scholarly journals Studies on luminescence. Attraction of animals to a weak light

1959 ◽  
Vol 38 (3) ◽  
pp. 477-479 ◽  
Author(s):  
J. A. C. Nicol
Keyword(s):  
Biological Significance ◽  
Point Sources ◽  
Marine Animals ◽  
Weak Point ◽  
Know How ◽  
Weak Light

In order to evaluate the biological significance of luminescence, it is desirable to know how weak light affects the behaviour of marine animals, and what intensities they can see. Much information is available concerning the attractive power of bright lights, and light directed movements (see Verheijen, 1958, for example), but little for weak point sources. Weak coloured lights have been used by Baylor & Smith (1953) to trap freshwater arthropods.

On the Aggregate Flux of Weak Point Sources at 1404 MHZ

1976 ◽  
Vol 210 ◽  
pp. 321 ◽  
Author(s):  
S. J., Jr. Goldstein ◽  
A. P. Marscher ◽  
R. T. Rood
Keyword(s):  
Point Sources ◽  
Weak Point

scholarly journals Terrorist Attacks: Do We Know How to Assess the Results?

2001 ◽  
Vol 1 ◽  
pp. 588-589
Author(s):  
William J. Manning
Keyword(s):  
New York ◽  
Fine Particles ◽  
World Trade Center ◽  
Point Sources ◽  
Know How ◽  
Particulate Air Pollution ◽  
Volatile Organic ◽  
Dust Fraction ◽  
Trade Center ◽  
Complete Collapse

On September 11, 2001, terrorists destroyed the World Trade Center (WTC) in New York City. Explosions and fires resulted in the complete collapse of the two WTC towers. The collapsing towers served as enormous point sources of gaseous and particulate air pollution, seen as huge plumes of smoke and dust. The smoke contained volatile organic compounds and fine particles and aerosols. The dust fraction contained parts of ceiling tiles, carpets, concrete, adhesives, asbestos, chromium, lead, titanium, and many other elements and materials. Whether there were unusually toxic ingredients in the plumes is largely unknown.

On the chemistry of EDC-tar and its biological significance in the sea

1975 ◽  
Vol 189 (1096) ◽  
pp. 333-346 ◽  
Keyword(s):  
Acute Toxicity ◽  
Vinyl Chloride ◽  
Biological Effects ◽  
Biological Significance ◽  
Long Term Effects ◽  
Marine Animals ◽  
Waste Products ◽  
Chlorinated Aliphatic Hydrocarbons ◽  
Medical Reports

The composition of EDC-tars originating as waste products in two different processes of vinyl chloride production has been studied. In total, 80 substances have been detected. Most of the chlorinated aliphatic hydrocarbons identified were found to contain one or two double bonds. 15 out of the 80 substances are aromatics, and most of these are chlorinated as well. Possible chemical or biological conversions of EDC-tar components in the marine environment are discussed. Data on acute toxicity of the EDC-tar to coastal water phytoplankton and some marine animals are given. It is shown that EDC-tar in concentrations as low as 10-100/10 9 may cause acute biological effects. In the light of the chemical data presented and recent medical reports on serious diseases in workers employed in vinyl chloride production plants, the possibility of similar long term effects in marine animals is briefly discussed.

Resistance Monitor and Control for Vacuum Evaporation of Metals and Carbon

1976 ◽  
Vol 34 ◽  
pp. 572-573
Author(s):  
Russell L. Steere ◽  
Eric F. Erbe ◽  
J. Michael Moseley
Keyword(s):  
Electronic Device ◽  
Point Sources ◽  
High Contrast ◽  
Variable Resistor ◽  
Quality Of Results ◽  
Low Contrast ◽  
Evaporation Source ◽  
And Control ◽  
At Will

We have designed and built an electronic device which compares the resistance of a defined area of vacuum evaporated material with a variable resistor. When the two resistances are matched, the device automatically disconnects the primary side of the substrate transformer and stops further evaporation.This approach to controlled evaporation in conjunction with the modified guns and evaporation source permits reliably reproducible multiple Pt shadow films from a single Pt wrapped carbon point source. The reproducibility from consecutive C point sources is also reliable. Furthermore, the device we have developed permits us to select a predetermined resistance so that low contrast high-resolution shadows, heavy high contrast shadows, or any grade in between can be selected at will. The reproducibility and quality of results are demonstrated in Figures 1-4 which represent evaporations at various settings of the variable resistor.

