Microbial Purification of Shellfish: A Review of Depuration and Relaying

1988 ◽  
Vol 51 (3) ◽  
pp. 218-251 ◽  
Author(s):  
GARY P. RICHARDS
Keyword(s):  
Enteric Virus ◽  
Intestinal Cells ◽  
Review Of The Literature ◽  
Indicator Microorganisms ◽  
Virus Contamination ◽  
Pathogenic Viruses ◽  
Proper Design ◽  
Flow Through ◽  
Low Levels ◽  
Vibrio Spp

A review of the literature on shellfish depuration and relaying revealed wide diversity in microbial uptake and elimination among shellfish species and for different microorganisms. Information on relaying of five commercial shellfish species and on controlled purification (depuration) of 11 species indicates that such processes are effective in reducing the levels of bioconcentrated bacteria and viruses from shellfish. The degree of bacterial and viral bioconcentration varies with shellfish species; however, the primary sites of bioconcentration are the hepatopancreas and digestive diverticula. Low levels of enteric viruses and coliphage may be sequestered in shellfish hemolymph and tissues, thus protecting them from elimination through depurative processes. Vibrio spp. appear to proliferate when closely associated with intestinal cells of shellfish. Shellfish relaying techniques offer effective microbial depletion provided water quality is acceptable and shellfish remain physiologically active. The current body of literature on controlled purification demonstrates a broad spectrum of conditions under which shellfish are depurated. Optimal times, temperatures and salinities for effective depuration vary among shellfish species. Proper design and operation of depuration plants is crucial to insure process integrity. Recirculating and flow-through purification systems are effective in reducing the levels of pathogenic and indicator microorganisms from shellfish, but the extent to which they reduce viruses from shellfish is uncertain. Studies are needed to validate the effectiveness of depuration processes in eliminating pathogenic viruses and to address the adequacy of indicator bacteria as measures of enteric virus contamination.

Outbreaks of Shellfish-Associated Enteric Virus Illness in the United States: Requisite for Development of Viral Guidelines

1985 ◽  
Vol 48 (9) ◽  
pp. 815-823 ◽  
Author(s):  
GARY P. RICHARDS
Keyword(s):  
United States ◽  
Hepatitis A ◽  
Hepatitis A Virus ◽  
Enteric Virus ◽  
The United States ◽  
Viral Gastroenteritis ◽  
Norwalk Virus ◽  
Virus Contamination ◽  
Pathogenic Viruses

Outbreaks of hepatitis A, Norwalk illness, and nonspecific viral gastroenteritis are associated with consumption of sewage-contaminated shellfish. Over 100 outbreaks have been reported in the United States during the past 50 years. Reported cases of shellfish-associated enteric virus illness are on the increase, whereas bacterial illness from shellfish is on the decline. As yet, there are no procedures for detecting hepatitis A virus, Norwalk virus and numerous other pathogenic viruses in environmental samples, but virus extraction and assay procedures for water and shellfish are available for the more easily cultivated enteric viruses. Current standards rely on bacterial indicators as a means to evaluate the sanitary quality of shellfish and their growing waters, but the adequacy of using bacteria as indicators of possible virus contamination is questionable. The feasibility of employing enteroviruses or rotaviruses as possible viral indiators is discussed. It is proposed that easily cultivated enteroviruses, such as poliovirus, be used as an interim indicator for the possible presence of human pathogenic viruses in seafoods, with the subsequent formulation of guidelines to limit the levels of virus contamination in shellfish.

