Nutritional quality of heat-sensitive food materials in intermittent microwave convective drying

Background

The retention of health promoting components in nutrient-rich dried food is significantly affected by the dehydration method. Theoretical and experimental investigations reported in the literature have demonstrated that intermittent microwave convective drying (IMCD) can effectively improve the drying performance. However, the impact of this advanced drying method on the quality food has not been adequately investigated.

Design

A programmable NN-SD691S Panasonic inverter microwave oven (1100 W, 2450 MHz) was employed for the experiments. The microwave power level was set at 100 W and ran for 20 seconds at different power ratios and the constant hot air conditions was set to a temperature of 60°C and 0.86 m/s air velocity.

Objective

In this study, natural bioactive compounds (ascorbic acid and total polyphenol), water activity, colour and microstructure modifications which can occur in IMCD were investigated, taking kiwifruit as a sample.

Results and Discussion

The microwave (MW) power ratio (PR) had significant impact on different quality attributes of dried samples. The results demonstrate that applying optimum level MW power and intermittency could be an appropriate strategy to significantly improve the preservation of nutrient contents, microstructure and colour of the dried sample. The IMCD at PR 1:4 was found to be the ideal drying condition with the highest ascorbic acid retention (3.944 mg/g DM), lowest colour change (ΔERGB = 43.86) and a porous microstructure. However, the total polyphenol content was better maintained (3.701 mg GAE/g DM) at higher microwave density (PR 1:3). All samples attained a desirable level of water activity which is unsusceptible for microorganism growth and reproduction.

Conclusion

Overall, IMCD significantly improved the drying performance and product quality compared to traditional convective drying.

Magnetic Resonance Imaging of Human Dental Pulp Stem Cells in Vitro and in Vivo

Recent advances in stem cell research have shown the promising nature of mesenchymal stem cells as plausible candidates for cell-based regenerative medicine. Many studies reported the use of human dental pulp stem cells (hDPSCs), which possess self-renewal capacity, high proliferation potential, and the ability to undergo multilineage differentiation. Together with this therapeutic approach, development of effective, noninvasive and nontoxic imaging techniques for visualizing and tracking the cells in vivo is crucial for the evaluation and improvement of stem cell therapy. Magnetic resonance imaging (MRI) is one of the most powerful diagnostic imaging techniques currently available for in vivo diagnosis and has been proposed as the most attractive modality for monitoring stem cell migration. The aim of this study was to investigate the labeling efficiency of hDPSCs using superparamagnetic iron oxide (SPIO) particles in order to allow visualization using in vitro and in vivo MRI without influencing cellular metabolism. MRI and transmission electron microscopy (TEM) showed optimal uptake with low SPIO concentrations of 15 μg/ml in combination with 0.75 μg/ml poly-l-lysine (PLL) resulting in more than 13 pg iron/cell and an in vitro detection limit of 50 labeled cells/μl. Very low SPIO concentrations in the culture medium resulted in extremely high labeling efficiency not reported before. For these conditions, tetrazolium salt assays showed no adverse effects on cell viability. Furthermore, in vivo MRI was performed to detect labeled hDPSCs transplanted into the brain of Rag 2-γ C immune-deficient mice. Transplanted cells did not show any signs of tumorgenecity or teratoma formation during the studied time course. We have reported on a labeling and imaging strategy to visualize human dental pulp stem cells in vivo using MRI. These data provide a solid base to allow cell tracking in future regenerative studies in the brain longitudinally.

Dental stem cells and their promising role in neural regeneration: an update

INTRODUCTION

Stem cell-based therapies are considered to be a promising treatment method for several clinical conditions such as Alzheimer's disease, Parkinson's disease, spinal cord injury, and many others. However, the ideal stem cell type for stem cell-based therapy remains to be elucidated.

DISCUSSION

Stem cells are present in a variety of tissues in the embryonic and adult human body. Both embryonic and adult stem cells have their advantages and disadvantages concerning the isolation method, ethical issues, or differentiation potential. The most described adult stem cell population is the mesenchymal stem cells due to their multi-lineage (trans)differentiation potential, high proliferative capacity, and promising therapeutic values. Recently, five different cell populations with mesenchymal stem cell characteristics were identified in dental tissues: dental pulp stem cells, stem cells from human exfoliated deciduous teeth, periodontal ligament stem cells, dental follicle precursor cells, and stem cells from apical papilla.

