samanta Cristina das Chagas; Roque, André Luiz Rodrigues; Lima, Valdirene dos Santos; Monteiro, Kerla Joeline Lima; Otaviano, Joel Carlos Rodrigues; Ferreira da Silva, Luiz Felipe Coutinho; Jansen, Ana Maria

    2012-01-01

    A new epidemiological scenario involving the oral transmission of Chagas disease, mainly in the Amazon basin, requires innovative control measures. Geospatial analyses of the Trypanosoma cruzi transmission cycle in the wild mammals have been scarce. We applied interpolation and map algebra methods to evaluate mammalian fauna variables related to small wild mammals and the T. cruzi infection pattern in dogs to identify hotspot areas of transmission. We also evaluated the use of dogs as sentinels of epidemiological risk of Chagas disease. Dogs (n = 649) were examined by two parasitological and three distinct serological assays. kDNA amplification was performed in patent infections, although the infection was mainly sub-patent in dogs. The distribution of T. cruzi infection in dogs was not homogeneous, ranging from 11-89% in different localities. The interpolation method and map algebra were employed to test the associations between the lower richness in mammal species and the risk of exposure of dogs to T. cruzi infection. Geospatial analysis indicated that the reduction of the mammal fauna (richness and abundance) was associated with higher parasitemia in small wild mammals and higher exposure of dogs to infection. A Generalized Linear Model (GLM) demonstrated that species richness and positive hemocultures in wild mammals were associated with T. cruzi infection in dogs. Domestic canine infection rates differed significantly between areas with and without Chagas disease outbreaks (Chi-squared test). Geospatial analysis by interpolation and map algebra methods proved to be a powerful tool in the evaluation of areas of T. cruzi transmission. Dog infection was shown to not only be an efficient indicator of reduction of wild mammalian fauna richness but to also act as a signal for the presence of small wild mammals with high parasitemia. The lower richness of small mammal species is discussed as a risk factor for the re-emergence of Chagas disease.

  18. Prism adaptation enhances activity of intact fronto-parietal areas in both hemispheres in neglect patients.

    PubMed

    Saj, Arnaud; Cojan, Yann; Vocat, Roland; Luauté, Jacques; Vuilleumier, Patrik

    2013-01-01

    Unilateral spatial neglect involves a failure to report or orient to stimuli in the contralesional (left) space due to right brain damage, with severe handicap in everyday activities and poor rehabilitation outcome. Because behavioral studies suggest that prism adaptation may reduce spatial neglect, we investigated the neural mechanisms underlying prism effects on visuo-spatial processing in neglect patients. We used functional magnetic resonance imaging (fMRI) to examine the effect of (right-deviating) prisms on seven patients with left neglect, by comparing brain activity while they performed three different spatial tasks on the same visual stimuli (bisection, search, and memory), before and after a single prism-adaptation session. Following prism adaptation, fMRI data showed increased activation in bilateral parietal, frontal, and occipital cortex during bisection and visual search, but not during the memory task. These increases were associated with significant behavioral improvement in the same two tasks. Changes in neural activity and behavior were seen only after prism adaptation, but not attributable to mere task repetition. These results show for the first time the neural substrates underlying the therapeutic benefits of prism adaptation, and demonstrate that visuo-motor adaptation induced by prism exposure can restore activation in bilateral brain networks controlling spatial attention and awareness. This bilateral recruitment of fronto-parietal networks may counteract the pathological biases produced by unilateral right hemisphere damage, consistent with recent proposals that neglect may reflect lateralized deficits induced by bilateral hemispheric dysfunction. Copyright © 2011 Elsevier Ltd. All rights reserved.

  19. Activation of the cerebellar cortex and the dentate nucleus in a prism adaptation fMRI study.

    PubMed

    Küper, Michael; Wünnemann, Meret J S; Thürling, Markus; Stefanescu, Roxana M; Maderwald, Stefan; Elles, Hans G; Göricke, Sophia; Ladd, Mark E; Timmann, Dagmar

    2014-04-01

    During prism adaptation two types of learning processes can be distinguished. First, fast strategic motor control responses are predominant in the early course of prism adaptation to achieve rapid error correction within few trials. Second, slower spatial realignment occurs among the misaligned visual and proprioceptive sensorimotor coordinate system. The aim of the present ultra-highfield (7T) functional magnetic resonance imaging (fMRI) study was to explore cerebellar cortical and dentate nucleus activation during the course of prism adaptation in relation to a similar visuomotor task without prism exposure. Nineteen young healthy participants were included into the study. Recently developed normalization procedures were applied for the cerebellar cortex and the dentate nucleus. By means of subtraction analysis (early prism adaptation > visuomotor, early prism adaptation > late prism adaptation) we identified ipsilateral activation associated with strategic motor control responses within the posterior cerebellar cortex (lobules VIII and IX) and the ventro-caudal dentate nucleus. During the late phase of adaptation we observed pronounced activation of posterior parts of lobule VI, although subtraction analyses (late prism adaptation > visuomotor) remained negative. These results are in good accordance with the concept of a representation of non-motor functions, here strategic control, within the ventro-caudal dentate nucleus. Copyright © 2013 Wiley Periodicals, Inc.

  20. Chronic Chagas cardiomyopathy: a review of the main pathogenic mechanisms and the efficacy of aetiological treatment following the BENznidazole Evaluation for Interrupting Trypanosomiasis (BENEFIT) trial.

    PubMed

    Rassi, Anis; Marin, José Antonio; Rassi, Anis

    2017-03-01

    Chagas cardiomyopathy is the most frequent and most severe manifestation of chronic Chagas disease, and is one of the leading causes of morbidity and death in Latin America. Although the pathogenesis of Chagas cardiomyopathy is incompletely understood, it may involve several mechanisms, including parasite-dependent myocardial damage, immune-mediated myocardial injury (induced by the parasite itself and by self-antigens), and microvascular and neurogenic disturbances. In the past three decades, a consensus has emerged that parasite persistence is crucial to the development and progression of Chagas cardiomyopathy. In this context, antiparasitic treatment in the chronic phase of Chagas disease could prevent complications related to the disease. However, according to the results of the BENEFIT trial, benznidazole seems to have no benefit for arresting disease progression in patients with chronic Chagas cardiomyopathy. In this review, we give an update on the main pathogenic mechanisms of Chagas disease, and re-examine and discuss the results of the BENEFIT trial, together with its limitations and implications.

  1. Prion-like nanofibrils of small molecules (PriSM) selectively inhibit cancer cells by impeding cytoskeleton dynamics.

    PubMed

    Kuang, Yi; Long, Marcus J C; Zhou, Jie; Shi, Junfeng; Gao, Yuan; Xu, Chen; Hedstrom, Lizbeth; Xu, Bing

    2014-10-17

    Emerging evidence reveals that prion-like structures play important roles to maintain the well-being of cells. Although self-assembly of small molecules also affords prion-like nanofibrils (PriSM), little is known about the functions and mechanisms of PriSM. Previous works demonstrated that PriSM formed by a dipeptide derivative selectively inhibiting the growth of glioblastoma cells over neuronal cells and effectively inhibiting xenograft tumor in animal models. Here we examine the protein targets, the internalization, and the cytotoxicity pathway of the PriSM. The results show that the PriSM selectively accumulate in cancer cells via macropinocytosis to impede the dynamics of cytoskeletal filaments via promiscuous interactions with cytoskeletal proteins, thus inducing apoptosis. Intriguingly, Tau proteins are able to alleviate the effect of the PriSM, thus protecting neuronal cells. This work illustrates PriSM as a new paradigm for developing polypharmacological agents that promiscuously interact with multiple proteins yet result in a primary phenotype, such as cancer inhibition. © 2014 by The American Society for Biochemistry and Molecular Biology, Inc.

  2. Chagas disease and globalization of the Amazon.

    PubMed

    Briceño-León, Roberto

    2007-01-01

    The increasing number of autochthonous cases of Chagas disease in the Amazon since the 1970s has led to fear that the disease may become a new public health problem in the region. This transformation in the disease's epidemiological pattern in the Amazon can be explained by environmental and social changes in the last 30 years. The current article draws on the sociological theory of perverse effects to explain these changes as the unwanted result of the shift from the "inward" development model prevailing until the 1970s to the "outward" model that we know as globalization, oriented by industrial forces and international trade. The current article highlights the implementation of five new patterns in agriculture, cattle-raising, mining, lumbering, and urban occupation that have generated changes in the environment and the traditional indigenous habitat and have led to migratory flows, deforestation, sedentary living, the presence of domestic animals, and changes in the habitat that facilitate colonization of human dwellings by vectors and the domestic and work-related transmission of the disease. The expansion of Chagas disease is thus a perverse effect of the globalization process in the Amazon.

  3. Post-licensure rapid immunization safety monitoring program (PRISM) data characterization.

    PubMed

    Baker, Meghan A; Nguyen, Michael; Cole, David V; Lee, Grace M; Lieu, Tracy A

    2013-12-30

    The Post-Licensure Rapid Immunization Safety Monitoring (PRISM) program is the immunization safety monitoring component of FDA's Mini-Sentinel project, a program to actively monitor the safety of medical products using electronic health information. FDA sought to assess the surveillance capabilities of this large claims-based distributed database for vaccine safety surveillance by characterizing the underlying data. We characterized data available on vaccine exposures in PRISM, estimated how much additional data was gained by matching with select state and local immunization registries, and compared vaccination coverage estimates based on PRISM data with other available data sources. We generated rates of computerized codes representing potential health outcomes relevant to vaccine safety monitoring. Standardized algorithms including ICD-9 codes, number of codes required, exclusion criteria and location of the encounter were used to obtain the background rates. The majority of the vaccines routinely administered to infants, children, adolescents and adults were well captured by claims data. Immunization registry data in up to seven states comprised between 5% and 9% of data for all vaccine categories with the exception of 10% for hepatitis B and 3% and 4% for rotavirus and zoster respectively. Vaccination coverage estimates based on PRISM's computerized data were similar to but lower than coverage estimates from the National Immunization Survey and Healthcare Effectiveness Data and Information Set. For the 25 health outcomes of interest studied, the rates of potential outcomes based on ICD-9 codes were generally higher than rates described in the literature, which are typically clinically confirmed cases. PRISM program's data on vaccine exposures and health outcomes appear complete enough to support robust safety monitoring. Copyright © 2013 Elsevier Ltd. All rights reserved.

  4. Beyond the Sensorimotor Plasticity: Cognitive Expansion of Prism Adaptation in Healthy Individuals.

    PubMed

    Michel, Carine

    2015-01-01

    Sensorimotor plasticity allows us to maintain an efficient motor behavior in reaction to environmental changes. One of the classical models for the study of sensorimotor plasticity is prism adaptation. It consists of pointing to visual targets while wearing prismatic lenses that shift the visual field laterally. The conditions of the development of the plasticity and the sensorimotor after-effects have been extensively studied for more than a century. However, the interest taken in this phenomenon was considerably increased since the demonstration of neglect rehabilitation following prism adaptation by Rossetti et al. (1998). Mirror effects, i.e., simulation of neglect in healthy individuals, were observed for the first time by Colent et al. (2000). The present review focuses on the expansion of prism adaptation to cognitive functions in healthy individuals during the last 15 years. Cognitive after-effects have been shown in numerous tasks even in those that are not intrinsically spatial in nature. Altogether, these results suggest the existence of a strong link between low-level sensorimotor plasticity and high-level cognitive functions and raise important questions about the mechanisms involved in producing unexpected cognitive effects following prism adaptation. Implications for the functional mechanisms and neuroanatomical network of prism adaptation are discussed to explain how sensorimotor plasticity may affect cognitive processes.

  5. Beyond the Sensorimotor Plasticity: Cognitive Expansion of Prism Adaptation in Healthy Individuals

    PubMed Central

    Michel, Carine

    2016-01-01

    Sensorimotor plasticity allows us to maintain an efficient motor behavior in reaction to environmental changes. One of the classical models for the study of sensorimotor plasticity is prism adaptation. It consists of pointing to visual targets while wearing prismatic lenses that shift the visual field laterally. The conditions of the development of the plasticity and the sensorimotor after-effects have been extensively studied for more than a century. However, the interest taken in this phenomenon was considerably increased since the demonstration of neglect rehabilitation following prism adaptation by Rossetti et al. (1998). Mirror effects, i.e., simulation of neglect in healthy individuals, were observed for the first time by Colent et al. (2000). The present review focuses on the expansion of prism adaptation to cognitive functions in healthy individuals during the last 15 years. Cognitive after-effects have been shown in numerous tasks even in those that are not intrinsically spatial in nature. Altogether, these results suggest the existence of a strong link between low-level sensorimotor plasticity and high-level cognitive functions and raise important questions about the mechanisms involved in producing unexpected cognitive effects following prism adaptation. Implications for the functional mechanisms and neuroanatomical network of prism adaptation are discussed to explain how sensorimotor plasticity may affect cognitive processes. PMID:26779088

  6. Engaging Students in GeoPRISMS Science Planning: Preparing the Leaders of Tomorrow

    NASA Astrophysics Data System (ADS)

    Henning, A. T.; Benoit, M. H.; Marshall, J.; Goodliffe, A. M.; Morgan, J. K.; Bopp, C. J.

    2011-12-01

    GeoPRISMS is the legacy of the NSF MARGINS Program. It is a new decadal program, funded by NSF, committed to the amphibious study of the origin and evolution of continental margins through interdisciplinary, community-based investigations. MARGINS and GeoPRISMS have had notable success in fostering this team-based approach in graduate students who then continue on to become GeoPRISMS PIs. GeoPRISMS is enhancing its student outreach efforts through the development of a student symposium program, in which graduate students are invited to be more active participants in GeoPRISMS workshops, and are provided with valuable background and reference materials to enable them. This approach has been applied and updated at four GeoPRISMS workshops so far: two implementation workshops and two science planning workshops. Graduate students participated in the GeoPRISMS Rift Initiation and Evolution (RIE) implementation workshop in November 2010 and the Subduction Cycles and Deformation (SCD) workshop in January 2011, contributing to the overall design of the GeoPRISMS research program, and the selection of primary sites for study. In addition to participating in the regular meeting activities, students gave "pop-up" presentations to summarize their research and poster presentations and also worked together to develop their own draft implementation plan that was presented to the larger audience. Students responded positively to the experience of drafting their own implementation plans, which fostered a sense of community among participants and created an environment in which students felt comfortable speaking up during the meeting. Scientists attending the workshops were impressed by the students' draft implementation plans, as well as their work ethic and enthusiasm, and felt they made a very positive contribution to the workshops. Student feedback suggested providing students with a better understanding of the main scientific questions addressed at the meeting, as well as

  7. Therapy of Chagas Disease: Implications for Levels of Prevention

    PubMed Central

    Sosa-Estani, Sergio; Colantonio, Lisandro; Segura, Elsa Leonor

    2012-01-01

    This paper reviews the evidence supporting the use of etiological treatment for Chagas disease that has changed the standard of care for patients with Trypanosoma cruzi infection in the last decades. Implications of this evidence on different levels of prevention as well as gaps in current knowledge are also discussed. In this regard, etiological treatment has shown to be beneficial as an intervention for secondary prevention to successfully cure the infection or to delay, reduce, or prevent the progression to disease, and as primary disease prevention by breaking the chain of transmission. Timely diagnosis during initial stages would allow for the prescription of appropriate therapies mainly in the primary health care system thus improving chances for a better quality of life. Based on current evidence, etiological treatment has to be considered as an essential public health strategy useful to reduce disease burden and to eliminate Chagas disease altogether. PMID:22523499

  8. Neglected Parasitic Infections in the United States: Chagas Disease

    PubMed Central

    Montgomery, Susan P.; Starr, Michelle C.; Cantey, Paul T.; Edwards, Morven S.; Meymandi, Sheba K.

    2014-01-01

    Chagas disease, which is caused by the protozoan parasite Trypanosoma cruzi, can lead to severe cardiac and gastrointestinal disease. Most persons acquire this infection through contact with vector bugs carrying T. cruzi in endemic areas of Latin America. Infection can also be acquired by congenital, transfusion, transplantation, and foodborne transmission. Although an estimated 300,000 persons with Chagas disease live in the United States, little is known about the burden of chagasic heart disease. It is not known how often congenital or vector-borne transmission of T. cruzi occurs in the United States, although it is known that infected mothers and infected vector bugs are found in this country. Better diagnostic tests and treatment drugs are needed to improve patient care, and research is needed to define transmission risks and develop strategies to prevent new infections and reduce the burden of disease. PMID:24808250

  9. Prism adaptation and generalization during visually guided locomotor tasks.

    PubMed

    Alexander, M Scott; Flodin, Brent W G; Marigold, Daniel S

    2011-08-01

    The ability of individuals to adapt locomotion to constraints associated with the complex environments normally encountered in everyday life is paramount for survival. Here, we tested the ability of 24 healthy young adults to adapt to a rightward prism shift (∼11.3°) while either walking and stepping to targets (i.e., precision stepping task) or stepping over an obstacle (i.e., obstacle avoidance task). We subsequently tested for generalization to the other locomotor task. In the precision stepping task, we determined the lateral end-point error of foot placement from the targets. In the obstacle avoidance task, we determined toe clearance and lateral foot placement distance from the obstacle before and after stepping over the obstacle. We found large, rightward deviations in foot placement on initial exposure to prisms in both tasks. The majority of measures demonstrated adaptation over repeated trials, and adaptation rates were dependent mainly on the task. On removal of the prisms, we observed negative aftereffects for measures of both tasks. Additionally, we found a unilateral symmetric generalization pattern in that the left, but not the right, lower limb indicated generalization across the 2 locomotor tasks. These results indicate that the nervous system is capable of rapidly adapting to a visuomotor mismatch during visually demanding locomotor tasks and that the prism-induced adaptation can, at least partially, generalize across these tasks. The results also support the notion that the nervous system utilizes an internal model for the control of visually guided locomotion.

  10. Adaptive beam tracking and steering via electrowetting-controlled liquid prism

    NASA Astrophysics Data System (ADS)

    Cheng, Jiangtao; Chen, Chung-Lung

    2011-11-01

    We report an electrowetting-controlled optofluidic system for adaptive beam tracking and agile steering. With two immiscible fluids in a transparent cell, we can actively control the contact angle along the fluid-fluid-solid tri-junction line and hence the orientation of the fluid-fluid interface via electrowetting. The naturally formed meniscus between the two liquids can function as an optical prism. We have fabricated a liquid prism module with an aperture size of 10 mm × 10mm. With 1 wt. % KCl and 1 wt. % Sodium Dodecyl Sulfate added into deionized water, the orientation of the water-silicone oil interface has been modulated between -26° and 26° that can deflect and steer beam within the incidence angle of 0°-15°. The wide-range beam tracking and steering enables the liquid prism work as an electrowetting solar cell.

  11. Pupillary Light Reflexes are Associated with Autonomic Dysfunction in Bolivian Diabetics But Not Chagas Disease Patients.

    PubMed

    Halperin, Anthony; Pajuelo, Monica; Tornheim, Jeffrey A; Vu, Nancy; Carnero, Andrés M; Galdos-Cardenas, Gerson; Ferrufino, Lisbeth; Camacho, Marilyn; Justiniano, Juan; Colanzi, Rony; Bowman, Natalie M; Morris, Tiffany; MacDougall, Hamish; Bern, Caryn; Moore, Steven T; Gilman, Robert H

    2016-06-01

    Autonomic dysfunction is common in Chagas disease and diabetes. Patients with either condition complicated by cardiac autonomic dysfunction face increased mortality, but no clinical predictors of autonomic dysfunction exist. Pupillary light reflexes (PLRs) may identify such patients early, allowing for intensified treatment. To evaluate the significance of PLRs, adults were recruited from the outpatient endocrine, cardiology, and surgical clinics at a Bolivian teaching hospital. After testing for Chagas disease and diabetes, participants completed conventional autonomic testing (CAT) evaluating their cardiovascular responses to Valsalva, deep breathing, and orthostatic changes. PLRs were measured using specially designed goggles, then CAT and PLRs were compared as measures of autonomic dysfunction. This study analyzed 163 adults, including 96 with Chagas disease, 35 patients with diabetes, and 32 controls. PLRs were not significantly different between Chagas disease patients and controls. Patients with diabetes had longer latency to onset of pupil constriction, slower maximum constriction velocities, and smaller orthostatic ratios than nonpatients with diabetes. PLRs correlated poorly with CAT results. A PLR-based clinical risk score demonstrated a 2.27-fold increased likelihood of diabetes complicated by autonomic dysfunction compared with the combination of blood tests, CAT, and PLRs (sensitivity 87.9%, specificity 61.3%). PLRs represent a promising tool for evaluating subclinical neuropathy in patients with diabetes without symptomatic autonomic dysfunction. Pupillometry does not have a role in the evaluation of Chagas disease patients. © The American Society of Tropical Medicine and Hygiene.

  12. Enteromegaly and cardiomegaly in Chagas disease

    PubMed Central

    Köberle, Fritz

    1963-01-01

    Chagas disease due to a trypanosome infection may lead to extensive destruction of ganglion cells in the peripheral autonomic system and may result in gross enlargement of the oesophagus, colon, and heart. From studies on nerve cell counts it is concluded that the number of ganglion cells in the oesophagus must be reduced to less than half to produce functional disturbances in the oesophagus and to one tenth to produce a megaoesophagus. Problems of terminology are discussed. PMID:14084752

  13. Forward and inverse solutions for Risley prism based on the Denavit-Hartenberg methodology

    NASA Astrophysics Data System (ADS)

    Beltran-Gonzalez, A.; Garcia-Torales, G.; Strojnik, M.; Flores, J. L.; Garcia-Luna, J. L.

    2017-08-01

    In this work forward and inverse solutions for two-element Risley prism for pointing and scanning beam systems are developed. A more efficient and faster algorithm is proposed to make an analogy of the Risley prism system compared with a robotic system with two degrees of freedom. This system of equations controls each Risley prism individually as a planar manipulator arm of two links. In order to evaluate the algorithm we implement it in a pointing system. We perform popular routines such as the linear, spiral and loops traces. Using forward and inverse solutions for two-element Risley prism it is also possible to point at coordinates specified by the user, provided they are within the pointer area of work area. Experimental results are showed as a validation of our proposal.

  14. Chagas disease diagnostic applications: present knowledge and future steps

    PubMed Central

    Balouz, Virginia; Agüero, Fernán; Buscaglia, Carlos A.

    2017-01-01

    Chagas disease, caused by the protozoan Trypanosoma cruzi, is a life-long and debilitating illness of major significance throughout Latin America, and an emergent threat to global public health. Being a neglected disease, the vast majority of Chagasic patients have limited access to proper diagnosis and treatment, and there is only a marginal investment into R&D for drug and vaccine development. In this context, identification of novel biomarkers able to transcend the current limits of diagnostic methods surfaces as a main priority in Chagas disease applied research. The expectation is that these novel biomarkers will provide reliable, reproducible and accurate results irrespective of the genetic background, infecting parasite strain, stage of disease, and clinical-associated features of Chagasic populations. In addition, they should be able to address other still unmet diagnostic needs, including early detection of congenital T. cruzi transmission, rapid assessment of treatment efficiency or failure, indication/prediction of disease progression and direct parasite typification in clinical samples. The lack of access of poor and neglected populations to essential diagnostics also stress the necessity of developing new methods operational in Point-of-Care (PoC) settings. In summary, emergent diagnostic tests integrating these novel and tailored tools should provide a significant impact on the effectiveness of current intervention schemes and on the clinical management of Chagasic patients. In this chapter, we discuss the present knowledge and possible future steps in Chagas disease diagnostic applications, as well as the opportunity provided by recent advances in high-throughput methods for biomarker discovery. PMID:28325368

  15. Accelerating the development of a therapeutic vaccine for human Chagas disease: rationale and prospects

    PubMed Central

    Zhan, Bin; Heffernan, Michael J; Jones, Kathryn; Valenzuela, Jesus G; Kamhawi, Shaden; Ortega, Jaime; de Leon Rosales, Samuel Ponce; Lee, Bruce Y; Bacon, Kristina M; Fleischer, Bernhard; Slingsby, BT; Cravioto, Miguel Betancourt; Tapia-Conyer, Roberto

    2013-01-01

    Chagas disease is a leading cause of heart disease affecting approximately 10 million people in Latin America and elsewhere worldwide. The two major drugs available for the treatment of Chagas disease have limited efficacy in Trypanosoma cruzi-infected adults with indeterminate (patients who have seroconverted but do not yet show signs or symptoms) and determinate (patients who have both seroconverted and have clinical disease) status; they require prolonged treatment courses and are poorly tolerated and expensive. As an alternative to chemotherapy, an injectable therapeutic Chagas disease vaccine is under development to prevent or delay Chagasic cardiomyopathy in patients with indeterminate or determinate status. The bivalent vaccine will be comprised of two recombinant T. cruzi antigens, Tc24 and TSA-1, formulated on alum together with the Toll-like receptor 4 agonist, E6020. Proof-of-concept for the efficacy of these antigens was obtained in preclinical testing at the Autonomous University of Yucatan. Here the authors discuss the potential for a therapeutic Chagas vaccine as well as the progress made towards such a vaccine, and the authors articulate a roadmap for the development of the vaccine as planned by the nonprofit Sabin Vaccine Institute Product Development Partnership and Texas Children’s Hospital Center for Vaccine Development in collaboration with an international consortium of academic and industrial partners in Mexico, Germany, Japan, and the USA. PMID:23151163

  16. Accelerating the development of a therapeutic vaccine for human Chagas disease: rationale and prospects.

    PubMed

    Dumonteil, Eric; Bottazzi, Maria Elena; Zhan, Bin; Heffernan, Michael J; Jones, Kathryn; Valenzuela, Jesus G; Kamhawi, Shaden; Ortega, Jaime; de Leon Rosales, Samuel Ponce; Lee, Bruce Y; Bacon, Kristina M; Fleischer, Bernhard; Slingsby, B T; Cravioto, Miguel Betancourt; Tapia-Conyer, Roberto; Hotez, Peter J

    2012-09-01

    Chagas disease is a leading cause of heart disease affecting approximately 10 million people in Latin America and elsewhere worldwide. The two major drugs available for the treatment of Chagas disease have limited efficacy in Trypanosoma cruzi-infected adults with indeterminate (patients who have seroconverted but do not yet show signs or symptoms) and determinate (patients who have both seroconverted and have clinical disease) status; they require prolonged treatment courses and are poorly tolerated and expensive. As an alternative to chemotherapy, an injectable therapeutic Chagas disease vaccine is under development to prevent or delay Chagasic cardiomyopathy in patients with indeterminate or determinate status. The bivalent vaccine will be comprised of two recombinant T. cruzi antigens, Tc24 and TSA-1, formulated on alum together with the Toll-like receptor 4 agonist, E6020. Proof-of-concept for the efficacy of these antigens was obtained in preclinical testing at the Autonomous University of Yucatan. Here the authors discuss the potential for a therapeutic Chagas vaccine as well as the progress made towards such a vaccine, and the authors articulate a roadmap for the development of the vaccine as planned by the nonprofit Sabin Vaccine Institute Product Development Partnership and Texas Children's Hospital Center for Vaccine Development in collaboration with an international consortium of academic and industrial partners in Mexico, Germany, Japan, and the USA.

