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Customer
Applications |
Description |
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Agricultural and Food |
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Plant Reflectance |
Spectral
reflectance from plants can
indicates
plant
stress and predict growth rate |
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Lumber Colorimetery |
Initial
high-temperature schedule to reduce drying time
and control kiln brown stain in ponderosa pine
shop lumber. The
surface color and lightness of rough green and
dry fleshly planed boards were determined using
a StellarNet Spectrometers |
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Surface Characterization of Weathered
Wood-Plastic Composites Produced from
Modified Wood Flour |
The
effects of weathering on the surface properties
of wood-plastic composites
(WPC) were examined.
High-density polyethylene
WPCs made from
modified wood flour
were subjected to
accelerated (xenon-arc)
weathering.
Colorimetery and
Fourier-transform infrared spectroscopy were
employed to monitor the color change and
surface chemistries of
the weathered WPC surface.
The study
showed that longer exposure time caused higher
oxidation,
lower wood lignin and higher plastic content of
the weathered WPC surface. |
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Onions |
A fiber
optic sensor measures
percent soluble
solids in onions for a big pay off at
market time. |
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Contaminants on
Poultry Processing Equipment |
Detection of Fecal/Ingesta
Contaminants on Poultry Processing Equipment
Surfaces By Visible and Near-Infrared
Reflectance Spectroscopy |
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Environmental and Ecology |
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Remote Sensing
Monitoring- Tallapoosa Watershed |
Hyperspectral Reflectance Measurements of
Chlorophyll Concentration and
Related Water Quality Predictors |
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Influence of plumage colour on prey response:
does habitat alter heron crypsis to prey? |
The foraging strategies of wading birds may be
influenced by their degree of crypsis to aquatic
prey. White
plumage has been hypothesized to be adaptive for
herons hunting in open water habitats.
We tested this
hypothesis with laboratory and field experiments
with multiple prey species.
The foraging strategies of wading birds
may be influenced by their degree of crypsis to
aquatic prey. White
plumage has been hypothesized to
be adaptive for herons hunting in open
water habitats. We
tested this hypothesis
with laboratory and field experiments with
multiple prey species. |
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Spectral
Signatures of surface materials in pig buildings |
Spectral Signatures of the
reflectance of visual and near infrared
radiation are used to make statistically
significant discrimination between clean and
dirty pig building areas |
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Birds- Black
Phoebes |
Exploring how
the Black Phoebe’s (a small bird that is a
sit-and-wait predator) vision, the reflectance
of prey items and the background, and irradiance
interacted to change how the bird looked for
food items. |
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Removing Organic
Compounds from Aqueous Medium via Wet
Peroxidation by Gold Catalysts |
A new heterogeneous
Fenton-like system,
consisting of
supported Au
catalysts and
hydrogen peroxide,
was proved to be
effective in
removing low level
organic compounds
(ca. 100 ppm) such
as phenol, ethanol,
formaldehyde, and
acetone in aqueous
solution. Among all
gold catalysts the
Au/hydroxyapatite
(Au/HAp) exhibits
the highest
activity, and even
better than the
conventional iron
ions exchanged
zeolite (Fe/ZSM-5)
catalyst. In
particular, unlike
the limited
operational pH range
(pH: 2 5)
for the other
heterogeneous Fenton
catalysts such as
Fe/ZSM-5, Au/HAp
shows higher
stability even in
strong acid solution
(pH
2), due to almost no
leaching of active
metal from supports
into solution. It
can be potentially
applied in treating
the industrial
wastewaters with
strong acidity and
purifying drinking
water. In addition,
in the case of
complete oxidation
of phenol, a
plausible route was
suggested for deep
understanding of
this process.
