Ambient Room Light Research Articles

Barrage Zone Formation Between Vegetatively Incompatible Fusarium graminearum (Gibberella zeae) Isolates

ABSTRACT Vegetative compatibility has been used to assess the population biology of many fungal plant pathogens. However, for many species, including Fusarium graminearum, this has meant making auxotrophic mutants to force heterokaryon formation. A method was developed to observe barrage zones of thick, raised mycelium at the junctions of vegetatively incompatible F. graminearum isolates. The appearance of the barrage zones was influenced by the growth medium and the light. Barrage zones on V8 agar were thicker and better defined than those on potato dextrose agar, Spezieller Nahrstoffarmer agar, and water agar. The addition of ground wheat kernels to V8 agar enhanced barrage zone formation. Incubating the cultures under constant light at 2,150 lx produced more distinct barrage zones than constant light at 3,400 lx, constant darkness, or ambient room light. Forty-three F. graminearum isolates from 34 vegetative compatibility groups, determined previously using nit auxotrophic mutants, were paired in all combinations using these optimized conditions. Isolates in different vegetative compatibility groups typically formed distinct, thick barrage zones at their junctions. Pairs of isolates in the same vegetative compatibility group had a very slight or no visible reaction, or rarely, a distinct "line gap" of sparse mycelium. Subcultures from the same isolate typically had no visible reaction at their colony junctions; however, subcultures from some isolates had thin, slight barrage zones. This method was used to identify the proportion of each of four F. graminearum isolates from infected barley spikes in the field, inoculated previously with a mixture of conidia from these four isolates. Barrage zone formation represents a rapid method to screen vegetative compatibility groups in F. graminearum and may be useful for other Fusarium species.

Importance and effects of altered workplace ergonomics in modern radiology suites.

The transition from a film-based to a filmless soft-copy picture archiving and communication system (PACS)-based environment has resulted in improved work flow as well as increased productivity, diagnostic accuracy, and job satisfaction. Adapting to this filmless environment in an efficient manner requires seamless integration of various components such as PACS workstations, the Internet and hospital intranet, speech recognition software, paperless electronic hospital medical records, e-mail, office software, and telecommunications. However, the importance of optimizing workplace ergonomics has received little attention. Factors such as the position of the work chair, workstation table, keyboard, mouse, and monitors, along with monitor refresh rates and ambient room lighting, have become secondary considerations. Paying close attention to the basics of workplace ergonomics can go a long way in increasing productivity and reducing fatigue, thus allowing full realization of the potential benefits of a PACS. Optimization of workplace ergonomics should be considered in the basic design of any modern radiology suite.

Lipid peroxidation assessment by malondialdehyde measurement in parenteral nutrition solutions for newborn infants: a pilot study

To determine malondialdehyde (MDA) concentrations in parenteral nutrition admixtures exposed to ambient room light, and in the serum of neonates. Using a new method to measure MDA specifically, this study analysed MDA of lipid-containing all-in-one admixtures provided by the pharmacy, with a composition identical to that used in routine clinical conditions. First, 12 admixtures were exposed to ambient light for 24 h, in the neonatal intensive care unit. Secondly, 18 solutions were either exposed to (n = 9) or protected from ambient light (n = 9) during the same period. Samples of admixtures were collected at baseline and 24 h later, for MDA measurement. Serum MDA was also randomly measured in orally fed healthy neonates. After 24 h exposure to ambient room light, MDA concentrations in parenteral nutrition admixtures increased from 179 (129, 348) nmol l(-1) to 5800 (1632, 14679) nmol l(-1) (p = 0.0002) [50th (10th, 90th) centiles]. When admixtures were protected from light, the increase in MDA was significantly lower than without protection: 187 (60, 429)nmol l(-1) versus 13 696 (3472, 26 049)nmol l(-1) (p = 0.0003). In 54 infants with a gestational age of 33 (28, 39) wk and a birthweight of 1750 (960, 3388) g, plasma MDA concentrations were 173 (98, 315) nmol l(-1). In solutions protected from light, MDA concentrations were low and were close to the serum MDA concentrations observed in orally fed neonates. Administration of all-in-one admixtures containing lipids in ambient lighting results in intravenous infusion of high levels of MDA which may present an additional source of morbidity in immature infants. This study confirms the need to protect parenteral admixtures from light.