  17. Antagonistic Effect of Atorvastatin on High Fat Diet Induced Survival during Acute Chagas Disease

    PubMed Central

    Zhao, Dazhi; Lizardo, Kezia; Cui, Min Hui; Ambadipudi, Kamalakar; Lora, Jose; Jelicks, Linda A; Nagajyothi, Jyothi F

    2016-01-01

    Chagasic cardiomyopathy, which is seen in Chagas Disease, is the most severe and life-threatening manifestation of infection by the kinetoplastid Trypanosoma cruzi. Adipose tissue and diet play a major role in maintaining lipid homeostasis and regulating cardiac pathogenesis during the development of Chagas cardiomyopathy. We have previously reported that T. cruzi has a high affinity for lipoproteins and that the invasion rate of this parasite increases in the presence of cholesterol, suggesting that drugs that inhibit cholesterol synthesis, such as statins, could affect infection and the development of Chagasic cardiomyopathy. The dual epidemic of diabetes and obesity in Latin America, the endemic regions for Chagas Disease, has led to many patients in the endemic region of infection having hyperlipidemia that is being treated with statins such as atorvastatin. The current study was performed to examine using mice fed on either regular or high fat diet the effect of atorvastatin on T. cruzi infection-induced myocarditis and to evaluate the effect of this treatment during infection on adipose tissue physiology and cardiac pathology. Atorvastatin was found to regulate lipolysis and cardiac lipidopathy during acute T. cruzi infection in mice and to enhance tissue parasite load, cardiac LDL levels, inflammation, and mortality in during acute infection. Overall, these data suggest that statins, such as atorvastatin, have deleterious effects during acute Chagas disease. PMID:27416748

  18. PRISM, a Novel Visual Metaphor Measuring Personally Salient Appraisals, Attitudes and Decision-Making: Qualitative Evidence Synthesis

    PubMed Central

    Sensky, Tom; Büchi, Stefan

    2016-01-01

    Background PRISM (the Pictorial Representation of Illness and Self Measure) is a novel, simple visual instrument. Its utility was initially discovered serendipitously, but has been validated as a quantitative measure of suffering. Recently, new applications for different purposes, even in non-health settings, have encouraged further exploration of how PRISM works, and how it might be applied. This review will summarise the results to date from applications of PRISM and propose a generic conceptualisation of how PRISM works which is consistent with all these applications. Methods A systematic review, in the form of a qualitative evidence synthesis, was carried out of all available published data on PRISM. Results Fifty-two publications were identified, with a total of 8254 participants. Facilitated by simple instructions, PRISM has been used with patient groups in a variety of settings and cultures. As a measure of suffering, PRISM has, with few exceptions, behaved as expected according to Eric Cassell’s seminal conceptualisation of suffering. PRISM has also been used to assess beliefs about or attitudes to stressful working conditions, interpersonal relations, alcohol consumption, and suicide, amongst others. Discussion This review supports PRISM behaving as a visual metaphor of the relationship of objects (eg ‘my illness’) to a subject (eg ‘myself’) in a defined context (eg ‘my life at the moment’). As a visual metaphor, it is quick to complete and yields personally salient information. PRISM is likely to have wide applications in assessing beliefs, attitudes, and decision-making, because of its properties, and because it yields both quantitative and qualitative data. In medicine, it can serve as a generic patient-reported outcome measure. It can serve as a tool for representational guidance, can be applied to developing strategies visually, and is likely to have applications in coaching, psychological assessment and therapeutic interventions. PMID

  19. PRISM, a Novel Visual Metaphor Measuring Personally Salient Appraisals, Attitudes and Decision-Making: Qualitative Evidence Synthesis.

    PubMed

    Sensky, Tom; Büchi, Stefan

    2016-01-01

    PRISM (the Pictorial Representation of Illness and Self Measure) is a novel, simple visual instrument. Its utility was initially discovered serendipitously, but has been validated as a quantitative measure of suffering. Recently, new applications for different purposes, even in non-health settings, have encouraged further exploration of how PRISM works, and how it might be applied. This review will summarise the results to date from applications of PRISM and propose a generic conceptualisation of how PRISM works which is consistent with all these applications. A systematic review, in the form of a qualitative evidence synthesis, was carried out of all available published data on PRISM. Fifty-two publications were identified, with a total of 8254 participants. Facilitated by simple instructions, PRISM has been used with patient groups in a variety of settings and cultures. As a measure of suffering, PRISM has, with few exceptions, behaved as expected according to Eric Cassell's seminal conceptualisation of suffering. PRISM has also been used to assess beliefs about or attitudes to stressful working conditions, interpersonal relations, alcohol consumption, and suicide, amongst others. This review supports PRISM behaving as a visual metaphor of the relationship of objects (eg 'my illness') to a subject (eg 'myself') in a defined context (eg 'my life at the moment'). As a visual metaphor, it is quick to complete and yields personally salient information. PRISM is likely to have wide applications in assessing beliefs, attitudes, and decision-making, because of its properties, and because it yields both quantitative and qualitative data. In medicine, it can serve as a generic patient-reported outcome measure. It can serve as a tool for representational guidance, can be applied to developing strategies visually, and is likely to have applications in coaching, psychological assessment and therapeutic interventions.

  20. Usefulness of FC-TRIPLEX Chagas/Leish IgG1 as confirmatory assay for non-negative results in blood bank screening of Chagas disease.

    PubMed

    Campos, Fernanda Magalhães Freire; Repoles, Laura Cotta; de Araújo, Fernanda Fortes; Peruhype-Magalhães, Vanessa; Xavier, Marcelo Antônio Pascoal; Sabino, Ester Cerdeira; de Freitas Carneiro Proietti, Anna Bárbara; Andrade, Mariléia Chaves; Teixeira-Carvalho, Andréa; Martins-Filho, Olindo Assis; Gontijo, Célia Maria Ferreira

    2018-04-01

    A relevant issue in Chagas disease serological diagnosis regards the requirement of using several confirmatory methods to elucidate the status of non-negative results from blood bank screening. The development of a single reliable method may potentially contribute to distinguish true and false positive results. Our aim was to evaluate the performance of the multiplexed flow-cytometry anti-T. cruzi/Leishmania IgG1 serology/(FC-TRIPLEX Chagas/Leish IgG1) with three conventional confirmatory criteria (ELISA-EIA, Immunofluorescence assay-IIF and EIA/IIF consensus criterion) to define the final status of samples with actual/previous non-negative results during anti-T. cruzi ELISA-screening in blood banks. Apart from inconclusive results, the FC-TRIPLEX presented a weak agreement index with EIA, while a strong agreement was observed when either IIF or EIA/IIF consensus criteria were applied. Discriminant analysis and Spearman's correlation further corroborates the agreement scores. ROC curve analysis showed that FC-TRIPLEX performance indexes were higher when IIF and EIA/IIF consensus were used as a confirmatory criterion. Logistic regression analysis further demonstrated that the probability of FC-TRIPLEX to yield positive results was higher for inconclusive results from IIF and EIA/IIF consensus. Machine learning tools illustrated the high level of categorical agreement between FC-TRIPLEX versus IIF or EIA/IIF consensus. Together, these findings demonstrated the usefulness of FC-TRIPLEX as a tool to elucidate the status of non-negative results in blood bank screening of Chagas disease. Copyright © 2018. Published by Elsevier B.V.

  1. Ischemic stroke classification and risk of embolism in patients with Chagas disease.

    PubMed

    Montanaro, Vinícius Viana Abreu; da Silva, Creuza Maria; de Viana Santos, Carla Verônica; Lima, Maria Inacia Ruas; Negrão, Edson Marcio; de Freitas, Gabriel R

    2016-12-01

    Ischemic stroke (IS) and Chagas disease are strongly related. Nevertheless, little attention has been paid to this association and its natural history. The current guidelines concerning the management and secondary prevention of IS are largely based on the incomplete information or extrapolation of knowledge from other stroke etiologies. We performed a retrospective study which compared stroke etiologies among a cohort of hospitalized patients with IS and Chagas disease. The Instituto de Pesquisa Evandro Chagas/Fundação Oswaldo Cruz (IPEC/FIOCRUZ) embolic score was also used to identify and evaluate the risk of embolism in this population. A total of 86 patients were included in the analysis. The mean age of the study population was 58 years, and 60 % were men. According to the Trial of Org 10172 in Acute Stroke Treatment (TOAST) Classification, 45 % of the strokes were of undetermined etiology and 45 % of cardioembolic origin, while the Stop Stroke Study/Causative Classification System (SSS/CCS) TOAST indicated that 34 % were undetermined and 50 % cardioembolic (p < 0.01); 44 % of these patients were classified as having a high embolic risk according to the IPEC/FIOCRUZ score. Among the undetermined causes, 83.3 % fulfilled the criteria for embolic stroke of undetermined source (ESUS). The SSS/CCS TOAST etiological classification system was superior to the classical TOAST criteria in identifying a cardioembolic etiology in patients with ischemic stroke and Chagas disease. The IPEC/FIOCRUZ score did not correlate with the number of patients who were determined to have cardioembolic stroke etiologies. The current guidelines for stroke prevention should be reviewed in this population.

  2. [Knowledge of vector-borne diseases (dengue, rickettsiosis and Chagas disease) in physicians].

    PubMed

    Lugo-Caballero, César I; Dzul-Rosado, Karla; Dzul-Tut, Irving; Balam-May, Ángel; Zavala-Castro, Jorge

    2017-01-01

    The ecological conditions of Yucatan made it a suitable region for the acquisition of vector-borne diseases such as dengue, rickettsiosis, and Chagas disease. As the epidemiological burden of these diseases shows an alarming increase of severe cases, the early establishment of diagnosis and therapeutics by first-contact physicians is a critical step that is not being fulfilled due to several reasons, including poor knowledge. To determine the level of knowledge related to dengue, Chagas disease, and rickettsiosis among rural first-contact physicians of Yucatan. A survey was applied to 90 first-contact physicians from rural clinics of Yucatan, which included 32 items related to the diagnosis, treatment, and prevention of dengue, rickettsiosis, and Chagas disease. Answers were analyzed by central tendency statistics. Differences were observed among every category, however; diagnosis and therapeutics showed the lower values. Globally, 62.5% of respondents showed moderate knowledge, 37.5% poor knowledge, and 0% adequate knowledge. Results suggest that a strong campaign for a continuous diffusion of knowledge regarding these diseases is needed. In regions with high prevalence of these kinds of diseases, like Yucatan, the impact of these results on the epidemiological burden of these diseases must be evaluated.

  3. PRISM4: Pliocene Research, Interpretation and Synoptic Mapping mid Piacenzian paleoenvironmental reconstruction

    NASA Astrophysics Data System (ADS)

    Dowsett, H. J.; Dolan, A. M.; Rowley, D. B.; Moucha, R.; Forte, A. M.; Mitrovica, J. X.; Pound, M. J.; Salzmann, U.; Robinson, M. M.; Chandler, M. A.; Foley, K.; Haywood, A.

    2016-12-01

    Past Intervals in Earth history provide unique windows into conditions much different than those observed today. We investigated the paleoenvironments of a past warm interval in the mid Piacenzian ( 3 million years ago). The PRISM4 reconstruction contains twelve internally consistent and integrated data sets representing our best synoptic understanding of surface temperature, vegetation, soils, lakes, ice sheets, topography, and bathymetry. Starting points in the generation of our Piacenzian reconstruction are basic geochemical, faunal, floral, soil, cryospheric, topographic, bathymetric, sedimentologic, and stratigraphic data. Marine and terrestral temperature estimates are based upon multiple proxies (including faunal, floral, geochemical, and biomarker analyses). The reconstruction of Piacenzian global vegetation is based on the integration of paleobotanical data and BIOME4 model outputs. Antarctic and Greenland ice sheets are derived from the previous PRISM3 and PLISMIP (Pliocene Ice Sheet Model Intercomparison Project) results, respectively. Paleogeography is based upon an initial ETOPO1 digital elevation model incorporating PRISM4 ice sheets, GIA, and adjustments due to mantle convection. Soils are determined through comparison of sedimentological and stratigraphic data with the BIOME reconstruction. Lakes are determined from stratigraphic and sedimentological data. Sea-level equivalent (+20 m) is estimated from the reduced volume of the PRISM4 ice sheets and is consistent with our PRISM4 paleogeography. While not an analog for future conditions, the PRISM4 conceptual reconstruction provides insights into processes that occurred in the past and can inform us about the future. We will discuss the use of these data as boundary conditions and verification for global climate model simulations of the Pliocene, aimed at improving our understanding of the climate system as we prepare for future changes.

  4. XeCl excimer laser with new prism resonator configurations and its performance characteristics

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Benerji, N. S., E-mail: nsb@rrcat.gov.in, E-mail: bsingh@rrcat.gov.in; Singh, A.; Varshnay, N.

    2015-07-15

    New resonator cavity configurations, namely, the prism resonator and unstable prism resonator, are demonstrated for the first time in an excimer (XeCl) laser with interesting and novel results. High misalignment tolerance ∼50 mrad is achieved with considerably reduced beam divergence of less than ∼1 mrad without reduction in output power capabilities of the laser. The misalignment tolerance of ∼50 mrad is a dramatic improvement of ∼25 times compared to ∼2 mrad normally observed in standard excimer laser with plane-plane cavity. Increase in depth of focus from 3 mm to 5.5 mm was also achieved in case of prism resonator configurationmore » with an improvement of about 60%. Unstable prism resonator configuration is demonstrated here in this paper with further reduction in beam divergence to about 0.5 mrad using plano-convex lens as output coupler. The misalignment tolerance in case of unstable prism resonator was retained at about 30 mrad which is a high value compared to standard unstable resonators. The output beam spot was completely filled with flat-top profile with prism resonator configurations, which is desired for various material processing applications. Focusing properties and beam divergence in case of prism resonator have been investigated using SEM (scanning electron microscope) images. SEM images of the focused spot size (∼20 μm holes) on metal sheet indicate beam divergence of about 0.05 mrad which is about 1.5 times diffraction limit. Energy contained in this angle is thus sufficient for micro-machining applications. Clean and sharp edges of the micro-holes show high pointing stability with multiple shot exposures. Such characteristics of the excimer laser system will be extremely useful in micro-machining and other field applications.« less

  5. XeCl excimer laser with new prism resonator configurations and its performance characteristics.

    PubMed

    Benerji, N S; Singh, A; Varshnay, N; Singh, Bijendra

    2015-07-01

    New resonator cavity configurations, namely, the prism resonator and unstable prism resonator, are demonstrated for the first time in an excimer (XeCl) laser with interesting and novel results. High misalignment tolerance ∼50 mrad is achieved with considerably reduced beam divergence of less than ∼1 mrad without reduction in output power capabilities of the laser. The misalignment tolerance of ∼50 mrad is a dramatic improvement of ∼25 times compared to ∼2 mrad normally observed in standard excimer laser with plane-plane cavity. Increase in depth of focus from 3 mm to 5.5 mm was also achieved in case of prism resonator configuration with an improvement of about 60%. Unstable prism resonator configuration is demonstrated here in this paper with further reduction in beam divergence to about 0.5 mrad using plano-convex lens as output coupler. The misalignment tolerance in case of unstable prism resonator was retained at about 30 mrad which is a high value compared to standard unstable resonators. The output beam spot was completely filled with flat-top profile with prism resonator configurations, which is desired for various material processing applications. Focusing properties and beam divergence in case of prism resonator have been investigated using SEM (scanning electron microscope) images. SEM images of the focused spot size (∼20 μm holes) on metal sheet indicate beam divergence of about 0.05 mrad which is about 1.5 times diffraction limit. Energy contained in this angle is thus sufficient for micro-machining applications. Clean and sharp edges of the micro-holes show high pointing stability with multiple shot exposures. Such characteristics of the excimer laser system will be extremely useful in micro-machining and other field applications.

  6. Effect of prescribed prism on monocular interpupillary distances and fitting heights for progressive add lenses.

    PubMed

    Brooks, C W; Riley, H D

    1994-06-01

    Success in fitting progressive addition lenses is dependent upon the accurate placement of the progressive zone. Both eyes must track simultaneously within the boundary of the progressive corridor. Vertical prism will displace the wearer's lines of sight and consequently eye position. Because fitting heights are measured using an empty frame, subjects with vertical phorias usually will fuse, and not show the vertical differences in pupil heights during the measuring process. Therefore, when prescriptions contain vertical prism one must consider the changes in measured fitting heights that will occur once the lenses are placed in the frame. Fitting heights must be altered approximately 0.3 mm for each vertical prism diopter prescribed. The fitting height adjustment is opposite from the base direction of the prescribed prism. An explanation of the effect of prescribed horizontal prism on monocular interpupillary distance (PD) measurements is also included.

  7. Reflecting Schmidt/Littrow Prism Imaging Spectrometer

    NASA Technical Reports Server (NTRS)

    Breckinridge, J. B.; Page, N. A.; Shack, R. V.; Shannon, R. R.

    1985-01-01

    High resolution achieved with wide field of view. Imaging Spectrometer features off-axis reflecting optics, including reflecting "slit" that also serves as field flattener. Only refracting element is prism. By scanning slit across object or scene and timing out signal, both spectral and spatial information in scene are obtained.

  8. Prism adaptation and spatial neglect: the need for dose-finding studies.

    PubMed

    Goedert, Kelly M; Zhang, Jeffrey Y; Barrett, A M

    2015-01-01

    Spatial neglect is a devastating disorder in 50-70% of right-brain stroke survivors, who have problems attending to, or making movements towards, left-sided stimuli, and experience a high risk of chronic dependence. Prism adaptation is a promising treatment for neglect that involves brief, daily visuo-motor training sessions while wearing optical prisms. Its benefits extend to functional behaviors such as dressing, with effects lasting 6 months or longer. Because one to two sessions of prism adaptation induce adaptive changes in both spatial-motor behavior (Fortis et al., 2011) and brain function (Saj et al., 2013), it is possible stroke patients may benefit from treatment periods shorter than the standard, intensive protocol of ten sessions over two weeks-a protocol that is impractical for either US inpatient or outpatient rehabilitation. Demonstrating the effectiveness of a lower dose will maximize the availability of neglect treatment. We present preliminary data suggesting that four to six sessions of prism treatment may induce a large treatment effect, maintained three to four weeks post-treatment. We call for a systematic, randomized clinical trial to establish the minimal effective dose suitable for stroke intervention.

  9. Prism adaptation and spatial neglect: the need for dose-finding studies

    PubMed Central

    Goedert, Kelly M.; Zhang, Jeffrey Y.; Barrett, A. M.

    2015-01-01

    Spatial neglect is a devastating disorder in 50–70% of right-brain stroke survivors, who have problems attending to, or making movements towards, left-sided stimuli, and experience a high risk of chronic dependence. Prism adaptation is a promising treatment for neglect that involves brief, daily visuo-motor training sessions while wearing optical prisms. Its benefits extend to functional behaviors such as dressing, with effects lasting 6 months or longer. Because one to two sessions of prism adaptation induce adaptive changes in both spatial-motor behavior (Fortis et al., 2011) and brain function (Saj et al., 2013), it is possible stroke patients may benefit from treatment periods shorter than the standard, intensive protocol of ten sessions over two weeks—a protocol that is impractical for either US inpatient or outpatient rehabilitation. Demonstrating the effectiveness of a lower dose will maximize the availability of neglect treatment. We present preliminary data suggesting that four to six sessions of prism treatment may induce a large treatment effect, maintained three to four weeks post-treatment. We call for a systematic, randomized clinical trial to establish the minimal effective dose suitable for stroke intervention. PMID:25983688

  10. Jones matrix formulation of a Porro prism laser resonator with waveplates: theoretical and experimental analysis

    NASA Astrophysics Data System (ADS)

    Agrawal, L.; Bhardwaj, A.; Pal, S.; Kumar, A.

    2007-11-01

    This article presents the results of a detailed theoretical and experimental analysis carried out on a folded Z-shaped polarization coupled, electro-optically Q-switched laser resonator with Porro prisms and waveplates. The advantages of adding waveplates in a Porro prism resonator have been explored for creating high loss condition prior to Q-switching and obtaining variable reflectivity with fixed orientation of Porro prism. Generalized expressions have been derived in terms of azimuth angles and phase shifts introduced by the polarizing elements. These expressions corroborate with known reported results under appropriate substitutions. A specific case of a crossed Porro prism diode-pumped Nd:YAG laser has been theoretically and experimentally investigated. In the feedback arm, a 0.57λ waveplate oriented at 135° completely compensates the phase shift of a fused silica Porro prism and provides better tolerances than a BK-7 prism/0.60λ waveplate combination to stop prelasing. The fused silica prism/0.57λ combination with waveplate at 112° acts like a 100% mirror and was utilized for optimization of free running performance. The effective reflectivity was determined for various orientations of the quarter waveplate in the gain arm to numerically estimate the Q-switched laser pulse parameters through rate equation analysis. Experimental results match well with the theoretical analysis.

  11. Chagas disease: review of needs, neglect, and obstacles to treatment access in Latin America.

    PubMed

    Pinheiro, Eloan; Brum-Soares, Lucia; Reis, Renata; Cubides, Juan-Carlos

    2017-01-01

    After more than one century since its discovery, Chagas disease is still extremely prevalent in 21 Latin American countries. Chagas disease is one of the most concerning public health problems in Latin America; the overall cost of CD treatment is approximately 7 billion United States dollars per year and it has a strong social impact on populations. Little progress has been made regarding the access to diagnosis and treatment at the primary health care level, calling into question the current policies to ensure the right to health and access to essential medications. In this article, diverse dimensions of access to treatment for Chagas disease are reviewed, illustrating the present state of benznidazole medication in relation to global production capacity, costs, and needs. The findings are based on an investigation requested by Médecins Sans Frontières Brazil through a consultancy in 2015, aiming to estimate the current costs of benznidazole production.

  12. Spatial effects of shifting prisms on properties of posterior parietal cortex neurons

    PubMed Central

    Karkhanis, Anushree N; Heider, Barbara; Silva, Fabian Muñoz; Siegel, Ralph M

    2014-01-01

    The posterior parietal cortex contains neurons that respond to visual stimulation and motor behaviour. The objective of the current study was to test short-term adaptation in neurons in macaque area 7a and the dorsal prelunate during visually guided reaching using Fresnel prisms that displaced the visual field. The visual perturbation shifted the eye position and created a mismatch between perceived and actual reach location. Two non-human primates were trained to reach to visual targets before, during and after prism exposure while fixating the reach target in different locations. They were required to reach to the physical location of the reach target and not the perceived, displaced location. While behavioural adaptation to the prisms occurred within a few trials, the majority of neurons responded to the distortion either with substantial changes in spatial eye position tuning or changes in overall firing rate. These changes persisted even after prism removal. The spatial changes were not correlated with the direction of induced prism shift. The transformation of gain fields between conditions was estimated by calculating the translation and rotation in Euler angles. Rotations and translations of the horizontal and vertical spatial components occurred in a systematic manner for the population of neurons suggesting that the posterior parietal cortex retains a constant representation of the visual field remapping between experimental conditions. PMID:24928956

  13. Evaluation of the Elecsys Chagas Assay for Detection of Trypanosoma cruzi-Specific Antibodies in a Multicenter Study in Europe and Latin America.

    PubMed

    Flores-Chavez, Maria Delmans; Sambri, Vittorio; Schottstedt, Volkmar; Higuera-Escalante, Fernando Aparicio; Roessler, Dieter; Chaves, Monica; Laengin, Tina; Martinez, Alfredo; Fleischer, Bernhard

    2018-05-01

    Serology is the preferred method to confirm a Chagas disease diagnosis and to screen blood donors. A battery of assays is often required due to the limited accuracy of single assays. The Elecsys Chagas assay is a newly developed, double-antigen sandwich assay for use on the Elecsys and cobas e immunoassay analyzers, intended to identify individuals infected with Trypanosoma cruzi , for diagnosis and screening. The performance of the Elecsys Chagas assay was evaluated in comparison with those of other widely used T. cruzi antibody assays, at multiple sites (Europe/Latin America). Relative sensitivity and specificity were assessed by using samples from blood donors, pregnant women, and hospitalized patients from regions where Chagas disease is endemic and from regions of nonendemicity. The Elecsys Chagas assay had an overall relative sensitivity of 100% ( n = 674). Overall relative specificities were 99.90% ( n = 14,681), 100% ( n = 313), and 100% ( n = 517) for samples from blood donors, pregnant women, and hospitalized patients, respectively. The analytical specificity was 99.83% ( n = 594). The Elecsys Chagas assay detected T. cruzi antibodies in two World Health Organization (WHO) standard T. cruzi reference panels (panels 09/188 and 09/186) at a 1:512 dilution, corresponding to a cutoff sensitivity of approximately 1 mIU/ml. The Elecsys Chagas assay demonstrated robust performance under routine conditions at multiple sites in Europe and Latin America. In contrast to other available Chagas assays, the Elecsys assay uses a reduced number of recombinant T. cruzi antigens, resulting in a significantly smaller number of cross-reactions and improved analytical specificity while being highly sensitive. Copyright © 2018 Flores-Chavez et al.

  14. Evaluation of the Elecsys Chagas Assay for Detection of Trypanosoma cruzi-Specific Antibodies in a Multicenter Study in Europe and Latin America

    PubMed Central

    Sambri, Vittorio; Schottstedt, Volkmar; Higuera-Escalante, Fernando Aparicio; Roessler, Dieter; Chaves, Monica; Laengin, Tina; Martinez, Alfredo; Fleischer, Bernhard

    2018-01-01

    ABSTRACT Serology is the preferred method to confirm a Chagas disease diagnosis and to screen blood donors. A battery of assays is often required due to the limited accuracy of single assays. The Elecsys Chagas assay is a newly developed, double-antigen sandwich assay for use on the Elecsys and cobas e immunoassay analyzers, intended to identify individuals infected with Trypanosoma cruzi, for diagnosis and screening. The performance of the Elecsys Chagas assay was evaluated in comparison with those of other widely used T. cruzi antibody assays, at multiple sites (Europe/Latin America). Relative sensitivity and specificity were assessed by using samples from blood donors, pregnant women, and hospitalized patients from regions where Chagas disease is endemic and from regions of nonendemicity. The Elecsys Chagas assay had an overall relative sensitivity of 100% (n = 674). Overall relative specificities were 99.90% (n = 14,681), 100% (n = 313), and 100% (n = 517) for samples from blood donors, pregnant women, and hospitalized patients, respectively. The analytical specificity was 99.83% (n = 594). The Elecsys Chagas assay detected T. cruzi antibodies in two World Health Organization (WHO) standard T. cruzi reference panels (panels 09/188 and 09/186) at a 1:512 dilution, corresponding to a cutoff sensitivity of approximately 1 mIU/ml. The Elecsys Chagas assay demonstrated robust performance under routine conditions at multiple sites in Europe and Latin America. In contrast to other available Chagas assays, the Elecsys assay uses a reduced number of recombinant T. cruzi antigens, resulting in a significantly smaller number of cross-reactions and improved analytical specificity while being highly sensitive. PMID:29444836

  15. Use of a Chagas Urine Nanoparticle Test (Chunap) to Correlate with Parasitemia Levels in T. cruzi/HIV Co-infected Patients

    PubMed Central

    Castro-Sesquen, Yagahira E.; Gilman, Robert H.; Mejia, Carolina; Clark, Daniel E.; Choi, Jeong; Reimer-McAtee, Melissa J.; Castro, Rosario; Valencia-Ayala, Edward; Flores, Jorge; Bowman, Natalie; Castillo-Neyra, Ricardo; Torrico, Faustino; Liotta, Lance; Bern, Caryn; Luchini, Alessandra

    2016-01-01

    Background Early diagnosis of reactivated Chagas disease in HIV patients could be lifesaving. In Latin America, the diagnosis is made by microscopical detection of the T. cruzi parasite in the blood; a diagnostic test that lacks sensitivity. This study evaluates if levels of T. cruzi antigens in urine, determined by Chunap (Chagas urine nanoparticle test), are correlated with parasitemia levels in T. cruzi/HIV co-infected patients. Methodology/Principal Findings T. cruzi antigens in urine of HIV patients (N = 55: 31 T. cruzi infected and 24 T. cruzi serology negative) were concentrated using hydrogel particles and quantified by Western Blot and a calibration curve. Reactivation of Chagas disease was defined by the observation of parasites in blood by microscopy. Parasitemia levels in patients with serology positive for Chagas disease were classified as follows: High parasitemia or reactivation of Chagas disease (detectable parasitemia by microscopy), moderate parasitemia (undetectable by microscopy but detectable by qPCR), and negative parasitemia (undetectable by microscopy and qPCR). The percentage of positive results detected by Chunap was: 100% (7/7) in cases of reactivation, 91.7% (11/12) in cases of moderate parasitemia, and 41.7% (5/12) in cases of negative parasitemia. Chunap specificity was found to be 91.7%. Linear regression analysis demonstrated a direct relationship between parasitemia levels and urine T. cruzi antigen concentrations (p<0.001). A cut-off of > 105 pg was chosen to determine patients with reactivation of Chagas disease (7/7). Antigenuria levels were 36.08 times (95% CI: 7.28 to 64.88) higher in patients with CD4+ lymphocyte counts below 200/mL (p = 0.016). No significant differences were found in HIV loads and CD8+ lymphocyte counts. Conclusion Chunap shows potential for early detection of Chagas reactivation. With appropriate adaptation, this diagnostic test can be used to monitor Chagas disease status in T. cruzi/HIV co

  16. Comparing Volumes of Prisms and Pyramids

    ERIC Educational Resources Information Center

    Vinogradova, Natalya

    2012-01-01

    Students' experience in using formulas for volumes is often limited to substituting numbers into given formulas. An activity presented in this article may help students make connections between the formulas for volumes of prisms and volumes of pyramids. In addition, some interesting facts from number theory arise, demonstrating strong connections…

  17. Longitudinal study of patients with chronic Chagas cardiomyopathy in Brazil (SaMi-Trop project): a cohort profile.

    PubMed

    Cardoso, Clareci Silva; Sabino, Ester Cerdeira; Oliveira, Claudia Di Lorenzo; de Oliveira, Lea Campos; Ferreira, Ariela Mota; Cunha-Neto, Edécio; Bierrenbach, Ana Luiza; Ferreira, João Eduardo; Haikal, Desirée Sant'Ana; Reingold, Arthur L; Ribeiro, Antonio Luiz P

    2016-05-04

    We have established a prospective cohort of 1959 patients with chronic Chagas cardiomyopathy to evaluate if a clinical prediction rule based on ECG, brain natriuretic peptide (BNP) levels, and other biomarkers can be useful in clinical practice. This paper outlines the study and baseline characteristics of the participants. The study is being conducted in 21 municipalities of the northern part of Minas Gerais State in Brazil, and includes a follow-up of 2 years. The baseline evaluation included collection of sociodemographic information, social determinants of health, health-related behaviours, comorbidities, medicines in use, history of previous treatment for Chagas disease, functional class, quality of life, blood sample collection, and ECG. Patients were mostly female, aged 50-74 years, with low family income and educational level, with known Chagas disease for >10 years; 46% presented with functional class >II. Previous use of benznidazole was reported by 25.2% and permanent use of pacemaker by 6.2%. Almost half of the patients presented with high blood cholesterol and hypertension, and one-third of them had diabetes mellitus. N-terminal of the prohormone BNP (NT-ProBNP) level was >300 pg/mL in 30% of the sample. Clinical and laboratory markers predictive of severe and progressive Chagas disease were identified as high NT-ProBNP levels, as well as symptoms of advanced heart failure. These results confirm the important residual morbidity of Chagas disease in the remote areas, thus supporting political decisions that should prioritise in addition to epidemiological surveillance the medical treatment of chronic Chagas cardiomyopathy in the coming years. The São Paulo-Minas Gerais Tropical Medicine Research Center (SaMi-Trop) represents a major challenge for focused research in neglected diseases, with knowledge that can be applied in primary healthcare. We will continue following this patients' cohort to provide relevant information about the development

  18. Prevalence of Chagas disease in pregnant women and congenital transmission of Trypanosoma cruzi in Brazil: a systematic review and meta-analysis.