The variation of H2O2
concentration during reaction was analyzed
colorimetrically using a UV–vis
spectrophotometer (Epp2000,
StellarNet Inc.) after complexation with a
TiOSO4/H2SO4
reagent (16). ... |
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Female
Preferences for Aposematic Signal Components in
a Polymorphic Poison Frog |
Aposematic signals may be
subject to conflicting selective pressures from
predators and conspecifics. We studied
female preferences for
different components of aposematic coloration in
the polymorphic poison frog Oophaga pumilio
across several phenotypically
distinct populations. |
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Physics |
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OH Emission
Spectra of Hybrid Rocket Motors
Using PMMA and HTPB
Ultraviolet-Visible Spectrometry
Characterization of
Combustion in Hybrid Rocket Motors |
The development of
sensors for hybrid
rocket motors has lead to the
use of near-infrared
diode lasers
for characterizing hybrid rocket plumes.
Emission Spectra
obtained can be used to calculate species
concentrations and temperatures, both
spatially and temporally, in rocket
exhaust plumes. In this paper we
report our findings from a study of the
emission spectra of
hybrid rocket exhaust plumes in the ultraviolet,
UV, visible, VIS, and near-infrared, NIR,
regions of the
electromagnetic spectrum. |
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Spectroscopic
Diagnostics of an Atmospheric Microwave
Plasma for
Monitoring Metals Pollution |
A 1.5 kW, 2.45 GHz microwave
sustained plasma in a flowing sample of stack
exhaust gas has been
shown in recent DOE/EPA testing to be an
accurate monitor of trace
hazardous metals (in the part per billion
range) such as lead, chromium, and beryllium.
Optical-UV spectroscopic studies are
being carried out to better understand this
particular atmospheric
pressure plasma torch. |
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Organic semiconductor devices for micro-optical
applications |
The use of organic optoelectronic devices such
as organic light-emitting diodes and organic
photodiodes in micro-optical
systems is discussed. Potential
applications like optical interconnects and
optical sensor systems are examined.
Device characteristics including emission
spectra, I-V-curves and the dynamic behaviour
are analyzed. In the
combination with a polymeric optical
fibre (POF) a transmission line comprising a
organic light emitting diode and
organic photodiodes is demonstrated. An
important step towards integration is realized
by coupling the amplified
spontaneous emission of an organic
semiconductor material into a single
mode polymethylmethacrylate (PMMA)
waveguide. |
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Colour-tunable spiral photonic actuators |
Combining the multi-faceted environmental
responsiveness of polymers with photonically
active structures, we developed spiral
photonic actuators which can reversibly
change both shape and colour in response to
the chemical environment.
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Wavelength-scalable hollow optical
fibres with large photonic bandgaps
for CO2 laser transmission |
Here we report on the design and
drawing of a hollow
optical fibre lined with an interior
omnidirectional dielectric
mirror.
Confinement of light in the hollow core is
provided by the large
photonic bandgaps
established by the multiple alter-nating
submicrometre-thick layers of a
high-refractive-index
glass and a low-refractive-index polymer. The
fundamental and
high-order transmission windows are determined
by the layer
dimensions and can be scaled from 0.75 to 10.6mm
in wavelength.The transmission losses are found
to be less than 1.0 dB
m 21,
orders of magnitude lower than those of
the intrinsic fibre
material, thus demonstrating that low
attenuation can be achieved
through structural design rather than
high-transparency
material selection. |
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Physical properties of CdS/ITO thin films growth
by CBD technique with substrate oscillating
agitation |
Cadmium sulphide (CdS) thin films
deposited on indium tin oxide (ITO)
substrates were prepared by chemical
bath deposition technique by using
different conditions to agitate the
bath and the substrate. The
deposited films were characterized
on their morphology, on the band gap
energy, and on thickness. The
implemented novel technique for
substrate oscillation has shown to
improve the films quality, by the
chemical bath without colloidal
precipitates and by the clean film
surfaces obtained. CdS films with
variable deposition time can be
achieved depending on the agitating
technique.
In addition, by oscillating only the
substrate during deposition is
possible to obtain clean films and
avoid the formation of colloidal
precipitates on the chemical bath,
normally presented when it is
magnetically or ultrasonically
agitated.
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High Power UV and
VUV Pulsed Excilamps |
Emission characteristics of a
nanosecond discharge in inert gases and its
halo-genides without preionization of the gap
from an auxiliary source have been investigated.