CONCLUSION

Each dental stem cell population possesses specific characteristics and advantages which will be summarized in this review. Furthermore, the neural characteristics of dental pulp stem cells and their potential role in (peripheral) neural regeneration will be discussed.

Effect of isolation methodology on stem cell properties and multilineage differentiation potential of human dental pulp stem cells

Dental pulp stem cells (DPSCs) are an attractive alternative mesenchymal stem cell (MSC) source because of their isolation simplicity compared with the more invasive methods associated with harvesting other MSC sources. However, the isolation method to be favored for obtaining DPSC cultures remains under discussion. This study compares the stem cell properties and multilineage differentiation potential of DPSCs obtained by the two most widely adapted isolation procedures. DPSCs were isolated either by enzymatic digestion of the pulp tissue (DPSC-EZ) or by the explant method (DPSC-OG), while keeping the culture media constant throughout all experiments and in both isolation methods. Assessment of the stem cell properties of DPSC-EZ and DPSC-OG showed no significant differences between the two groups with regard to proliferation rate and colony formation. Phenotype analysis indicated that DPSC-EZ and DPSC-OG were positive for CD29, CD44, CD90, CD105, CD117 and CD146 expression without any significant differences. The multilineage differentiation potential of both stem cell types was confirmed by using standard immuno(histo/cyto)chemical staining together with an in-depth ultrastructural analysis by means of transmission electron microscopy. Our results indicate that both DPSC-EZ and DPSC-OG could be successfully differentiated into adipogenic, chrondrogenic and osteogenic cell types, although the adipogenic differentiation of both stem cell populations was incomplete. The data suggest that both the enzymatic digestion and outgrowth method can be applied to obtain a suitable autologous DPSC resource for tissue replacement therapies of both bone and cartilage.

Ultrastructural and immunocytochemical analysis of multilineage differentiated human dental pulp- and umbilical cord-derived mesenchymal stem cells

Mesenchymal stem cells (MSCs) are one of the most promising stem cell types due to their availability and relatively simple requirements for in vitro expansion and genetic manipulation. Besides the well-characterized MSCs derived from bone marrow, there is growing evidence suggesting that dental pulp and the umbilical cord matrix both contain a substantial amount of cells having properties similar to those of MSCs. In order to assess the potential of dental pulp-derived MSCs (DPSC) and umbilical cord-derived MSCs (UCSC) in future clinical applications, it is essential to gain more insight into their differentiation capacity and to evaluate the tissues formed by these cells. In the present study, the morphological and ultrastructural characteristics of DPSC and UCSC induced towards osteogenic, adipogenic, and chondrogenic lineages were investigated. Cultured DPSC and UCSC showed a similar expression pattern of antigens characteristic of MSCs including CD105, CD29, CD44, CD146, and STRO-1. Under appropriate culture conditions, both DPSC and UCSC showed chondrogenic and osteogenic potential. Adipogenesis could be only partially induced in DPSC resulting in the de novo expression of fatty acid binding protein (FABP), whereas UCSC expressed FABP combined with a very high accumulation of lipid droplets in the cytoplasm. Our results demonstrate, at the biochemical and ultrastructural level, that DPSC display at least bilineage potential, whereas UCSC, which are developmentally more primitive cells, show trilineage potential. We emphasize that transmission electron microscopical analysis is useful to elucidate detailed structural information and provides indisputable evidence of differentiation. These findings highlight their potential therapeutic value for cell-based tissue engineering.

Overview of the ability of different treatment methods for liquid and solid manure to inactivate pathogens

The use of manure as a fertilizer in agriculture includes the risk of spreading pathogenic infectious agents to the environment, to animals and humans. The treatment of manure can help avoid or reduce these risks. Even if the treatment is dominated by economic considerations such as biogas production, ammonia stripping or phosphorous precipitation, the hygienic aspect should be kept in mind. Otherwise, new infection chains may be established by the use of insufficiently treated manure by-products such as fertilizers still containing infective pathogens. Treatment plants should use a concept according to HACCP principles that includes hazard analysis, risk assessment, the determination of process relevant CCPs and the validation of the process by determining the hygienizing efficiency using representative test organisms as well as microbial end product supervision. Treatment methods can be divided into physical, chemical and microbiological treatment, sometimes used in combination. For economical reasons, only composting or anaerobic treatment (biogas) or, to a minor extent, aerobic thermophilic stabilization (ATS) are used as routine preventive measures on a farm level. In cases of outbreaks of notifiable diseases both physical and chemical treatment of manure can lead to reliable disinfected/pasteurised end products which can be used in agriculture without long-lasting risks for soil fertility or the environment.