    PubMed

    Martins-Melo, Francisco Rogerlândio; Lima, Mauricélia da Silveira; Ramos, Alberto Novaes; Alencar, Carlos Henrique; Heukelbach, Jörg

    2014-08-01

    To estimate the prevalence of Chagas disease in pregnant women and the risk of congenital transmission of Trypanosoma cruzi infection in Brazil, through a systematic review and meta-analysis. We searched electronic databases, grey literature and reference lists of included publications to identify epidemiological studies on the prevalence of Chagas disease in pregnant women and on the congenital transmission rate of T. cruzi infection in Brazil published between January 1980 and June 2013. Pooled estimates and 95% confidence intervals (95% CIs) were calculated using fixed- and random-effects models. Sixteen articles were included - 12 studies on the prevalence of Chagas disease in pregnant women (549,359 pregnant women) and nine on congenital transmission rates (1687 children born to infected mothers). Prevalence of Chagas disease in pregnant women ranged from 0.1% to 8.5%, and congenital transmission rates from 0% to 5.2%. The pooled prevalence of Chagas disease among pregnant women across studies was 1.1% (95% CI: 0.6-2.0); the pooled congenital transmission rate was 1.7% (95% CI: 0.9-3.1). In 2010, 34,629 pregnant women were estimated to be infected with T. cruzi, and 312-1073 children born (mean: 589 cases) with congenital infection. Congenital Chagas disease is a neglected public health problem in Brazil. Systematic congenital Chagas disease control programs through routine prenatal screening for T. cruzi should be widely implemented in Brazil's endemic areas, to identify infected pregnant women and newborns at risk of congenital infection. © 2014 John Wiley & Sons Ltd.

  19. Anomalous refraction of light colors by a metamaterial prism.

    PubMed

    Silveirinha, Mário G

    2009-05-15

    A prism of glass separates white light into its spectral components in such a manner that colors associated with shorter wavelengths are more refracted than the colors associated with longer wavelengths. Here, we demonstrate that this property is not universal, and that a lossless metamaterial prism with a suitable microstructure may enable a broadband regime of anomalous dispersion, where the spectral components of light are separated in an unconventional way, so that "violet light" is less refracted than "red light." This phenomenon is fundamentally different from conventional anomalous dispersion effects, which are invariably accompanied by significant loss and are typically very narrow band.

  20. Adaptive beam tracking and steering via electrowetting-controlled liquid prism

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Cheng, JT; Chen, CL

    2011-11-07

    We report an electrowetting-controlled optofluidic system for adaptive beam tracking and agile steering. With two immiscible fluids in a transparent cell, we can actively control the contact angle along the fluid-fluid-solid tri-junction line and hence the orientation of the fluid-fluid interface via electrowetting. The naturally formed meniscus between the two liquids can function as an optical prism. We have fabricated a liquid prism module with an aperture size of 10 mm -10mm. With 1 wt.% KCl and 1 wt.% Sodium Dodecyl Sulfate added into deionized water, the orientation of the water-silicone oil interface has been modulated between -26 degrees andmore » 26 degrees that can deflect and steer beam within the incidence angle of 0 degrees-15 degrees. The wide-range beam tracking and steering enables the liquid prism work as an electrowetting solar cell. (C) 2011 American Institute of Physics. [doi: 10.1063/1.3660578]« less

  1. Compact, semi-passive beam steering prism array for solar concentrators.

    PubMed

    Zheng, Cheng; Li, Qiyuan; Rosengarten, Gary; Hawkes, Evatt; Taylor, Robert A

    2017-05-10

    In order to maximize solar energy utilization in a limited space (e.g., rooftops), solar collectors should track the sun. As an alternative to rotational tracking systems, this paper presents a compact, semi-passive beam steering prism array which has been designed, analyzed, and tested for solar applications. The proposed prism array enables a linear concentrator system to remain stationary so that it can integrate with a variety of different solar concentrators, and which should be particularly useful for systems which require a low profile (namely rooftop-mounted systems). A case study of this prism array working within a specific rooftop solar collector demonstrates that it can boost the average daily optical efficiency of the collector by 32.7% and expand its effective working time from 6 h to 7.33 h. Overall, the proposed design provides an alternative way to "follow" the sun for a wide range of solar thermal and photovoltaic concentrator systems.

  2. Single-frequency Nd:YAG ring lasers with corner cube prism

    NASA Astrophysics Data System (ADS)

    Wu, Ke Ying; Yang, Su Hui; Zhao, Chang Ming; Wei, Guang Hui

    2000-04-01

    Kane and Byer reported the first monolithic non-planar miniature ring lasers in 1985. An intrinsic optical diode enforces unidirectional and hence single-frequency oscillation of this device. It has the advantages of compactness, reliability and high efficiency. We put forward another form of the non-planar ring lasers, in which the corner cube prism is the key element and the Nd:YAG crystal is used as a Porro prism to enclose the ring resonator. The phase shift due to the total internal reflections of the three differently orientated reflection planes of the corner cube prism, Faraday rotation in the Nd:YAG crystal placed in a magnetic field and the different output coupling in S and P polarization form an optical diode and enforce the single- frequency generating. A round trip analysis of the polarization properties of the resonator is made by the evaluation of Jones matrix. The results of our initial experiment are given in the paper.

  3. High resolution neutron Larmor diffraction using superconducting magnetic Wollaston prisms

    DOE PAGES

    Li, Fankang; Feng, Hao; Thaler, Alexander N.; ...

    2017-04-13

    The neutron Larmor diffraction technique has been implemented using superconducting magnetic Wollaston prisms in both single-arm and double-arm configurations. Successful measurements of the coefficient of thermal expansion of a single-crystal copper sample demonstrates that the method works as expected. Our experiment involves a new method of tuning by varying the magnetic field configurations in the device and the tuning results agree well with previous measurements. The difference between single-arm and double-arm configurations has been investigated experimentally. Here, we conclude that this measurement benchmarks the applications of magnetic Wollaston prisms in Larmor diffraction and shows in principle that the setup canmore » be used for inelastic phonon line-width measurements. The achievable resolution for Larmor diffraction is comparable to that using Neutron Resonance Spin Echo (NRSE) coils. Furthermore, the use of superconducting materials in the prisms allows high neutron polarization and transmission efficiency to be achieved.« less

  4. Evaluation of the Chagas disease control program in Açucena Municipality, Rio Doce Valley, State of Minas Gerais, Brazil.

    PubMed

    Santos, Adriana dos; Letro, Rejane Balmant; Lemos do Bem, Vitor Antônio; Azeredo, Bernardino Vaz de Melo; Coelho, George Luiz Lins Machado; Diotaiuti, Liléia; Machado-de-Assis, Girley Francisco; de Lana, Marta

    2014-01-01

    Açucena Municipality, Rio Doce Valley, State of Minas Gerais, Brazil temporarily (2001-2005) interrupted epidemiological surveillance for Chagas disease. The objective of this work was to evaluate the Chagas Disease Control Program (CDCP) in Açucena and to offer suggestions for improving local epidemiological surveillance. This study was conducted in three phases: I) a serological investigation of schoolchildren aged 5 to 15 years using an enzyme-linked immunosorbent assay (ELISA) test performed on blood collected on filter paper followed by ELISA, indirect immunofluorescence (IIF) and indirect hemaglutination (IHA) on venous blood for borderline cases and those in the gray zone of reactivity; II) vector evaluation using the data obtained by local health agents during 2006-2010; and III) examination by ELISA, IIF and IHA of serum samples from the inhabitants of houses where infected Triatoma vitticeps was found and evaluation of their knowledge about Chagas disease. Five individuals had inconclusive results in the ELISA screening but were seronegative for Chagas disease. The triatomine evaluation revealed the presence of three species: Triatoma vitticeps, Panstrongylus megistus and Panstrongylus diasi. Triatoma vitticeps was the most prevalent and widespread, with a higher (67%) index of Trypanosoma cruzi flagellates and evidence of colonization. Most of the inhabitants of the infested houses recognized triatomines and had basic knowledge about Chagas disease. Although T. vitticeps is not clearly associated with Chagas disease transmission, these results highlight the importance of maintaining CDCP in endemic areas and the need for greater emphasis on epidemiological surveillance, especially in areas with important vectorial changes or that have been modified by human intervention.

  5. Comparing the Volumes of Rectangular Prisms

    ERIC Educational Resources Information Center

    Assuah, Charles K.; Wiest, Lynda R.

    2010-01-01

    Can middle-grades students determine which of two rectangular prisms has a larger volume? Can they do so without using a formula? Geometry, and particularly the concept of volume, is important in many subjects, such as physics and chemistry. Students greatly enhance their mathematics knowledge when they make generalizations and construct arguments…

  6. Analytic Expressions for the Gravity Gradient Tensor of 3D Prisms with Depth-Dependent Density

    NASA Astrophysics Data System (ADS)

    Jiang, Li; Liu, Jie; Zhang, Jianzhong; Feng, Zhibing

    2017-12-01

    Variable-density sources have been paid more attention in gravity modeling. We conduct the computation of gravity gradient tensor of given mass sources with variable density in this paper. 3D rectangular prisms, as simple building blocks, can be used to approximate well 3D irregular-shaped sources. A polynomial function of depth can represent flexibly the complicated density variations in each prism. Hence, we derive the analytic expressions in closed form for computing all components of the gravity gradient tensor due to a 3D right rectangular prism with an arbitrary-order polynomial density function of depth. The singularity of the expressions is analyzed. The singular points distribute at the corners of the prism or on some of the lines through the edges of the prism in the lower semi-space containing the prism. The expressions are validated, and their numerical stability is also evaluated through numerical tests. The numerical examples with variable-density prism and basin models show that the expressions within their range of numerical stability are superior in computational accuracy and efficiency to the common solution that sums up the effects of a collection of uniform subprisms, and provide an effective method for computing gravity gradient tensor of 3D irregular-shaped sources with complicated density variation. In addition, the tensor computed with variable density is different in magnitude from that with constant density. It demonstrates the importance of the gravity gradient tensor modeling with variable density.

  7. Improving Social Support for Older Adults Through Technology: Findings From the PRISM Randomized Controlled Trial.

    PubMed

    Czaja, Sara J; Boot, Walter R; Charness, Neil; Rogers, Wendy A; Sharit, Joseph

    2018-05-08

    Information and communication technology holds promise in terms of providing support and reducing isolation among older adults. We evaluated the impact of a specially designed computer system for older adults, the Personal Reminder Information and Social Management (PRISM) system. The trial was a multisite randomized field trial conducted at 3 sites. PRISM was compared to a Binder condition wherein participants received a notebook that contained paper content similar to that contained in PRISM. The sample included 300 older adults at risk for social isolation who lived independently in the community (Mage = 76.15 years). Primary outcome measures included indices of social isolation, social support, loneliness, and well-being. Secondary outcome measures included indices of computer proficiency and attitudes toward technology. Data were collected at baseline and at 6 and 12 months post-randomization. The PRISM group reported significantly less loneliness and increased perceived social support and well-being at 6 months. There was a trend indicating a decline in social isolation. Group differences were not maintained at 12 months, but those in the PRISM condition still showed improvements from baseline. There was also an increase in computer self-efficacy, proficiency, and comfort with computers for PRISM participants at 6 and 12 months. The findings suggest that access to technology applications such as PRISM may enhance social connectivity and reduce loneliness among older adults and has the potential to change attitudes toward technology and increase technology self-efficacy.

  8. Echocardiographic features of impaired left ventricular diastolic function in Chagas's heart disease.

    PubMed Central

    Combellas, I; Puigbo, J J; Acquatella, H; Tortoledo, F; Gomez, J R

    1985-01-01

    To study left ventricular diastolic function in Chagas's disease, simultaneous echocardiograms, phonocardiograms, and apexcardiograms were recorded in 20 asymptomatic patients with positive Chagas's serology and no signs of heart disease (group 1), 12 with Chagas's heart disease and symptoms of ventricular arrhythmia but no heart failure (group 2), 20 normal subjects (group 3), and 12 patients with left ventricular hypertrophy (group 4). The recordings were digitised to determine left ventricular isovolumic relaxation time and the rate and duration of left ventricular cavity dimension increase and wall thinning. In groups 1 and 2 (a) aortic valve closure (A2) and mitral valve opening were significantly delayed relative to minimum dimension and were associated with prolonged isovolumic relaxation, (b) left ventricular cavity size was abnormally increased during isovolumic relaxation and abnormally reduced during isovolumic contraction, and (c) peak rate of posterior wall thinning and dimension increase were significantly reduced and duration of posterior wall thinning was significantly prolonged; both of these abnormalities occurred at the onset of diastolic filling. These abnormalities were more pronounced in group 2 and were accompanied by an increase in the height of the apexcardiogram "a" wave, an indication of pronounced atrial systole secondary to end diastolic filling impairment due to reduced left ventricular distensibility. Group 4, which had an established pattern of diastolic abnormalities, showed changes similar to those in group 2; however, the delay in aortic valve closure (A2) and in mitral valve opening and the degree of dimension change were greater in the latter group. Thus early isovolumic relaxation and left ventricular abnormalities were pronounced in the patients with Chagas's heart disease and may precede systolic compromise, which may become apparent in later stages of the disease. The digitised method is valuable in the early detection of

  9. Cardiac Repolarization Abnormalities and Potential Evidence for Loss of Cardiac Sodium Currents on ECGs of Patients with Chagas' Heart Disease

    NASA Technical Reports Server (NTRS)

    Schlegel, T. T.; Medina, R.; Jugo, D.; Nunez, T. J.; Borrego, A.; Arellano, E.; Arenare, B.; DePalma, J. L.; Greco, E. C.; Starc, V.

    2007-01-01

    Some individuals with Chagas disease develop right precordial lead ST segment elevation in response to an ajmaline challenge test, and the prevalence of right bundle branch block (RBBB) is also high in Chagas disease. Because these same electrocardiographic abnormalities occur in the Brugada syndrome, which involves genetically defective cardiac sodium channels, acquired damage to cardiac sodium channels may also occur in Chagas disease. We studied several conventional and advanced resting 12-lead/derived Frank-lead ECG parameters in 34 patients with Chagas -related heart disease (mean age 39 14 years) and in 34 age-/gender-matched healthy controls. All ECG recordings were of 5-10 min duration, obtained in the supine position using high fidelity hardware/software (CardioSoft, Houston, TX). Even after excluding those Chagas patients who had resting BBBs, tachycardia and/or pathologic arrhythmia (n=8), significant differences remained in multiple conventional and advanced ECG parameters between the Chagas and control groups (n=26/group), especially in their respective QT interval variability indices, maximal spatial QRS-T angles and low frequency HRV powers (p=0.0006, p=0.0015 and p=0.0314 respectively). In relation to the issue of potential damage to cardiac sodium channels, the Chagas patients had: 1) greater than or equal to twice the incidence of resting ST segment elevation in leads V1-V3 (n=10/26 vs. n=5/26) and of both leftward (n=5/26 versus n=0/26) and rightward (n=7/26 versus n=3/26) QRS axis deviation than controls; 2) significantly increased filtered (40-250 Hz) QRS interval durations (92.1 8.5 versus 85.3 plus or minus 9.0 ms, p=0.022) versus controls; and 3) significantly decreased QT and especially JT interval durations versus controls (QT interval: 387.5 plus or minus 26.4 versus 408.9 plus or minus 34.6 ms, p=0.013; JT interval: 290.5 plus or minus 26.3 versus 314.8 plus or minus 31.3 ms; p=0.0029). Heart rates and Bazett-corrected QTc/JTc intervals

  10. Fusional vergence detected by prism bar and synoptophore in chinese childhood intermittent exotropia.

    PubMed

    Fu, Tao; Wang, Jing; Levin, Moran; Su, Qing; Li, Dongguo; Li, Junfa

    2015-01-01

    Purpose. To measure the changes in fusional vergence in Chinese children with intermittent exotropia (IXT) and the association with the control of IXT. Methods. Ninety-two patients with IXT (8-15 years old) were compared with 86 controls. Exodeviation control was evaluated using the Revised Newcastle Control Score. Angle of deviation was measured using prism and alternate cover testing at distance and near. Fusional vergence was measured using prism bar and synoptophore. This study was registered with ChiCTR-RCC-13003920. Results. Using prism bar, convergence break points were lower whereas divergence break points were higher in children with IXT at distance (P < 0.001) and near (P < 0.001) compared with controls. There was no significant difference in mean divergence amplitudes between the two groups when testing using a synoptophore (P = 0.53). In children with IXT, the distance between recovery point and break point in both convergence (distance: P = 0.02; near: P = 0.02) and divergence (distance: P < 0.001; near: P < 0.001) was larger than controls when detected by prism bar and synoptophore (convergence: P = 0.005; divergence: P = 0.006). Conclusions. Children with IXT have reduced convergence amplitudes as detected by both prism bar and synoptophore.

  11. Predicting protein-protein interactions on a proteome scale by matching evolutionary and structural similarities at interfaces using PRISM.

    PubMed

    Tuncbag, Nurcan; Gursoy, Attila; Nussinov, Ruth; Keskin, Ozlem

    2011-08-11

    Prediction of protein-protein interactions at the structural level on the proteome scale is important because it allows prediction of protein function, helps drug discovery and takes steps toward genome-wide structural systems biology. We provide a protocol (termed PRISM, protein interactions by structural matching) for large-scale prediction of protein-protein interactions and assembly of protein complex structures. The method consists of two components: rigid-body structural comparisons of target proteins to known template protein-protein interfaces and flexible refinement using a docking energy function. The PRISM rationale follows our observation that globally different protein structures can interact via similar architectural motifs. PRISM predicts binding residues by using structural similarity and evolutionary conservation of putative binding residue 'hot spots'. Ultimately, PRISM could help to construct cellular pathways and functional, proteome-scale annotation. PRISM is implemented in Python and runs in a UNIX environment. The program accepts Protein Data Bank-formatted protein structures and is available at http://prism.ccbb.ku.edu.tr/prism_protocol/.

  12. Quantitative evaluation of human cerebellum-dependent motor learning through prism adaptation of hand-reaching movement.

    PubMed

    Hashimoto, Yuji; Honda, Takeru; Matsumura, Ken; Nakao, Makoto; Soga, Kazumasa; Katano, Kazuhiko; Yokota, Takanori; Mizusawa, Hidehiro; Nagao, Soichi; Ishikawa, Kinya

    2015-01-01

    The cerebellum plays important roles in motor coordination and learning. However, motor learning has not been quantitatively evaluated clinically. It thus remains unclear how motor learning is influenced by cerebellar diseases or aging, and is related with incoordination. Here, we present a new application for testing human cerebellum-dependent motor learning using prism adaptation. In our paradigm, the participant wearing prism-equipped goggles touches their index finger to the target presented on a touchscreen in every trial. The whole test consisted of three consecutive sessions: (1) 50 trials with normal vision (BASELINE), (2) 100 trials wearing the prism that shifts the visual field 25° rightward (PRISM), and (3) 50 trials without the prism (REMOVAL). In healthy subjects, the prism-induced finger-touch error, i.e., the distance between touch and target positions, was decreased gradually by motor learning through repetition of trials. We found that such motor learning could be quantified using the "adaptability index (AI)", which was calculated by multiplying each probability of [acquisition in the last 10 trials of PRISM], [retention in the initial five trials of REMOVAL], and [extinction in the last 10 trials of REMOVAL]. The AI of cerebellar patients less than 70 years old (mean, 0.227; n = 62) was lower than that of age-matched healthy subjects (0.867, n = 21; p < 0.0001). While AI did not correlate with the magnitude of dysmetria in ataxic patients, it declined in parallel with disease progression, suggesting a close correlation between the impaired cerebellar motor leaning and the dysmetria. Furthermore, AI decreased with aging in the healthy subjects over 70 years old compared with that in the healthy subjects less than 70 years old. We suggest that our paradigm of prism adaptation may allow us to quantitatively assess cerebellar motor learning in both normal and diseased conditions.

  13. Quantitative Evaluation of Human Cerebellum-Dependent Motor Learning through Prism Adaptation of Hand-Reaching Movement

    PubMed Central

    Hashimoto, Yuji; Honda, Takeru; Matsumura, Ken; Nakao, Makoto; Soga, Kazumasa; Katano, Kazuhiko; Yokota, Takanori; Mizusawa, Hidehiro; Nagao, Soichi; Ishikawa, Kinya

    2015-01-01

    The cerebellum plays important roles in motor coordination and learning. However, motor learning has not been quantitatively evaluated clinically. It thus remains unclear how motor learning is influenced by cerebellar diseases or aging, and is related with incoordination. Here, we present a new application for testing human cerebellum-dependent motor learning using prism adaptation. In our paradigm, the participant wearing prism-equipped goggles touches their index finger to the target presented on a touchscreen in every trial. The whole test consisted of three consecutive sessions: (1) 50 trials with normal vision (BASELINE), (2) 100 trials wearing the prism that shifts the visual field 25° rightward (PRISM), and (3) 50 trials without the prism (REMOVAL). In healthy subjects, the prism-induced finger-touch error, i.e., the distance between touch and target positions, was decreased gradually by motor learning through repetition of trials. We found that such motor learning could be quantified using the “adaptability index (AI)”, which was calculated by multiplying each probability of [acquisition in the last 10 trials of PRISM], [retention in the initial five trials of REMOVAL], and [extinction in the last 10 trials of REMOVAL]. The AI of cerebellar patients less than 70 years old (mean, 0.227; n = 62) was lower than that of age-matched healthy subjects (0.867, n = 21; p < 0.0001). While AI did not correlate with the magnitude of dysmetria in ataxic patients, it declined in parallel with disease progression, suggesting a close correlation between the impaired cerebellar motor leaning and the dysmetria. Furthermore, AI decreased with aging in the healthy subjects over 70 years old compared with that in the healthy subjects less than 70 years old. We suggest that our paradigm of prism adaptation may allow us to quantitatively assess cerebellar motor learning in both normal and diseased conditions. PMID:25785588

  14. Train integrity detection risk analysis based on PRISM

    NASA Astrophysics Data System (ADS)

    Wen, Yuan

    2018-04-01

    GNSS based Train Integrity Monitoring System (TIMS) is an effective and low-cost detection scheme for train integrity detection. However, as an external auxiliary system of CTCS, GNSS may be influenced by external environments, such as uncertainty of wireless communication channels, which may lead to the failure of communication and positioning. In order to guarantee the reliability and safety of train operation, a risk analysis method of train integrity detection based on PRISM is proposed in this article. First, we analyze the risk factors (in GNSS communication process and the on-board communication process) and model them. Then, we evaluate the performance of the model in PRISM based on the field data. Finally, we discuss how these risk factors influence the train integrity detection process.

  15. Limited infant exposure to benznidazole through breast milk during maternal treatment for Chagas disease.

    PubMed

    García-Bournissen, Facundo; Moroni, Samanta; Marson, Maria Elena; Moscatelli, Guillermo; Mastrantonio, Guido; Bisio, Margarita; Cornou, Laura; Ballering, Griselda; Altcheh, Jaime

    2015-01-01

    Benznidazole (BNZ) is safe and effective for the treatment of paediatric Chagas disease. Treatment of adults is also effective in many cases, but discouraged in breastfeeding women because no information on BNZ transfer into breast milk is available. We aimed to evaluate the degree of BNZ transfer into breast milk in lactating women with Chagas disease. Prospective cohort study of lactating women with Chagas disease treated with BNZ administered for 30 days. Patients and their breastfed infants were evaluated at admission, the 7th and 30th day of treatment (and monthly thereafter, for 6 months). BNZ was measured in plasma and milk by high performance liquid chromatography. The protocol was registered in ClinicalTrials.gov (#NCT01547533). 12 lactating women with chronic Chagas disease were enrolled (median age 28.5 years, range 20-34). Median BNZ dose was 5.65 mg/kg/day twice daily. Five mothers had adverse drug events (45%), but no adverse drug reactions or any untoward outcomes were observed in the breastfed infants. Median milk BNZ concentration was 3.8 mg/L (range 0.3-5.9) and 6.26 mg/L (range 0.3-12.6) in plasma. Median BNZ milk to plasma ratio was 0.52 (range 0.3-2.79). Median relative BNZ dose received by the infant (assuming a daily breast milk intake of 150 mL/kg/day) was 12.3% of the maternal dose per kg (range 5.5%-17%). The limited transference of BNZ into breast milk and the reassuring normal clinical evaluation of the breastfed babies suggest that maternal BNZ treatment for Chagas disease during breast feeding is unlikely to present a risk for the breastfed infant. ClinicalTrials.gov NCT01547533. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

  16. Access to benznidazole for Chagas disease in the United States-Cautious optimism?

    PubMed

    Alpern, Jonathan D; Lopez-Velez, Rogelio; Stauffer, William M

    2017-09-01

    Drugs for neglected tropical diseases (NTD) are being excessively priced in the United States. Benznidazole, the first-line drug for Chagas disease, may become approved by the Food and Drug Administration (FDA) and manufactured by a private company in the US, thus placing it at risk of similar pricing. Chagas disease is an NTD caused by Trypanosoma cruzi; it is endemic to Latin America, infecting 8 million individuals. Human migration has changed the epidemiology causing nonendemic countries to face increased challenges in diagnosing and managing patients with Chagas disease. Only 2 drugs exist with proven efficacy: benznidazole and nifurtimox. Benznidazole has historically faced supply problems and drug shortages, limiting accessibility. In the US, it is currently only available under an investigational new drug (IND) protocol from the CDC and is provided free of charge to patients. However, 2 companies have stated that they intend to submit a New Drug Application (NDA) for FDA approval. Based on recent history of companies acquiring licensing rights for NTD drugs in the US with limited availability, it is likely that benznidazole will become excessively priced by the manufacturer-paradoxically making it less accessible. However, if the companies can be taken at their word, there may be reason for optimism.

  17. Omega-3 supplementation on inflammatory markers in patients with chronic Chagas cardiomyopathy: a randomized clinical study.