Beam-radiation effects on wool in the ESEM

1986 ◽  
Vol 44 ◽  
pp. 674-675
Author(s):  
G.D. Danilatos
Keyword(s):  
Electron Beam ◽  
Radiation Effects ◽  
Research Work ◽  
Beam Radiation ◽  
Liquid Environment ◽  
Know How ◽  
Environmental Sem

The advent of the environmental SEM (ESEM) has made possible the examination of uncoated and untreated specimen surfaces in the presence of a gaseous or liquid environment. However, the question arises as to what degree the examined surface remains unaffected by the action of the electron beam. It is reasonable to assume that the beam invariably affects all specimens but the type and degree of effect may be totally unimportant for one class of applications and totally unacceptable for another; yet, for a third class, it is imperative to know how our observations are modified by the presence of the beam. The aim of this report is to create an awareness of the need to initiate research work in various fields in order to determine the guiding rules of the limitations (or even advantages) due to irradiation.

Microstructural morphology of sphingolipid dispersions as investigated by freeze-fracture EM

1995 ◽  
Vol 53 ◽  
pp. 944-945
Author(s):  
Vitthal S. Kulkarni ◽  
Wayne H. Anderson ◽  
Rhoderick E. Brown
Keyword(s):  
Acyl Chain ◽  
Biological Significance ◽  
Freeze Fracture ◽  
Fatty Acyl ◽  
Fatty Acyl Moiety ◽  
Aqueous Dispersions ◽  
Head Groups ◽  
Lipid Species ◽  
Microstructural Morphology ◽  
Layer Chromatography

The biological significance of the sphingomyelins (SM) and monoglycosylated sphingolipids like galactosylceramides (GalCer) are well documented Our recent investigation showed tubular bilayers in the aqueous dispersions of N-nervonoyl GalCer [N-(24:lΔ15,cls) GalCer] (a major fatty acyl moiety of natural GalCer). To determine the influence of lipid head groups on the resulting mesophasic morphology, we investigated microstructural self-assemblies of N-nervonoyl-SM [N-(24:1 Δ15,cls) SM; the second most abundant sphingomyelin in mammalian cell membranes], 1- palmitoyl-2-nervonoyl phosphatidylcholine [PNPC] (the lipid species with the same acyl chain configuration as in N-(24: 1) GalCer) and also compared it with egg-SM by freeze-fracture EM.Procedures for synthesizing and purifying N-(24:1) GalCer, N-(24:1) SM, and PNPC have been reported . Egg-SM was purchased from Avanti Polar Lipids, Alabaster AL. All lipids were >99% pure as checked by thin layer chromatography. Lipid dispersions were prepared by hydrating dry lipid with phosphate buffer (pH 6.6) at 80-90°C (3-5 min), vigorously vortexing (1 min) and repeating this procedure for three times prior to three freeze-thaw cycles.

Computer programs for the calculation of x-ray intensities emitted by elements in multi-layer structures

1990 ◽  
Vol 48 (2) ◽  
pp. 216-217
Author(s):  
G.F. Bastin ◽  
H.J.M. Heijligers ◽  
J.M. Dijkstra
Keyword(s):  
Software Package ◽  
Light Element ◽  
Matrix Correction ◽  
Excellent Performance ◽  
Element Analysis ◽  
X Ray ◽  
Know How ◽  
Accurate Knowledge ◽  
Layer Structures ◽  
Bulk Matrix

