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PubMed2001

Attentional capture by color without any relevant attentional set.

The aim of the present study was to investigate mechanisms underlying attentional capture by color. Previous work has shown that a color singleton is able to summon attention only in the presence of a relevant attentional set, whereas when a color singleton is not useful for a task, evidence for purely stimulus-driven attentional capture is controversial. Three visual search experiments (T-L task) were conducted using a method different from that based on set sizes, consisting of monitoring target-singleton distance in a unique display size. In Experiment 1, we demonstrated that attention can be summoned in a real stimulus-driven manner by an irrelevant color singleton. Experiment 2A extended this observation, showing that the color singleton attracted attention even when capture was detrimental. However, Experiment 2B showed that such capture can be strategically prevented. Finally, in Experiment 3, we examined whether such a capture was due to a spatial shift or to a filtering cost, providing evidence supporting the shift hypothesis. Stimulus-driven capture was observed when color was neither the defining nor the reported target attribute (Yantis, 1993) and when subjects naive of visual search tasks were used. The present results give experimental support to many contemporary models of visual attention.

Adult↗

PubMed2003

Attentional capture by auto- and allo-cues.

In a host of studies, the ability of various types of cues to capture attention has been examined. This article reviews a number of these studies by organizing them into a classification scheme based on the relationship between the putative attention-capturing item (the cue) and the item used to assess the distribution of attention (the probe). The second dimension of this taxonomy divides paradigms of attentional capture into those in which capture is indexed by performance benefits and those in which capture is indexed by performance costs. The relative methodological merits and disadvantages of the paradigms that occupy each of the cells of the resulting two-by-two matrix are discussed. A final section offers a new interpretation of the finding that dynamic cues capture attention.

Attention↗

PubMed2005

The onset of receding motion captures attention: comment on Franconeri and Simons (2003).

Franconeri & Simons (2003) reported that some but not all types of motion capture attention in a visual search task, ostensibly because some types of motion are behaviorally significant. In the present article, we argue that a more parsimonious explanation of their results is that the onset of motion, but not motion per se, captures attention. This conclusion helps to resolve inconsistencies between the Franconeri and Simons findings and earlier reports from other investigators and is consistent with results that we have recently reported (Abrams & Christ, 2003). The Franconeri and Simons interpretation rests largely on their failure to find attentional capture by one type of motion-simulated receding motion. We report here the results of two experiments that demonstrate that the onset of receding motion does indeed capture attention when the motion is produced using stereo depth cues. As we have argued elsewhere, the capture of attention in displays containing motion appears to be dependent on the onset of the motion, rather than on the mere presence of specific types of motion as suggested by Franconeri and Simons. One possible explanation is that the onset of motion captures attention because it serves as a strong cue to animacy--and the detection of nearby animals can have important consequences for survival.

Attention↗

PubMed2003

Effects of acepromazine on capture stress in roe deer (Capreolus capreolus).

The aim of this study was to evaluate effect of a short-acting neuroleptic (acepromazine) on capture stress response in roe deer (Capreolus capreolus). Sixteen roe deer were captured by drive-nets in the winters of 1998, 1999, and 2001. Roe deer were divided into two groups: animals in the treatment group received an intramuscular injection of acepromazine (0.093 mg/kg +/- 0.003 SEM; n = 8) while animals in the control group (n = 8) did not receive tranquilizer. Heart rate and body temperature, as well as hematologic and biochemical indicators of stress, were used to evaluate effect of the neuroleptic over 3 hr. Heart rate decreased over time after capture in both groups (P < 0.05), but stabilized sooner in the treated roe deer (75 min after capture) than in the controls (105 min after capture). Body temperature decreased over 45 min and then stabilized in both groups (P < 0.05). Comparisons of blood parameters revealed significantly lower red blood cell count (RBC), lymphocyte count, hemoglobin concentration, packed cell volume (PCV), and serum alanine aminotransferase (ALT), aspartate aminotransferase (AST), creatine kinase (CK), and lactate dehydrogenase (LDH) activities in tranquilized animals compared with controls (at least P < 0.05). A reduction in PCV, lymphocyte count, and serum cortisol concentrations (at least P < 0.05) and an increase in serum creatinine levels (P < 0.05) were recorded over time in control animals, while a reduction in RBC and hemoglobin concentration (at least P < 0.05) and an increase in serum urea concentrations (P < 0.05) over time were observed in the treated group. Finally, a decrease in serum lactate and potassium levels and an increase in CK, AST, ALT, and LDH activities were recorded over time in both groups. Results obtained showed the suitability of using acepromazine in capture operations in order to reduce stress response and prevent its adverse effects in roe deer. The beneficial effect was not only due to the sedative effect of acepromazine, but also to peripheral vasodilatation.