    PubMed

    Silva, Paula Simplício da; Mediano, Mauro Felippe Felix; Silva, Gilberto Marcelo Sperandio da; Brito, Patricia Dias de; Cardoso, Claudia Santos de Aguiar; Almeida, Cristiane Fonseca de; Sangenis, Luiz Henrique Conde; Pinheiro, Roberta Olmo; Hasslocher-Moreno, Alejandro Marcel; Brasil, Pedro Emmanuel Alvarenga Americano do; Sousa, Andrea Silvestre de

    2017-06-09

    Several studies have been focusing on the effect of omega-3 polyunsaturated fatty acids on modulation of inflammatory markers in several cardiopathies. Although immunoregulatory dysfunction has been associated to the chronic cardiac involvement in Chagas disease, there is no study examining the effects of omega-3 supplementation in these patients. We investigated the effects of omega-3 PUFAs on markers of inflammation and lipid profile in chronic Chagas cardiomyopathy patients. The present study was a single-center double-blind clinical trial including patients with chronic Chagas cardiomyopathy. Patients were randomly assigned to receive omega-3 PUFAs capsules (1.8g EPA and 1.2g DHA) or placebo (corn oil) during an 8-week period. Cytokines, fasting glucose, lipid, and anthropometric profiles were evaluated. Forty-two patients (23 women and 19 men) were included in the study and there were only two losses to follow-up during the 8-week period. Most of sociodemographic and clinical characteristics were similar between the groups at baseline, except for the cytokines IL-1β, IL-6, IL-8, IL-10, IL-17α, and IFNγ. The omega-3 PUFAs group demonstrated greater improvements in serum triglycerides (-21.1 vs. -4.1; p = 0.05) and IL-10 levels (-10.6 vs. -35.7; p = 0.01) in comparison to controls after 8 weeks of intervention. No further differences were observed between groups. Omega-3 PUFAs supplementation may favorably affect lipid and inflammatory profile in chronic Chagas cardiomyopathy patients, demonstrated by a decrease in triglycerides and improvements on IL-10 concentration. Further studies examining the clinical effects of omega-3 fatty acids supplementation in chronic Chagas cardiomyopathy are necessary. NCT01863576.

  18. Metallothionein-1 and nitric oxide expression are inversely correlated in a murine model of Chagas disease

    PubMed Central

    Gonzalez-Mejia, Martha Elba; Torres-Rasgado, Enrique; Porchia, Leonardo M; Salgado, Hilda Rosas; Totolhua, José-Luis; Ortega, Arturo; Hernández-Kelly, Luisa Clara Regina; Ruiz-Vivanco, Guadalupe; Báez-Duarte, Blanca G; Pérez-Fuentes, Ricardo

    2014-01-01

    Chagas disease, caused by Trypanosoma cruzi, represents an endemic among Latin America countries. The participation of free radicals, especially nitric oxide (NO), has been demonstrated in the pathophysiology of seropositive individuals with T. cruzi. In Chagas disease, increased NO contributes to the development of cardiomyopathy and megacolon. Metallothioneins (MTs) are efficient free radicals scavengers of NO in vitro and in vivo. Here, we developed a murine model of the chronic phase of Chagas disease using endemic T. cruzi RyCH1 in BALB/c mice, which were divided into four groups: infected non-treated (Inf), infected N-monomethyl-L-arginine treated (Inf L-NAME), non-infected L-NAME treated and non-infected vehicle-treated. We determined blood parasitaemia and NO levels, the extent of parasite nests in tissues and liver MT-I expression levels. It was observed that NO levels were increasing in Inf mice in a time-dependent manner. Inf L-NAME mice had fewer T. cruzi nests in cardiac and skeletal muscle with decreased blood NO levels at day 135 post infection. This affect was negatively correlated with an increase of MT-I expression (r = -0.8462, p < 0.0001). In conclusion, we determined that in Chagas disease, an unknown inhibitory mechanism reduces MT-I expression, allowing augmented NO levels. PMID:24676665

  19. Discrete typing units of Trypanosoma cruzi detected by real-time PCR in Chilean patients with chronic Chagas cardiomyopathy.

    PubMed

    Muñoz-San Martín, Catalina; Zulantay, Inés; Saavedra, Miguel; Fuentealba, Cristián; Muñoz, Gabriela; Apt, Werner

    2018-05-07

    Chagas disease is a major public health problem in Latin America and has spread to other countries due to immigration of infected persons. 10-30% of patients with chronic Chagas disease will develop cardiomyopathy. Chagas cardiomyopathy is the worst form of the disease, due to its high morbidity and mortality. Because of its prognostic value and adequate medical monitoring, it is very important to identify infected people who could develop Chagas cardiomyopathy. The aim of this study was to determine if discrete typing units (DTUs) of Trypanosoma cruzi are related to the presence of heart disease in patients with chronic Chagas disease. A total of 86 untreated patients, 41 with cardiomyopathy and 45 without heart involvement were submitted to clinical study. Electrocardiograms and echocardiograms were performed on the group of cardiopaths, in which all important known causes of cardiomyopathy were discarded. Sinus bradycardia and prolonged QTc interval were the most frequent electrocardiographic alterations and patients were classified in group I (46%) and group II (54%) of New York Hearth Association. In all cases real-time PCR genotyping assays were performed. In the group with cardiomyopathy, the most frequent DTU was TcI (56.1%), followed by TcII (19.5%). Mixed infections TcI + TcII were observed in 7.3% of the patients. In the group without cardiac pathologies, TcI and TcII were found at similar rates (28.9 and 31.1%, respectively) and mixed infections TcI + TcII in 17.8% of the cases. TcIII and TcIV were not detected in any sample. Taken together, our data indicate that chronic Chagas cardiomyopathy in Chile can be caused by strains belonging to TcI and TcII. Copyright © 2018 Elsevier B.V. All rights reserved.

  20. PRISM, Volume 6, Number 1, 2016: Women, Peace and Inclusive Security

    DTIC Science & Technology

    2016-03-01

    Operations. PRISM is a security studies journal chartered to inform members of U.S. Federal agencies, allies, and other partners on complex and...thrown the national security community into disarray. Faced with such diverse challenges, the U.S. and its allies must step up with a response equally...pool? PRISM is not a journal of advocacy, but rather a venue for informed and rational discourse. The Editors’ goal is to further American and

  1. PRISM3 DOT1 Atlantic Basin Reconstruction

    USGS Publications Warehouse

    Dowsett, Harry; Robinson, Marci; Dwyer, Gary S.; Chandler, Mark; Cronin, Thomas

    2006-01-01

    PRISM3 DOT1 (Pliocene Research, Interpretation and Synoptic Mapping 3, Deep Ocean Temperature 1) provides a three-dimensional temperature reconstruction for the mid-Pliocene Atlantic basin, the first of several regional data sets that will comprise a global mid-Pliocene reconstruction. DOT1 is an alteration of modern temperature values for the Atlantic Ocean in 4 degree x 5 degree cells in 13 depth layers for December 1 based on Mg/Ca-derived BWT estimates from seventeen DSDP and ODP Sites and SST estimates from the PRISM2 reconstruction (Dowsett et al., 1999). DOT1 reflects a vaguely modern circulation system, assuming similar processes of deep-water formation; however, North Atlantic Deep Water (NADW) production is increased, and Antarctic Bottom Water (AABW) production is decreased. Pliocene NADW was approximately 2 degreesC warmer than modern temperatures, and Pliocene AABW was approximately 0.3 degreesC warmer than modern temperatures.

  2. Further genetic characterization of the two Trypanosoma cruzi Berenice strains (Be-62 and Be-78) isolated from the first human case of Chagas disease (Chagas, 1909).

    PubMed

    Cruz, R E; Macedo, A M; Barnabé, C; Freitas, J M; Chiari, E; Veloso, V M; Carneiro, C M; Bahia, M T; Tafuri, Washington L; Lana, M

    2006-03-01

    We describe here an extension of a previous genetic characterization of Trypanosoma cruzi strains (Be-62 and Be-78) isolated from the patient Berenice, the first human case of Chagas disease [Chagas, C., 1909. Nova Tripanomíase humana. Estudos sobre morfologia e o ciclo evolutivo do Schizotrypanum cruzi, n. gen., n. sp., agente etiolójico da nova entidade morbida do homem. Mem. Inst. Oswaldo Cruz 1, 159-218]. We wanted to verify the composition of T. cruzi populations originated from these two isolates. In the present work, 22 enzymatic loci (MLEE), nine RAPD primers and 7 microsatellite loci were analyzed. Clones from both strains were also characterized to verify whether these strains are mono or polyclonal. Be-62 and Be-78 strains were different in 3 out of 22 enzymatic systems, in 3 out of 9 RAPD primers tested and in all microsatellite loci investigated. However, our data suggests that both strains are phylogenetically closely related, belonging to genetic group 32 from Tibayrenc and Ayala [Tibayrenc, M., Ayala, F.J., 1988. Isoenzime variability in Trypanosoma cruzi, the agent of Chagas' disease: genetical, taxonomical, and epidemiological significance. Evolution 42, 277-292], equivalent to zymodeme 2 and T. cruzi II major lineage which, in Brazil, comprises parasites from the domestic cycle of the disease. Microsatellite analyses showed differences between the parental strains but suggested that both populations are monoclonal since each strain and their respective clones showed the same amplification products.

  3. Trypanosoma cruzi discrete typing units in Chagas disease patients from endemic and non-endemic regions of Argentina.

    PubMed

    Cura, C I; Lucero, R H; Bisio, M; Oshiro, E; Formichelli, L B; Burgos, J M; Lejona, S; Brusés, B L; Hernández, D O; Severini, G V; Velazquez, E; Duffy, T; Anchart, E; Lattes, R; Altcheh, J; Freilij, H; Diez, M; Nagel, C; Vigliano, C; Favaloro, L; Favaloro, R R; Merino, D E; Sosa-Estani, S; Schijman, A G

    2012-04-01

    Genetic diversity of Trypanosoma cruzi may play a role in pathogenesis of Chagas disease forms. Natural populations are classified into 6 Discrete Typing Units (DTUs) Tc I-VI with taxonomical status. This study aimed to identify T. cruzi DTUs in bloodstream and tissue samples of Argentinean patients with Chagas disease. PCR-based strategies allowed DTU identification in 256 clinical samples from 239 Argentinean patients. Tc V prevailed in blood from both asymptomatic and symptomatic cases and Tc I was more frequent in bloodstream, cardiac tissues and chagoma samples from immunosuppressed patients. Tc II and VI were identified in a minority of cases, while Tc III and Tc IV were not detected in the studied population. Interestingly, Tc I and Tc II/VI sequences were amplified from the same skin biopsy slice from a kidney transplant patient suffering Chagas disease reactivation. Further data also revealed the occurrence of mixed DTU populations in the human chronic infection. In conclusion, our findings provide evidence of the complexity of the dynamics of T. cruzi diversity in the natural history of human Chagas disease and allege the pathogenic role of DTUs I, II, V and VI in the studied population.

  4. Pathology of Chronic Chagas Cardiomyopathy in the United States:  A Detailed Review of 13 Cardiectomy Cases.

    PubMed

    Kransdorf, Evan P; Fishbein, Mike C; Czer, Lawrence S C; Patel, Jignesh K; Velleca, Angela; Tazelaar, Henry D; Roy, R Raina; Steidley, D Eric; Kobashigawa, Jon A; Luthringer, Daniel J

    2016-08-01

    The pathologic features of chronic Chagas cardiomyopathy may not be widely appreciated in the United States. We sought to describe the gross, microscopic, immunohistochemical, and molecular pathology features useful to diagnose chronic Chagas cardiomyopathy. The features from a case series of cardiectomy specimens of patients undergoing heart transplantation (12 patients) or mechanical circulatory support device implantation (one patient) for chronic Chagas cardiomyopathy at three institutions in the United States are reported and analyzed. Gross findings included enlarged and dilated ventricles (100% of cases), mural thrombi (54%), epicardial plaques (42%), and left ventricular aneurysm (36%). Microscopic evaluation revealed myocarditis (100% of cases) characterized by mononuclear cell infiltration, fibrosis (100%), nonnecrotizing granulomas (62%), and giant cells (38%). Two specimens (15%) showed rare intracellular amastigotes. Immunohistochemical assays for Trypanosoma cruzi organisms were negative in all cardiectomy specimens, whereas tissue polymerase chain reaction was positive in six (54%) of 11 cases. The gross and microscopic features of chronic Chagas cardiomyopathy in the United States appear similar to those reported in endemic countries. Importantly, tissue polymerase chain reaction may be useful to confirm the diagnosis. © American Society for Clinical Pathology, 2016. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  5. Prism Foil from an LCD Monitor as a Tool for Teaching Introductory Optics

    ERIC Educational Resources Information Center

    Planinsic, Gorazd; Gojkosek, Mihael

    2011-01-01

    Transparent prism foil is part of a backlight system in LCD monitors that are widely used today. This paper describes the optical properties of the prism foil and several pedagogical applications suitable for undergraduate introductory physics level. Examples include experiments that employ refraction, total internal reflection, diffraction and…

  6. Prevalence and Risk Factors for Chagas Disease in Pregnant Women in Casanare, Colombia

    PubMed Central

    Cucunubá, Zulma M.; Flórez, Astrid C.; Cárdenas, Ángela; Pavía, Paula; Montilla, Marleny; Aldana, Rodrigo; Villamizar, Katherine; Ríos, Lyda C.; Nicholls, Rubén S.; Puerta, Concepción J.

    2012-01-01

    Knowledge of the prevalence and risk factors associated with maternal infection is the first step to develop a surveillance system for congenital transmission of Chagas disease. We conducted a cross-sectional study in Casanare, a disease-endemic area in Colombia. A total of 982 patients were enrolled in the study. A global prevalence of Trypanosoma cruzi infection of 4.0% (95% confidence interval [CI] = 2.8–5.3%) was found. Multivariate analysis showed that the most important risk-associated factors were age > 29 years (adjusted odds ratio [aOR] = 3.4, 95% CI = 0.9–12.4), rural residency (aOR = 2.2, 95% CI = 1.0–4.6), low education level (aOR = 10.2, 95% CI = 1.6–82.7), and previous knowledge of the vector (aOR = 2.2, 95% CI = 1.0–4.9). Relatives and siblings of infected mothers showed a prevalence of 9.3%. These findings may help physicians to investigate congenital cases, screen Chagas disease in siblings and relatives, and provide early treatment to prevent the chronic complications of Chagas disease. PMID:23033397

  7. Triatominae Biochemistry Goes to School: Evaluation of a Novel Tool for Teaching Basic Biochemical Concepts of Chagas Disease Vectors

    ERIC Educational Resources Information Center

    Cunha, Leonardo Rodrigues; de Oliveria Cudischevitch, Cecília; Carneiro, Alan Brito; Macedo, Gustavo Bartholomeu; Lannes, Denise; da Silva-Neto, Mário Alberto Cardoso

    2014-01-01

    We evaluate a new approach to teaching the basic biochemistry mechanisms that regulate the biology of Triatominae, major vectors of "Trypanosoma cruzi," the causative agent of Chagas disease. We have designed and used a comic book, "Carlos Chagas: 100 years after a hero's discovery" containing scientific information obtained by…

  8. Controllable Sonar Lenses and Prisms Based on ERFs

    NASA Technical Reports Server (NTRS)

    Bar-Cohen, Yoseph; Sherrit, Stewart; Chang, Zensheu; Bao, Xiaoqi; Paustian, Iris; Lopes, Joseph; Folds, Donald

    2004-01-01

    Sonar-beam-steering devices of the proposed type would contain no moving parts and would be considerably smaller and less power-hungry, relative to conventional multiple-beam sonar arrays. The proposed devices are under consideration for installation on future small autonomous underwater vehicles because the sizes and power demands of conventional multiple-beam arrays are excessive, and motors used in single-beam mechanically scanned systems are also not reliable. The proposed devices would include a variety of electrically controllable acoustic prisms, lenses, and prism/lens combinations both simple and compound. These devices would contain electrorheological fluids (ERFs) between electrodes. An ERF typically consists of dielectric particles floating in a dielectric fluid. When an electric field is applied to the fluid, the particles become grouped into fibrils aligned in rows, with a consequent increase in the viscosity of the fluid and a corresponding increase in the speed of sound in the fluid. The change in the speed of sound increases with an increase in the applied electric field. By thus varying the speed of sound, one varies the acoustic index of refraction, analogously to varying the index of refraction of an optical lens or prism. In the proposed acoustic devices, this effect would be exploited to control the angles of refraction of acoustic beams, thereby steering the beams and, in the case of lenses, controlling focal lengths.

  9. American Trypanosomiasis (Also Known as Chagas Disease) Blood Screening FAQs

    MedlinePlus

    ... For Health Care Providers, Emergency Consultations, and General Public. Contact Us Parasites Home Blood Screening FAQs Language: English (US) Español (Spanish) Recommend on Facebook Tweet Share Compartir On this Page Why are blood banks now screening for Chagas disease? How does the ...

  10. Improvements in Fabrication of 3D SU-8 Prisms for Low-Coupling-Loss Interconnections Between Fibers and Waveguides

    NASA Astrophysics Data System (ADS)

    Nguyen, Minh-Hang; Chu, Thi-Xuan; Nguyen, Long; Nguyen, Hai-Binh; Lee, Chun-Wei; Tseng, Fan-Gang; Chen, Te-Chang; Lee, Ming-Chang

    2016-11-01

    Fabrication of three-dimensional (3D) SU-8 (an epoxy-based negative photoresist from MicroChem) prisms as low-loss couplers for interconnection between optical components, particularly optical fibers and silicon-on-isolator waveguides (SOI WGs), which have mismatched mode sizes, has been investigated. With an interfacial structure formed by a 3D SU-8 prism partly overlaying an SOI WG end with a portion of buried oxide (BOX) removed under the interface, low-loss coupling is ensured and the transmission efficiency can reach 70%. To fabricate these 3D SU-8 prisms, a simple method with two photolithography steps was used for SU-8 hinges and CYTOP (an amorphous fluoropolymer from AGC Chemicals) prism windows, with mild soft and hard bakes, to define the prism profiles with diluted SU-8 filled in the CYTOP prism windows. A buffered oxide etchant is used to remove BOX parts under the interfaces. Some of the fabricated structures were tested, demonstrating the contribution of overlaying SU-8 prisms to the transmission efficiency of optical interconnections between fibers and SOI WGs.

  11. Hybrid grating-prism dispersion eraser

    NASA Astrophysics Data System (ADS)

    Wang, Cheng; Li, Shuai; Liu, Yanqi; Liu, Xingyan; Leng, Yuxin; Li, Ruxin

    2018-03-01

    A hybrid grating-prism dispersion eraser is proposed to achieve broadband dispersion compensation. A ray-tracing model is built up for its phase spectrum and derivatives. The numerical calculation shows that the eraser can compensate dispersion up to fourth-order. When it is used in chirped-pulse amplifiers, it can obtain aberration-free phase with above 120 nm bandwidth at 0 . 8 μm central wavelength and support near-Fourier-transform-limited femtosecond pulses output.

  12. Effect of prism adaptation on left dichotic listening deficit in neglect patients: glasses to hear better?

    PubMed

    Jacquin-Courtois, S; Rode, G; Pavani, F; O'Shea, J; Giard, M H; Boisson, D; Rossetti, Y

    2010-03-01

    Unilateral neglect is a disabling syndrome frequently observed following right hemisphere brain damage. Symptoms range from visuo-motor impairments through to deficient visuo-spatial imagery, but impairment can also affect the auditory modality. A short period of adaptation to a rightward prismatic shift of the visual field is known to improve a wide range of hemispatial neglect symptoms, including visuo-manual tasks, mental imagery, postural imbalance, visuo-verbal measures and number bisection. The aim of the present study was to assess whether the beneficial effects of prism adaptation may generalize to auditory manifestations of neglect. Auditory extinction, whose clinical manifestations are independent of the sensory modalities engaged in visuo-manual adaptation, was examined in neglect patients before and after prism adaptation. Two separate groups of neglect patients (all of whom exhibited left auditory extinction) underwent prism adaptation: one group (n = 6) received a classical prism treatment ('Prism' group), the other group (n = 6) was submitted to the same procedure, but wore neutral glasses creating no optical shift (placebo 'Control' group). Auditory extinction was assessed by means of a dichotic listening task performed three times: prior to prism exposure (pre-test), upon prism removal (0 h post-test) and 2 h later (2 h post-test). The total number of correct responses, the lateralization index (detection asymmetry between the two ears) and the number of left-right fusion errors were analysed. Our results demonstrate that prism adaptation can improve left auditory extinction, thus revealing transfer of benefit to a sensory modality that is orthogonal to the visual, proprioceptive and motor modalities directly implicated in the visuo-motor adaptive process. The observed benefit was specific to the detection asymmetry between the two ears and did not affect the total number of responses. This indicates a specific effect of prism adaptation on

  13. Retracing Micro-Epidemics of Chagas Disease Using Epicenter Regression

    PubMed Central

    Levy, Michael Z.; Small, Dylan S.; Vilhena, Daril A.; Bowman, Natalie M.; Kawai, Vivian; Cornejo del Carpio, Juan G.; Cordova-Benzaquen, Eleazar; Gilman, Robert H.; Bern, Caryn; Plotkin, Joshua B.

    2011-01-01

    Vector-borne transmission of Chagas disease has become an urban problem in the city of Arequipa, Peru, yet the debilitating symptoms that can occur in the chronic stage of the disease are rarely seen in hospitals in the city. The lack of obvious clinical disease in Arequipa has led to speculation that the local strain of the etiologic agent, Trypanosoma cruzi, has low chronic pathogenicity. The long asymptomatic period of Chagas disease leads us to an alternative hypothesis for the absence of clinical cases in Arequipa: transmission in the city may be so recent that most infected individuals have yet to progress to late stage disease. Here we describe a new method, epicenter regression, that allows us to infer the spatial and temporal history of disease transmission from a snapshot of a population's infection status. We show that in a community of Arequipa, transmission of T. cruzi by the insect vector Triatoma infestans occurred as a series of focal micro-epidemics, the oldest of which began only around 20 years ago. These micro-epidemics infected nearly 5% of the community before transmission of the parasite was disrupted through insecticide application in 2004. Most extant human infections in our study community arose over a brief period of time immediately prior to vector control. According to our findings, the symptoms of chronic Chagas disease are expected to be absent, even if the strain is pathogenic in the chronic phase of disease, given the long asymptomatic period of the disease and short history of intense transmission. Traducción al español disponible en Alternative Language Text S1/A Spanish translation of this article is available in Alternative Language Text S1 PMID:21935346

  14. Retracing micro-epidemics of Chagas disease using epicenter regression.

    PubMed

    Levy, Michael Z; Small, Dylan S; Vilhena, Daril A; Bowman, Natalie M; Kawai, Vivian; Cornejo del Carpio, Juan G; Cordova-Benzaquen, Eleazar; Gilman, Robert H; Bern, Caryn; Plotkin, Joshua B

    2011-09-01

    Vector-borne transmission of Chagas disease has become an urban problem in the city of Arequipa, Peru, yet the debilitating symptoms that can occur in the chronic stage of the disease are rarely seen in hospitals in the city. The lack of obvious clinical disease in Arequipa has led to speculation that the local strain of the etiologic agent, Trypanosoma cruzi, has low chronic pathogenicity. The long asymptomatic period of Chagas disease leads us to an alternative hypothesis for the absence of clinical cases in Arequipa: transmission in the city may be so recent that most infected individuals have yet to progress to late stage disease. Here we describe a new method, epicenter regression, that allows us to infer the spatial and temporal history of disease transmission from a snapshot of a population's infection status. We show that in a community of Arequipa, transmission of T. cruzi by the insect vector Triatoma infestans occurred as a series of focal micro-epidemics, the oldest of which began only around 20 years ago. These micro-epidemics infected nearly 5% of the community before transmission of the parasite was disrupted through insecticide application in 2004. Most extant human infections in our study community arose over a brief period of time immediately prior to vector control. According to our findings, the symptoms of chronic Chagas disease are expected to be absent, even if the strain is pathogenic in the chronic phase of disease, given the long asymptomatic period of the disease and short history of intense transmission. Traducción al español disponible en Alternative Language Text S1/A Spanish translation of this article is available in Alternative Language Text S1.

  15. Affective three-dimensional brain-computer interface created using a prism array-based display

    NASA Astrophysics Data System (ADS)

    Mun, Sungchul; Park, Min-Chul

    2014-12-01

    To avoid the vergence-accommodation mismatch and provide a strong sense of presence to users, we applied a prism array-based display when presenting three-dimensional (3-D) objects. Emotional pictures were used as visual stimuli to increase the signal-to-noise ratios of steady-state visually evoked potentials (SSVEPs) because involuntarily motivated selective attention by affective mechanisms can enhance SSVEP amplitudes, thus producing increased interaction efficiency. Ten male and nine female participants voluntarily participated in our experiments. Participants were asked to control objects under three viewing conditions: two-dimension (2-D), stereoscopic 3-D, and prism. The participants performed each condition in a counter-balanced order. One-way repeated measures analysis of variance showed significant increases in the positive predictive values in the prism condition compared to the 2-D and 3-D conditions. Participants' subjective ratings of realness and engagement were also significantly greater in the prism condition than in the 2-D and 3-D conditions, while the ratings for visual fatigue were significantly reduced in the prism condition than in the 3-D condition. The proposed methods are expected to enhance the sense of reality in 3-D space without causing critical visual fatigue. In addition, people who are especially susceptible to stereoscopic 3-D may be able to use the affective brain-computer interface.

  16. Parasite-Vector Interaction of Chagas Disease: A Mini-Review.

    PubMed

    de Oliveira, Ana Beatriz Bortolozo; Alevi, Kaio Cesar Chaboli; Imperador, Carlos Henrique Lima; Madeira, Fernanda Fernandez; Azeredo-Oliveira, Maria Tercília Vilela de

    2018-03-01

    Trypanosoma cruzi is a protozoan of great importance to public health: it has infected millions of people in the world and is the etiologic agent of Chagas disease, which can cause cardiac and gastrointestinal disorders in patients and may even lead to death. The main vector of transmission of this parasite is triatomine bugs, which have a habit of defecating while feeding on blood and passing the parasite to their own hosts through their feces. Although it has been argued that T. cruzi is not pathogenic for this vector, other studies indicate that the success of the infection depends on several molecules and factors, including the insect's intestinal microbiota, which may experience changes as a result of infection that include decreased fitness. Moreover, the effects of infection depend on the insect species, the parasite strain, and environmental conditions involved. However, the parasite-vector interaction is still underexplored. A deeper understanding of this relationship is an important tool for discovering new approaches to T. cruzi transmission and Chagas disease.

  17. Multimodality imaging evaluation of Chagas disease: an expert consensus of Brazilian Cardiovascular Imaging Department (DIC) and the European Association of Cardiovascular Imaging (EACVI).

    PubMed

    Nunes, Maria Carmo P; Badano, Luigi Paolo; Marin-Neto, J Antonio; Edvardsen, Thor; Fernández-Golfín, Covadonga; Bucciarelli-Ducci, Chiara; Popescu, Bogdan A; Underwood, Richard; Habib, Gilbert; Zamorano, Jose Luis; Saraiva, Roberto Magalhães; Sabino, Ester Cerdeira; Botoni, Fernando A; Barbosa, Márcia Melo; Barros, Marcio Vinicius L; Falqueto, Eduardo; Simões, Marcus Vinicius; Schmidt, André; Rochitte, Carlos Eduardo; Rocha, Manoel Otávio Costa; Ribeiro, Antonio Luiz Pinho; Lancellotti, Patrizio

    2018-04-01

    To develop a document by Brazilian Cardiovascular Imaging Department (DIC) and the European Association of Cardiovascular Imaging (EACVI) to review and summarize the most recent evidences about the non-invasive assessment of patients with Chagas disease, with the intent to set up a framework for standardized cardiovascular imaging to assess cardiovascular morphologic and functional disturbances, as well as to guide the subsequent process of clinical decision-making. Chagas disease remains one of the most prevalent infectious diseases in Latin America, and has become a health problem in non-endemic countries. Dilated cardiomyopathy is the most severe manifestation of Chagas disease, which causes substantial disability and early mortality in the socially most productive population leading to a significant economical burden. Prompt and correct diagnosis of Chagas disease requires specialized clinical expertise to recognize the unique features of this disease. The appropriate and efficient use of cardiac imaging is pivotal for diagnosing the cardiac involvement in Chagas disease, to stage the disease, assess patients' prognosis and address management. Echocardiography is the most common imaging modality used to assess, and follow-up patients with Chagas disease. The presence of echocardiographic abnormalities is of utmost importance, since it allows to stage patients according to disease progression. In early stages of cardiac involvement, echocardiography may demonstrate segmental left ventricuar wall motion abnormalities, mainly in the basal segments of inferior, inferolateral walls, and the apex, which cannot be attributed to obstructive coronary artery arteries. The prevalence of segmental wall motion abnormalities varies according to the stage of the disease, reaching about 50% in patients with left ventricular dilatation and dysfunction. Speckle tracking echocardiography allows a more precise and quantitative measurement of the regional myocardial function. Since

  18. Correlation of transforming growth factor-β1 and tumour necrosis factor levels with left ventricular function in Chagas disease.