Photochemical synthesis of a palladium dichloromethyl complex, {(hexyl)HC( N-methyl-imidazol-2-yl) 2}Pd(CHCl 2)Cl. : X-ray molecular structures of {(hexyl)HC( N-methylimidazolyl-2-yl) 2}Pd(X)Cl, X=Cl, and CHCl 2

The reaction of (hexyl)HC(mim) 2 ( 1, mim= N-methyl-imidazol-2-yl) with (cod)PdMeCl in C 6H 6 yields {(hexyl)HC(mim) 2}Pd(Me)Cl ( 3). The photochemical reaction of 3 with CH 2Cl 2 at 23 °C in ambient room light yields {(hexyl)HC(mim) 2}Pd(CHCl 2)Cl ( 4). It is proposed that this reaction proceeds by homolytic scission of the PdMe bond of 3.

Phase sensitive demodulation in multiphoton microscopy.

Multiphoton laser scanning microscopy offers advantages in depth of penetration into intact samples over other optical sectioning techniques. To achieve these advantages it is necessary to detect the emitted light without spatial filtering. In this nondescanned (nonconfocal) approach, ambient room light can easily contaminate the signal, forcing experiments to be performed in absolute darkness. For multiphoton microscope systems employing mode-locked lasers, signal processing can be used to reduce such problems by taking advantage of the pulsed characteristics of such lasers. Specifically, by recovering fluorescence generated at the mode-locked frequency, interference from stray light and other ambient noise sources can be significantly reduced. This technology can be adapted to existing microscopes by inserting demodulation circuitry between the detector and data collection system. The improvement in signal-to-noise ratio afforded by this approach yields a more robust microscope system and opens the possibility of moving multiphoton microscopy from the research lab to more demanding settings, such as the clinic.

Effects of pre-adaptation conditions and ambient room lighting on the multifocal ERG.

The purpose of the study was to evaluate the effects of pre-adaptation and ambient room luminance on the multifocal ERG (mfERG). We recorded mfERGs on 18 normal subjects (average age 32) using a VERIS system, with either 61 or 103 stimulus hexagons. mfERGs were recorded sequentially under different conditions of pre-adaptation and room lighting. Changing pre-adaptation conditions between darkness for 20 min, or light at 1.43 log cd/m2 for 10 min, had essentially no effect on the mfERG, regardless of ambient room lighting. However, mfERG parameters were sensitive to the level of ambient room lighting during the recordings. As room luminance was increased from darkness, there was a gradual attenuation of N1 and P1 amplitudes both centrally and peripherally that approached 25% reduction at 1.6 log cd/m2, and a decrease in P1 time-to-peak. These effects were greatest in the blind spot. The mfERG is largely independent of pre-adaptation conditions, but waveform amplitudes and times-to-peak diminish with increasing ambient room luminance. The exaggerated attenuation of signals in the blind spot with room lighting suggests that mfERGs recorded in the dark are contaminated by light scattered to dark-adapted peripheral retina. The most stable mfERG recording condition appears to be a fully lighted room (1.6 log cd/m2).

Interactions of ribosome nascent chain complexes of the chloroplast-encoded D1 thylakoid membrane protein with cpSRP54.