Universal influenza A M2e-HBc vaccine protects against disease even in the presence of pre-existing anti-HBc antibodies

The extracellular domain of influenza A virus matrix protein 2 (M2e) is strongly conserved. Therefore, vaccines based on M2e can induce broad-spectrum immunity against influenza. We have mainly used recombinant virus-like particles derived from Hepatitis B virus core (HBc) as carrier for efficacious presentation of the M2e antigen. Here, we address whether pre-existing HBc-specific immunity interferes with the protective immune response obtained by M2e-HBc vaccination. Anti-HBc antibodies were induced by immunizing mice with unsubstituted HBc virus-like particles in the presence of two different adjuvants. We demonstrate that pre-existing HBc-specific antibodies affect neither the induction of M2e-specific antibody responses to vaccination with M2e-HBc particles, nor the protective efficacy of the resulting response. These results suggest that vaccination with M2e-HBc can induce protective anti-M2e antibodies even in anti-HBc positive individuals. The implications of these findings are discussed in the context of the clinical development of an M2e-based universal influenza vaccine, which recently successfully completed a Phase I trial.

Thermal decomposition studies of the polyhedral oligomeric silsesquioxane, POSSh, and when it is impregnated with the metallocene bis(eta5-cyclopentadienyl)zirconium (IV) dichloride or immobilized on silica

Thermal decomposition studies of the free polyhedral oligomeric silsesquioxane, POSSh, and when this compound has been impregnated with Cp2ZrCl2 (Cp = eta5-C5H5) or immobilized on SiO2 were conducted using infrared emission spectroscopy (IES) over a 100-1000 degrees C temperature range and by thermogravimetric analysis (TGA). The organic groups in POSS(h) apparently decompose thermally into Si-CH3, Si-H and other fragments. Upon impregnation with Cp2ZrCl2, however, a different thermal decomposition pathway was followed and new infrared emission bands appeared in the 1000-900 cm(-1) region suggesting the formation of Si-O-Zr moieties. When immobilized on SiO2 and subjected to thermal decomposition, the POSSh compound lost its organic groups and the inorganic structure remaining was incorporated into the SiO2 framework.

An influenza A vaccine based on tetrameric ectodomain of matrix protein 2

Matrix protein 2 (M2) of influenza A is a tetrameric type III membrane protein that functions as a proton-selective channel. The extracellular domain (M2e) has remained nearly invariable since the first human influenza strain was isolated in 1933. By linking a modified form of the leucine zipper of the yeast transcription factor GCN4 to M2e, we obtained a recombinant tetrameric protein, M2e-tGCN4. This protein mimics the quaternary structure of the ectodomain of the natural M2 protein. M2e-tGCN4 was purified, biochemically characterized, and used to immunize BALB/c mice. High M2e-specific serum IgG antibody titers were obtained following either intraperitoneal or intranasal administration. Immunized mice were protected fully against a potentially lethal influenza A virus challenge. Antibodies raised by M2e-tGCN4 immunization specifically bound to the surface of influenza-infected cells and to an M2-expressing cell line. Using a M2e peptide competition enzyme-linked immunosorbent assay with M2-expressing cells as target, we obtained evidence that M2e-tGCN4 induces antibodies that are specific for the native tetrameric M2 ectodomain. Therefore, fusion of an oligomerization domain to the extracellular part of a transmembrane protein allows it to mimic the natural quaternary structure and can promote the induction of oligomer-specific antibodies.