Acepromazine↗

PubMed1998

Capture of human monoclonal antibodies from cell culture supernatant by ion exchange media exhibiting high charge density.

A shortcut purification sequence for therapeutic proteins should consist of three steps: capture, purification, and polishing. Special emphasis has been put on direct capture of human monoclonal antibodies from culture supernatants with ion-exchangers avoiding pretreatment steps such as desalting, dilution, and other means to reduce the ionic strength. CM-HyperD, a cation-exchanger composed of an inorganic macroporous support filled with a viscoelastic gel with a high charge density was used. Capture of monoclonal antibodies from clarified hybridoma cell culture grown in media supplemented with fetal calf serum was investigated. Screening of different pH conditions and buffers for the load step showed that monoclonal antibodies were efficiently bound by CM-HyperD at pH 4.0 and 5.0 at an ionic strength equivalent to culture supernatant. Combination of negative purification with Q-Sepharose FF and capturing with CM-HyperD gave sufficient yield and resolution. Implementation of wash steps with higher conductivity did not improve the purity, but decreased the yield. Interestingly, high flow rates improved the purity. When antibodies were captured from serumfree culture supernatant the antibody could be eluted in a single peak with substantial reduction of contaminants. Capturing of antibodies by ion-exchange sorbents from culture supernatant is possible despite the high salt content.

Antibodies, Monoclonal↗

PubMed1999

Capture-recapture analysis of batterer reassaults: an epidemiological innovation for batterer program evaluation.

Capture-recapture analysis is an analytical tool being used in epidemiological research to estimate incidence rates for missing cases and unreliable reporting. Its contribution to batterer program evaluations is examined through a capture-recapture analysis of a multisite evaluation of batterer programs (n = 853). Capture-recapture analysis is applied to various subsamples of the multisite study and to different outcomes (i.e., any reassault, "severe" reassault) to explore the utility of capture-recapture. Finally, the capture-recapture estimates are compared to only the women's reports and to adjusted women's reports (women's reports supplemented with arrest records and men's reports), which are the basis of existing batterer program evaluation. The capture-recapture reassault estimate for the 15-month follow-up is equal to the adjusted women's reports (39%), but is 7% greater than the women reports. The subsample estimates for the individual sites appear to vary as a result of unreliable or unavailable arrest records.

Battered Women↗

PubMedDate not supplied

Effect of field capture on the measurement of cellular immune responses in wild ferrets (Mustela furo), vectors of bovine tuberculosis in New Zealand.

