scholarly journals Anticoccidial resistance in poultry

2021 ◽  
Vol 53 (3) ◽  
Author(s):  
Abdelkrim Ferdji ◽  
Nora Mimoune ◽  
Tahar Amrouche ◽  
Djilali Degui ◽  
Soraya Temim ◽  
...  
Keyword(s):  
Control Strategy ◽  
Partial Resistance ◽  
Eimeria Species ◽  
The Other ◽  
Cross Resistance ◽  
Total Resistance ◽  
Eimeria Acervulina ◽  
Eimeria Maxima ◽  
Uniform Composition

This study aimed to determine the resistance of coccidia to ionophores used in broiler farms in Tizi-Ouzou province, Algeria. Droppings were collected and recovered Eimeria oocyst isolates were analysed by morphometry to determine their composition, and then inoculated by peros into chicks of the Arbor Acres strain, reared on the ground. Four of six groups of chicks were treated to test the sensitivity of oocysts to four anticoccidial agents added to their growth feeds [(robenidine (33 ppm), monensin (120 ppm), narasin-nicarbazin (80 ppm) and salinomycin (60 ppm)], while the other two groups were controls. The results revealed the presence of total resistance to monensin and robenidine, and partial resistance to salinomycin and the narasin-nicarbazin combination. The lack of sensitivity to monensin and robenidine was unsurprising, given their inappropriate and unreasonable use for years as the only anticoccidial compounds. The appearance of partial resistance to narasin-nicarbazin and salinomycin suggests the development of cross-resistance in the Eimeria population. The possibility of a relatively uniform composition of Eimeria species collected in these farms indicates that Eimeria acervulina and Eimeria maxima develop resistance more quickly to these ionophores. Finally, a control strategy must be rigorously developed by considering other molecules that are alternatives to anticoccidials.

Dry chip feedrate control using online chip moisture

TAPPI Journal ◽  
2018 ◽  
Vol 17 (05) ◽  
pp. 295-305
Author(s):  
Wesley Gilbert ◽  
Ivan Trush ◽  
Bruce Allison ◽  
Randy Reimer ◽  
Howard Mason
Keyword(s):  
Production Rate ◽  
Control Strategy ◽  
Rate Control ◽  
Near Infrared ◽  
Dry Mass ◽  
The Other ◽  
Process Variability ◽  
Moisture Sensor ◽  
Feedback Control Strategy ◽  
And Control

Normal practice in continuous digester operation is to set the production rate through the chip meter speed. This speed is seldom, if ever, adjusted except to change production, and most of the other digester inputs are ratioed to it. The inherent assumption is that constant chip meter speed equates to constant dry mass flow of chips. This is seldom, if ever, true. As a result, the actual production rate, effective alkali (EA)-to-wood and liquor-to-wood ratios may vary substantially from assumed values. This increases process variability and decreases profits. In this report, a new continuous digester production rate control strategy is developed that addresses this shortcoming. A new noncontacting near infrared–based chip moisture sensor is combined with the existing weightometer signal to estimate the actual dry chip mass feedrate entering the digester. The estimated feedrate is then used to implement a novel feedback control strategy that adjusts the chip meter speed to maintain the dry chip feedrate at the target value. The report details the results of applying the new measurements and control strategy to a dual vessel continuous digester.

VII.–The Effect of the Transport of Heat on the Rate of Evaporation of Small Droplets I. Evaporation into a Large Excess of a Gas

1962 ◽  
Vol 66 (2) ◽  
pp. 65-80
Author(s):  
P. G. Wright
Keyword(s):  
Gaseous Phase ◽  
The Other ◽  
Total Resistance ◽  
Large Excess ◽  
Stationary Growth ◽  
In Series ◽  
Finite Period ◽  
Rate Of Evaporation ◽  
Latent Heat Of Vaporization ◽  
Algebraic Formulation

SynopsisBeginning with fundamental results obtained by Mason for the effect of self-cooling on the evaporation of drops, and by Fuchs for the diffusional retardation of evaporation for small droplets of any radius, explicit expressions for the effect of the transport of heat on the rate of quasi-stationary growth or evaporation, are discussed.The simplest algebraic formulation of the results lends itself to interpretation as expressing a resistance to evaporation, the total resistance being the sum of four resistances in series. Two of these resistances, one to diffusion and one to the conduction of heat, are offered by the gaseous phase in bulk; and there are two corresponding resistances at the interface. Corrections are formulated for the effect of the heating of the droplet by radiation. These corrections may be expressed as a (finite) resistance in parallel with the other two resistances to the transfer of heat. Simplified equations are obtained for the evaporation of a liquid whose latent heat of vaporization is very large.Some remarks are made on the formation of a monodisperse aerosol by the growth of smaller droplets. Integrated expressions are obtained for particular cases of the evaporation of a droplet over a finite period of time.