A volume discharge, initiated by an
avalanche electron beam (VDIAEB) was realized at
pressures up to 12 atm. In xenon at
pressure of 1.2 atm, the energy of spontaneous
radiation in the full
solid angle was 45 mJ/cm
3 , and the FWHM of a radiation pulse was
110ns. The spontaneous radiation power
rise in xenon was observed at pressures up to 12
atm.
Pulsed radiant exitance of inert gases
halogenides excited by VDIAEB was
4.5 kW/cm 2 at
e±ciency up to 5.5 %. |
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Chemistry |
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Living
anionic polymerization of methyl methacrylate
controlled by metal-free phosphazene
catalyst as observed
by small-angle neutron scattering, gel
permeation chromatography and UV-visible
spectroscopy |
Phosphazene (PZN) catalyst, PZN catalyst
coexisting with a co-catalyst
1-hydroxycyclohexyl phenyl ketone and
polymethylmethacrylate (PMMA)
have been observed for the first time by
small-angle neutron scattering (SANS) and
UV-visible spectroscopy to elucidate the
aggregation behavior of the PZN molecules
themselves and the state of living chain ends in
a living polymer solution. |
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Electrochemical Synthesis of Conducting Polymers
on Carbon Nanotube
Films and Its Effect on
Electrochemical Capacitance |
Polyaniline and polypyrrole were considered as
pseudocapacitive
coatings for carbon nanotube film electrodes.
The conducting polymers
were deposited electrochemically using
cyclic voltammetry. The
electrochemical effects of the number of
voltage cycles and monomer and
electrolyte concentrations on film
thickness were studied. The effects of the
polymer coating on the capacitance of the
CNT electrodes were analyzed as well.
The final results were evaluated using CV
and scanning electron
microscopy techniques. |
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Nano@micro: General Method for Entrapment of
Nanocrystals in Sol−Gel-Derived Composite
Hydrophobic Silica Spheres |
A general method for
entrapment of
hydrophobically
coated nanocrystals
in micrometer and
submicrometer
composite silica
spheres, nano@micro,
was developed. The
method employs two
starting solutions hydrophobic
solvent containing
the sol−gel
precursor, a
polymer, and the
nanocrystals, and an
emulsifying
hydrophilic phase
which catalyzes the
sol−gel process. The
use of a hydrophobic
polymer,
polystyrene, serves
to encapsulate the
nanocrystals inside
the spheres while
maintaining many of
their original
properties. The
obtained nano@micro
spheres were
characterized
structurally by
transmission
electron microscopy
and scanning
electron microscopy,
chemically by energy
dispersive X-ray
spectroscopy, and
optically by
ensemble and
single-particle
fluorescence
spectroscopy. It is
possible to control
the size of the
microspheres from
the 100 nm scale to
the micrometer
scale, with good
monodispersivity and
with good separation
between the
microspheres. The
method is
demonstrated for
encapsulating a wide
variety of
nanocrystals,
primarily
semiconductors
covering different
spectral bands, and
of different shapes
including spheres
and rods. The
semiconductor
nanocrystals impart
widely tunable
emission to the
microspheres. A
similar
encapsulation
technique was also
applied to thiol-coated
Au particles. The
technique is
generally applicable
to other hydrophobic
nanocrystal systems
of magnetic, oxide,
and other materials.
Fluorescence spectra were recorded using a
spectrometer/CCD setup (StellarNet
model EPP2000). ... |
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Multiple-Color
Electrochromism from Layer-by-Layer-Assembled
Polyaniline/Prussian Blue Nanocomposite Thin
Films |
The creation of new
materials systems
for lightweight and
flexible displays is
an extremely active
research field.
Electrochromic
displays possess a
keen advantage over
other technologies
because it is
possible for a
single
electrochromic pixel
to produce multiple
colors in addition
to white, depending
on applied
potential. This
possibility has
proven quite
challenging to
achieve in practice.