Modelling Liquid Flow Through Carbon Nanotubes

2013 ◽  
pp. 297-309
Author(s):  
Faig Bakhman Ogli Naghiyev
Keyword(s):  
Mass Transfer ◽  
Continuum Hypothesis ◽  
Flow Characteristics ◽  
Bingham Fluid ◽  
Length Scale ◽  
Review Of The Literature ◽  
Nanoscale Systems ◽  
Flow Through ◽  
Intermolecular Distances ◽  
Moving Fluid

In this paper, the structure of a liquid and character of its flow in carbon nanotube is investigated. A review of the literature and the results of experiments show that the simulation of fluid flow for nanoscale systems should be based on the continuum hypothesis taking into account the quantized character of the liquid in the length scale of intermolecular distances. Consideration of the flow characteristics allowed construction of the analogy of behavior of the liquid in a nanotube with a flow of a viscoplastic Bingham fluid. A model of mass transfer of liquid in a nanotube, based on the possibility of forming an empty interlayer between the moving fluid particles and the particles of the wall of the nanotube, is presented.

Demonstration of Viral Contamination of Oysters Responsible for an Outbreak of Viral Gastroenteritis

1981 ◽  
Vol 44 (4) ◽  
pp. 294-296 ◽  
Author(s):  
M. J. EYLES ◽  
G. R. DAVEY ◽  
E. J. HUNTLEY
Keyword(s):  
Causative Agent ◽  
Enteric Virus ◽  
Fecal Specimen ◽  
Viral Gastroenteritis ◽  
Norwalk Virus ◽  
Viral Contamination ◽  
Virus Contamination ◽  
Human Enteric Virus ◽  
Viral Illness ◽  
Echovirus Type

Two viruses, echovirus type 8 and a reovirus, were isolated from a batch of oysters responsible for an outbreak of gastroenteritis. Characteristics of the illness, detection of Norwalk virus in the feces of one of the victims and other factors indicated strongly that the illness was due to infection with Norwalk virus. Examination of the implicated oysters and a fecal specimen from a victim failed to provide evidence of the involvement of any other causative agent. Thus laboratory evidence of human enteric virus contamination of a batch of food responsible for a viral illness has been provided.

Sensory Analysis of Trout Tainted by Diesel Fuel in Ambient Water

1992 ◽  
Vol 25 (2) ◽  
pp. 11-18 ◽  
Author(s):  
H. K. Davis ◽  
E. N. Geelhoed ◽  
A. W. MacRae ◽  
P. Howgate
Keyword(s):  
Rainbow Trout ◽  
Diesel Fuel ◽  
Sensory Analysis ◽  
Rating Scale ◽  
Ambient Water ◽  
Quantitative Rating ◽  
Flow Through ◽  
Low Levels ◽  
Water Tanks ◽  
Combined Data

Rainbow trout (Salmo gairdnen) were kept in fresh water tanks for 24 h and exposed to one of seven concentrations of diesel, using a flow-through system with used water discharged to waste. The concentrations ranged from 0.0087 to 0.87 mg.l−1 (0.01 to 1.0 µ1.1−1). An experienced taste panel assessed the degree of taint in the cooked fish by four different procedures. These were the triangular test, three-alternative forced-choice (3-AFC) and two forms of rating scale. The triangular and 3-AFC procedures yielded similar estimates of threshold, the estimate from the combined data being approximately 0.08 mg.l−1. Although the 3-AFC procedure has some advantages, they are not sufficient to recommend it in place of the triangular test. Both methods showed better ability to discriminate low levels of taint than the quantitative rating procedures.

scholarly journals Arterialized Venous Flow-Through Flaps in the Reconstruction of Digital Defects: Case Series and Review of the Literature

Hand ◽  
2014 ◽  
Vol 10 (2) ◽  
pp. 184-190 ◽  
Author(s):  
Jared W. Garlick ◽  
Isak A. Goodwin ◽  
Keith Wolter ◽  
Jayant P. Agarwal
Keyword(s):  
Case Series ◽  
Review Of The Literature ◽  
Venous Flow ◽  
Flow Through