    PubMed

    Curvo, Eduardo Ov; Ferreira, Roberto R; Madeira, Fabiana S; Alves, Gabriel F; Chambela, Mayara C; Mendes, Veronica G; Sangenis, Luiz Henrique C; Waghabi, Mariana C; Saraiva, Roberto M

    2018-02-19

    Transforming growth factor β1 (TGF-β1) and tumour necrosis factor (TNF) have been implicated in Chagas disease pathophysiology and may correlate with left ventricular (LV) function. We determined whether TGF-β1 and TNF serum levels correlate with LV systolic and diastolic functions and brain natriuretic peptide (BNP) serum levels in chronic Chagas disease. This cross-sectional study included 152 patients with Chagas disease (43% men; 57 ± 12 years old), classified as 53 patients with indeterminate form and 99 patients with cardiac form (stage A: 24, stage B: 25, stage C: 44, stage D: 6). TGF-β1, TNF, and BNP were determined by enzyme-linked immunosorbent assay ELISA. Echocardiogram was used to determine left atrial and LV diameters, as well as LV ejection fraction and diastolic function. TGF-b1 serum levels were lower in stages B, C, and D, while TNF serum levels were higher in stages C and D of the cardiac form. TGF-β1 presented a weak correlation with LV diastolic function and LV ejection fraction. TNF presented a weak correlation with left atrial and LV diameters and LV ejection fraction. TNF is increased, while TGF-β1 is decreased in the cardiac form of chronic Chagas disease. TNF and TGF-β1 serum levels present a weak correlation with LV systolic and diastolic function in Chagas disease patients.

  19. Evaluation of the Performance of Routine Information System Management (PRISM) framework: evidence from Uganda.

    PubMed

    Hotchkiss, David R; Aqil, Anwer; Lippeveld, Theo; Mukooyo, Edward

    2010-07-03

    Sound policy, resource allocation and day-to-day management decisions in the health sector require timely information from routine health information systems (RHIS). In most low- and middle-income countries, the RHIS is viewed as being inadequate in providing quality data and continuous information that can be used to help improve health system performance. In addition, there is limited evidence on the effectiveness of RHIS strengthening interventions in improving data quality and use. The purpose of this study is to evaluate the usefulness of the newly developed Performance of Routine Information System Management (PRISM) framework, which consists of a conceptual framework and associated data collection and analysis tools to assess, design, strengthen and evaluate RHIS. The specific objectives of the study are: a) to assess the reliability and validity of the PRISM instruments and b) to assess the validity of the PRISM conceptual framework. Facility- and worker-level data were collected from 110 health care facilities in twelve districts in Uganda in 2004 and 2007 using records reviews, structured interviews and self-administered questionnaires. The analysis procedures include Cronbach's alpha to assess internal consistency of selected instruments, test-retest analysis to assess the reliability and sensitivity of the instruments, and bivariate and multivariate statistical techniques to assess validity of the PRISM instruments and conceptual framework. Cronbach's alpha analysis suggests high reliability (0.7 or greater) for the indices measuring a promotion of a culture of information, RHIS tasks self-efficacy and motivation. The study results also suggest that a promotion of a culture of information influences RHIS tasks self-efficacy, RHIS tasks competence and motivation, and that self-efficacy and the presence of RHIS staff have a direct influence on the use of RHIS information, a key aspect of RHIS performance. The study results provide some empirical support

  20. Surveillance, health promotion and control of Chagas disease in the Amazon Region - Medical attention in the Brazilian Amazon Region: a proposal

    PubMed Central

    Coura, José Rodrigues; Junqueira, Angela CV

    2015-01-01

    We refer to Oswaldo Cruz's reports dating from 1913 about the necessities of a healthcare system for the Brazilian Amazon Region and about the journey of Carlos Chagas to 27 locations in this region and the measures that would need to be adopted. We discuss the risks of endemicity of Chagas disease in the Amazon Region. We recommend that epidemiological surveillance of Chagas disease in the Brazilian Amazon Region and Pan-Amazon region should be implemented through continuous monitoring of the human population that lives in the area, their housing, the environment and the presence of triatomines. The monitoring should be performed with periodic seroepidemiological surveys, semi-annual visits to homes by health agents and the training of malaria microscopists and healthcare technicians to identify Trypanosoma cruzi from patients' samples and T. cruzi infection rates among the triatomines caught. We recommend health promotion and control of Chagas disease through public health policies, especially through sanitary education regarding the risk factors for Chagas disease. Finally, we propose a healthcare system through base hospitals, intermediate-level units in the areas of the Brazilian Amazon Region and air transportation, considering the distances to be covered for medical care. PMID:26560976

  1. Prion-like nanofibrils of small molecules (PriSM): A new frontier at the intersection of supramolecular chemistry and cell biology.

    PubMed

    Zhou, Jie; Du, Xuewen; Xu, Bing

    2015-01-01

    Formed by non-covalent interactions and not defined at genetic level, the assemblies of small molecules in biology are complicated and less explored. A common morphology of the supramolecular assemblies of small molecules is nanofibrils, which coincidentally resembles the nanofibrils formed by proteins such as prions. So these supramolecular assemblies are termed as prion-like nanofibrils of small molecules (PriSM). Emerging evidence from several unrelated fields over the past decade implies the significance of PriSM in biology and medicine. This perspective aims to highlight some recent advances of the research on PriSM. This paper starts with description of the intriguing similarities between PriSM and prions, discusses the paradoxical features of PriSM, introduces the methods for elucidating the biological functions of PriSM, illustrates several examples of beneficial aspects of PriSM, and finishes with the promises and current challenges in the research of PriSM. We anticipate that the research of PriSM will contribute to the fundamental understanding at the intersection of supramolecular chemistry and cell biology and ultimately lead to a new paradigm of molecular (or supramolecular) therapeutics for biomedicine.

  2. Prion-like nanofibrils of small molecules (PriSM): A new frontier at the intersection of supramolecular chemistry and cell biology

    PubMed Central

    Zhou, Jie; Du, Xuewen; Xu, Bing

    2015-01-01

    Abstract Formed by non-covalent interactions and not defined at genetic level, the assemblies of small molecules in biology are complicated and less explored. A common morphology of the supramolecular assemblies of small molecules is nanofibrils, which coincidentally resembles the nanofibrils formed by proteins such as prions. So these supramolecular assemblies are termed as prion-like nanofibrils of small molecules (PriSM). Emerging evidence from several unrelated fields over the past decade implies the significance of PriSM in biology and medicine. This perspective aims to highlight some recent advances of the research on PriSM. This paper starts with description of the intriguing similarities between PriSM and prions, discusses the paradoxical features of PriSM, introduces the methods for elucidating the biological functions of PriSM, illustrates several examples of beneficial aspects of PriSM, and finishes with the promises and current challenges in the research of PriSM. We anticipate that the research of PriSM will contribute to the fundamental understanding at the intersection of supramolecular chemistry and cell biology and ultimately lead to a new paradigm of molecular (or supramolecular) therapeutics for biomedicine. PMID:25738892

  3. Orally-transmitted Chagas disease.

    PubMed

    Filigheddu, Maria Teresa; Górgolas, Miguel; Ramos, José Manuel

    2017-02-09

    Chagas disease is a zoonosis caused by protozoan parasite Trypanosoma cruzi, which is most frequently associated with a vectorial transmission. However, in recent years we have observed a significant increase in the oral transmission of the disease, associated mainly with the consumption of drinks made from fruit or other vegetables contaminated with triatomine faeces or secretions from infected mammals. After a latency period of 3 to 22 days after ingestion, the oral infection is characterized by more severe manifestations than those associated with vectorial transmission: prolonged fever, acute myocarditis with heart failure and, in some cases, meningoencephalitis. Mortality can reach up to 33% of those infected. The aim of this paper is to review this matter and to promote prevention practices. Copyright © 2016 Elsevier España, S.L.U. All rights reserved.

  4. Establishment and correction of an Echelle cross-prism spectrogram reduction model

    NASA Astrophysics Data System (ADS)

    Zhang, Rui; Bayanheshig; Li, Xiaotian; Cui, Jicheng

    2017-11-01

    The accuracy of an echelle cross-prism spectrometer depends on the matching degree between the spectrum reduction model and the actual state of the spectrometer. However, the error of adjustment can change the actual state of the spectrometer and result in a reduction model that does not match. This produces an inaccurate wavelength calibration. Therefore, the calibration of a spectrogram reduction model is important for the analysis of any echelle cross-prism spectrometer. In this study, the spectrogram reduction model of an echelle cross-prism spectrometer was established. The image position laws of a spectrometer that varies with the system parameters were simulated to the influence of the changes in prism refractive index, focal length and so on, on the calculation results. The model was divided into different wavebands. The iterative method, least squares principle and element lamps with known characteristic wavelength were used to calibrate the spectral model in different wavebands to obtain the actual values of the system parameters. After correction, the deviation of actual x- and y-coordinates and the coordinates calculated by the model are less than one pixel. The model corrected by this method thus reflects the system parameters in the current spectrometer state and can assist in accurate wavelength extraction. The instrument installation and adjustment would be guided in model-repeated correction, reducing difficulty of equipment, respectively.

  5. Prioritization Risk Integration Simulation Model (PRISM) For Environmental Remediation and Waste Management - 12097

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Pentz, David L.; Stoll, Ralph H.; Greeves, John T.

    2012-07-01

    The PRISM (Prioritization Risk Integration Simulation Model), a computer model was developed to support the Department of Energy's Office of Environmental Management (DOE-EM) in its mission to clean up the environmental legacy from the Nation's nuclear weapons materials production complex. PRISM provides a comprehensive, fully integrated planning tool that can tie together DOE-EM's projects. It is designed to help DOE managers develop sound, risk-informed business practices and defend program decisions. It provides a better ability to understand and manage programmatic risks. The underlying concept for PRISM is that DOE-EM 'owns' a portfolio of environmental legacy obligations (ELOs), and that itsmore » mission is to transform the ELOs from their current conditions to acceptable conditions, in the most effective way possible. There are many types of ELOs - - contaminated soils and groundwater plumes, disused facilities awaiting D and D, and various types of wastes waiting for processing or disposal. For a given suite of planned activities, PRISM simulates the outcomes as they play out over time, allowing for all key identified uncertainties and risk factors. Each contaminated building, land area and waste stream is tracked from cradle to grave, and all of the linkages affecting different waste streams are captured. The progression of the activities is fully dynamic, reflecting DOE-EM's prioritization approaches, precedence requirements, available funding, and the consequences of risks and uncertainties. The top level of PRISM is the end-user interface that allows rapid evaluation of alternative scenarios and viewing the results in a variety of useful ways. PRISM is a fully probabilistic model, allowing the user to specify uncertainties in input data (such as the magnitude of an existing groundwater plume, or the total cost to complete a planned activity) as well as specific risk events that might occur. PRISM is based on the GoldSim software that is widely used

  6. Chagas disease vector control and Taylor's law

    PubMed Central

    Rodríguez-Planes, Lucía I.; Gaspe, María S.; Cecere, María C.; Cardinal, Marta V.

    2017-01-01

    Background Large spatial and temporal fluctuations in the population density of living organisms have profound consequences for biodiversity conservation, food production, pest control and disease control, especially vector-borne disease control. Chagas disease vector control based on insecticide spraying could benefit from improved concepts and methods to deal with spatial variations in vector population density. Methodology/Principal findings We show that Taylor's law (TL) of fluctuation scaling describes accurately the mean and variance over space of relative abundance, by habitat, of four insect vectors of Chagas disease (Triatoma infestans, Triatoma guasayana, Triatoma garciabesi and Triatoma sordida) in 33,908 searches of people's dwellings and associated habitats in 79 field surveys in four districts in the Argentine Chaco region, before and after insecticide spraying. As TL predicts, the logarithm of the sample variance of bug relative abundance closely approximates a linear function of the logarithm of the sample mean of abundance in different habitats. Slopes of TL indicate spatial aggregation or variation in habitat suitability. Predictions of new mathematical models of the effect of vector control measures on TL agree overall with field data before and after community-wide spraying of insecticide. Conclusions/Significance A spatial Taylor's law identifies key habitats with high average infestation and spatially highly variable infestation, providing a new instrument for the control and elimination of the vectors of a major human disease. PMID:29190728

  7. Trypanosoma cruzi strain TcI is associated with chronic Chagas disease in the Brazilian Amazon.

    PubMed

    Santana, Rosa Amélia Gonçalves; Magalhães, Laylah Kelre Costa; Magalhães, Laise Kelman Costa; Prestes, Suzane Ribeiro; Maciel, Marcel Gonçalves; da Silva, George Allan Villarouco; Monteiro, Wuelton Marcelo; de Brito, Felipe Rocha; de Aguiar Raposo Câmara Coelho, Leila Inês; Barbosa-Ferreira, João Marcos; Guerra, Jorge Augusto Oliveira; Silveira, Henrique; das Graças Vale Barbosa, Maria

    2014-06-11

    Chagas disease in the Amazon region is considered an emerging anthropozoonosis with a predominance of the discrete typing units (DTUs) TcI and TcIV. These DTUs are responsible for cases of acute disease associated with oral transmission. Chronic disease cases have been detected through serological surveys. However, the mode of transmission could not be determined, or any association of chronic disease with a specific T. cruzi DTU's. The aim of this study was to characterize Trypanosoma cruzi in patients with chronic Chagas disease in the State of Amazonas, Brazil. Blood culture and xenodiagnosis were performed in 36 patients with positive serology for Chagas disease who participated in a serological survey performed in urban and rural areas of Manaus, Amazonas. DNA samples were extracted from the feces of triatomines used for xenodiagnosis, and the nontranscribed spacer of the mini-exon gene and the mitochondrial gene cytochrome oxidase subunit II (COII) were amplified by PCR and sequenced. Blood culture and xenodiagnosis were negative in 100% of samples; however, molecular techniques revealed that in 13 out of 36 (36%) fecal samples from xenodiagnosis, T. cruzi was characterized as the DTU TcI, and different haplotypes were identified within the same DTU. The DTU TcI, which is mainly associated with acute cases of Chagas disease in the Amazon region, is also responsible for chronic infection in patients from a region in the State of Amazonas.

  8. Trypanosoma cruzi strain TcI is associated with chronic Chagas disease in the Brazilian Amazon

    PubMed Central

    2014-01-01

    Background Chagas disease in the Amazon region is considered an emerging anthropozoonosis with a predominance of the discrete typing units (DTUs) TcI and TcIV. These DTUs are responsible for cases of acute disease associated with oral transmission. Chronic disease cases have been detected through serological surveys. However, the mode of transmission could not be determined, or any association of chronic disease with a specific T. cruzi DTU’s. The aim of this study was to characterize Trypanosoma cruzi in patients with chronic Chagas disease in the State of Amazonas, Brazil. Methods Blood culture and xenodiagnosis were performed in 36 patients with positive serology for Chagas disease who participated in a serological survey performed in urban and rural areas of Manaus, Amazonas. DNA samples were extracted from the feces of triatomines used for xenodiagnosis, and the nontranscribed spacer of the mini-exon gene and the mitochondrial gene cytochrome oxidase subunit II (COII) were amplified by PCR and sequenced. Results Blood culture and xenodiagnosis were negative in 100% of samples; however, molecular techniques revealed that in 13 out of 36 (36%) fecal samples from xenodiagnosis, T. cruzi was characterized as the DTU TcI, and different haplotypes were identified within the same DTU. Conclusion The DTU TcI, which is mainly associated with acute cases of Chagas disease in the Amazon region, is also responsible for chronic infection in patients from a region in the State of Amazonas. PMID:24916362

  9. [Cardiac involvement in Acute Chagas' Disease cases in the Amazon region].

    PubMed

    Barbosa-Ferreira, João Marcos; Guerra, Jorge Augusto de Oliveira; Santana Filho, Franklin Simões de; Magalhães, Belisa Maria Lopes; Coelho, Leíla I A R C; Barbosa, Maria das Graças Vale

    2010-06-01

    The cardiac involvement of five patients from the Amazon region with Acute Chagas' Disease (ACD) is described. Four of these patients presented probable oral transmission. All of them presented some degree of cardiac involvement, but there were no deaths.

  10. Assessing the Impact of Atopic Dermatitis on the Patients' Parents with the Visual Instrument 'Caregiver-PRISM'.

    PubMed

    Marinello, Elena; Linder, Dennis; Spoto, Andrea; Palmer, Katie; Rohrer, Peter Michael; Büchi, Stefan; Trapp, Michael; Trapp, Eva-Maria; Hoerlesberger, Nina; Piaserico, Stefano; Peserico, Andrea; Gatta, Michela; Belloni Fortina, Anna

    2016-01-01

    There is a need to improve the quality of communication between clinicians and parents of young patients with atopic eczema (AE). To create a tool to measure the suffering that caregivers experience in association with their child's AE (Caregiver Pictorial Representation of Illness and Self-Measure, Caregiver-PRISM), assess the validity and reliability, and identify factors associated with caregiver suffering. Caregiver-PRISM was administered to 45 parents of patients from an AE outpatient service (Padua, Italy). Caregiver-PRISM had a good test-retest reliability (r = 0.85; t7 = 4.13; p < 0.05), content validity and construct validity when used in parents of AE children. Parents with a less positive family affective climate, higher education, or with children following a diet experienced higher suffering associated with their child's AE, demonstrated by lower Caregiver-PRISM scores (p < 0.05). Our results support the use of Caregiver-PRISM in parents of AE patients to assess suffering associated with patients' illness. © 2016 S. Karger AG, Basel.

  11. PRISM: Processing routines in IDL for spectroscopic measurements (installation manual and user's guide, version 1.0)

    USGS Publications Warehouse

    Kokaly, Raymond F.

    2011-01-01

    This report describes procedures for installing and using the U.S. Geological Survey Processing Routines in IDL for Spectroscopic Measurements (PRISM) software. PRISM provides a framework to conduct spectroscopic analysis of measurements made using laboratory, field, airborne, and space-based spectrometers. Using PRISM functions, the user can compare the spectra of materials of unknown composition with reference spectra of known materials. This spectroscopic analysis allows the composition of the material to be identified and characterized. Among its other functions, PRISM contains routines for the storage of spectra in database files, import/export of ENVI spectral libraries, importation of field spectra, correction of spectra to absolute reflectance, arithmetic operations on spectra, interactive continuum removal and comparison of spectral features, correction of imaging spectrometer data to ground-calibrated reflectance, and identification and mapping of materials using spectral feature-based analysis of reflectance data. This report provides step-by-step instructions for installing the PRISM software and running its functions.

  12. Applicability of a novel immunoassay based on surface plasmon resonance for the diagnosis of Chagas disease.

    PubMed

    Luz, João G G; Souto, Dênio E P; Machado-Assis, Girley F; de Lana, Marta; Luz, Rita C S; Martins-Filho, Olindo A; Damos, Flávio S; Martins, Helen R

    2016-02-15

    We defined the methodological criteria for the interpretation of the results provided by a novel immunoassay based on surface plasmon resonance (SPR) to detect antibodies anti-Trypanosoma cruzi in human sera (SPRCruzi). Then, we evaluated its applicability as a diagnostic tool for Chagas disease. To define the cut-off point and serum dilution factor, 57 samples were analyzed at SPRCruzi and the obtained values of SPR angle displacement (ΔθSPR) were submitted to statistical analysis. Adopting the indicated criteria, its performance was evaluated into a wide panel of samples, being 99 Chagas disease patients, 30 non-infected subjects and 42 with other parasitic/infectious diseases. In parallel, these samples were also analyzed by ELISA. Our data demonstrated that 1:320 dilution and cut-off point at ∆θSPR=17.2 m° provided the best results. Global performance analysis demonstrated satisfactory sensitivity (100%), specificity (97.2%), positive predictive value (98%), negative predictive value (100%) and global accuracy (99.6%). ELISA and SPRCruzi showed almost perfect agreement, mainly between chagasic and non-infected individuals. However, the new immunoassay was better in discriminate Chagas disease from other diseases. This work demonstrated the applicability of SPRCruzi as a feasible, real time, label free, sensible and specific methodology for the diagnosis of Chagas disease. Copyright © 2015 Elsevier B.V. All rights reserved.

  13. Diagnosis of Chagas' cardiomyopathy. Non-invasive techniques.

    PubMed Central

    Puigbó, J. J.; Valecillos, R.; Hirschhaut, E.; Giordano, H.; Boccalandro, I.; Suárez, C.; Aparicio, J. M.

    1977-01-01

    The natural history of Chagas' disease and its manifestations when the heart is involved are detailed clinically and pathologically. Three phases are recognized: the acute phase, lasting from 1-3 months, the latent phase, which may last from 10-20 years, and the chronic phase, which has the most serious manifestations. This phase is subdivided into three clinical stages. An analysis of the varied cardiac manifestations on 235 patients is included. Images Fig. 1 Fig. 2 Fig. 3 Fig. 4 PMID:412174

  14. Prisms with total internal reflection as solar reflectors

    DOEpatents

    Rabl, Arnulf; Rabl, Veronika

    1978-01-01

    An improved reflective wall for radiant energy collection and concentration devices is provided. The wall is comprised of a plurality of prisms whose frontal faces are adjacent and which reflect the desired radiation by total internal reflection.

  15. Pictorial Representation of Illness and Self Measure (PRISM): A novel visual instrument to measure quality of life in dermatological inpatients.

    PubMed

    Mühleisen, Beda; Büchi, Stefan; Schmidhauser, Simone; Jenewein, Josef; French, Lars E; Hofbauer, Günther F L

    2009-07-01

    To validate the PRISM (Pictorial Representation of Illness and Self Measure) tool, a novel visual instrument, for the assessment of health-related quality of life in dermatological inpatients compared with the Dermatology Life Quality Index (DLQI) and the Skindex-29 questionnaires and to report qualitative information on PRISM. In an open longitudinal study, PRISM and Skindex-29 and DLQI questionnaires were completed and HRQOL measurements compared. Academic dermatological inpatient ward. The study population comprised 227 sequential dermatological inpatients on admission. Patients completed the PRISM tool and the Skindex-29 and DLQI questionnaires at admission and discharge. PRISM Self-Illness Separation (SIS) score; Skindex-29 and DLQI scores; and qualitative PRISM information by Mayring inductive qualitative context analysis. The PRISM scores correlated well with those from the Skindex-29 (rho = 0.426; P < .001) and DLQI (rho = 0.304; P < .001) questionnaires. Between PRISM and Skindex-29 scores, the highest correlations were for dermatitis (rho = 0.614) and leg ulcer (rho = 0.554), and between PRISM and DLQI scores, the highest correlations were for psoriasis (rho = 0.418) and tumor (rho = 0.399). The PRISM tool showed comparable or higher sensitivity than quality of life questionnaires to assess changes in the burden of suffering during hospitalization. Inductive qualitative context analysis revealed impairment of adjustment and self-image as major aspects. Patients overall expected symptomatic and functional improvement. In patients with psoriasis and leg ulcers, many expected no treatment benefit. The PRISM tool proved to be convenient and reliable for health-related quality of life assessment, applicable for a wide range of skin diseases, and correlated with DLQI and Skindex-29 scores. With the PRISM tool, free-text answers allow for the assessment of individual information and potentially customized therapeutic approaches.

  16. Characterizing structures on borehole images and logging data of the Nankai trough accretionary prism: new insights

    NASA Astrophysics Data System (ADS)

    Jurado, Maria Jose

    2016-04-01

    IODP has extensively used the D/V Chikyu to drill the Kumano portion of the Nankai Trough, including two well sites within the Kumano Basin. IODP Expeditions 338 and 348 drilled deep into the inner accretionary prism south of the Kii Peninsula collecting a suite of LWD data, including natural gamma ray, electrical resistivity logs and borehole images, suitable to characterize structures (fractures and faults) inside the accretionary prism. Structural interpretation and analysis of logging-while-drilling data in the deep inner prism revealed intense deformation of a generally homogenous lithology characterized by bedding that dips steeply (60-90°) to the NW, intersected by faults and fractures. Multiple phases of deformation are characterized. IODP Expedition borehole images and LWD data acquired in the last decade in previous and results of NantroSEIZE IODP Expeditions (314, 319) were also analyzed to investigate the internal geometries and structures of the Nankai Trough accretionary prism. This study focused mainly on the characterization of the different types of structures and their specific position within the accretionary prism structures. New structural constraints and methodologies as well as a new approach to the characterization of study of active structures inside the prism will be presented.

  17. Spatial compression impairs prism adaptation in healthy individuals.

    PubMed

    Scriven, Rachel J; Newport, Roger

    2013-01-01

    Neglect patients typically present with gross inattention to one side of space following damage to the contralateral hemisphere. While prism-adaptation (PA) is effective in ameliorating some neglect behaviors, the mechanisms involved and their relationship to neglect remain unclear. Recent studies have shown that conscious strategic control (SC) processes in PA may be impaired in neglect patients, who are also reported to show extraordinarily long aftereffects compared to healthy participants. Determining the underlying cause of these effects may be the key to understanding therapeutic benefits. Alternative accounts suggest that reduced SC might result from a failure to detect prism-induced reaching errors properly either because (a) the size of the error is underestimated in compressed visual space or (b) pathologically increased error-detection thresholds reduce the requirement for error correction. The purpose of this study was to model these two alternatives in healthy participants and to examine whether SC and subsequent aftereffects were abnormal compared to standard PA. Each participant completed three PA procedures within a MIRAGE mediated reality environment with direction errors recorded before, during and after adaptation. During PA, visual feedback of the reach could be compressed, perturbed by noise, or represented veridically. Compressed visual space significantly reduced SC and aftereffects compared to control and noise conditions. These results support recent observations in neglect patients, suggesting that a distortion of spatial representation may successfully model neglect and explain neglect performance while adapting to prisms.

  18. Major Trypanosoma cruzi antigenic determinant in Chagas' heart disease shares homology with the systemic lupus erythematosus ribosomal P protein epitope.

    PubMed Central

    Mesri, E A; Levitus, G; Hontebeyrie-Joskowicz, M; Dighiero, G; Van Regenmortel, M H; Levin, M J

    1990-01-01

    A Trypanosoma cruzi lambda gt11 cDNA clone, JL5, expressed a recombinant protein which was found to react predominantly with chronic Chagas' heart disease sera. The cloned 35-residue-long peptide was identified as the carboxyl-terminal portion of a T. cruzi ribosomal P protein. The JL5 13 carboxyl-terminal residues shared a high degree of homology with the systemic lupus erythematosus (SLE) ribosomal P protein epitope. Synthetic peptides comprising the 13 (R-13), 10 (R-10), and 7 (R-7) carboxyl-terminal residues of the JL5 protein were used to study, by enzyme-linked immunosorbent assay, the specificity of the Chagas' disease anti-JL5 and SLE anti-P antibodies. The R-13 peptide defined a linear antigenic determinant of the JL5 recombinant protein. As was proved for JL5, R-13 defined antibody specificities which were significantly increased in chronic Chagas' heart disease patients. Only SLE anti-P positive sera were found to react with JL5 and R-13. Fine epitope mapping showed that Chagas' disease anti-JL5 and SLE anti-P antibodies define similar epitopes within the R-13 peptide. The binding of the SLE sera to JL5 was completely blocked by the R-13 peptide, indicating that the shared specificity between anti-JL5 and anti-P autoantibodies was exclusively limited to the conserved linear epitope(s) within the R-13 peptide. The prevalence of high anti-R-13 antibody titers in Chagas' heart disease patients supports the hypothesis that postulates the existence of autoimmune disorders in Chagas' heart disease. PMID:1696282

  19. Respiratory sinus arrhythmia in Chagas disease.

    PubMed

    Neves, Victor Ribeiro; Peltola, Mirja; Huikuri, Heikki; Rocha, Manoel Otávio da Costa; Ribeiro, Antonio Luiz

    2014-10-01

    We applied the respiratory sinus arrhythmia (RSA) quantification algorithm to 24-hour ECG recordings of Chagas disease (ChD) patients with (G1, n=148) and without left ventricular dysfunction (LVD) (G2, n=33), and in control subjects (G0, n=28). Both ChD groups displayed a reduced RSA index; G1=299 (144-812); G2=335 (162-667), p=0.011, which was correlated with vagal indexes of heart rate variability analysis. RSA index is a marker of vagal modulation in ChD patients. Copyright © 2014 Elsevier B.V. All rights reserved.