Improved design and intranasal delivery of an M2e-based human influenza A vaccine

M2 is the third integral membrane protein of influenza A. M2e, the extracellular, 23 amino acid residues of M2, has been remarkably conserved in all human influenza A strains. This prompted us to evaluate the use of M2e as a potential broad-spectrum immunogen in a mouse model for influenza infection. Genetic fusion of the M2e and hepatitis B virus core (HBc) coding sequences allowed us to obtain highly immunogenic virus-like particles. This M2e-HBc vaccine induced complete protection in mice against a lethal influenza challenge. Protective immunity was obtained regardless of the position of M2e in the M2e-HBc chimera at the amino-terminus or inserted in the immuno-dominant loop of the HBc protein. Increasing the copy number of M2e inserted at the N-terminus from one to three per monomer (240-720 per particle) significantly enhanced the immune response and reduced the number of vaccinations required for complete protection against a lethal challenge with influenza A virus. A series of M2e-HBc constructs was subsequently combined with CTA1-DD, a recombinant cholera toxin A1 derived mucosal adjuvant, to test its efficacy as an intranasally delivered vaccine. All hybrid VLPs tested with CTA1-DD completely protected mice from a potentially lethal infection and, in addition, significantly reduced morbidity. Overall, increased resistance to influenza challenge in the mice correlated with an enhanced Th1-type M2e-specific antibody response induced by vaccination. These results show that M2e is a valid and versatile vaccine candidate to protect against any strain of human influenza A.

Do alcoholic liver transplantation candidates merit lower medical priority than non-alcoholic candidates?

Alcoholic patients are frequently regarded as responsible for their alcoholism and alcohol-related diseases, such as liver damage. These patients run the risk of receiving lower medical priority for liver transplantation than patients who are considered as not responsible for their liver damage. However, hardly any scientific research findings support this supposed responsibility of the alcoholic patient for his addiction and the related diseases. Many alcoholic patients have comorbid psychiatric disorders such as antisocial personality disorder, schizophrenia and social phobia, and these cormorbid diseases are often linked specifically and also in a neurobiological way to alcohol abuse. Furthermore, concepts such as responsibility and health have multiple dimensions, which can be contrasted against each other. Useful and fair criteria are presented for the assessment of responsibility for our health.

Reduction potential of microbial, odour and ammonia emissions from a pig facility by biofilters

The intention of this study was the determination of the potential to reduce specific microbial bioaerosol (cultivable bacteria and fungi, total cell counts of microbes, airborne endotoxins and microbial volatile organic compounds, MVOC), odour and ammonia emissions from a pig facility by biofilters. Five identical biofilter units in half technical scale were filled with different filter materials (Biochips, coconut-peat, wood-bark, pellets + bark and compost) and connected in parallel to a piggery. The results showed obvious differences between the filter materials. Numbers of airborne cultivable bacteria were decreased by ca. 70 to 95% and the total counts of bacterial cells from ca. 25 to (>) 90%. The total amount of fungal cells was reduced by at least 60%, although the percentage of cultivable moulds in the air after passing the filters was sometimes higher than before. Airborne endotoxins and MVOC were effectively reduced by all filter materials to at least 90%. Regarding odour, the average reduction was between 40 and 83%, whereas only one of the filters proved to be capable of slightly reducing the ammonia emissions. No relationships between odour/ammonia and microbial bioaerosols with regard to the reduction efficiency of the different filter materials or the total load of the emitted air could be established. A tendency could be shown, that biofilters best capable to reduce odour emitted slightly more airborne bacteria, both cultivable and total cell counts.

How can we avoid some psychotic patients becoming violent offenders?

Every year a number of psychotic patients commit violent crimes and are recommended for forensic psychiatric treatment. Many of these patients already show risk symptoms before their fatal offense. Despite these risk signs the physicians and psychiatrists, who have the task of intervening in crisis situations of psychotic patients, are frequently waiting too long before compulsory admission of potentially dangerous psychotic patients to a general psychiatric hospital. A physician or psychiatrist, who admits a "harmless" patient against his or her will may risk prosecution. Therefore, many involved professionals are very careful with regard to a forced admission of problematic psychotic patients to a general psychiatric hospital. It is timely, that some risk signs, which are evidently linked to a significantly, increased risk of violent behavior in psychotic patients, become recognized officially by law as a good reason for compulsory admission to a general psychiatric hospital.

["Microbial air pollutants--methods for detection of endotoxins, mycotoxins and MVOC"]

In the context of microbial emissions from composting facilities the methods for the detection and identification of the groups of substances released, i.e. endotoxins, mycotoxins and Microbial Volatile Compounds (MVOC) are discussed. With the aid of an overview of the different methods employed for the investigation of the single groups of compounds the current state of the art in this field is presented. In conclusion the enormous research needs, especially with regard to the mycotoxins and MVOC, are pointed out.