scholarly journals Activities of Atazanavir (BMS-232632) against a Large Panel of Human Immunodeficiency Virus Type 1 Clinical Isolates Resistant to One or More Approved Protease Inhibitors

2003 ◽  
Vol 47 (4) ◽  
pp. 1324-1333 ◽  
Author(s):  
Richard J. Colonno ◽  
Alexandra Thiry ◽  
Kay Limoli ◽  
Neil Parkin
Keyword(s):  
Human Immunodeficiency Virus ◽  
Amino Acid ◽  
Human Immunodeficiency Virus Type ◽  
Virus Type ◽  
The Other ◽  
Clinical Isolates ◽  
Cross Resistance ◽  
Resistance Profile ◽  
Immunodeficiency Virus

ABSTRACT To evaluate the cross-resistance profile of the human immunodeficiency virus type 1 protease inhibitor (PI) atazanavir (BMS-232632), a panel of 551 clinical isolates exhibiting a wide array of PI resistance profiles and a variety of genotypic patterns were assayed for susceptibility to atazanavir and six other PIs: amprenavir, indinavir, lopinavir, nelfinavir, ritonavir, and saquinavir. In general, reductions in atazanavir susceptibility in vitro required several amino acid changes and were relatively modest in degree, and susceptibility was retained among isolates resistant to one or two of the currently approved PIs. There was a clear trend toward loss of susceptibility to atazanavir, as isolates exhibited increasing levels of cross-resistance to multiple PIs. Atazanavir appeared to have a distinct resistance profile relative to each of the other six PIs tested based on susceptibility comparisons against this panel of resistant isolates. Analysis of the genotypic profiles of 943 PI-susceptible and -resistant clinical isolates identified a strong correlation between the presence of amino acid changes at specific residues (10I/V/F, 20R/M/I, 24I, 33I/F/V, 36I/L/V, 46I/L, 48V, 54V/L, 63P, 71V/T/I, 73C/S/T/A, 82A/F/S/T, 84V, and 90M) and decreased susceptibility to atazanavir. While no single substitution or combination of substitutions was predictive of atazanavir resistance (change, >3.0-fold), the presence of at least five of these substitutions correlated strongly with loss of atazanavir susceptibility. Mutations associated with reduced susceptibility to each of the other six PIs were also determined.

An Empirical Formula to Estimate the Resistance of a Convoy in a Restricted Waterway

1996 ◽  
Vol 40 (02) ◽  
pp. 107-111
Author(s):  
J.L.J. Marchal ◽  
Y.-D. Shen ◽  
D. Kicheva
Keyword(s):  
Cross Section ◽  
Empirical Formula ◽  
The Other ◽  
Total Resistance ◽  
Empirical Methods ◽  
Joint Research ◽  
Ship Hydrodynamics ◽  
Joint Research Project ◽  
Length Width ◽  
The Subject

An examination of the literature produced very few references related to the subject of estimating the resistance of a convoy navigating in a waterway of limited cross section. This paper reports the findings of one such study—a joint research project undertaken by Belgium's University of Liege and the Bulgarian Ship Hydrodynamics Centre. A polynomial is presented here for evaluating the total resistance of a convoy moving in a restricted waterway. The resistance was found to depend on Froude number and on the relative dimensions (length, width and depth) between the convoy and the channel. The results obtained by the suggested polynomial are compared with those obtained by the other three existing empirical methods.