Lack of Effects of Carbon Monoxide on Human Vigilance

1977 ◽  
Vol 45 (3) ◽  
pp. 1007-1014 ◽  
Author(s):  
Vernon A. Benignus ◽  
David A. Otto ◽  
James D. Prah ◽  
Gayla Benignus
Keyword(s):  
Carbon Monoxide ◽  
Critical Review ◽  
Statistical Test ◽  
Review Of The Literature ◽  
Vigilance Performance ◽  
Monitoring Task ◽  
Human Male ◽  
Exposure Levels ◽  
Low Levels ◽  
Male Subjects

Previous publications on the effects of low levels of carbon monoxide (CO) on human vigilance performance have found conflicting results. While several studies have found statistically reliable effects, none have gone unchallenged. This article presents a critical review of the literature and the results of a study employing 52 human male subjects performing a numeric monitoring task. CO levels were 0, 100, and 200 ppm which produced mean carboxyhemoglobin levels 0.01, 4.61 and 12.62 percent respectively. No CO-exposure levels produced any effect on vigilance performance. The power of the statistical test for CO effects was shown to be quite high, even for fairly trivial possible decrements of performance.

Bacteriophages and bacteria as indicators of enteric viruses in oysters and their harvest waters

1998 ◽  
Vol 38 (12) ◽  
pp. 37-44 ◽  
Author(s):  
H. Chung ◽  
L.-A. Jaykus ◽  
G. Lovelace ◽  
M. D. Sobsey
Keyword(s):  
Enteric Viruses ◽  
Enteric Virus ◽  
Indicator Bacteria ◽  
Faecal Coliforms ◽  
Rt Pcr ◽  
E Coli ◽  
Virus Contamination ◽  
Receiving Waters ◽  
Male Specific ◽  
Receiving Water

Reliable indicators are needed to detect enteric virus contamination of bivalve molluscan shellfish and their harvest waters. Concentrations of male-specific (F+) coliphages, Bacteroides fragilis phages, Salmonella phages and several indicator bacteria in wastewater, estuarine receiving water and its oysters were examined for their ability to predict the presence and levels of faecal contamination and enteric viruses in oysters. Enteric viruses in oysters were detected by cell culture and RT-PCR methods. F+ coliphages, Salmonella phages, B fragilis phages and faecal indicator bacteria (faecal coliforms, E coli, enterococci and Clostridium perfringens) were generally positively associated and were highest in raw sewage and progressively lower in sewage effluent and in receiving waters at increasing distance from the wastewater discharge. Indicator levels in oysters were highest for F+ coliphages and C perfringens. One F+ RNA coliphage serotype (Group II) predominated in the wastewater, receiving water and oysters. Human enteric viruses were detected in 17/31 oyster samples. The levels of most indicators in oysters and water were higher when oysters were enteric virus-positive and lower when oysters were enteric virus-negative. F+ coliphages and C perfringens were the only indicators significantly associated with the presence of enteric viruses in oysters. F+ coliphages and their serotypes are promising indicators of human enteric virus contamination in oysters and their harvest waters.

scholarly journals The role of resources in recombinations and the degree of novelty of products

2021 ◽  
Vol 9 (3) ◽  
pp. 522-556
Author(s):  
Juan Pablo Camani
Keyword(s):  
Theoretical Model ◽  
Emerging Markets ◽  
Integrative Review ◽  
The Novel ◽  
Review Of The Literature ◽  
Ex Ante ◽  
Low Levels ◽  
Resource Characteristics ◽  
Novel Products

Objective of the study: To explain the characteristics and dynamics of resources and recombinations associated with developing products with low and high novelty.Methodology/Approach: The method was an integrative review of the literature on recombinant innovation. It included a creative synthesis that resulted in a theoretical model. Originality/Relevance: The research addresses topics the literature neglects, like explaining which resources and recombinations and why could relate to high or low product novelty.Main results: Certain features of resources (i.e., heterogeneity, specificity, accessibility) with high and low levels may differently influence costs, variety, and frequency of recombinations and, in turn, product novelty. To develop highly novel products, tangible resources, and internally produced new resources may be essential, as knowledge by itself may not be sufficient.Theoretical contributions: Different resource characteristics and their influence on recombinations may help explain whether a product will have low or high novelty. By going beyond the novel recombinations, the research expands the literature's understanding of recombinations and product novelty.Managerial contributions: Companies could assess ex ante which degree of product novelty besides types and costs of recombinations would result from their pools of resources. This assessment would make innovation more efficient for companies with fewer resources, like may occur in emerging markets.