[Microbial emissions in collection of residential garbage]

Two exemplary investigations with different questions were carried out in Munich and Stuttgart by sampling bio-aerosols due to and during the collection and emptying of different types of waste bins. The emissions were regarded qualitatively and quantitatively, in order to answer the question, whether and to which amount differences of bio-aerosol emissions occurred due to the kind of wastes collected. The lowest emissions of airborne microorganisms were found during the collection of the paper waste fraction. In comparison, the amounts of them during the collection of unseparated household wastes as well as source separated bio-wastes and the remaining residual waste fraction were higher. Between the three latter, no significant differences could be found, only a tendency of higher values for the thermotolerant mould A. fumigatus during the collection of bio- and residual wastes was observed. Maybe this was caused by special features of the different sampling locations, but it could also be due to the longer collection intervals (bio- and residual wastes were partially collected every two weeks, unseparated wastes every week).

[Detection of airborne cultivatable microorganisms from compost sites--emissions and imissions]

The statement presented here gives an overview and assessment of the procedures and concepts currently used for the collection and determination of airborne, culturable microorganisms at sources of emission within composting plants and in their near vicinity. The paper focuses on "classical" methods, which involve cultivation as an intermediate step for the determination of viable, airborne microorganisms. The theoretical and practical requirements on such methods are discussed. Results and experiences from recent investigations are described.

[Recent methods for the detection of airborne microorganisms and source identification]

The detection of airborne microorganisms including selected cell constituents (e.g. allergens or endotoxins) depends on suitable methods and instruments for their collection. Furthermore, microbiological methods are necessary for their quantification and qualification. In the past these methods were largely based on the classical cultivation dependent approach. Modern molecular methods, e.g. direct staining procedures, hybridization assays with nucleic acids including the PCR-technology or immunological assays are promising new tools for a more sophisticated detection of bioaerosols. They allow a better detection rate, a more precise identification of certain members of the aerosol including cell constituents. With respect to speed and lower costs they are an important alternative to established detection methods.

What shall we do with untreatable forensic psychiatric patients?

The destiny of untreatable forensic psychiatric patients in many western countries is uncertain, because governments, staff members of forensic psychiatric hospitals, lawyers and other involved groups do not know what to do with this category of patients. The debate concerning this matter, and related cost saving measures, very frequently ignores two important questions. Who is responsible for the untreatability of these patients? What are the criteria for untreatability? These core questions, which are related to each other, must be answered before the debate can go further. An exact definition of untreatability is needed for a) a fair screening of the patients, and b) getting more insight in the precise nature of, and interactions of the factors which play a role in the phenomenon of untreatability. To say that some patients are not (totally) responsible for their untreatability is not justifiable, as they may eventually become the victims of cost saving measures.

The integration of psychosocial care in a general hospital: development of an interdisciplinary consultation program

The problems of multiple competing psychosocial services led to the development of an interdisciplinary consultation program in a university-affiliated Veterans Administration Hospital. The need for integration of services is frequently recognized but difficult to achieve. Representatives from Psychiatry, Psychology, Social Work, and Nursing worked out and carried through a coordinated plan to provide psychosocial consultation to the general hospital. Description of the initial experience focuses on the process of change within a traditional system. A case example which reflects the role and interaction of the disciplines is included. We found that the psychosocial system improved communication, established a pattern of interdisciplinary teaching and stressed preventive work.

Analysis of the haemagglutinin gene of current wild-type canine distemper virus isolates from Germany

The haemagglutinin (H) gene sequences from three wild-type canine distemper viruses (CDV) isolated during 1994-1995 were sequenced to determine whether contemporary strains had undergone significant genetic changes relative to the currently used vaccine strains. The new isolates were closely related to each other (> 99%) and displayed about 90-91% sequence homology to the Onderstepoort and Convac vaccine strains. There were one to four additional potential glycosylation sites compared to the vaccine strains which were also present in a German dog CDV isolate dating from 1990. However, only a very slight reduction in neutralizing titre against the new isolates was found when compared with the Onderstepoort and Rockborn vaccine strains. Cysteine and proline residues were well conserved indicating a conserved three dimensional structure for the protein. By phylogenetic analysis the recent isolates showed a narrow clustering close to the previous canine isolates indicating a linear pattern of evolutionary changes. A comparison with published CDV H gene sequences suggested the presence of different lineages of CDV on a global scale and possible cocirculation of more than one genotype of CDV.