Here we present the
successful
fabrication of a
multiply colored
electrochromic
electrode using
layer-by-layer (LBL)
assembly. The
electrode films are
created by
exploiting intrinsic
electrostatic
attraction between
the polycation
poly(aniline) (PANI)
and a negatively
ionized Prussian
Blue (PB)
nanoparticle
dispersion. The
resultant
organic/inorganic
nanocomposites
exhibit excellent
smoothness and a
classical linear
increase in film
thickness with
assembly exposure
steps.
Electrochemical and
spectrophotometric
characterization
confirms the
distinct and
noninteracting
contributions from
PANI and PB and
reveals that both
are fully
electrochemically
accessible even in
thick, high contrast
films. Switching
speed is accelerated
due to the
incorporation of
electronically
conducting PANI. The
PANI/PB
nanocomposite
undergoes an
uncolored to green
to blue transition
over the potential
range from −0.2 to
0.6 V vs K-SCE.
These results
validate an LBL-assembly-based
intermixing strategy
for the design of
multiple-hue
electrochromic
electrode films.
Future horizons
include extension to
other materials,
with the eventual
goal of creating a
single electrode
film or
electrochemical cell
capable of
displaying any
visible color on
demand.
Spectral characterization was performed with
a StellarNet EPP2000
concave grating UV−vis−NIR spectrophotometer
with combined incandescent and deuterium lamp
sources.... |
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Chemical Synthesis
of a Polyaniline/Gold Composite Using
Tetrachloroaurate |
The chemical
synthesis of
polyaniline (PANI)
is explored using
tetrachloroaurate,
AuCl4-.
These studies
provide a simple
method for the
oxidation of aniline
by AuCl4-
and simultaneous
formation of bulk
quantities of a PANI/Au
composite. In situ
UV/vis spectroscopy
indicates that the
rate of formation of
gold colloids and
intermediate
(short-chain) PANI
species is rapid in
comparison to that
of the long-chain
PANI. Longer PANI
chains are produced
at a slower rate, at
the expense of
short-chain
intermediate
species. The gold
particles act as
nucleation sites for
the oxidative
formation of PANI,
encapsulating the
metal in the form of
a polymer/metal
composite. Results
from the elemental
analysis and the
FTIR spectra of the
composite material
are consistent with
PANI produced using
only ammonium
persulfate as the
oxidant. In
addition, XPS,
optical microscopy,
and TEM diffraction
show that the gold
particles are
polycrystalline with
relatively constant
diameter (0.8−1 μm).
Finally, the PANI/Au/HBF4
conductance does not
change significantly
with the
introduction of Au
particles, relative
to that of PANI/HBF4
without Au
particles. These
studies provide a
new method for
growth of PANI/metal
composites where the
presence of the
metal in the polymer
does not adversely
affect the
electronic
structure.
All spectra were obtained using a
StellarNet EPP2000 fiber
optic spectrophotometer equipped with a D2
lamp and tungsten filament source that were
coupled into a single fiber. ... |
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Titania−Acrylic Coil Reactor for Photocatalytic
Water Purification and Sterilization |
A titania−acrylic
composite reactor
was constructed with
a coil geometry. The
presence of multiple
titania layers
within the reactor
increases the
titania surface area
while making maximum
use of the
illumination
provided. Both
compact fluorescent
blacklight (CFL) and
ultraviolet light
emitting diodes
(LEDs) were used as
illumination
sources. An external
pump was used to
recirculate 650−800
mL of water
containing organic,
metallic, or
bacterial
contamination
through the coil
reactor. Complete
purification of the
water was achieved
within 300 min with
10 ppm methylene
blue, 10 ppm methyl
orange, 20 ppm Pb2+,
and 2200 colony
forming units per
milliliter (CFU/mL)
of E. coli
respectively using
the CFL source. The
effectiveness, low
cost, durability,
ruggedness, and
energy efficiency of
this reactor are
advantageous for
both portable and
fixed-base
applications.