Ferrets are recognised as significant wildlife vectors of bovine tuberculosis (Tb) in New Zealand. Disease management strategies, such as the development of a protective wildlife vaccine, could be assisted by the ability to measure pertinent cellular immune responses among wild animals. In the present study, we investigated whether it is possible to measure in vitro lymphocyte reactivity in wild-caught ferrets, and also determined levels of physiological stress in these animals, and we compared these responses to those observed in laboratory-maintained domesticated ferrets. Over a 12-month period, 80 ferrets were live-captured from a Tb-endemic region (Otago, southern New Zealand); cardiac blood was withdrawn on-site, and mononuclear cell cultures were successfully established from 75 of these animals. Lymphocyte transformation (LT) responses to T cell and T/B cell mitogens (Concanavalin A [Con A] and pokeweed mitogen) were measured via uridine incorporation assay. The magnitude of these responses did not differ significantly between animals that had been captured in wire-framed cage traps and those captured using soft-jawed leg-hold traps. Levels of serum cortisol and glucose (as indicators of physiological and oxidative stress, respectively) were highest in animals captured using leg-hold traps. In comparison to domesticated ferrets, wild-caught ferrets had lower overall LT responses to Con A, but significantly higher levels of serum cortisol. Finally, 10/80 animals captured from the wild were severely diseased (Tb+), as evidenced by gross tuberculous lesions at autopsy. Successful mononuclear cell cultures were established from nine of these animals; LT responses to Con A were significantly lower in Tb+ ferrets than in either wild-caught/non-diseased (Tb-) or domesticated ferrets. These results demonstrate that it is possible to measure cellular immune responses from the blood of wild-caught ferrets, but that field capture and disease status may have detrimental effects on in vitro T cell function, possibly due to the influence of physiological stress.

Animals↗

PubMed2001

Comparison of anti-PR3 capture and anti-PR3 direct ELISA for detection of antineutrophil cytoplasmic antibodies (ANCA) in long-term clinical follow-up of PR3-ANCA-associated vasculitis patients.

A total of 118 sera from 11 patients with anti-neutrophil cytoplasmic antibodies against proteinase-3- (PR3-ANCA) associated vasculitis were retrospectively screened by anti-PR3 capture and anti-PR3 direct ELISA tests. We studied the relationship between capture and direct ELISA scores and the clinical activity of PR3-ANCA-associated vasculitis patients during follow-up. We also studied the ability of the anti-PR3 capture ELISA to detect positive values of PR3-ANCA in clinical vasculitis relapses. Only capture ELISA presented a significant relationship (p < 0.05) with clinical activity of PR3-ANCA-associated vasculitis patients over time. Capture ELISA appears to be a reliable method for detecting clinical relapses in this group of patients. Our results indicate that the new capture ELISA test is more effective than direct ELISA in the follow-up of patients with PR3-ANCA-associated vasculitis and in the detection of relapses.

Adult↗

PubMed2002

Evaluation of video capture equipment for secondary image acquisition in the PACS.

There are many cases in which picture archiving and communication systems (PACS) are built with old-type existing modalities with no DICOM output. One of the methods for interfacing them to the PACS is to implement video capture (/ frame grabber) equipment. This equipment takes analog video signal output from medical imaging modalities, and amplitude of the video signal is A/D converted and supplied to the PACS. In this report, we measured and evaluated the accuracy at which this video capture equipment could capture the image. From the physical evaluation, we found the pixel values of an original image and its captured image were almost equal in gray level from 20%-90%. The change in the pixel values of a captured image was +/-3 on average. The change of gray level concentration was acceptable and had an average standard deviation of around 0.63. As for resolution, the degradation was observed at the highest physical level. In a subjective evaluation, the evaluation value of the CT image had a grade of 2.81 on the average (the same quality for a reference image was set to a grade of 3.0). Abnormalities in heads, chests, and abdomens were judged not to influence diagnostic accuracy. Some small differences were seen when comparing captured and reference images, but they are recognized as having no influence on the diagnoses.

Humans↗

PubMed2006

[Posterior continuous curvilinear capsulorhexis with optic capture of the posterior chamber intraocular lens in pediatric cataract].