Spot synthesis of overlapping peptides on paper membrane supports enables the identification of linear monoclonal antibody binding determinants on morbillivirus phosphoproteins

In order to map antigenic domains on the P-protein of morbillivirus, a series of overlapping peptides, representing the P-protein sequences of phocid distemper virus strain 2558/Han88 and canine distemper virus strain Onderstepoort, were synthesized on a paper support by the spot-technique. The reactivity of six monoclonal antibodies with the peptides was tested in an enzyme immunoassay and compared to their reactivity in Western blots and in an ELISA using detergent extracts from virus-infected cells. Three linear determinants could be localized on the P-protein. Two antibody-binding sites were delineated within the C-terminal (between amino acids 307-322 and 382-400, respectively), and a third one was located on the N-terminal part (amino acids 13-31) of the protein. Fine mapping of this binding site revealed that this was a part of an antigenic domain. In Western blots, the monoclonal antibodies reacting with this domain also reacted with a second protein which was possibly the V-protein.

[Stomach ulcer healing with enprostil, an orally effective prostaglandin E2 analog: direct comparative study with ranitidine]

In a randomized, endoscopically controlled double-blind trial the effectiveness of a twice daily dose of the prostaglandin E2-analogue enprostil was compared with ranitidine given to 93 ambulatory patients with benign gastric ulcers. Under 35 micrograms b.i.d. enprostil the ulcer healing rates after 2, 4, 6 and 8 weeks averaged 22% (10/46), 58% (26/45), 80% (35/44) and 86% (37/43). The corresponding values for ranitidine 150 mg b.i.d. were 22% (10/46), 66% (29/44), 84% (38/45) and 89% (41/46). The differences were not statistically significant. Both drugs had a similar influence on the ulcer symptoms and were well tolerated. The findings suggest that enprostil can be given in a twice daily dosage in the treatment of benign gastric ulcers.

20 versus 30 mg omeprazole once daily: effect on healing rates in 115 duodenal ulcer patients

In a double-blind, dose comparison multicenter trial 115 patients with duodenal ulcer were treated with either 20 or 30 mg oral omeprazole once daily for 4 weeks. There was no difference in the healing rates for the two groups after 2 and 4 weeks. After 2 weeks with 20 and 30 mg healing frequencies were 79.0 and 72.7%, after 4 weeks 96.5 and 92.7%. No difference was observed between the groups in the number of pain episodes during day and night. No side effects to the drug occurred. A daily dose of 20 mg omeprazole may be effective in ulcer therapy.

Critical bands in cat spatial vision

1. The ability of cats to detect sinusoidal grating patterns superimposed on one-dimensional visual noise was assessed using behavioural methods. 2. The magnitude of elevation in contrast threshold due to noise increased monotonically within limits with increasing noise contrast. 3. Visual noise was filtered using various techniques (band-reject, low-pass, high-pass and band-pass noise); filtered noise resulted in threshold elevation only when it contained frequencies similar to the test frequency. 4. In all cases the masking functions indicated that the band widths of the channels mediating detection ranged from +/- 0.50 to +/- 0.75 octaves across three spatial frequencies and that the channel sensitive to low spatial frequencies was asymmetrical in its tuning. 5. The spatial properties of these psychophysical detecting channels closely resemble the spatial frequency selectivity exhibited by some cat cortical neurones, both in the general narrowness of tuning and the asymmetry in tuning at lower, but not higher, spatial frequencies.

Reaction time as a measure of binocular interaction in human vision

In a series of psychophysical experiments monocular and binocular reaction times (RTs) were measured in response to the presentation of sinusoidal grating patterns. Over a wide range of contrast values, binocular RT was consistently faster than monocular RT, even at high-contrast levels where RT had reached asymptotic levels. For observers with good stereopsis this binocular summation effect was greater than that expected on the basis of probability summation alone, whereas observers with deficient stereopsis performed at the level of probability summation. For normal observers broadband random noise presented to one eye produced an elevation in RT to gratings presented to the other eye; no such dichoptic masking effect was found in a stereoblind observer. These results validate the use of RT as an efficient, reliable measure of binocular interaction in human vision.