Spectra from both light sources and UV−vis
spectra for MB and MO were collected on a
StellarNet ... Irradiance
spectra were collected with a fiber-mounted
cosine receptor (StellarNet
model CR2). ... |
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Electron Exchange
between α-Keggin Tungstoaluminates and a
Well-Defined Cluster-Anion Probe for Studies in
Electron Transfer |
Fully oxidized α-AlIIIW12O405-
(1ox),
and
one-electron-reduced
α-AlIIIW12O406-
(1red),
are well-behaved
(stable and free of
ion pairing) over a
wide range of pH and
ionic-strength
values at room
temperature in
water. Having
established this,
27Al NMR
spectroscopy is used
to measure rates of
electron exchange
between 1ox
(27Al NMR:
72.2 ppm relative to
Al(H2O)63+;
ν1/2 =
0.77 Hz) and 1red
(74.1 ppm; ν1/2
= 0.76 Hz).
Bimolecular rate
constants, k,
are obtained from
line broadening in
27Al NMR
signals as ionic
strength, μ, is
increased by
addition of NaCl at
the slow-exchange
limit of the NMR
time scale. The
dependence of k
on μ is plotted
using the extended
Debye−Hückel
equation:
log k = log
k0
+ 2αz1z2μ1/2/(1
+ βrμ1/2),
where z1
and z2
are the charges of
1ox
and 1red,
α and β are
constants, and r,
the distance of
closest contact, is
fixed at 1.12 nm,
the crystallographic
diameter of a Keggin
anion. Although not
derived for highly
charged ions, this
equation gives a
straight line (R2
= 0.996), whose
slope gives a charge
product, z1z2,
of 29 ± 2,
statistically
identical to the
theoretical value of
30. Extrapolation to
μ = 0 gives a rate
constant k11
of (6.5 ± 1.5) × 10-3
M-1 s-1,
more than 7 orders
of magnitude smaller
than the rate
constant [(1.1 ±
0.2) × 105
M-1 s-1]
determined by
31P NMR for
self-exchange
between PVW12O403-
and its
one-electron-reduced
form, PVW12O404-.
Sutin's
semiclassical model
reveals that this
dramatic difference
arises from the
large negative
charges of 1ox
and 1red.
These results,
including
independent
verification of k11,
recommend 1red
as a well-behaved
electron donor for
investigating
outer-sphere
electron transfer to
molecules or
nanostructures in
water, while
addressing a larger
issue, the
prediction of
collision rates
between uniformly
charged nanospheres,
for which 1ox
and 1red
provide a working
model.
Instrumentation. UV−vis spectra were
acquired using Hewlett-Packard 8452A or
StellarNet Inc. EPP2000
spectrophotometers equipped with diode-array
detectors and immersible fiber-optic probes. ... |
|
Evaluation of Photon Absorption in an Aqueous
TiO2 Slurry Reactor Using Monte Carlo
Simulations and Macroscopic Balance |
The radiation field
in an annular
photocatalytic
reactor is simulated
using a Monte Carlo
method (MC) for two
TiO2
suspensions in
water. Simulations
are performed by
using both the
spectral
distribution and the
wavelength-averaged
scattering and
absorption
coefficients. The
Henyey−Greenstein
phase function is
adopted to represent
forward, isotropic,
and backward
scattering modes. It
is assumed that the
UV lamp reflects the
backscattered
photons by the
slurred medium.
Photoabsorption
rates using MC
simulations and
spectral
distribution of the
optical coefficients
agree closely with
experimental
observations from a
macroscopic balance.
It is found that the
scattering mode of
the probability
density function is
not a critical
factor for a
consistent
representation of
the radiation field.
MC simulation for
the optimal catalyst
concentration
reveals that the
maximum LVREA is
reached at a
concentration of
0.14 g L−1
for TiO2
Degussa P25. From
this concentration,
the apparent optical
thickness is
determined to be
2.8476 which is in
agreement with the
optimal one
previously reported.
This concentration
is comparable to
that determined
experimentally for
phenol
photocatalytic
degradation.