OBJECTIVE: To assess the clinical effects of posterior continuous curvilinear capsulorhexis with optic capture of the posterior chamber intraocular lens in pediatric cataract. METHODS: Fifty-one cases (83 eyes) received posterior continuous curvilinear capsulorhexis with optic capture of the posterior chamber intraocular lens. Preoperative and postoperative visual acuity and refractive error were recorded. Intraoperative and postoperative complications were observed. The follow-up period was from 6 to 36 months. RESULTS: Implantation of optic capture of the posterior chamber intraocular lens was successfully performed in 75 eyes (90.4%). The mean postoperative best corrected distant visual acuity achieved 0.5 or better in 75 eyes (48.0%). No eyes with optic capture were found optic axis opaque. The major complications of optic capture were anterior chamber fibrous exudation, iris posterior synechia and lenticular precipitates. CONCLUSION: Optic capture of the posterior chamber intraocular lens is safe and effective in the treatment of pediatric cataract to posterior continuous curvilinear capsulorhexis especially in the prevention of secondary opacification from the visual axis.

Adolescent↗

PubMed1994

Measurement of augmentation of 252Cf implant by 10B and 157Gd neutron capture.

252Cf has been used as a brachytherapy source since the early 1970s. The dominant mechanism of interactions of 252Cf neutrons with tissue is elastic scattering. The scattered neutrons lose part of their energy, which is released as kinetic energy of the recoiling nuclei. By multiple scattering, neutrons lose their energy and eventually become thermalized (in energetic equilibrium with tissue atoms with an average energy of 0.025 eV) and do not play any role in radiotherapy. These thermal neutrons may interact with hydrogen nuclei or with nitrogen, but the cell killing effects by these reaction products are negligibly small compared to the elastic scattering by fast neutrons or by photons emitted by californium. Nonetheless, these thermal neutrons are still potentially usable for neutron capture therapy and can be used to enhance californium brachytherapy effects. Neutron capture therapy is a two-part therapy relying on the selective loading of tumor cells with compounds containing 10B or 157Gd and subsequent irradiation with thermal neutrons. To calculate neutron capture doses one has to know thermal neutron flux. This paper presents results of an experimental study of thermal neutron flux and calculations of boron neutron capture and gadolinium neutron capture doses in the vicinity of 252Cf sources.

Boron Neutron Capture Therapy↗

PubMed1999

Dosimetry of the boron neutron capture reaction for BNCT and BNCEFNT.

The use of paired proportional counters, constructed from A-150 tissue equivalent plastic (TEP) and A-150 TEP loaded with an appropriate amount of 10B (50 to 200 ppm), for the dosimetry of the boron neutron capture reaction has been investigated for several years at the Gershenson Radiation Oncology Center. This method has been used for determining the dose components (fast neutron, gamma ray and boron capture product dose) in both Boron Neutron Capture Therapy (BNCT) beams and in beams proposed for boron neutron capture enhancement of fast neutron therapy (BNCEFNT). A disadvantage of this method, when standard 1/2" diameter Rossi type proportional counters are used, is that the beam intensity must be relatively low in order to avoid saturation effects (pulse pile-up) in the counter. This is a major problem if measurements are to be made in a reactor beam, since reducing the beam intensity generally results in a change in the neutron spectrum. In order to overcome this problem, miniature cylindrical proportional counters have been developed which may be used in high intensity beams. The operational characteristics of these counters are compared with the standard 1/2" spherical counters. A further disadvantage of proportional counters is the relatively long time it takes to collect data, particularly if detailed information (depth-dose curves and beam profiles) is required. This problem could be overcome by using a set of ionization chambers (an A-150 TEP chamber, a Mg chamber and a Mg chamber with a 25 microns boron loaded inner wall) which can be scanned in a water phantom. After calibration against the paired proportional counters it should be possible to extract the fast neutron, gamma ray and boron neutron capture product doses from measurements made with these three ionization chambers. A set of such chambers has been used to make preliminary measurements in a fast neutron beam and the results of these measurements are presented.

Boron Neutron Capture Therapy↗

PubMed1994

Response of the central nervous system to boron neutron capture irradiation: evaluation using rat spinal cord model.