For the calculation of X-ray intensities emitted by elements present in multi-layer systems it is vital to have an accurate knowledge of the x-ray ionization vs. mass-depth (ϕ(ρz)) curves as a function of accelerating voltage and atomic number of films and substrate. Once this knowledge is available the way is open to the analysis of thin films in which both the thicknesses as well as the compositions can usually be determined simultaneously.Our bulk matrix correction “PROZA” with its proven excellent performance for a wide variety of applications (e.g., ultra-light element analysis, extremes in accelerating voltage) has been used as the basis for the development of the software package discussed here. The PROZA program is based on our own modifications of the surface-centred Gaussian ϕ(ρz) model, originally introduced by Packwood and Brown. For its extension towards thin film applications it is required to know how the 4 Gaussian parameters α, β, γ and ϕ(o) for each element in each of the films are affected by the film thickness and the presence of other layers and the substrate.

Ultrastructural Localization Study of Carcinoembryonic Antigen (CEA) in Gastric Cancer: Immunoelectron Microscopic Observation

1990 ◽  
Vol 48 (3) ◽  
pp. 252-253
Author(s):  
Dong Yuming ◽  
Yang Guanglin ◽  
Wu Jifeng ◽  
Chen Xiaolin
Keyword(s):  
Gastric Cancer ◽  
Intestinal Metaplasia ◽  
Cancer Cells ◽  
Microscopic Observation ◽  
Biological Significance ◽  
Ultrastructural Localization ◽  
Mucinous Carcinoma ◽  
Surface Glycoprotein ◽  
Tubular Adenocarcinoma ◽  
Pap Method

On the basis of light microscopic observation, the ultrastructural localization of CEA in gastric cancer was studied by immunoelectron microscopic technique. The distribution of CEA in gastric cancer and its biological significance and the mechanism of abnormal distribution of CEA were further discussed.Among 104 surgically resected specimens of gastric cancer with PAP method at light microscopic level, the incidence of CEA(+) was 85.58%. All of mucinous carcinoma exhibited CEA(+). In tubular adenocarcinoma the incidence of CEA(+) showed a tendency to rising with the increase of degree of differentiation. In normal epithelia and intestinal metaplasia CEA was faintly present and was found only in the luminal surface. The CEA staining patterns in cancer cells were of three types--- cytoplasmic, membranous and weak reactive type. The ultrastructural localization of CEA in 14 cases of gastric cancer was studied by immunoelectron microscopic technique.There was a little or no CEA in the microvilli of normal epithelia. In intestinal metaplasia CEA was found on the microvilli of absorptive cells and among the mucus particles of goblet cells. In gastric cancer CEA was also distributed on the lateral and basal surface or even over the entire surface of cancer cells and lost their polarity completely. Many studies had proved that the alterations in surface glycoprotein were characteristic changes of tumor cells. The antigenic determinant of CEA was glycoprotein, so the alterations of tumor-associated surface glycoprotein opened up a new way for the diagnosis of tumors.

Spreading the Word: Raise Your Profession's Profile With Local Angles on National News

ASHA Leader ◽  
2013 ◽  
Vol 18 (2) ◽  
Keyword(s):  
Know How ◽  
The Media

How to use your local know-how to get the media to pay attention.

Experience With Grant Writing: Where Do I Even Begin?

2010 ◽  
Vol 11 (1) ◽  
pp. 21-24
Author(s):  
Nicole M. Mancini
Keyword(s):  
Lessons Learned ◽  
Economic Situation ◽  
Grant Writing ◽  
Personal Journey ◽  
Know How ◽  
Daunting Task

Abstract At first, grant writing may look like a daunting task. You may ask yourself, “Is it really worth the time and effort?” With today's economic situation, teachers and therapists need ways to supplement their programs and grants provide such an opportunity. However, many of us do not know how to get started. After a few experiences and many lessons learned, I have come to enjoy researching and writing grants to supplement my students' learning. It is well worth the time and effort. This article provides information about a personal journey, lessons learned, and resources to get you started.

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