The radiation field in an annular
photocatalytic reactor is simulated using a
Monte Carlo method (MC) for two TiO2
suspensions in water. Simulations are performed
by using both the spectral distribution and the
wavelength-averaged scattering and . |
Soluble Narrow Band Gap Polymers
(Dry-Box) |
Soluble
Narrow Band Gap and Blue
Propylenedioxythiophene-Cyanovinylene Polymers
as Multifunctional Materials for
Photovoltaic and Electrochromic Applications |
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Bio-Science |
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Human Pigmentation
Variation: Evolution, Genetic
Basis, and
Implications for Public Health
|
Pigmentation, which is primarily
deter-mined by the
amount, the type, and the distribution of
melanin, shows a remarkable diversity in
human populations, and
in this sense, it is an atypical trait.Numerous
genetic studies have indicated that the average
proportion of genetic
variation due to differences among
major continental groups is just 10–15%
of the total genetic
variation. In contrast, skin pigmentation shows
large differences among continental
populations. The
reasons for this discrepancy can be traced back
primarily to the
strong influence of
natural selection, which has
shaped the distribution of pigmentation
according to a
latitudinal gradient. Research during the last 5
years has
substantially increased our understanding of the
genes involved in normal pigmentation
variation in human
populations. At least six genes have been
identified using
genotype/phenotype association studies and/or
direct functional assays, and there is
evidence indicating
that several additional genes may be playing a
role in skin, hair,
and iris pigmentation. The information that is
emerging from recent studies points to a
complex picture where
positive selection has been acting at different
genomic locations, and for some genes
only in certain
population groups. |
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Extinction
Cross-Section Measurements of
Bacillus globigii Aerosols |
In a
continuing series of experiments designed to
determine the spectral extinction
cross section of bacterial aerosols,
spectral transmittance was
measured as a function of particle
concentration, and
extinction cross sections were calculated.
Visible band measurements of Bacillus
globigii aerosols indicated a slight increase in
the extinction cross section with increasing
wavelength. The
extinction cross section was
estimated to be 2.58 (±0.25)10 8 cm 2 at
the 543-nm wavelength. |
|
Mitochondrial succinic-semialdehyde
dehydrogenase of the γ-aminobutyrate shunt is
required to restrict levels of reactive oxygen
intermediates in plants |
The γ-aminobutyrate (GABA) shunt
is a metabolic pathway that bypasses two steps
of the tricarboxylic acid cycle, and it is
present in both prokaryotes and eukaryotes. In
plants the pathway is composed of the calcium/calmodulin-regulated
cytosolic enzyme glutamate decarboxylase and the
mitochondrial enzymes GABA transaminase and
succinic-semialdehyde dehydrogenase (SSADH). The
activity of the GABA shunt in plants is rapidly
enhanced in response to various biotic and
abiotic stresses. However the physiological role
of this pathway remains obscure. To elucidate
its role in plants, we analyzed Arabidopsis
T-DNA knockout mutants of SSADH, the ultimate
enzyme of the pathway. Four alleles of the
ssadh mutation were isolated, and these
exhibited a similar phenotype. When exposed to
white light (100 μmol of photons per m2
per s), they appear dwarfed with necrotic
lesions. Detailed spectrum analysis revealed
that UV-B has the most adverse effect on the
mutant phenotype, whereas photosynthetic active
range light has a very little effect. The
ssadh mutants are also sensitive to heat,
as they develop necrosis when submitted to such
stress. Moreover, both UV and heat cause a rapid
increase in the levels of hydrogen peroxide in
the ssadh mutants, which is associated
with enhanced cell death. Surprisingly, our
study also shows that trichomes are
hypersensitive to stresses in ssadh
mutants. Our work establishes a role for the
GABA shunt in preventing the accumulation of
reactive oxygen intermediates and cell death,
which appears to be essential for plant defense
against environmental stress. |
|
Sensitivity
analysis of CDOM spectral slope in artificial
and natural samples: an application in the
central eastern Mediterranean Basin
|
In the past two decades, optical properties of chromophoric dissolved organic matter (CDOM) in marine environments have been
extensively studied. Many of these studies report CDOM properties for the offshore environment where this complex mixture
of optically active compounds is strongly diluted. Nevertheless, autochthonous and allochthonous sources have been identified
and sinks related to photodegradation and bacterial activity have been demonstrated. The calculation of the spectral slope
of the CDOM absorption curve has been proven to be useful and is often reported. However, a rigorous uncertainty analysis
of the slope calculation is rarely reported. In this paper, we propose a method to evaluate the uncertainty of CDOM spectral
slope calculated between 270 and 400 nm, using both naturally sampled and artificial solutions. We use these results to study
the ultra-oligotrophic waters of the Mediterranean Sea (central eastern basin), where little is known about CDOM spatial distribution.