  20. A Novel Vaccine Approach for Chagas Disease Using Rare Adenovirus Serotype 48 Vectors

    PubMed Central

    Farrow, Anitra L.; Peng, Binghao J.; Gu, Linlin; Krendelchtchikov, Alexandre; Matthews, Qiana L.

    2016-01-01

    Due to the increasing amount of people afflicted worldwide with Chagas disease and an increasing prevalence in the United States, there is a greater need to develop a safe and effective vaccine for this neglected disease. Adenovirus serotype 5 (Ad5) is the most common adenovirus vector used for gene therapy and vaccine approaches, but its efficacy is limited by preexisting vector immunity in humans resulting from natural infections. Therefore, we have employed rare serotype adenovirus 48 (Ad48) as an alternative choice for adenovirus/Chagas vaccine therapy. In this study, we modified Ad5 and Ad48 vectors to contain T. cruzi’s amastigote surface protein 2 (ASP-2) in the adenoviral early gene. We also modified Ad5 and Ad48 vectors to utilize the “Antigen Capsid-Incorporation” strategy by adding T. cruzi epitopes to protein IX (pIX). Mice that were immunized with the modified vectors were able to elicit T. cruzi-specific humoral and cellular responses. This study indicates that Ad48-modified vectors function comparable to or even premium to Ad5-modified vectors. This study provides novel data demonstrating that Ad48 can be used as a potential adenovirus vaccine vector against Chagas disease. PMID:26978385

  1. Current Understanding of Immunity to Trypanosoma cruzi Infection and Pathogenesis of Chagas Disease

    PubMed Central

    Machado, Fabiana S.; Dutra, Walderez O.; Esper, Lisia; Gollob, Kenneth; Teixeira, Mauro M.; Factor, Stephen M.; Weiss, Louis M.; Nagajyothi, Fnu; Tanowitz, Herbert B.; Garg, Nisha J.

    2012-01-01

    Chagas disease caused by Trypanosoma cruzi remains an important neglected tropical disease and a cause of significant morbidity and mortality. No longer confined to endemic areas of Latin America, it is now found in non-endemic areas due to immigration. The parasite may persist in any tissue, but in recent years there has been increased recognition of adipose tissue both as an early target of infection and a reservoir of chronic infection. The major complications of this disease are cardiomyopathy and megasyndromes involving the gastrointestinal tract. The pathogenesis of Chagas disease is complex and multifactorial involving many interactive pathways. The significance of innate immunity, including the contributions of cytokines, chemokines, reactive oxygen species, and oxidative stress, has been emphasized. The role of the components of the eicosanoid pathway such as thromboxane A2 and the lipoxins has been demonstrated to have profound effects as both pro-and anti-inflammatory factors. Additionally, we discuss the vasoconstrictive actions of thromboxane A2 and endothelin-1n Chagas disease. Human immunity to T. cruzi infection and its role in pathogen control and disease progression have not been fully investigated. However, recently, it was demonstrated that a reduction in the anti-inflammatory cytokine IL-10 was associated with clinically significant chronic chagasic cardiomyopathy. PMID:23076807

  2. The current screening programme for congenital transmission of Chagas disease in Catalonia, Spain.

    PubMed

    Basile, L; Oliveira, I; Ciruela, P; Plasencia, A

    2011-09-22

    Due to considerable numbers of migrants from Chagas disease-endemic countries living in Catalonia, the Catalonian Health Department has recently implemented a screening programme for preventing congenital transmission, targeting Latin American pregnant women who attend antenatal consultations. Diagnosis of Trypanosoma cruzi infection in women is based on two positive serological tests. Screening of newborns from mothers with positive serology is based on a parasitological test during the first 48 hours of life and/or conventional serological analysis at the age of nine months. If either of these tests is positive, treatment with benznidazole is started following the World Health Organization's recommendations. The epidemiological surveillance of the programme is based on the Microbiological Reporting System of Catalonia, a well established network of laboratories. Once a positive case is reported, the responsible physician is asked to complete a structured epidemiological questionnaire. Clinical and demographic data are registered in the Voluntary Case Registry of Chagas Disease, a database administered by the Catalonian Health Department. It is expected that this programme will improve the understanding of the real burden of Chagas disease in the region. Furthermore, this initiative could encourage the implementation of similar programmes in other regions of Spain and even in other European countries.

  3. Positive deviance study to inform a Chagas disease control program in southern Ecuador.

    PubMed

    Nieto-Sanchez, Claudia; Baus, Esteban G; Guerrero, Darwin; Grijalva, Mario J

    2015-05-01

    Chagas disease is caused by Trypanosoma cruzi, which is mainly transmitted by the faeces of triatomine insects that find favourable environments in poorly constructed houses. Previous studies have documented persistent triatomine infestation in houses in the province of Loja in southern Ecuador despite repeated insecticide and educational interventions. We aim to develop a sustainable strategy for the interruption of Chagas disease transmission by promoting living environments that are designed to prevent colonisation of rural houses by triatomines. This study used positive deviance to inform the design of an anti-triatomine prototype house by identifying knowledge, attitudes and practices used by families that have remained triatomine-free (2010-2012). Positive deviants reported practices that included maintenance of structural elements of the house, fumigation of dwellings and animal shelters, sweeping with "insect repellent" plants and relocation of domestic animals away from the house, among others. Participants favoured construction materials that do not drastically differ from those currently used (adobe walls and tile roofs). They also expressed their belief in a clear connection between a clean house and health. The family's economic dynamics affect space use and must be considered in the prototype's design. Overall, the results indicate a positive climate for the introduction of housing improvements as a protective measure against Chagas disease in this region.

  4. A Holographic Prism Based on Photo-Thermo-Refractive Glass: Requirements and Possibilities

    NASA Astrophysics Data System (ADS)

    Angervaks, A. E.; Gorokhovskii, K. S.; Granovskii, V. A.; Van Bac, Doan; Ivanov, S. A.; Okun', R. A.; Nikonorov, N. V.; Ryskin, A. I.

    2017-12-01

    A technology for multivalued holographic measurement of a plane angle—a holographic prism, which serves as the basis for a device for calibrating the testing tools for navigational equipment under rolling— has been developed. The holographic prism is a miniature sample of photosensitive material, which contains a system of superimposed holographic gratings, and a laser the radiation of which passes through gratings to form a fan of diffracted beams. The fan in a prism based on a calcium fluoride (fluorite) crystal with color centers contained six out-of-plane beams radiating from a region with a hard-to-localize center. This fact hindered calibration of the measure and its application in the testing device. The use of photothermo-refractive glass as a material for preparing a sample and recording a system of holograms in it makes it possible to eliminate the drawbacks of fluorite-based prism. The number of holograms rises up to 21, the fan becomes in-plane, and its center is localized in a small region, with a size of several tenths of the sample thickness (1-2 mm). The fan beams are energetically homogeneous, and each can be identified when using the fan in a testing device.

  5. Immunoregulatory mechanisms in Chagas disease: modulation of apoptosis in T-cell mediated immune responses.

    PubMed

    Chaves, Ana Thereza; de Assis Silva Gomes Estanislau, Juliana; Fiuza, Jacqueline Araújo; Carvalho, Andréa Teixeira; Ferreira, Karine Silvestre; Fares, Rafaelle Christine Gomes; Guimarães, Pedro Henrique Gazzinelli; de Souza Fagundes, Elaine Maria; Morato, Maria José; Fujiwara, Ricardo Toshio; da Costa Rocha, Manoel Otávio; Correa-Oliveira, Rodrigo

    2016-04-30

    Chronic Chagas disease presents different clinical manifestations ranging from asymptomatic (namely indeterminate) to severe cardiac and/or digestive. Previous results have shown that the immune response plays an important role, although no all mechanisms are understood. Immunoregulatory mechanisms such as apoptosis are important for the control of Chagas disease, possibly affecting the morbidity in chronic clinical forms. Apoptosis has been suggested to be an important mechanism of cellular response during T. cruzi infection. We aimed to further understand the putative role of apoptosis in Chagas disease and its relation to the clinical forms of the disease. Apoptosis of lymphocytes, under antigenic stimuli (soluble T. cruzi antigens - TcAg) where compared to that of non-stimulated cells. Apoptosis was evaluated using the expression of annexin and caspase 3(+) by T cells and the percentage of cells positive evaluated by flow cytometry. In addition activation and T cell markers were used for the identification of TCD4(+) and TCD8(+) subpopulations. The presence of intracellular and plasma cytokines were also evaluated. Analysis of the activation status of the peripheral blood cells showed that patients with Chagas disease presented higher levels of activation determined by the expression of activation markers, after TcAg stimulation. PCR array were used to evaluate the contribution of this mechanism in specific cell populations from patients with different clinical forms of human Chagas disease. Our results showed a reduced proliferative response associated a high expression of T CD4(+)CD62L(-) cells in CARD patients when compared with IND group and NI individuals. We also observed that both groups of patients presented a significant increase of CD4(+) and CD8(+) T cell subsets in undergoing apoptosis after in vitro stimulation with T. cruzi antigens. In CARD patients, both CD4(+) and CD8(+) T cells expressing TNF-α were highly susceptible to undergo apoptosis

  6. Hierarchically triangular prism structured Co3O4: Self-supported fabrication and photocatalytic property

    EPA Science Inventory

    The formation of ammonium cobalt (II) phosphate was utilized to synthesize unprecedented 3D structures of Co3O4, triangular prisms and trunk-like structures, via a self-supported and organics-free method. The length of a triangular side of the prepared 3D triangular prisms is ~1...

  7. A Multi-species Bait for Chagas Disease Vectors

    PubMed Central

    Mota, Theo; Vitta, Ana C. R.; Lorenzo-Figueiras, Alicia N.; Barezani, Carla P.; Zani, Carlos L.; Lazzari, Claudio R.; Diotaiuti, Liléia; Jeffares, Lynne; Bohman, Björn; Lorenzo, Marcelo G.

    2014-01-01

    Background Triatomine bugs are the insect vectors of Trypanosoma cruzi, the etiological agent of Chagas disease. These insects are known to aggregate inside shelters during daylight hours and it has been demonstrated that within shelters, the aggregation is induced by volatiles emitted from bug feces. These signals promote inter-species aggregation among most species studied, but the chemical composition is unknown. Methodology/Principal Findings In the present work, feces from larvae of the three species were obtained and volatile compounds were identified by solid phase microextraction-gas chromatography-mass spectrometry (SPME-GC-MS). We identified five compounds, all present in feces of all of the three species: Triatoma infestans, Panstrongylus megistus and Triatoma brasiliensis. These substances were tested for attractivity and ability to recruit insects into shelters. Behaviorally active doses of the five substances were obtained for all three triatomine species. The bugs were significantly attracted to shelters baited with blends of 160 ng or 1.6 µg of each substance. Conclusions/Significance Common compounds were found in the feces of vectors of Chagas disease that actively recruited insects into shelters, which suggests that this blend of compounds could be used for the development of baits for early detection of reinfestation with triatomine bugs. PMID:24587457

  8. Correlation of transforming growth factor-β1 and tumour necrosis factor levels with left ventricular function in Chagas disease

    PubMed Central

    Curvo, Eduardo OV; Ferreira, Roberto R; Madeira, Fabiana S; Alves, Gabriel F; Chambela, Mayara C; Mendes, Veronica G; Sangenis, Luiz Henrique C; Waghabi, Mariana C; Saraiva, Roberto M

    2018-01-01

    BACKGROUND Transforming growth factor β1 (TGF-β1) and tumour necrosis factor (TNF) have been implicated in Chagas disease pathophysiology and may correlate with left ventricular (LV) function. OBJECTIVES We determined whether TGF-β1 and TNF serum levels correlate with LV systolic and diastolic functions and brain natriuretic peptide (BNP) serum levels in chronic Chagas disease. METHODS This cross-sectional study included 152 patients with Chagas disease (43% men; 57 ± 12 years old), classified as 53 patients with indeterminate form and 99 patients with cardiac form (stage A: 24, stage B: 25, stage C: 44, stage D: 6). TGF-β1, TNF, and BNP were determined by enzyme-linked immunosorbent assay ELISA. Echocardiogram was used to determine left atrial and LV diameters, as well as LV ejection fraction and diastolic function. FINDINGS TGF-b1 serum levels were lower in stages B, C, and D, while TNF serum levels were higher in stages C and D of the cardiac form. TGF-β1 presented a weak correlation with LV diastolic function and LV ejection fraction. TNF presented a weak correlation with left atrial and LV diameters and LV ejection fraction. CONCLUSIONS TNF is increased, while TGF-β1 is decreased in the cardiac form of chronic Chagas disease. TNF and TGF-β1 serum levels present a weak correlation with LV systolic and diastolic function in Chagas disease patients. PMID:29513876

  9. Standardization of Questions in Rare Disease Registries: The PRISM Library Project.

    PubMed

    Richesson, Rachel Lynn; Shereff, Denise; Andrews, James Everett

    2012-10-10

    Patient registries are often a helpful first step in estimating the impact and understanding the etiology of rare diseases - both requisites for the development of new diagnostics and therapeutics. The value and utility of patient registries rely on the use of both well-constructed structured research questions and relevant answer sets accompanying them. There are currently no clear standards or specifications for developing registry questions, and there are no banks of existing questions to support registry developers. This paper introduces the [Rare Disease] PRISM (Patient Registry Item Specifications and Metadata for Rare Disease) project, a library of standardized questions covering a broad spectrum of rare diseases that can be used to support the development of new registries, including Internet-based registries. A convenience sample of questions was identified from well-established (>5 years) natural history studies in various diseases and from several existing registries. Face validity of the questions was determined by review by many experts (both terminology experts at the College of American Pathologists (CAP) and research and informatics experts at the University of South Florida (USF)) for commonality, clarity, and organization. Questions were re-worded slightly, as needed, to make the full semantics of the question clear and to make the questions generalizable to multiple diseases where possible. Questions were indexed with metadata (structured and descriptive information) using a standard metadata framework to record such information as context, format, question asker and responder, and data standards information. At present, PRISM contains over 2,200 questions, with content of PRISM relevant to virtually all rare diseases. While the inclusion of disease-specific questions for thousands of rare disease organizations seeking to develop registries would present a challenge for traditional standards development organizations, the PRISM library could

  10. Standardization of Questions in Rare Disease Registries: The PRISM Library Project

    PubMed Central

    Shereff, Denise; Andrews, James Everett

    2012-01-01

    Background Patient registries are often a helpful first step in estimating the impact and understanding the etiology of rare diseases - both requisites for the development of new diagnostics and therapeutics. The value and utility of patient registries rely on the use of both well-constructed structured research questions and relevant answer sets accompanying them. There are currently no clear standards or specifications for developing registry questions, and there are no banks of existing questions to support registry developers. Objective This paper introduces the [Rare Disease] PRISM (Patient Registry Item Specifications and Metadata for Rare Disease) project, a library of standardized questions covering a broad spectrum of rare diseases that can be used to support the development of new registries, including Internet-based registries. Methods A convenience sample of questions was identified from well-established (>5 years) natural history studies in various diseases and from several existing registries. Face validity of the questions was determined by review by many experts (both terminology experts at the College of American Pathologists (CAP) and research and informatics experts at the University of South Florida (USF)) for commonality, clarity, and organization. Questions were re-worded slightly, as needed, to make the full semantics of the question clear and to make the questions generalizable to multiple diseases where possible. Questions were indexed with metadata (structured and descriptive information) using a standard metadata framework to record such information as context, format, question asker and responder, and data standards information. Results At present, PRISM contains over 2,200 questions, with content of PRISM relevant to virtually all rare diseases. While the inclusion of disease-specific questions for thousands of rare disease organizations seeking to develop registries would present a challenge for traditional standards development

  11. [Urbanization of Chagas disease in Peru: experiences in prevention and control].

    PubMed

    Náquira, César

    2014-04-01

    In Peru, Chagas disease has an epidemiological significance in three macro-regions, one of them is the southern macro-region formed by the departments of Arequipa, Moquegua and Tacna. In 1965 a successful control was performed by house spraying insecticides, however, the persistence of the vector made it necessary for a second control plan that was implemented in 2000 and followed the guidelines of CONAL Plan, based on the elimination of Triatoma infestans and screening in blood banks.This plan was successful in Tacna and Moquegua, therefore these departments were considered free of vectorial transmission by the Pan American Health Organization. A ssimilar situation has not been achieved in the department of Arequipa because of the presence, among other factors, of rural migration to the city, in this way the urbanization of Chagas disease is a new epidemiological scenario of which we need to know more.

  12. Coronary Microvascular Disease in Chronic Chagas Cardiomyopathy Including an Overview on History, Pathology, and Other Proposed Pathogenic Mechanisms

    PubMed Central

    Rossi, Marcos A.; Tanowitz, Herbert B.; Malvestio, Lygia M.; Celes, Mara R.; Campos, Erica C.; Blefari, Valdecir; Prado, Cibele M.

    2010-01-01

    This review focuses on the short and bewildered history of Brazilian scientist Carlos Chagas's discovery and subsequent developments, the anatomopathological features of chronic Chagas cardiomyopathy (CCC), an overview on the controversies surrounding theories concerning its pathogenesis, and studies that support the microvascular hypothesis to further explain the pathological features and clinical course of CCC. It is our belief that knowledge of this particular and remarkable cardiomyopathy will shed light not only on the microvascular involvement of its pathogenesis, but also on the pathogenetic processes of other cardiomyopathies, which will hopefully provide a better understanding of the various changes that may lead to an end-stage heart disease with similar features. This review is written to celebrate the 100th anniversary of the discovery of Chagas disease. PMID:20824217

  13. Why Is White Light Dispersed by a Prism?

    ERIC Educational Resources Information Center

    Crawford, Frank S.

    1979-01-01

    Presents the answer to a question, which is intended for high school students, about the dispersion of white light by a glass prism. Why the high frequency waves travel slower than the lower frequencies in glass is also presented. (HM)

  14. Forest Biomass Mapping from Prism Triplet, Palsar and Landsat Data

    NASA Astrophysics Data System (ADS)

    Ranson, J.; Sun, G.; Ni, W.

    2014-12-01

    The loss of sensitivity at higher biomass levels is a common problem in biomass mapping using optical multi-spectral data or radar backscattering data due to the lack of information on canopy vertical structure. Studies have shown that adding implicit information of forest vertical structure improves the performance of forest biomass mapping from optical reflectance and radar backscattering data. LiDAR, InSAR and stereo imager are the data sources for obtaining forest structural information. The potential of providing information on forest vertical structure by stereoscopic imagery data has drawn attention recently due to the availability of high-resolution digital stereo imaging from space and the advances of digital stereo image processing software. The Panchromatic Remote-sensing Instrument for Stereo Mapping (PRISM) onboard the Advanced Land Observation Satellite (ALOS) has acquired multiple global coverage from June 2006 to April 2011 providing a good data source for regional/global forest studies. In this study, five PRISM triplets acquired on June 14, 2008, August 19 and September 5, 2009; PALSAR dual-pol images acquired on July 12, 2008 and August 30, 2009; and LANDSAT 5 TM images acquired on September 5, 2009 and the field plot data collected in 2009 and 2010 were used to map forest biomass at 50m pixel in an area of about 4000 km2in Maine, USA ( 45.2 deg N 68.6 deg W). PRISM triplets were used to generate point cloud data at 2m pixel first and then the average height of points above NED (National Elevation Dataset) within a 50m by 50m pixel was calculated. Five images were mosaicked and used as canopy height information in the biomass estimation along with the PALSAR HH, HV radar backscattering and optical reflectance vegetation indices from L-5 TM data. A small portion of this region was covered by the Land Vegetation and Ice Sensor (LVIS) in 2009. The biomass maps from the LVIS data was used to evaluate the results from combined use of PRISM, PALSAR and

  15. A Scientometric Evaluation of the Chagas Disease Implementation Research Programme of the PAHO and TDR

    PubMed Central

    Carbajal-de-la-Fuente, Ana Laura; Yadón, Zaida E.

    2013-01-01

    The Special Programme for Research and Training in Tropical Diseases (TDR) is an independent global programme of scientific collaboration cosponsored by the United Nations Children's Fund, the United Nations Development Program, the World Bank, and the World Health Organization. TDR's strategy is based on stewardship for research on infectious diseases of poverty, empowerment of endemic countries, research on neglected priority needs, and the promotion of scientific collaboration influencing global efforts to combat major tropical diseases. In 2001, in view of the achievements obtained in the reduction of transmission of Chagas disease through the Southern Cone Initiative and the improvement in Chagas disease control activities in some countries of the Andean and the Central American Initiatives, TDR transferred the Chagas Disease Implementation Research Programme (CIRP) to the Communicable Diseases Unit of the Pan American Health Organization (CD/PAHO). This paper presents a scientometric evaluation of the 73 projects from 18 Latin American and European countries that were granted by CIRP/PAHO/TDR between 1997 and 2007. We analyzed all final reports of the funded projects and scientific publications, technical reports, and human resource training activities derived from them. Results about the number of projects funded, countries and institutions involved, gender analysis, number of published papers in indexed scientific journals, main topics funded, patents inscribed, and triatomine species studied are presented and discussed. The results indicate that CIRP/PAHO/TDR initiative has contributed significantly, over the 1997–2007 period, to Chagas disease knowledge as well as to the individual and institutional-building capacity. PMID:24244761

  16. 3. ELEVATION. FROM SOUTH WITH CANAL PRISM. Canal Road ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    3. ELEVATION. FROM SOUTH WITH CANAL PRISM. - Canal Road Bridge, Canal Road spanning Delaware Canal Diversion, Locks 22 & 23 in Delaware Canal State Park in Williams Township, Raubsville, Northampton County, PA

  17. Prism adaptation does not change the rightward spatial preference bias found with ambiguous stimuli in unilateral neglect

    PubMed Central

    Sarri, Margarita; Greenwood, Richard; Kalra, Lalit; Driver, Jon

    2011-01-01

    Previous research has shown that prism adaptation (prism adaptation) can ameliorate several symptoms of spatial neglect after right-hemisphere damage. But the mechanisms behind this remain unclear. Recently we reported that prisms may increase leftward awareness for neglect in a task using chimeric visual objects, despite apparently not affecting awareness in a task using chimeric emotional faces (Sarri et al., 2006). Here we explored potential reasons for this apparent discrepancy in outcome, by testing further whether the lack of a prism effect on the chimeric face task task could be explained by: i) the specific category of stimuli used (faces as opposed to objects); ii) the affective nature of the stimuli; and/or iii) the particular task implemented, with the chimeric face task requiring forced-choice judgements of lateral ‘preference’ between pairs of identical, but left/right mirror-reversed chimeric face tasks (as opposed to identification for the chimeric object task). We replicated our previous pattern of no impact of prisms on the emotional chimeric face task here in a new series of patients, while also similarly finding no beneficial impact on another lateral ‘preference’ measure that used non-face non-emotional stimuli, namely greyscale gradients. By contrast, we found the usual beneficial impact of prism adaptation (prism adaptation) on some conventional measures of neglect, and improvements for at least some patients in a different face task, requiring explicit discrimination of the chimeric or non-chimeric nature of face stimuli. The new findings indicate that prism therapy does not alter spatial biases in neglect as revealed by ‘lateral preference tasks’ that have no right or wrong answer (requiring forced-choice judgements on left/right mirror-reversed stimuli), regardless of whether these employ face or non-face stimuli. But our data also show that prism therapy can beneficially modulate some aspects of visual awareness in spatial

  18. Prism adaptation in Parkinson disease: comparing reaching to walking and freezers to non-freezers.

    PubMed

    Nemanich, Samuel T; Earhart, Gammon M

    2015-08-01

    Visuomotor adaptation to gaze-shifting prism glasses requires recalibration of the relationship between sensory input and motor output. Healthy individuals flexibly adapt movement patterns to many external perturbations; however, individuals with cerebellar damage do not adapt movements to the same extent. People with Parkinson disease (PD) adapt normally, but exhibit reduced after-effects, which are negative movement errors following the removal of the prism glasses and are indicative of true spatial realignment. Walking is particularly affected in PD, and many individuals experience freezing of gait (FOG), an episodic interruption in walking, that is thought to have a distinct pathophysiology. Here, we examined how individuals with PD with (PD + FOG) and without (PD - FOG) FOG, along with healthy older adults, adapted both reaching and walking patterns to prism glasses. Participants completed a visually guided reaching and walking task with and without rightward-shifting prism glasses. All groups adapted at similar rates during reaching and during walking. However, overall walking adaptation rates were slower compared to reaching rates. The PD - FOG group showed smaller after-effects, particularly during walking, compared to PD + FOG, independent of adaptation magnitude. While FOG did not appear to affect characteristics of prism adaptation, these results support the idea that the distinct neural processes governing visuomotor adaptation and storage are differentially affected by basal ganglia dysfunction in PD.

  19. A compact and lightweight off-axis lightguide prism in near to eye display

    NASA Astrophysics Data System (ADS)

    Zhuang, Zhenfeng; Cheng, Qijia; Surman, Phil; Zheng, Yuanjin; Sun, Xiao Wei

    2017-06-01

    We propose a method to improve the design of an off-axis lightguide configuration for near to eye displays (NED) using freeform optics technology. The advantage of this modified optical system, which includes an organic light-emitting diode (OLED), a doublet lens, an imaging lightguide prism and a compensation prism, is that it increases optical length path, offers a smaller size, as well as avoids the obstructed views, and matches the user's head shape. In this system, the light emitted from the OLED passes through the doublet lens and is refracted/reflected by the imaging lightguide prism, which is used to magnify the image from the microdisplay, while the compensation prism is utilized to correct the light ray shift so that a low-distortion image can be observed in a real-world setting. A NED with a 4 mm diameter exit pupil, 21.5° diagonal full field of view (FoV), 23 mm eye relief, and a size of 33 mm by 9.3 mm by 16 mm is designed. The developed system is compact, lightweight and suitable for entertainment and education application.