The response of the central nervous system to boron neutron capture irradiation, with either p-boronophenylalanine (BPA) or borocaptate sodium (BSH) as neutron capture agents, has been assessed using a rat spinal cord model. The mean latency times for the development of myelopathy after irradiation with the thermal neutron beam-alone, or in combination with BPA or BSH, were 23.7 +/- 0.3, 21.8 +/- 0.4 and 19.6 +/- 0.4 weeks, respectively. The radiation-induced lesion in the spinal cord was characterised by white matter necrosis. Due to the variations in the microdistribution of different neutron capture agents in body tissues, it was considered inappropriate to define the biological effectiveness of the high LET radiation, resulting from the 10B(n, alpha)7Li neutron capture reaction, relative to photon radiation, using the term 'relative biological effectiveness' (RBE). The term 'compound biological effectiveness' (CBE) factor was used as an alternative. ED50 values for the various irradiation modalities were calculated from probit fitted dose effect curves. Expressed as total physical absorbed doses these values were 13.6 +/- 0.4, 30.3 +/- 2.7 and 13.8 +/- 0.5 Gy after irradiation with the thermal neutron beam alone, or the thermal neutron beam in combination with BSH or BPA, respectively. The RBE of the thermal neutron beam was 1.4 +/- 0.04. The microdistribution of the two neutron capture agents played a crucial role in the determination of the overall biological effect, after thermal neutron activation. BSH, which is excluded from the CNS parenchyma by the blood brain barrier, had a low CBE factor value of 0.46 +/- 0.5. BPA, on the other hand, which crosses the blood brain barrier and distributes in the CNS parenchyma, had a higher CBE factor value of 1.33 +/- 0.16.

Absorption↗

PubMed2006

Gadolinium neutron capture brachytherapy (GdNCB), a new treatment method for intravascular brachytherapy.

Restenosis is a major problem after balloon angioplasty and stent implantation. The aim of this study is to introduce gadolinium neutron capture brachytherapy (GdNCB) as a suitable modality for treatment of stenosis. The utility of GdNCB in intravascular brachytherapy (IVBT) of stent stenosis is investigated by using the GEANT4 and MCNP4B Monte Carlo radiation transport codes. To study capture rate, Kerma, absorbed dose and absorbed dose rate around a Gd-containing stent activated with neutrons, a 30 mm long, 5 mm diameter gadolinium foil is chosen. The input data is a neutron spectrum used for clinical neutron capture therapy in Studsvik, Sweden. Thermal neutron capture in gadolinium yields a spectrum of high-energy gamma photons, which due to the build-up effect gives an almost flat dose delivery pattern to the first 4 mm around the stent. The absorbed dose rate is 1.33 Gy/min, 0.25 mm from the stent surface while the dose to normal tissue is in order of 0.22 Gy/min, i.e., a factor of 6 lower. To spare normal tissue further fractionation of the dose is also possible. The capture rate is relatively high at both ends of the foil. The dose distribution from gamma and charge particle radiation at the edges and inside the stent contributes to a nonuniform dose distribution. This will lead to higher doses to the surrounding tissue and may prevent stent edge and in-stent restenosis. The position of the stent can be verified and corrected by the treatment plan prior to activation. Activation of the stent by an external neutron field can be performed days after catherization when the target cells start to proliferate and can be expected to be more radiation sensitive. Another advantage of the nonradioactive gadolinium stent is the possibility to avoid radiation hazard to personnel.

Blood Vessel Prosthesis↗

PubMed1992

Present status of boron neutron capture therapy.