The mechanisms of targeting, insertion and assembly of the chloroplast-encoded thylakoid membrane proteins are unknown. In this study, we investigated these mechanisms for the chloroplast-encoded polytopic D1 thylakoid membrane protein, using a homologous translation system isolated from tobacco chloroplasts. Truncated forms of the psbA gene were translated and stable ribosome nascent chain complexes were purified. To probe the interactions with the soluble components of the targeting machinery, we used UV-activatable cross-linkers incorporated at specific positions in the nascent chains, as well as conventional sulfhydryl cross-linkers. With both cross-linking approaches, the D1 ribosome nascent chain was photocross-linked to cpSRP54. cpSRP54 was shown to interact only when the D1 nascent chain was still attached to the ribosome. The interaction was strongly dependent on the length of the nascent chain that emerged from the ribosome, as well as the cross-link position. No interactions with soluble SecA or cpSRP43 were found. These results imply a role for cpSRP54 in D1 biogenesis.

Stability and compatibility of anakinra with ceftriaxone sodium injection in 0.9% sodium chloride or 5% dextrose injection.

The stability and compatibility of anakinra (recombinant human interleukin-1 receptor antagonist) with ceftriaxone sodium in 0.9% sodium chloride or 5% dextrose injection was determined during a 4-h period at ambient room temperature and light. Anakinra was diluted in 0.9% sodium chloride or 5% dextrose to the concentrations of 4 and 36 mg/ml. Anakinra, at each concentration was mixed with ceftriaxone sodium (20 mg/ml) in a 50:50 proportion and stored in plastic culture vials with polypropylene caps. The samples were collected at 0, 2 and 4 h after mixing. Anakinra and ceftriaxone concentrations were measured using stability-indicating HPLC methods. In 0.9% sodium chloride injection, the mean concentrations of anakinra and ceftriaxone exceeded 98% of initial concentrations at the end of the study period. In 5% dextrose, however, anakinra concentrations were below 90% of the expected initial concentration at the time of first analysis (within 0.5 h). Thus, anakinra appears to be stable and compatible with ceftriaxone sodium when diluted in 0.9% sodium chloride injection, but not in 5% dextrose injection over 4 h at ambient room temperature and light.

Rejection of Background Light Using Single-Wavelength Detection in Nonlinear Raman Spectroscopy

A new method for single-wavelength detection (SWD) spectroscopy has been developed with the use of synchronous scanning of an optical parametric oscillator (OPO). With the combination of SWD with spatial and temporal discrimination, a high level of background light rejection is achieved. Results show sufficient ambient room light rejection for obtaining complete gas-phase nonlinear Raman spectra with no detectable signs of interference.

A Three-Color, Solid-State, Three-Dimensional Display

A three-color, solid-state, volumetric display based on two-step, two-frequency upconversion in rare earth-doped heavy metal fluoride glass is described. The device uses infrared laser beams that intersect inside a transparent volume of active optical material to address red, green, and blue voxels by sequential two-step resonant absorption. Three-dimensional wire-frame images, surface areas, and solids are drawn by scanning the point of intersection of the lasers around inside of the material. The prototype device is driven with laser diodes, uses conventional focusing optics and mechanical scanners, and is bright enough to be seen in ambient room lighting conditions. QuickTime movie of the three-dimensional display.

Surface roughness measurements in finish turning

A new approach is proposed for the on-line measurement of the maximum peak-to-valley roughness,Rmax, of a finished-turned surface in the feed direction. The method is based on solving the inverse problem of light scattering by using a linear least-square estimate of the angular scattered light pattern reflected from a surface. A laser system has been developed to capture the light reflected under different cutting conditions. The effects of the ambient room light as well as the workpiece's rotational speed and methods for thier compensation are also discussed. Good correlation was found between the optical and stylus-measuredRmax.

Stability and compatibility of anakinra with intravenous cimetidine hydrochloride or famotidine in 09% sodium chloride injection

We designed a study to evaluate the stability and compatibility of anakinra (recombinant human interleukin-1 receptor antagonist) with cimetidine hydrochloride or famotidine in 0.9% sodium chloride injection during a 4-h period at room temperature (22 degrees C) and light. Anakinra was diluted in 0.9% sodium chloride to concentrations of 4 and 36 mg/ml. At each concentration, anakinra was mixed with 3 mg/ml cimetidine or with 1 mg/ml famotidine, in a 50:50 proportion and stored in plastic culture vials with polypropylene caps. The mean concentrations of anakinra, cimetidine hydrochloride, and famotidine exceeded 95% of initial concentrations throughout the study. No changes were noted in the physical appearance, pH, or the chromatograms during the study period. Thus, anakinra appears to be stable and compatible with cimetidine hydrochloride or famotidine when diluted into 0.9% sodium chloride injection for 4 h at ambient room temperature and light.