  20. Squalene Synthase As a Target for Chagas Disease Therapeutics

    PubMed Central

    Chan, Hsiu-Chien; Li, Jikun; Zheng, Yingying; Huang, Chun-Hsiang; Ren, Feifei; Chen, Chun-Chi; Zhu, Zhen; Galizzi, Melina; Li, Zhu-Hong; Rodrigues-Poveda, Carlos A.; Gonzalez-Pacanowska, Dolores; Veiga-Santos, Phercyles; de Carvalho, Tecia Maria Ulisses; de Souza, Wanderley; Urbina, Julio A.; Wang, Andrew H.-J.; Docampo, Roberto; Li, Kai; Liu, Yi-Liang; Oldfield, Eric; Guo, Rey-Ting

    2014-01-01

    Trypanosomatid parasites are the causative agents of many neglected tropical diseases and there is currently considerable interest in targeting endogenous sterol biosynthesis in these organisms as a route to the development of novel anti-infective drugs. Here, we report the first x-ray crystallographic structures of the enzyme squalene synthase (SQS) from a trypanosomatid parasite, Trypanosoma cruzi, the causative agent of Chagas disease. We obtained five structures of T. cruzi SQS and eight structures of human SQS with four classes of inhibitors: the substrate-analog S-thiolo-farnesyl diphosphate, the quinuclidines E5700 and ER119884, several lipophilic bisphosphonates, and the thiocyanate WC-9, with the structures of the two very potent quinuclidines suggesting strategies for selective inhibitor development. We also show that the lipophilic bisphosphonates have low nM activity against T. cruzi and inhibit endogenous sterol biosynthesis and that E5700 acts synergistically with the azole drug, posaconazole. The determination of the structures of trypanosomatid and human SQS enzymes with a diverse set of inhibitors active in cells provides insights into SQS inhibition, of interest in the context of the development of drugs against Chagas disease. PMID:24789335

  1. Prism adaptation in the healthy brain: the shift in line bisection judgments is long lasting and fluctuates.

    PubMed

    Schintu, Selene; Pisella, Laure; Jacobs, Stéphane; Salemme, Romeo; Reilly, Karen T; Farnè, Alessandro

    2014-01-01

    Rightward prism adaptation has been shown to ameliorate visuospatial biases in right brain-damaged patients with neglect, and a single session of prism adaptation can lead to improvements that last up to several hours. Leftward prism adaptation in neurologically healthy individuals induces neglect-like biases in visuospatial tasks. The duration of these effects in healthy individuals, typically assumed to be ephemeral, has never been investigated. Here we assessed the time-course of the adaptation-induced modifications in a classical perceptual line bisection task that was repeatedly administered for approximately 40min after a single session of adaptation to either a leftward or rightward prismatic deviation. Consistent with previous reports, only adaptation to leftward-deviating prisms induced a visuospatial shift on perceptual line bisection judgments. The typical pattern of pseudoneglect was counteracted by a rightward shift in midline judgments, which became significant between 5 and 10 min after adaptation, fluctuated between being significant or not several times in the 40 min following adaptation, and was present as late as 35 min. In contrast, the sensorimotor aftereffect was present immediately after adaptation to both rightward and leftward deviating prisms, decayed initially then remained stable until 40 min. These results demonstrate that both the sensorimotor and visuospatial effects last for at least 35 min, but that the visuospatial shift needs time to fully develop and fluctuates. By showing that the effects of prism adaptation in the undamaged brain are not ephemeral, these findings reveal the presence of another, so-far neglected dimension in the domain of the cognitive effects induced by prism adaptation, namely time. The prolonged duration of the induced visuospatial shift, previously considered to be a feature of prism adaptation unique to brain-damaged subjects, also applies to the normal brain. © 2013 Published by Elsevier Ltd.

  2. In Situ Expression of Regulatory Cytokines by Heart Inflammatory Cells in Chagas' Disease Patients with Heart Failure

    PubMed Central

    Rodrigues, Denise Bertulucci Rocha; dos Reis, Marlene Antonia; Romano, Audrey; Pereira, Sanívia Aparecida de Lima; Teixeira, Vicente de Paula Antunes; Tostes Junior, Sebastião; Rodrigues, Virmondes

    2012-01-01

    Chagas' disease is caused by the protozoan parasite Trypanosoma cruzi. The immune system plays an important role in the reduction of parasite load, but may also contribute to the development of lesions observed during the chronic phase of the disease. We analyzed cytokines produced by inflammatory heart cells in 21 autopsy samples obtained from patients with Chagas' disease divided according to the presence or absence of heart failure (HF). Left ventricular sections were analyzed by immunohistochemistry using antibodies against human IL-4, IFN-γ, TGF-β, TNF-α, and NOS2. In situ mRNA expression was quantified by a Low Density Array. The number of IFN-γ-positive cells was significantly higher than IL-4 positive cells. TNF-α, TGF-β and NOS2 were detected in 65%, 62% and 94% of samples respectively. There was an association between TNF-α-producing cells and the presence of HF. Subjects with HF presented higher levels of STAT4 mRNA, whereas FoxP3 and STAT6 levels were similar in the two groups. A Th1 cytokine pattern predominated in the cardiac inflammatory cell infiltrate of Chagas' disease patients associated with HF. High degree of fibrosis was associated with low NOS2 expression. These results support the idea that Th1 immune responses are involved in heart lesions of Chagas' disease patients. PMID:22811738

  3. Chronic Chagas Disease Diagnosis: A Comparative Performance of Commercial Enzyme Immunoassay Tests

    PubMed Central

    Santos, Fred Luciano Neves; de Souza, Wayner Vieira; da Silva Barros, Michelle; Nakazawa, Mineo; Krieger, Marco Aurélio; de Miranda Gomes, Yara

    2016-01-01

    There is a significant heterogeneity in reported performance of serological assays for Chagas disease diagnosis. The conventional serology testing in laboratory diagnosis and in blood banks is unsatisfactory because of a high number of inconclusive and misclassified results. We aimed to assess the quality of four commercially available enzyme-linked immunosorbent assay tests for their ability to detect Trypanosoma cruzi antibodies in 685 sera samples. Cross-reactivity was assessed by using 748 sera from patients with unrelated diseases. Initially, we found that the reactivity index against T. cruzi antigen was statistically higher in sera from Chagas disease patients compared with those from non-chagasic patients, supporting the notion that all evaluated tests have a good discriminatory ability toward the diagnosis of T. cruzi infection in patients in the chronic phase of the disease. Although all tests were similarly sensitive for diagnosing T. cruzi infection, there were significant variations in terms of specificity and cross-reactivity among them. Indeed, we obtained divergent results when testing sera from patient with unrelated diseases, particularly leishmaniasis, with the levels of cross-reactivity being higher in tests using whole T. cruzi extracts compared with those using recombinant proteins. Our data suggest that all four tests may be used for the laboratory diagnosis and routine blood screening diagnose for Chagas disease. We also emphasize that, despite their general good performance, caution is needed when analyzing the results when these tests are performed in areas where other diseases, particularly leishmaniasis, are endemic. PMID:26976886

  4. Strategic Planning for Chronic Disease Prevention in Rural America: Looking Through a PRISM Lens.

    PubMed

    Honeycutt, Amanda A; Wile, Kristina; Dove, Cassandra; Hawkins, Jackie; Orenstein, Diane

    2015-01-01

    Community-level strategic planning for chronic disease prevention. To share the outcomes of the strategic planning process used by Mississippi Delta stakeholders to prevent and reduce the negative impacts of chronic disease in their communities. A key component of strategic planning was participants' use of the Prevention Impacts Simulation Model (PRISM) to project the reduction, compared with the status quo, in deaths and costs from implementing interventions in Mississippi Delta communities. Participants in Mississippi Delta strategic planning meetings used PRISM, a user-friendly, evidence-based simulation tool that includes 22 categories of policy, systems, and environmental change interventions, to pose what-if questions that explore the likely short- and long-term effects of an intervention or any desired combination of the 22 categories of chronic disease intervention programs and policies captured in PRISM. These categories address smoking, air pollution, poor nutrition, and lack of physical activity. Strategic planning participants used PRISM outputs to inform their decisions and actions to implement interventions. Rural communities in the Mississippi Delta. A diverse group of 29 to 34 local chronic disease prevention stakeholders, known as the Mississippi Delta Strategic Alliance. Community plans and actions that were developed and implemented as a result of local strategic planning. Existing strategic planning efforts were complemented by the use of PRISM. The Mississippi Delta Strategic Alliance decided to implement new interventions to improve air quality and transportation and to expand existing interventions to reduce tobacco use and increase access to healthy foods. They also collaborated with the Department of Transportation to raise awareness and use of the current transportation network. The Mississippi Delta Strategic Alliance strategic planning process was complemented by the use of PRISM as a tool for strategic planning, which led to the

  5. PRISM framework: a paradigm shift for designing, strengthening and evaluating routine health information systems

    PubMed Central

    Aqil, Anwer; Lippeveld, Theo; Hozumi, Dairiku

    2009-01-01

    The utility and effectiveness of routine health information systems (RHIS) in improving health system performance in developing countries has been questioned. This paper argues that the health system needs internal mechanisms to develop performance targets, track progress, and create and manage knowledge for continuous improvement. Based on documented RHIS weaknesses, we have developed the Performance of Routine Information System Management (PRISM) framework, an innovative approach to design, strengthen and evaluate RHIS. The PRISM framework offers a paradigm shift by putting emphasis on RHIS performance and incorporating the organizational, technical and behavioural determinants of performance. By describing causal pathways of these determinants, the PRISM framework encourages and guides the development of interventions for strengthening or reforming RHIS. Furthermore, it conceptualizes and proposes a methodology for measuring the impact of RHIS on health system performance. Ultimately, the PRISM framework, in spite of its challenges and competing paradigms, proposes a new agenda for building and sustaining information systems, for the promotion of an information culture, and for encouraging accountability in health systems. PMID:19304786

  6. Development and application of GIS-based PRISM integration through a plugin approach

    NASA Astrophysics Data System (ADS)

    Lee, Woo-Seop; Chun, Jong Ahn; Kang, Kwangmin

    2014-05-01

    A PRISM (Parameter-elevation Regressions on Independent Slopes Model) QGIS-plugin was developed on Quantum GIS platform in this study. This Quantum GIS plugin system provides user-friendly graphic user interfaces (GUIs) so that users can obtain gridded meteorological data of high resolutions (1 km × 1 km). Also, this software is designed to run on a personal computer so that it does not require an internet access or a sophisticated computer system. This module is a user-friendly system that a user can generate PRISM data with ease. The proposed PRISM QGIS-plugin is a hybrid statistical-geographic model system that uses coarse resolution datasets (APHRODITE datasets in this study) with digital elevation data to generate the fine-resolution gridded precipitation. To validate the performance of the software, Prek Thnot River Basin in Kandal, Cambodia is selected for application. Overall statistical analysis shows promising outputs generated by the proposed plugin. Error measures such as RMSE (Root Mean Square Error) and MAPE (Mean Absolute Percentage Error) were used to evaluate the performance of the developed PRISM QGIS-plugin. Evaluation results using RMSE and MAPE were 2.76 mm and 4.2%, respectively. This study suggested that the plugin can be used to generate high resolution precipitation datasets for hydrological and climatological studies at a watershed where observed weather datasets are limited.

  7. [Carlos Chagas Filho: an articulator of the history of sciences in Brazil].

    PubMed

    Domingues, Heloisa Maria Bertol

    2012-06-01

    A letter sent in 1982 by a group of scientists to the president of Conselho Nacional de Desenvolvimento Científico e Tecnológico appealed for a policy of preservation of Brazilian scientific culture. The name of Carlos Chagas Filho topped the list of signatures thereby proving his commitment to that proposal, the ideological structure of which was part of his experience in scientific policy in Brazil and abroad. This document harks back to the practice of the history of the sciences in Brazil and the creation of places for the safeguard and organization of scientific memory, such as the Museu de Astronomia e Ciências Afins, Casa de Oswaldo Cruz and the Sociedade Brasileira de História da Ciência, of which Carlos Chagas Filho was an inaugural member of the board of directors.

  8. Laser Oscillator Incorporating a Wedged Polarization Rotator and a Porro Prism as Cavity Mirror

    NASA Technical Reports Server (NTRS)

    Li, Steven

    2011-01-01

    A laser cavity was designed and implemented by using a wedged polarization rotator and a Porro prism in order to reduce the parts count, and to improve the laser reliability. In this invention, a z-cut quartz polarization rotator is used to compensate the wavelength retardance introduced by the Porro prism. The polarization rotator rotates the polarization of the linear polarized beam with a designed angle that is independent of the orientation of the rotator. This unique property was used to combine the retardance compensation and a Risley prism to a single optical component: a wedged polarization rotator. This greatly simplifies the laser alignment procedure and reduces the number of the laser optical components.

  9. On palms, bugs, and Chagas disease in the Americas.

    PubMed

    Abad-Franch, Fernando; Lima, Marli M; Sarquis, Otília; Gurgel-Gonçalves, Rodrigo; Sánchez-Martín, María; Calzada, José; Saldaña, Azael; Monteiro, Fernando A; Palomeque, Francisco S; Santos, Walter S; Angulo, Victor M; Esteban, Lyda; Dias, Fernando B S; Diotaiuti, Liléia; Bar, María Esther; Gottdenker, Nicole L

    2015-11-01

    Palms are ubiquitous across Neotropical landscapes, from pristine forests or savannahs to large cities. Although palms provide useful ecosystem services, they also offer suitable habitat for triatomines and for Trypanosoma cruzi mammalian hosts. Wild triatomines often invade houses by flying from nearby palms, potentially leading to new cases of human Chagas disease. Understanding and predicting triatomine-palm associations and palm infestation probabilities is important for enhancing Chagas disease prevention in areas where palm-associated vectors transmit T. cruzi. We present a comprehensive overview of palm infestation by triatomines in the Americas, combining a thorough reanalysis of our published and unpublished records with an in-depth review of the literature. We use site-occupancy modeling (SOM) to examine infestation in 3590 palms sampled with non-destructive methods, and standard statistics to describe and compare infestation in 2940 palms sampled by felling-and-dissection. Thirty-eight palm species (18 genera) have been reported to be infested by ∼39 triatomine species (10 genera) from the USA to Argentina. Overall infestation varied from 49.1-55.3% (SOM) to 62.6-66.1% (dissection), with important heterogeneities among sub-regions and particularly among palm species. Large palms with complex crowns (e.g., Attalea butyracea, Acrocomia aculeata) and some medium-crowned palms (e.g., Copernicia, Butia) are often infested; in slender, small-crowned palms (e.g., Euterpe) triatomines associate with vertebrate nests. Palm infestation tends to be higher in rural settings, but urban palms can also be infested. Most Rhodnius species are probably true palm specialists, whereas Psammolestes, Eratyrus, Cavernicola, Panstrongylus, Triatoma, Alberprosenia, and some Bolboderini seem to use palms opportunistically. Palms provide extensive habitat for enzootic T. cruzi cycles and a critical link between wild cycles and transmission to humans. Unless effective means to

  10. Congenital Chagas's disease in an urban population: investigation of infected twins.

    PubMed

    Hoff, R; Mott, K E; Milanesi, M L; Bittencourt, A L; Barbosa, H S

    1978-01-01

    In the Nordeste de Amaralina suburb of Salvador Bahia, Brazil, 47 of 285 pregnant women surveyed had complement fixing antibodies to Trypanosoma cruzi. At delivery T. cruzi was detected in one of 17 placentas from the sero-positive women. The offspring of this case were premature twins and T. cruzi was detected in the peripheral blood of each before death. At autopsy the gastro-intestinal tract and urinary bladder of both were severely affected. Immunofluorescence tests on cord sera, including the single case with T. cruzi in the placenta, were negative for IgM antibodies to T. cruzi. The mother of the infected twins and three of her living children, who were born and have resided in the city, were also infected with T. cruzi. Although the children had visited an area endemic for Chagas's disease for short periods, the mode of transmission in this family may have been transplacental. The value of the immunofluorescence test in the diagnosis of congenital Chagas's disease is discussed.

  11. How universal is coverage and access to diagnosis and treatment for Chagas disease in Colombia? A health systems analysis.

    PubMed

    Cucunubá, Zulma M; Manne-Goehler, Jennifer M; Díaz, Diana; Nouvellet, Pierre; Bernal, Oscar; Marchiol, Andrea; Basáñez, María-Gloria; Conteh, Lesong

    2017-02-01

    Limited access to Chagas disease diagnosis and treatment is a major obstacle to reaching the 2020 World Health Organization milestones of delivering care to all infected and ill patients. Colombia has been identified as a health system in transition, reporting one of the highest levels of health insurance coverage in Latin America. We explore if and how this high level of coverage extends to those with Chagas disease, a traditionally marginalised population. Using a mixed methods approach, we calculate coverage for screening, diagnosis and treatment of Chagas. We then identify supply-side constraints both quantitatively and qualitatively. A review of official registries of tests and treatments for Chagas disease delivered between 2008 and 2014 is compared to estimates of infected people. Using the Flagship Framework, we explore barriers limiting access to care. Screening coverage is estimated at 1.2% of the population at risk. Aetiological treatment with either benznidazol or nifurtimox covered 0.3-0.4% of the infected population. Barriers to accessing screening, diagnosis and treatment are identified for each of the Flagship Framework's five dimensions of interest: financing, payment, regulation, organization and persuasion. The main challenges identified were: a lack of clarity in terms of financial responsibilities in a segmented health system, claims of limited resources for undertaking activities particularly in primary care, non-inclusion of confirmatory test(s) in the basic package of diagnosis and care, poor logistics in the distribution and supply chain of medicines, and lack of awareness of medical personnel. Very low screening coverage emerges as a key obstacle hindering access to care for Chagas disease. Findings suggest serious shortcomings in this health system for Chagas disease, despite the success of universal health insurance scale-up in Colombia. Whether these shortcomings exist in relation to other neglected tropical diseases needs investigating

  12. Prisms for pain. Can visuo-motor rehabilitation strategies alleviate chronic pain?

    PubMed Central

    Torta, DM; Legrain, V; Rossetti, Y; Mouraux, A

    2017-01-01

    Background and aims Prism adaptation (PA) is a non-invasive procedure in which participants perform a visuo-motor pointing task while wearing prism goggles inducing a lateral displacement of the visual field and a mismatch between the seen and felt position of the pointing hand. PA is thought to induce a reorganization of sensorimotor coordination, and has been used successfully to rehabilitate neglect following right-hemisphere lesions. Because studies have shown that complex regional pain syndrome (CRPS) is associated with neglect-like symptoms, it was proposed that PA could be used to alleviate pain in these patients. Database A search for peer-reviewed articles on neglect-like symptoms in CRPS and on the use of prisms in CRPS was conducted using the PubMed database. Results There is still no agreement as to whether CRPS patients really present neglect symptoms and, if they do, what it is that they neglect. Furthermore, there is insufficient data to determine whether PA exerts an effect on CRPS symptoms. Finally, it remains unknown whether neglect can be observed in other types of lateralized pain, or whether PA could be useful for these patients. Conclusion By highlighting open issues, our review provides guidelines for future studies on the use of prisms in pain. The assessment of neglect in patients with CRPS as well as other types of lateralized chronic pain should be characterized using a combination of neuropsychological methods assessing the multiple aspects of neglect in a more refined manner. In addition, further studies should investigate the mechanisms through which PA may modulate pain. PMID:26095341

  13. Positive deviance study to inform a Chagas disease control program in southern Ecuador

    PubMed Central

    Nieto-Sanchez, Claudia; Baus, Esteban G; Guerrero, Darwin; Grijalva, Mario J

    2015-01-01

    Chagas disease is caused by Trypanosoma cruzi, which is mainly transmitted by the faeces of triatomine insects that find favourable environments in poorly constructed houses. Previous studies have documented persistent triatomine infestation in houses in the province of Loja in southern Ecuador despite repeated insecticide and educational interventions. We aim to develop a sustainable strategy for the interruption of Chagas disease transmission by promoting living environments that are designed to prevent colonisation of rural houses by triatomines. This study used positive deviance to inform the design of an anti-triatomine prototype house by identifying knowledge, attitudes and practices used by families that have remained triatomine-free (2010-2012). Positive deviants reported practices that included maintenance of structural elements of the house, fumigation of dwellings and animal shelters, sweeping with "insect repellent" plants and relocation of domestic animals away from the house, among others. Participants favoured construction materials that do not drastically differ from those currently used (adobe walls and tile roofs). They also expressed their belief in a clear connection between a clean house and health. The family's economic dynamics affect space use and must be considered in the prototype's design. Overall, the results indicate a positive climate for the introduction of housing improvements as a protective measure against Chagas disease in this region. PMID:25807468

  14. Processing and review interface for strong motion data (PRISM) software, version 1.0.0—Methodology and automated processing

    USGS Publications Warehouse

    Jones, Jeanne; Kalkan, Erol; Stephens, Christopher

    2017-02-23

    A continually increasing number of high-quality digital strong-motion records from stations of the National Strong-Motion Project (NSMP) of the U.S. Geological Survey (USGS), as well as data from regional seismic networks within the United States, call for automated processing of strong-motion records with human review limited to selected significant or flagged records. The NSMP has developed the Processing and Review Interface for Strong Motion data (PRISM) software to meet this need. In combination with the Advanced National Seismic System Quake Monitoring System (AQMS), PRISM automates the processing of strong-motion records. When used without AQMS, PRISM provides batch-processing capabilities. The PRISM version 1.0.0 is platform independent (coded in Java), open source, and does not depend on any closed-source or proprietary software. The software consists of two major components: a record processing engine and a review tool that has a graphical user interface (GUI) to manually review, edit, and process records. To facilitate use by non-NSMP earthquake engineers and scientists, PRISM (both its processing engine and review tool) is easy to install and run as a stand-alone system on common operating systems such as Linux, OS X, and Windows. PRISM was designed to be flexible and extensible in order to accommodate new processing techniques. This report provides a thorough description and examples of the record processing features supported by PRISM. All the computing features of PRISM have been thoroughly tested.

  15. Strain Variation in Accretionary Prisms Across Space and Time: Insights from the Makran Subduction Zone

    NASA Astrophysics Data System (ADS)

    Penney, C.; Tavakoli, F.; Saadat, A.; Nankali, H. R.; Sedighi, M.; Khorrami, F.; Sobouti, F.; Rafi, Z.; Copley, A.; Jackson, J. A.; Priestley, K. F.

    2017-12-01

    The Makran is one of the world's least-studied subduction zones. In particular, little is known about the accumulation and accommodation of strain in the onshore part of the subduction zone, which parallels the coasts of southern Iran and Pakistan. The deformation of the Makran accretionary prism results from both its subduction zone setting and N-S right-lateral shear between central Iran and Afghanistan. North of the Makran, this shear is accommodated by a series of right-lateral faults which offset the rocks of the Sistan Suture Zone, an abandoned accretionary prism. However, these right-lateral faults are not observed south of 27°N, and no major N-S faults cut the E-W trending structures of the Makran. How this right-lateral motion is accommodated at the southern end of the Sistan Suture Zone is a long-standing tectonic question. By combining results from geomorphology, GPS, seismology and modelling we conclude that right-lateral motion is transferred across the depression north of the accretionary prism to the region of right-lateral shear at the western end of the accretionary prism. This requires the Jaz Murian depression to be bounded by normal faults, consistent with the basin geomorphology. However, GPS data show compression across the margins of the basin, and no shallow normal-faulting earthquakes have been observed in the region. We therefore suggest that the behaviour of these faults may be time-dependent and controlled by the megathrust seismic cycle, as has been suggested elsewhere (e.g. Chile). Recent strike-slip earthquakes, including the 2013 Balochistan earthquake, have clustered at the prism's lateral edges, showing the importance of spatial, as well as temporal, variations in strain. These earthquakes have reactivated thrust faults in the Makran accretionary prism, showing that the style of strain within accretionary prisms can vary on multiple timescales and allowing us to calculate the coefficient of friction on the underlying megathrust.

  16. Cavity Enhanced Absorption Spectroscopy using a Prism Cavity and Supercontinuum Source

    NASA Astrophysics Data System (ADS)

    Lehmann, Kevin K.; Johnston, Paul S.

    2010-03-01

    The multiplex advantage of current cavity enhanced spectrometers is limited by the limited high reflectivity bandwidth of the dielectric mirrors used to construct the high finesse cavity. We report on our development of a spectrometer that uses Brewster's angle retroreflectors that is excited with supercontinuum radiation generated by a 1.06 μm pumped photonic crystal fiber, which covers the 500-1800 nm spectral range. Recent progress will be discussed including modeling of the prism cavity losses, alternative prism materials for use in the UV and mid-IR, and a new higher power source pumped by a mode-locked laser.

  17. Watching Nanoscale Self-Assembly Kinetics of Gold Prisms in Liquids

    NASA Astrophysics Data System (ADS)

    Kim, Juyeong; Ou, Zihao; Jones, Matthew R.; Chen, Qian

    We use liquid-phase transmission electron microscopy to watch self-assembly of gold triangular prisms into polymer-like structures. The in situ dynamics monitoring enabled by liquid-phase transmission electron microscopy, single nanoparticle tracking, and the marked conceptual similarity between molecular reactions and nanoparticle self-assembly combined elucidate the following mechanistic understanding: a step-growth polymerization based assembly statistics, kinetic pathways sampling particle curvature dependent energy minima and their interconversions, and directed assembly into polymorphs (linear or cyclic chains) through in situ modulation of the prism bonding geometry. Our study bridges the constituent kinetics on the molecular and nanoparticle length scales, which enriches the design rules in directed self-assembly of anisotropic nanoparticles.

  18. SU-G-IeP1-13: Sub-Nyquist Dynamic MRI Via Prior Rank, Intensity and Sparsity Model (PRISM)

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Jiang, B; Gao, H

    Purpose: Accelerated dynamic MRI is important for MRI guided radiotherapy. Inspired by compressive sensing (CS), sub-Nyquist dynamic MRI has been an active research area, i.e., sparse sampling in k-t space for accelerated dynamic MRI. This work is to investigate sub-Nyquist dynamic MRI via a previously developed CS model, namely Prior Rank, Intensity and Sparsity Model (PRISM). Methods: The proposed method utilizes PRISM with rank minimization and incoherent sampling patterns for sub-Nyquist reconstruction. In PRISM, the low-rank background image, which is automatically calculated by rank minimization, is excluded from the L1 minimization step of the CS reconstruction to further sparsify themore » residual image, thus allowing for higher acceleration rates. Furthermore, the sampling pattern in k-t space is made more incoherent by sampling a different set of k-space points at different temporal frames. Results: Reconstruction results from L1-sparsity method and PRISM method with 30% undersampled data and 15% undersampled data are compared to demonstrate the power of PRISM for dynamic MRI. Conclusion: A sub- Nyquist MRI reconstruction method based on PRISM is developed with improved image quality from the L1-sparsity method.« less

  19. Morphometric study of the fibrosis and mast cell count in the circular colon musculature of chronic Chagas patients with and without megacolon.

    PubMed

    Pinheiro, Simone Wanderley; Rua, Adilha Misson de Oliveira; Etchebehere, Renata Margarida; Cançado, Cristiane Gobbo; Chica, Javier Em lio Lazo; Lopes, Edison Reis; Adad, Sheila Jorge

    2003-01-01

    A morphometric study of the circular colon musculature was performed, in which the mast cell count was determined and the connective fibrous tissue in this layer was measured. The objective was to gain better understanding of Chagas megacolon morphology and contribute towards the knowledge of fibrosis pathogenesis in Chagas megas. An evaluation was made of 15 distal sigmoid rings from Chagas patients with megacolon (MCC), 15 without megacolon (CSMC) and 15 non-Chagas patients (NC). The rings were fixed in formol, embedded in paraffin, and 7mm thick sections were cut and stained using Azan-Heidenhain and Giemsa. The mast cell count and fibrosis were greater in the MCC group than in the CSMC and NC groups (p< 0,05; Kruskal-Wallis test) and there was no significant difference between the latter two. The fibrosis and increased mast cell count in the colon musculature of the MCC group possibly indicates that there is a relationship between mastocytosis and fibrosis, as has already been demonstrated in other pathologies.

  20. Prism adaptation in virtual and natural contexts: Evidence for a flexible adaptive process.

    PubMed

    Veilleux, Louis-Nicolas; Proteau, Luc

    2015-01-01

    Prism exposure when aiming at a visual target in a virtual condition (e.g., when the hand is represented by a video representation) produces no or only small adaptations (after-effects), whereas prism exposure in a natural condition produces large after-effects. Some researchers suggested that this difference may arise from distinct adaptive processes, but other studies suggested a unique process. The present study reconciled these conflicting interpretations. Forty participants were divided into two groups: One group used visual feedback of their hand (natural context), and the other group used computer-generated representational feedback (virtual context). Visual feedback during adaptation was concurrent or terminal. All participants underwent laterally displacing prism perturbation. The results showed that the after-effects were twice as large in the "natural context" than in the "virtual context". No significant differences were observed between the concurrent and terminal feedback conditions. The after-effects generalized to untested targets and workspace. These results suggest that prism adaptation in virtual and natural contexts involves the same process. The smaller after-effects in the virtual context suggest that the depth of adaptation is a function of the degree of convergence between the proprioceptive and visual information that arises from the hand.

  1. [Prism adaptation test before strabismus surgery : Results of a survey and literature review].

    PubMed

    Pichler, U; Rohleder, M; Ehrt, O

    2018-02-01

    Variable preoperative deviations and compensatory mechanisms may cause wrong dosage of strabismus surgery and result in over- or undercorrection. A long-lasting prism adaptation test (PAT) before surgery is supposed to reduce those difficulties and to improve the postoperative results. To date, the use of prism adaptation before surgery has not been systematically examined. A total of 15 strabismologists and 28 orthoptists in Austria were interviewed about their approach to prism adaptation in 9 types of strabismus. They were also asked about the basis of their decision for a certain treatment regime. Of those interviewed, 28% performed preoperative prism adaptation for weeks to years. Of those, 7% based their decision on evidence from the literature, 54% decide on personal experience, 15% due to guidelines of their institution, and 23% follow the teaching of their medical school. Reports in the literature reveal inconsistent results on PAT. In published studies, PAT was rarely performed longer than 4 weeks and only shows significant improvements on outcome in particular pathologies as acquired esotropia. Long-term PAT appears questionable as to date there is no evidence for a better postoperative outcome. Before setting up guidelines, further controlled, prospective studies on PAT must be conducted.