OESTROGEN AND PROGESTERONE CONTENT OF OVARIAN VEIN BLOOD OF THE EWE DURING THE OESTROUS CYCLE

1969 ◽  
Vol 44 (1) ◽  
pp. 55-62 ◽  
Author(s):  
N. W. MOORE ◽  
SUSAN BARRETT ◽  
J. B. BROWN ◽  
IRENE SCHINDLER ◽  
MARGERY A. SMITH ◽  
...  
Keyword(s):  
Plasma Concentrations ◽  
Follicular Phase ◽  
Oestrous Cycle ◽  
Ovarian Vein ◽  
Chemical Methods ◽  
Plasma Progesterone ◽  
Cyclic Variations ◽  
Flow Through ◽  
Low Levels ◽  
Almost All

SUMMARY Ovarian vein blood was collected by cannulating the ovarian vein of 37 ewes at various times during the oestrous cycle. Plasma progesterone and oestrogen concentrations, determined by chemical methods, showed marked cyclic variations during the cycle. Progesterone was detected at all stages of the cycle. Plasma concentrations were rising rapidly by the 4th day after the onset of oestrus and were maintained at levels greater than 100 μg./100 ml. plasma from the 8th to the 14th day of the cycle. They started to fall about 48 hr. before the onset of oestrus. Very low levels, of the order of 1 μg./100 ml. plasma, were maintained from 24 hr. before to 8–16 hr. after the onset of oestrus. Oestradiol-17β made up almost all of the oestrogens measured. Oestrone accounted for less than one-eighth of the total oestrogens. Oestradiol first appeared on the 14th day of the cycle and its concentration rose rapidly during the immediate pre-oestrous period to reach peak levels of over 100 ng./100 ml. plasma 20–30 hr. before the onset of oestrus. They then rapidly declined and by 24 hr. after the onset had reached almost non-detectable levels. The ovarian secretion rate of progesterone was calculated to be 3·5 mg./day at mid-cycle and the total secretion of oestradiol during the follicular phase was 4·9 μg. Blood flow through the cannula was not affected by either the stage of cycle at which blood was collected or by the structure (corpus luteum or Graafian follicle) in the ovary bled.

The Effects of Silicic Acid, Aluminate Ion Activity And Hydrosilicate Gel Development on the Dissolution Rate of a Simulated British Magnox Waste Glass

1999 ◽  
Vol 556 ◽  
Author(s):  
P. K. Abraitis ◽  
B. P. McGrail ◽  
D. P. Trivedi
Keyword(s):  
Dissolution Rate ◽  
Secondary Phase ◽  
Waste Glass ◽  
Alkaline Media ◽  
Glass Dissolution ◽  
Rate Of Dissolution ◽  
Flow Through ◽  
Low Levels ◽  
Aluminium Species

AbstractThe dissolution rate of a simulated Magnox waste glass has been investigated in single-pass flow-through experiments designed to investigate the role of Al and Si in the dissolution process. The results indicate that both Al and Si species suppress the rate of dissolution. These effects may be modelled using a combined Al/Si affinity term in a conventional glass dissolution rate law. Aluminium species may also play an inhibitory role when present at relatively high solution activities. In Si-rich alkaline media, the concentration of aluminium is controlled to very low levels by the development of secondary aluminosilicate phases. Removal of Al by secondary phase precipitation results in dissolved Al activities below that required to reach ‘saturation’ with respect to the glass.

Sign in / Sign up

Export Citation Format

Share Document