We show that dilutions of both artificial and natural samples produce a Gaussian distribution of spectral slopes, indicating
that consistent values may be determined, with a typical uncertainty of ±0.0004 nm−1 when absorption at 300 nm was greater then 0.1 m−1 (0.1 m pathlength). Comparing the distribution of spectral slopes from central eastern basin samples to a Gaussian distribution,
we show differences between measurements that were significantly different. These values allow us to distinguish possible
sources (algal derived CDOM), sinks (e.g. photo-bleaching) at different depths. We propose a subdivision of CDOM compounds
into refractory and semilabile/refractory pools and evaluate the CDOM spectral slope of algal derived CDOM released at or
near deep chlorophyll maximum. |
|
Optical Touch Pointer for Fluorescence Guided
Glioblastoma Resection Using
5-Aminolevulinic Acid |
Background and Objective: Total
tumor resection in
patients with
glioblastoma multiforme (GBM) is difficult to
achieve due to the tumor’s infiltrative
way of growing and
morphological similarity to the surrounding
functioning brain
tissue. The diagnosis is usually subjectively
performed using a
surgical microscope. The objective of this
study was to develop and evaluate a
hand-held optical
touch pointer using a fluorescence spectroscopy
system to
quantitatively distinguish healthy from
malignant brain tissue
intraoperatively.
Study Design/Materials and Methods: A
fluorescence
spectroscopy system with pulsed modulation was
designed considering
optimum energy
delivery to the tissue, minimal
photobleaching of PpIX and omission of
the ambient light
background in the operating room (OR).
5-Aminolevulinic acid
(5-ALA) of 5 mg/kg body weight was given to
the patients with a presumed
GBM prior to
surgery. During the
surgery a laser pulse at 405nm was delivered to
the tissue. PpIX in
glioblastoma tumor cells assigned with
peaks at 635 and 704nm was detected using
a fiber optical probe.
Results/Conclusion: By using the pulsed
fluorescence
spectroscopy,
PpIXfluorescence isquantitatively detected in
the GBM. An effective suppression of low
power lamp background
from the recorded spectra in addition to a
significant reduction of high power
surgical lights is
achieved. |
|
Ablation of Liver Cancer Cells
in Vitro by a Plasma Needle |
A plasma needle using a
dielectric barrier discharge reactor at
atmospheric pressure with a
funnel-shaped nozzle was developed. The
preliminary characteristics of the plume and
applications to the
ablation of cultured human hepatocellular
carcinoma HCC BEL-7402 cell line
are presented. |
|
Process Monitoring and Quality
Control |
|
|
Semi-Conductor |
The
MPSS (Multi Probe Spectrophotometer System) is a
multi-channel process control monitor used in
semi-conductor fabrication and other
real-time process applications. |
|
Alcohol |
A dual
beam process monitor using "Neural Networks" to
measure the concentration of alcohol in a
process stream. |
|
Film Deposition |
A
multi-channel system used to
monitor silver film deposition on a
moving roll of plastic using transmission and
reflectance. |
|
Dilatometer |
The "Dilatometer"
analytical instrument designed for specifically
for polymer chemists. |
|
Colorimeter |
A
triple-channel SpectroColorimeter
used as a process Quality Control monitor for
plastic injection molding operations. |
|
StellarNet Patents |
A list of patents filed using
StellarNet spectrometers |