The neutron capture reaction 10B(1n,4He)7Li produces two energetic particles, 4He2+ and 7Li3+ that are strongly cell toxic. Due to the short range of these nuclear fragments (5-9 microns) mainly those cells that have bound or internalized a 10B-containing substance are growth-inactivated. The most critical and difficult step in an efficient boron neutron capture therapy (BNCT) is the tumour targeting. It is today possible to synthesize a large number of boron compounds and conjugate them to tumour-seeking macromolecules, such as monoclonal antibodies or different polypeptides. The boron-containing substances presently considered for therapy are sulfhydryl boron hydride (BSH) and boron-phenylalanine, (BPA) for the treatment of gliomas and malignant melanomas respectively. Other boronated compounds considered are ligands for receptor-amplified tumour cells, antibodies for tumour cells with specific antigens and thioureas for treatment of melanotic melanomas. The required boron concentration is given by the relative dose due to neutron capture in 10B and that of the competing capture reactions in nitrogen and hydrogen. Capture in nitrogen produces protons with a range of about 10-11 microns and this gives a radiation dose to all cells in the neutron activated area. Calculations show that the local concentration of 10B near the critical radiation target, DNA, must be higher than 10 ppm (10 micrograms/g). Increased emphasis will be put on the development of combinations of treatments that fulfil the requirements for attacking the microscopic spread of the tumour.

Boron↗

PubMed1995

[Neutron capturing irradiation: principle, current results and perspectives].

Neutron capture irradiation aims to selectively destroy the tumoral cells with nuclear reactions produced inside themselves. Therefore, 10B is selectively carried into tumours, being linked to a molecular vehicle. The tissues are then irradiated with thermal neutrons, and the boron neutron capture leads to the formation of alpha and 7Li particles which produce high levels of radiolytic damage along their range of 10 microns. Boron neutron capture therapy (BNCT) uses a thermal/epithermal neutron beam for irradiation, while boron neutron capture potentiation uses the addition of the captures in a fast neutron irradiation. A first trial, conducted in 1951 to 1961 in the USA to test BNCT on patients suffering of glioblastoma, was a failure, essentially because 10B was located in the cerebral capillaries rather than in the tumoral cells. Today, with great improvement in the boronated compounds which show an uptake preferentially inside the cells; the quality of neutron beams; and the knowledge of the microdosimetry of the technique, this technique may be clinically used to increase the local control of radioresistant tumours, like the high grade gliomas, cutaneous or uveal melanoma, and perhaps soft tissue sarcomas.

Borohydrides↗

PubMed2007

Use of traps to capture black and gold howlers (Alouatta caraya) on the Islands of the upper Paraná River, Southern Brazil.

Howlers (genus Alouatta) are widely captured with the use of anesthetic projectiles; however, no capture protocol involving the use of traps has been described to date. In the present study we describe the first efficient capture program for black and gold howlers (Alouatta caraya) using traps, which was implemented on the islands of the upper Paraná River in southern Brazil. We constructed two trap models with either manual or automatic activation (trap A with two entrances and guillotine-type doors; trap B with one entrance and a guillotine-type door). The traps were suspended in the canopy by means of vertical climbing techniques, and were baited regularly and abundantly with bananas and mangoes. We captured 70 howlers (86% using manual activation and 14% using automatic activation) on four different islands. We restrained 41 of these animals and measured their body mass, which averaged 5.30 kg+/-1.79. Given our results, we suggest that the system described in the present study represents an alternative capture program for howlers in areas that have low food diversity and no other mammal species that will compete for the bait, as has been observed in riparian environments, islands, and forest fragments.

Alouatta↗

PubMed1994

Rapid detection of hepatitis C virus RNA by direct capture from blood.

A new diagnostic assay for hepatitis C virus RNA detection is described. HCV genomic RNA is captured onto streptavidin-coated magnetic beads by solution hybridization with biotinylated complementary oligonucleotides. The specificity of the capture assay is confirmed using different capture oligonucleotides as well as sera representing different types of HCV. Sensitivity was determined by testing serial dilutions of a HCV infected plasma. A panel of 50 sera was tested for anti-HCV by a Line Immunoassay and for HCV-RNA by both a conventional guanidinium extraction method and the new capture assay. The specificity of the capture assay was 95.8% and the sensitivity was 92.3% compared to the standard protocol. This method provides a rapid and simple alternative for HCV-RNA detection in blood samples.

Animals↗