Update on the recommended viewing protocol for FAXIL threshold contrast detail detectability test objects used in television fluoroscopy.

The significance of varying the viewing conditions that may affect the perceived threshold contrast of X-ray television fluoroscopy systems has been investigated. Factors investigated include the ambient room lighting and the viewing distance. The purpose of this study is to find the optimum viewing protocol with which to measure the threshold detection index. This is a particular problem when trying to compare the image quality of television fluoroscopy systems in different input field sizes. The results show that the viewing distance makes a significant difference to the perceived threshold contrast, whereas the ambient light conditions make no significant difference. Experienced observers were found to be capable of finding the optimum viewing distance for detecting details of each size, in effect using a flexible viewing distance. This allows the results from different field sizes to be normalized to account for both the magnification and the entrance air kerma rate differences, which in turn allow for a direct comparison of performance in different field sizes.

Stability of esmolol hydrochloride in intravenous solutions

The stability of esmolol hydrochloride in a variety of i.v. solutions was studied. Solutions of esmolol hydrochloride 10 mg/mL were prepared separately in 0.45% sodium chloride injection, 0.9% sodium chloride injection, 5% dextrose injection, 5% dextrose and 0.45% sodium chloride injection, 5% dextrose and 0.9% sodium chloride injection, 5% dextrose with lactated Ringer's injection, lactated Ringer's injection, 5% sodium bicarbonate injection, and 5% dextrose injection with potassium chloride 40 meq/L. One glass and one polyvinyl chloride container of each solution (except glass only in the case of the solution in 5% sodium bicarbonate injection) were stored in the dark at 5 degrees C, under ambient room light at 23-27 degrees C, in the dark at 40 degrees C, and under intense light at 25-30 degrees C. At storage intervals up to 168 hours, samples were tested for esmolol hydrochloride concentration by high-performance liquid chromatography. Optical density and pH were also measured. Esmolol hydrochloride was stable in the various i.v. fluids for at least 168 hours when stored at 5 degrees C or 23-27 degrees C, for at least 24 hours when stored under intense light, and, with one exception, for at least 48 hours when stored at 40 degrees C. When mixed with 5% sodium bicarbonate injection, the drug was stable for only about 24 hours at 40 degrees C. There were no substantial changes in optical density or pH. The type of container had no effect on stability. With one exception, esmolol hydrochloride was stable in all the i.v. solutions under all the conditions tested.

Bedside visual colorimetry of peritoneal lavage fluid in abdominal trauma patients

Abdominal injuries account for an important fraction of deaths from trauma. Some patients with abdominal trauma who need emergency surgery are difficult to identify because bedside diagnosis based on physical findings alone is often misleading. ‘+2 When the need for laparotomy is initially unclear physicians currently rely on clinical laboratory determinations, particularly the automated red blood cell count (RBC) count of fluid obtained by peritoneal lavage.3 Unfortunately, the time required by the clinical laboratory to process and assay these specimens may sometimes delay essential surgical intervention. In a prior in vitro study we investigated the feasibility of using visual calorimetry as a rapid method for estimating the RBC count in simulated peritoneal lavage fluid.4 Here, we report the successful application of this method to the bedside evaluation of trauma patients at a level I trauma center. METHODS A simple visual colorimete?-8 was built in a home woodworking shop (Figures 1 through 4). This device permits direct comparison of light transmitted through pairs of glass test tubes containing colored fluids, while reducing ambient room light and reflections. To prepare stable color comparison standards, a stock solution of simulated peritoneal lavage fluid was made as follows: whole blood was obtained in 7-mL Vacutainer (Becton Dickinson, Rutherford, NJ) tubes containing ethylenediamine tetraacetic acid from a single healthy volunteer donor known to be human immunodeficiency virus-negative, at low risk for acquired immunodeticiency syndrome, and willing to donate blood periodically. The complete blood count was determined in triplicate using a Sysmex NE-8000 automated cell counter (TOA Medical Electronics Co, Ltd, Kobe, Japan). The mean RBC count for this donor was 5.71