  2. Assessment of cross-reactive host-pathogen antibodies in patients with different stages of chronic Chagas disease.

    PubMed

    Vicco, Miguel H; Ferini, Franco; Rodeles, Luz; Cardona, Paula; Bontempi, Iván; Lioi, Susana; Beloscar, Juan; Nara, Takeshi; Marcipar, Iván; Bottasso, Oscar A

    2013-10-01

    Trypanosoma cruzi infection has been shown to induce humoral autoimmune responses against host antigens tissues. Particularly, antibodies cross-reacting with myocardial antigens may play a role in the development of the severe forms of chronic Chagas disease. The aim of this study was to determine the association between clinical stage of the disease and the presence of autoantibodies in patients with chronic Chagasic disease. We performed a cross-sectional study in T. cruzi-seropositive patients divided into 3 groups according to the classic classification of chronic Chagas heart of Storino et al. All participants underwent complete clinical examination and their sera were used to measure autoantibody levels. All patients had detectable levels of anti-p2β and anti-B13 autoantibodies but none had anti-Na-K-ATPase antibodies. No association was observed between electrocardiographic conduction disturbances and autoantibody levels. Patients with chronic Chagas disease stage III had the highest levels of anti-B13 antibodies and a high risk of mortality score, showing a clear association between disease stage and this score. Anti-B13 antibodies were significantly higher in chronic Chagas disease stage III patients, suggesting that these antibodies may be involved in disease progression and that they might be a useful marker of poor prognosis in terms of heart compromise. Our results also reveal an important correlation between the level of anti-B13 autoantibodies and symptomatic heart failure and/or dilated cardiomyopathy. Copyright © 2013 Sociedad Española de Cardiología. Published by Elsevier Espana. All rights reserved.

  3. Association of Bartonella spp bacteremia with Chagas cardiomyopathy, endocarditis and arrythmias in patients from South America

    PubMed Central

    Corrêa, F.G.; Pontes, C.L.S.; Verzola, R.M.M.; Mateos, J.C.P.; Velho, P.E.N.F.; Schijman, A.G.; Selistre-de-Araujo, H.S.

    2012-01-01

    Infection with Bartonella spp may cause cardiac arrhythmias, myocarditis and endocarditis in humans. The aim of the present study was to evaluate a possible association between Bartonella spp bacteremia and endocarditis, arrhythmia and Chagas cardiomyopathy in patients from Brazil and Argentina. We screened for the presence of bacterial 16S rRNA in human blood by PCR using oligonucleotides to amplify a 185-bp bacterial DNA fragment. Blood samples were taken from four groups of subjects in Brazil and Argentina: i) control patients without clinical disease, ii) patients with negative blood-culture endocarditis, iii) patients with arrhythmias, and iv) patients with chronic Chagas cardiomyopathy. PCR products were analyzed on 1.5% agarose gel to visualize the 185-bp fragment and then sequenced to confirm the identity of DNA. Sixty of 148 patients (40.5%) with cardiac disease and 1 of 56 subjects (1.8%) from the control group presented positive PCR amplification for Bartonella spp, suggesting a positive association of the bacteria with these diseases. Separate analysis of the four groups showed that the risk of a Brazilian patient with endocarditis being infected with Bartonella was 22 times higher than in the controls. In arrhythmic patients, the prevalence of infection was 45 times higher when compared to the same controls and 40 times higher for patients with Chagas cardiomyopathy. To the best of our knowledge this is the first report of the association between Bartonella spp bacteremia and Chagas disease. The present data may be useful for epidemiological and prevention studies in Brazil and Argentina. PMID:22584639

  4. Lineage Analysis of Circulating Trypanosoma cruzi Parasites and Their Association with Clinical Forms of Chagas Disease in Bolivia

    PubMed Central

    del Puerto, Ramona; Nishizawa, Juan Eiki; Kikuchi, Mihoko; Iihoshi, Naomi; Roca, Yelin; Avilas, Cinthia; Gianella, Alberto; Lora, Javier; Gutierrez Velarde, Freddy Udalrico; Renjel, Luis Alberto; Miura, Sachio; Higo, Hiroo; Komiya, Norihiro; Maemura, Koji; Hirayama, Kenji

    2010-01-01

    Background The causative agent of Chagas disease, Trypanosoma cruzi, is divided into 6 Discrete Typing Units (DTU): Tc I, IIa, IIb, IIc, IId and IIe. In order to assess the relative pathogenicities of different DTUs, blood samples from three different clinical groups of chronic Chagas disease patients (indeterminate, cardiac, megacolon) from Bolivia were analyzed for their circulating parasites lineages using minicircle kinetoplast DNA polymorphism. Methods and Findings Between 2000 and 2007, patients sent to the Centro Nacional de Enfermedades Tropicales for diagnosis of Chagas from clinics and hospitals in Santa Cruz, Bolivia, were assessed by serology, cardiology and gastro-intestinal examinations. Additionally, patients who underwent colonectomies due to Chagasic magacolon at the Hospital Universitario Japonés were also included. A total of 306 chronic Chagas patients were defined by their clinical types (81 with cardiopathy, 150 without cardiopathy, 100 with megacolon, 144 without megacolon, 164 with cardiopathy or megacolon, 73 indeterminate and 17 cases with both cardiopathy and megacolon). DNA was extracted from 10 ml of peripheral venous blood for PCR analysis. The kinetoplast minicircle DNA (kDNA) was amplified from 196 out of 306 samples (64.1%), of which 104 (53.3%) were Tc IId, 4 (2.0%) Tc I, 7 (3.6%) Tc IIb, 1 (0.5%) Tc IIe, 26 (13.3%) Tc I/IId, 1 (0.5%) Tc I/IIb/IId, 2 (1.0%) Tc IIb/d and 51 (25.9%) were unidentified. Of the 133 Tc IId samples, three different kDNA hypervariable region patterns were detected; Mn (49.6%), TPK like (48.9%) and Bug-like (1.5%). There was no significant association between Tc types and clinical manifestations of disease. Conclusions None of the identified lineages or sublineages was significantly associated with any particular clinical manifestations in the chronic Chagas patients in Bolivia. PMID:20502516

  5. A Longitudinal Study of Prism Adaptation in Infants from Six to Nine Months of Age.

    ERIC Educational Resources Information Center

    McDonnell, Paul M.; Abraham, Wayne C.

    1981-01-01

    Confirms that aftereffects of prism adaptation can be obtained in infants between 5 and 9 months of age and that the magnitude of these aftereffects is comparable to those found in adult studies. Evidence of a shift in hand preference toward the direction of prism displacement was replicated. (Author/RH)

  6. Challenges and perspectives of Chagas disease: a review

    PubMed Central

    2013-01-01

    Chagas disease (CD), also known as American trypanosomiasis, is caused by the flagellated protozoan Trypanosoma cruzi, and affects an estimated 8 to 10 million people worldwide. In Latin America, 25 million people live in risk areas, while in 2008 alone, 10,000 CD-related deaths were reported. This review aimed to evaluate the challenges of CD control, future perspectives, and actions performed worldwide to control expansion of the disease and its impact on public health in Latin America. PMID:24354455

  7. Generation of a high-accuracy regional DEM based on ALOS/PRISM imagery of East Antarctica

    NASA Astrophysics Data System (ADS)

    Shiramizu, Kaoru; Doi, Koichiro; Aoyama, Yuichi

    2017-12-01

    A digital elevation model (DEM) is used to estimate ice-flow velocities for an ice sheet and glaciers via Differential Interferometric Synthetic Aperture Radar (DInSAR) processing. The accuracy of DInSAR-derived displacement estimates depends upon the accuracy of the DEM. Therefore, we used stereo optical images, obtained with a panchromatic remote-sensing instrument for stereo mapping (PRISM) sensor mounted onboard the Advanced Land Observing Satellite (ALOS), to produce a new DEM ("PRISM-DEM") of part of the coastal region of Lützow-Holm Bay in Dronning Maud Land, East Antarctica. We verified the accuracy of the PRISM-DEM by comparing ellipsoidal heights with those of existing DEMs and values obtained by satellite laser altimetry (ICESat/GLAS) and Global Navigation Satellite System surveying. The accuracy of the PRISM-DEM is estimated to be 2.80 m over ice sheet, 4.86 m over individual glaciers, and 6.63 m over rock outcrops. By comparison, the estimated accuracy of the ASTER-GDEM, widely used in polar regions, is 33.45 m over ice sheet, 14.61 m over glaciers, and 19.95 m over rock outcrops. For displacement measurements made along the radar line-of-sight by DInSAR, in conjunction with ALOS/PALSAR data, the accuracy of the PRISM-DEM and ASTER-GDEM correspond to estimation errors of <6.3 mm and <31.8 mm, respectively.

  8. Propagation of rotational Risley-prism-array-based Gaussian beams in turbulent atmosphere

    NASA Astrophysics Data System (ADS)

    Chen, Feng; Ma, Haotong; Dong, Li; Ren, Ge; Qi, Bo; Tan, Yufeng

    2018-03-01

    Limited by the size and weight of prism and optical assembling, Rotational Risley-prism-array system is a simple but effective way to realize high power and superior beam quality of deflecting laser output. In this paper, the propagation of the rotational Risley-prism-array-based Gaussian beam array in atmospheric turbulence is studied in detail. An analytical expression for the average intensity distribution at the receiving plane is derived based on nonparaxial ray tracing method and extended Huygens-Fresnel principle. Power in the diffraction-limited bucket is chosen to evaluate beam quality. The effect of deviation angle, propagation distance and intensity of turbulence on beam quality is studied in detail by quantitative simulation. It reveals that with the propagation distance increasing, the intensity distribution gradually evolves from multiple-petal-like shape into the pattern that contains one main-lobe in the center with multiple side-lobes in weak turbulence. The beam quality of rotational Risley-prism-array-based Gaussian beam array with lower deviation angle is better than its counterpart with higher deviation angle when propagating in weak and medium turbulent (i.e. Cn2 < 10-13m-2/3), the beam quality of higher deviation angle arrays degrades faster as the intensity of turbulence gets stronger. In the case of propagating in strong turbulence, the long propagation distance (i.e. z > 10km ) and deviation angle have no influence on beam quality.

  9. Early clinics of the cardiac forms of Chagas' disease: Discovery and study of original medical files (1909-1915).

    PubMed

    Gachelin, Gabriel; Bestetti, Reinaldo B

    2017-10-01

    We have uncovered 80 medical files corresponding to original cases of Chagas' disease used for the classical description of the acute and cardiac forms of the disease. Sixty of them were diagnosed cardiac forms of the disease. The detailed clinical description of these 60 files is in excellent agreement with the nosography of progressive heart disease given by Chagas in his original 1922 paper. The reports we had access to, characterize a novel form of cardiac disease, dominated by progressive AV block, enlargement and displacement of the heart and sudden death, in relatively young adults including juveniles. In contrast to that remarkable clinical description, the assertion made by Chagas that this set of clinical signs was the consequence of an earlier infection by Trypanosoma cruzi rests on weak evidence, due to the difficulty to identify the parasite in most patients. Moreover, the association of thyroid dysfunction with cardiac disease emphasized by Chagas cannot be deduced from the files we have examined. Finally, the main reason why the disease had not been recognized for long as a defined clinical entity, is likely the absence of markedly distinctive clinical signs compared to most other parasitic diseases, poor sanitary conditions and the probable lack of clinical skills of the rare doctors working in the area where the disease was described. Copyright © 2017 Elsevier B.V. All rights reserved.

  10. Behaviour of concrete beams reinforced withFRP prestressed concrete prisms

    NASA Astrophysics Data System (ADS)

    Svecova, Dagmar

    The use of fibre reinforced plastics (FRP) to reinforce concrete is gaining acceptance. However, due to the relatively low modulus of FRP, in comparison to steel, such structures may, if sufficient amount of reinforcement is not used, suffer from large deformations and wide cracks. FRP is generally more suited for prestressing. Since it is not feasible to prestress all concrete structures to eliminate the large deflections of FRP reinforced concrete flexural members, researchers are focusing on other strategies. A simple method for avoiding excessive deflections is to provide sufficiently high amount of FRP reinforcement to limit its stress (strain) to acceptable levels under service loads. This approach will not be able to take advantage of the high strength of FRP and will be generally uneconomical. The current investigation focuses on the feasibility of an alternative strategy. This thesis deals with the flexural and shear behaviour of concrete beams reinforced with FRP prestressed concrete prisms. FRP prestressed concrete prisms (PCP) are new reinforcing bars, made by pretensioning FRP and embedding it in high strength grout/concrete. The purpose of the research is to investigate the feasibility of using such pretensioned rebars, and their effect on the flexural and shear behaviour of reinforced concrete beams over the entire loading range. Due to the prestress in the prisms, deflection of concrete beams reinforced with this product is substantially reduced, and is comparable to similarly steel reinforced beams. The thesis comprises both theoretical and experimental investigations. In the experimental part, nine beams reinforced with FRP prestressed concrete prisms, and two companion beams, one steel and one FRP reinforced were tested. All the beams were designed to carry the same ultimate moment. Excellent flexural and shear behaviour of beams reinforced with higher prestressed prisms is reported. When comparing deflections of three beams designed to have the

  11. Polymorphisms in the gene for lymphotoxin-alpha predispose to chronic Chagas cardiomyopathy.

    PubMed

    Ramasawmy, Rajendranath; Fae, Kellen C; Cunha-Neto, Edecio; Müller, Natalie G; Cavalcanti, Vanessa L; Ferreira, Renata C; Drigo, Sandra A; Ianni, Barbara; Mady, Charles; Goldberg, Anna C; Kalil, Jorge

    2007-12-15

    Chagas disease, caused by Trypanosoma cruzi infection, displays clinical heterogeneity and may be attributable to differential genetic susceptibility. Chronic Chagas cardiomyopathy (CCC) develops only in a subset of T. cruzi-infected individuals and may lead to heart failure that has a worse clinical course and that leads to reduced life expectancy, compared with heart failure of other etiologies. Proinflammatory cytokines play a key role in the development of CCC. Clinical, genetic, and epidemiological studies have linked lymphotoxin-alpha (LTA), a proinflammatory cytokine, to coronary artery disease and myocardial infarction. We used polymerase chain reaction to genotype the LTA +80A-->C and LTA +252A-->G variants in 169 patients with CCC and in 76 T. cruzi-infected asymptomatic (ASY) patients. Homozygosity with respect to the LTA +80C and LTA +252G alleles was significantly more frequent in the patients with CCC than in the ASY patients (homozygosity for LTA +80C, 47% vs. 33%; homozygosity for LTA +252G, 16% vs. 8%). Haplotype LTA +80A-252A was associated with protection against CCC, whereas haplotype LTA +80C-252G was associated with susceptibility to CCC. Furthermore, homozygosity for the LTA +80A allele correlated with the lowest levels of plasmatic tumor-necrosis factor-alpha. Our results suggest that the study of genetic variations in patients with Chagas disease may help in the identification of individuals at increased risk of progressing to CCC and, by providing early treatment, reduce the morbidity and mortality associated with this disease.

  12. Ecoepidemiology, short history and control of Chagas disease in the endemic countries and the new challenge for non-endemic countries

    PubMed Central

    Coura, José Rodrigues; Viñas, Pedro Albajar; Junqueira, Angela CV

    2014-01-01

    Chagas disease is maintained in nature through the interchange of three cycles: the wild, peridomestic and domestic cycles. The wild cycle, which is enzootic, has existed for millions of years maintained between triatomines and wild mammals. Human infection was only detected in mummies from 4,000-9,000 years ago, before the discovery of the disease by Carlos Chagas in 1909. With the beginning of deforestation in the Americas, two-three centuries ago for the expansion of agriculture and livestock rearing, wild mammals, which had been the food source for triatomines, were removed and new food sources started to appear in peridomestic areas: chicken coops, corrals and pigsties. Some accidental human cases could also have occurred prior to the triatomines in peridomestic areas. Thus, triatomines progressively penetrated households and formed the domestic cycle of Chagas disease. A new epidemiological, economic and social problem has been created through the globalisation of Chagas disease, due to legal and illegal migration of individuals infected by Trypanosoma cruzi or presenting Chagas disease in its varied clinical forms, from endemic countries in Latin America to non-endemic countries in North America, Europe, Asia and Oceania, particularly to the United States of America and Spain. The main objective of the present paper was to present a general view of the interchanges between the wild, peridomestic and domestic cycles of the disease, the development of T. cruzi among triatomine, their domiciliation and control initiatives, the characteristics of the disease in countries in the Americas and the problem of migration to non-endemic countries. PMID:25410988

  13. [Management of Chagas disease in Europe. Experiences and challenges in Spain, Switzerland and Italy].

    PubMed

    Jackson, Y; Angheben, A; Carrilero Fernandez, B; Jansa i Lopez del Vallado, J M; Jannin, J G; Albajar-Viñas, P

    2009-12-01

    The intention of this article is not to describe the illness or evaluate the number of cases diagnosed in Spain, Switzerland and Italy, nor to analyse the protocols followed in various centres. The authors rather seek to examine the main technical, local and national challenges involved in the care of patients with Chagas disease. To this end, they review concisely a number of themes which are common to the three countries. These are: the detection of disease; confirmation of the diagnosis; treatment; response to treatment; follow-up; the risk of transmission by transfusion, by organ donation and from mother to child; the psychosocial and socio-economic aspects of Chagas disease outside endemic areas; and what progress needs to be made in improving information about the condition.

  14. Genetic Susceptibility to Cardiac and Digestive Clinical Forms of Chronic Chagas Disease: Involvement of the CCR5 59029 A/G Polymorphism

    PubMed Central

    de Oliveira, Amanda Priscila; Bernardo, Cássia Rubia; Camargo, Ana Vitória da Silveira; Ronchi, Luiz Sérgio; Borim, Aldenis Albaneze; Brandão de Mattos, Cinara Cássia; de Campos Júnior, Eumildo; Castiglioni, Lílian; Netinho, João Gomes; Cavasini, Carlos Eugênio; Bestetti, Reinaldo Bulgarelli; de Mattos, Luiz Carlos

    2015-01-01

    The clinical manifestations of chronic Chagas disease include the cardiac form of the disease and the digestive form. Not all the factors that act in the variable clinical course of this disease are known. This study investigated whether the CCR5Δ32 (rs333) and CCR5 59029 A/G (promoter region—rs1799987) polymorphisms of the CCR5 gene are associated with different clinical forms of chronic Chagas disease and with the severity of left ventricular systolic dysfunction in patients with chronic Chagas heart disease (CCHD). The antibodies anti-T. cruzi were identified by ELISA. PCR and PCR-RFLP were used to identify the CCR5Δ32 and CCR5 59029 A/G polymorphisms. The chi-square test was used to compare variables between groups. There was a higher frequency of the AA genotype in patients with CCHD compared with patients with the digestive form of the disease and the control group. The results also showed a high frequency of the AG genotype in patients with the digestive form of the disease compared to the other groups. The results of this study show that the CCR5Δ32 polymorphism does not seem to influence the different clinical manifestations of Chagas disease but there is involvement of the CCR5 59029 A/G polymorphism in susceptibility to the different forms of chronic Chagas disease. Besides, these polymorphisms do not influence left ventricular systolic dysfunction in patients with CCHD. PMID:26599761

  15. Genetic Susceptibility to Cardiac and Digestive Clinical Forms of Chronic Chagas Disease: Involvement of the CCR5 59029 A/G Polymorphism.

    PubMed

    de Oliveira, Amanda Priscila; Bernardo, Cássia Rubia; Camargo, Ana Vitória da Silveira; Ronchi, Luiz Sérgio; Borim, Aldenis Albaneze; de Mattos, Cinara Cássia Brandão; de Campos Júnior, Eumildo; Castiglioni, Lílian; Netinho, João Gomes; Cavasini, Carlos Eugênio; Bestetti, Reinaldo Bulgarelli; de Mattos, Luiz Carlos

    2015-01-01

    The clinical manifestations of chronic Chagas disease include the cardiac form of the disease and the digestive form. Not all the factors that act in the variable clinical course of this disease are known. This study investigated whether the CCR5Δ32 (rs333) and CCR5 59029 A/G (promoter region--rs1799987) polymorphisms of the CCR5 gene are associated with different clinical forms of chronic Chagas disease and with the severity of left ventricular systolic dysfunction in patients with chronic Chagas heart disease (CCHD). The antibodies anti-T. cruzi were identified by ELISA. PCR and PCR-RFLP were used to identify the CCR5Δ32 and CCR5 59029 A/G polymorphisms. The chi-square test was used to compare variables between groups. There was a higher frequency of the AA genotype in patients with CCHD compared with patients with the digestive form of the disease and the control group. The results also showed a high frequency of the AG genotype in patients with the digestive form of the disease compared to the other groups. The results of this study show that the CCR5Δ32 polymorphism does not seem to influence the different clinical manifestations of Chagas disease but there is involvement of the CCR5 59029 A/G polymorphism in susceptibility to the different forms of chronic Chagas disease. Besides, these polymorphisms do not influence left ventricular systolic dysfunction in patients with CCHD.

  16. The Use of PRISM (Pictorial Representation of Illness and Self Measure) in Patients Affected by Chronic Cutaneous Ulcers.

    PubMed

    Monari, Paola; Pelizzari, Laura; Crotti, Silvia; Damiani, Giovanni; Calzavara-Pinton, Piergiacomo; Gualdi, Giulio

    2015-11-01

    PRISM (Pictorial Representation of Illness and Self Measure) is a nonverbal visualization instrument. The authors chose to use this tool to avoid the limitation of the other tests for the assessment of quality of life by using interview methods that depend on the cognitive and cultural level of the patient. The aim of the study was to assess the impact on the quality of life of different types of chronic wounds using the PRISM test. The PRISM test was administered by the same medical student to each patient visiting the dermatology department for a routine visit and medication. The PRISM test was administered to 77 patients with chronic cutaneous ulcers referred to the Dermatology Department of the Spedali Civili of Brescia, Italy. The authors analyzed the "Self-llness-Separation"' (SIS) value, which resulted from the PRISM test, and related it to sex, age, and ulcer etiology. Considering all categories, the mean SIS was 9.58 cm; a different perception of the disease between the sexes was noted and also in the subgroups based on the ulcer's different etiology. In addition, the age of the affected patients influenced the SIS value. PRISM is an easy and sensitive instrument to record information about the patient's expectations and suffering in order to improve the overall physician-patient relationship.

  17. Hexahedron Prism-Anchored Octahedronal CeO2: Crystal Facet-Based Homojunction Promoting Efficient Solar Fuel Synthesis.

    PubMed

    Li, Ping; Zhou, Yong; Zhao, Zongyan; Xu, Qinfeng; Wang, Xiaoyong; Xiao, Min; Zou, Zhigang

    2015-08-05

    An unprecedented, crystal facet-based CeO2 homojunction consisting of hexahedron prism-anchored octahedron with exposed prism surface of {100} facets and octahedron surface of {111} facets was fabricated through solution-based crystallographic-oriented epitaxial growth. The photocatalysis experiment reveals that growth of the prism arm on octahedron allows to activate inert CeO2 octahedron for an increase in phototocatalytic reduction of CO2 into methane. The pronounced photocatalytic performance is attributed to a synergistic effect of the following three factors: (1) band alignment of the {100} and {111} drives electrons and holes to octahedron and prism surfaces, respectively, aiming to reach the most stable energy configuration and leading to a spatial charge separation for long duration; (2) crystallographic-oriented epitaxial growth of the CeO2 hexahedron prism arm on the octahedron verified by the interfacial lattice fringe provides convenient and fast channels for the photogenerated carrier transportation between two units of homojuntion; (3) different effective mass of electrons and holes on {100} and {111} faces leads to high charge carrier mobility, more facilitating the charge separation. The proposed facet-based homojunction in this work may provide a new concept for the efficient separation and fast transfer of photoinduced charge carriers and enhancement of the photocatalytic performance.

  18. High-performance beam steering using electrowetting-driven liquid prism fabricated by a simple dip-coating method

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Enrico Clement, Carlos; Park, Sung-Yong, E-mail: mpeps@nus.edu.sg

    2016-05-09

    A high degree of beam steering is demonstrated using an electrowetting-driven liquid prism. While prism devices have typically relied on complex and expensive laboratory setups, such as high-vacuum facilities for fabrication of dielectric layers, this work utilizes a simple dip-coating method to provide an ion gel layer as a dielectric, offering 2 or 3 orders higher specific capacitance (c ≈ 10 μF/cm{sup 2}) than that of conventional dielectrics. Analytical studies present the effects of liquid selection and arrangement on overall prism performance. For experimental demonstrations of high-performance beam steering, we not only selected two immiscible liquids of water and 1-bromonaphthalene (1-BN)more » oil which provide the large refractive index difference (n{sub water} = 1.33 and n{sub 1-BN} = 1.65 at λ = 532 nm) between them, but also utilized a double-stacked prism configuration which increases the number of interfaces for incoming light to be steered. At a prism apex angle of φ = 27°, we were able to achieve significantly large beam steering of up to β = 19.06°, which is the highest beam steering performance ever demonstrated using electrowetting technology.« less

  19. The Prevalence of Chagas Heart Disease in a Central Bolivian Community Endemic for Trypanosoma Cruzi

    PubMed Central

    Yager, Jessica E.; Lozano Beltran, Daniel F.; Torrico, Faustino; Gilman, Robert H.; Bern, Caryn

    2015-01-01

    Background Though the incidence of new Trypanosoma cruzi infections has decreased significantly in endemic regions in the Americas, medical professionals continue to encounter a high burden of resulting Chagas disease among infected adults. The current prevalence of Chagas heart disease in a community setting is not known; nor is it known how recent insecticide vector control measures may have impacted the progression of cardiac disease in an infected population. Objectives and Methods Nested within a community serosurvey in rural and periurban communities in central Bolivia, we performed a cross-sectional cardiac substudy to evaluate adults for historical, clinical, and electrocardiographic evidence of cardiac disease. All adults between the ages of 20 and 60 years old with T. cruzi infection and those with a clinical history, physical exam, or ECG consistent with cardiac abnormalities were also scheduled for echocardiography. Results and conclusions Of the 604 cardiac substudy participants with definitive serology results, 183 were seropositive for infection with T. cruzi (30.3%). Participants who were seropositive for T. cruzi infection were more likely to have conduction system defects (1.6% versus 0 for complete right bundle branch block and 10.4% versus 1.9% for any bundle branch block; p=0.008 and p<0.001, respectively). However, there was no statistically significant difference in the prevalence of bradycardia among seropositive versus seronegative participants. Echocardiogram findings were not consistent with a high burden of Chagas cardiomyopathy: valvulopathies were the most common abnormality, and few participants were found to have low ejection fraction or left ventricular dilatation. No participants had significant heart failure. Though almost one third of adults in the community were seropositive for T. cruzi infection, few had evidence of Chagas heart disease. PMID:26407509

  20. A Patient with Erythema Nodosus Leprosum and Chagas Cardiopathy: Challenges in Patient Management and Review of the Literature

    PubMed Central

    Trindade, Maria Ângela B.; Carvalho, Noemia B.; Belfort, Elaini C.; Pagliari, Carla; Gakiya, Erika; Sakai-Valente, Neusa Y.; Benard, Gil; Shikanai-Yasuda, Maria A.

    2011-01-01

    We report a patient with severe multi-bacillary leprosy complicated by recurrent episodes of erythema nodosum necrotisans that required thalidomide and/or corticosteroids during follow-up. Although the patient was from an area to which Chagas disease is endemic, this diagnosis was initially missed and was only investigated when heart failure developed in the patient. The difficulties of managing erythema nodosum necrotisans and heart failure concomitantly and those involved in excluding the diagnosis of acute myocarditis caused by reactivation of Chagas disease secondary to the immunosuppressive regimen are discussed. Other potential causes for the heart failure and possible interactions between the two diseases and their treatments are discussed. We also reviewed the literature for the association between leprosy and Chagas disease, both of which are highly endemic in Brazil. This case emphasizes the importance of searching for subclinical co-infections in leprosy patients because reactions frequently develop during specific treatment in these patients, and these reactions require prolonged therapy with immunosuppressive drugs. PMID:21633036