Stability and sorption of calcitriol in plastic tuberculin syringes

The stability of commercially formulated calcitriol 1 and 2 micrograms/mL and calcitriol formulation subsequently diluted to 0.5 microgram/mL in 0.9% sodium chloride injection, 5% dextrose injection, or water for injection was evaluated after eight hours' storage in polypropylene syringes. The apparent affinities of calcitriol for polypropylene and polyvinyl chloride were also examined. Three calcitriol 0.5 microgram/mL solutions (diluted in 0.9% sodium chloride injection, 5% dextrose injection, or water for injection) and aqueous calcitriol formulations, 1 and 2 micrograms/mL, were placed in 1-mL polypropylene tuberculin syringes and assayed by high-performance liquid chromatography initially and after two, four, and eight hours' storage under room light at ambient temperature. Samples of calcitriol 2 micrograms/mL were also exposed to polypropylene or polyvinyl chloride at room temperature for 20 days. The remaining calcitriol concentrations were determined and apparent calcitriol polymer/water partition coefficients were calculated. Calcitriol concentrations did not change substantially during the eight-hour stability study. The mean apparent polymer/water partition coefficient for polyvinyl chloride was 66 times that for polypropylene, indicating that calcitriol has a definite affinity for polyvinyl chloride but no similar affinity for polypropylene. Aqueous calcitriol solution 1 or 2 micrograms/mL or 0.5 microgram/mL in 0.9% sodium chloride injection, 5% dextrose injection, or water for injection, when stored in polypropylene syringes exposed to ambient temperature and room light, appears to be stable for eight hours. Calcitriol appears to have greater affinity for polyvinyl chloride than for polypropylene.

Surface segregation of impurities induced by photon absorption in CdTe and (Hg,Cd)Te

Noble metal impurities have been observed to segregate toward the surface of p-type CdTe and heavily p-type (Hg,Cd)Te samples during room temperature aging in ambient room light. This behavior has not been observed in n-type CdTe or lightly p-type (Hg,Cd)Te. The photon-induced segregation is believed to involve the redistribution of positively charged impurity interstitials in a field generated by absorbed photons with energies greater than the band gap. A qualitative electromigration model based on the Dember effect and simple ionic conduction, has been used to explain the experimental results.

The Baylor Video Acuity Tester.

A device has been developed that offers many advantages not available with traditional visual acuity testing methods. The Baylor Video Acuity Tester (BVAT) produces randomized targets, size selectable at electronic speeds for testing even in normal ambient room light. Comparisons of the BVAT with the Project-O-Chart (American Optical Corp, Southbridge, Mass) on 60 subjects yield correlations of .93 and .95. A test-retest correlation of the BVAT of .88 was found.

Factors contributing to the deterioration of DODCI

A number of factors contributing to the deterioration of the optical absorption of DODCI (3,3'-diethyloxadicarbocyanine iodide) were investigated. The rate of deterioration of the absorption properties of DODCI was significantly increased when solutions of DODCI were placed in contact with brass and aluminum. Contact with stainless steel and ambient room light did not significantly increase the rate of deterioration of the optical absorption of DODCI.

Choosing surgical illumination

(1) Lighting systems for the surgical task are combinations of ambient room lighting to complement the operating task light. The two must match to produce a good effect. (2) Only a few surgical task lights are available, and their characteristics and relative merits should be studied. (3) Ideally the surgeon should test the task light to judge its suitability for his taste.