Numerical Modelling of a Planing Craft with a V-Shaped Spray Interceptor Arrangement in Calm Water

2020 ◽  
Author(s):  
Mikloš Lakatoš ◽  
Kristjan Tabri ◽  
Abbas Dashtimanesh ◽  
Henrik Andreasson
Keyword(s):  
Reaction Force ◽  
The Other ◽  
Numerical Comparison ◽  
Total Resistance ◽  
Stagnation Line ◽  
Planing Craft ◽  
Water Conditions ◽  
Calm Water ◽  
Wetted Surface Area ◽  
Novel Concept

V-shaped spray interceptors are a novel concept of spray deflection on planing craft. Conventional spray rails are positioned longitudinally on the bottom of the hull and detach the spray from hull deflecting it towards the sides or slightly down and aftward. The V-shaped spray interceptors, on the other hand, are located in the spray area forward of the stagnation line such that they would deflect the oncoming spray down and aftward, thereby producing a reaction force that reduces the total resistance. An experimental study reported that the V-shaped spray interceptors to reduce the total resistance at low planing speed by up to 4%. This paper features a numerical comparison of two planing craft, one equipped with a conventional setup of longitudinal spray rails and the other with a V-shaped spray interceptor. Both configurations were simulated in calm water conditions and were free to pitch and heave in a speed range of Fr∇ = 1.776 to 3.108. The numerical model was analyzed for grid sensitivity and numerical results were compared with experimental results. The two concepts were compared in terms of total resistance, lift, running position and wetted surface area. Conventional spray rails were shown to account for up to 5.6% of total lift and up to 6.5% of total resistance. The V-shaped spray interceptor was shown to reduce the total resistance by up to 8%. Since the V-shaped spray interceptor was located in the spray area forward of the stagnation line, it deflected the oncoming spray thereby producing a horizontal reaction force (-1.5% of RTM) in the direction of the craft’s motion. The rest of differences in the total resistance of the hulls equipped with the conventional spray rails and the V-shaped spray rails was due to absence of the resistance of the absent spray rails.

Resistance to Phytophthora medicaginis Hansen and Maxwell in wild Cicer species and its use in breeding root rot resistant chickpea (Cicer arietinum L.)

2008 ◽  
Vol 59 (4) ◽  
pp. 383 ◽  
Author(s):  
E. J. Knights ◽  
R. J. Southwell ◽  
M. W. Schwinghamer ◽  
S. Harden
Keyword(s):  
Field Experiment ◽  
Root Rot ◽  
Partial Resistance ◽  
The Other ◽  
Phytophthora Root Rot ◽  
Cicer Arietinum L ◽  
Cicer Species ◽  
Wild Cicer Species ◽  
Moderately Resistant ◽  
Chickpea Cultivars

Phytophthora root rot caused by Phytophthora medicaginis is a major disease of chickpea in Australia. Only partial resistance, derived from chickpea, is available in Australian cultivars. Five wild Cicer species were compared with chickpea cv. Jimbour (moderately resistant) in a field experiment. The proportions of accessions with significantly lower (P < 0.05) disease scores, where lower scores equate to higher resistance, were 9/9 for C. echinospermum, 9/21 for C. bijugum, 1/4 for C. judaicum, 1/29 for C. reticulatum, and 0/3 for C. pinnatifidum. The resistance of C. echinospermum (7/7 accessions) but not the other Cicer species was reproduced in a greenhouse test. Nine out of 30 chickpea × C. echinospermum-derived lines were as resistant as the C. echinospermum parents in a separate greenhouse experiment. C. echinospermum appears to be the best of the sources we examined for breeding chickpea cultivars resistant to P. medicaginis.

Effect of fasting on tubular phosphorus reabsorption

1979 ◽  
Vol 237 (3) ◽  
pp. F241-F246 ◽  
Author(s):  
N. Beck ◽  
S. K. Webster ◽  
H. J. Reineck
Keyword(s):  
Metabolic Acidosis ◽  
Cyclic Amp ◽  
Partial Resistance ◽  
Tubular Reabsorption ◽  
The Other ◽  
Partial Reduction ◽  
Phosphorus Excretion ◽  
Urinary Phosphorus Excretion

In the thyroparathyroidectomized (TPTX) rat, fasting increased urinary phosphorus excretion by decreasing the tubular reabsorption of P1 (TRP) and resulted in hypophosphatemia. The administration of either sucrose or NaHCO3 prevented the metabolic acidosis associated with fasting and decreased the phosphaturia, indicating that the phosphaturia in fasting is in part due to metabolic acidosis. In rats on partial reduction of P1 intake selectively, the phosphaturic response to parathyroid hormone (PTH) was completely suppressed. On the other hand, the fasting rat partially retained the phosphaturic response to PTH, although dietary P1 intake was totally absent. These findings suggest that the renal P1 wasting in fasting may take place by dual mechanisms: a) the PTH-independent decrease in TRP, and b) an inability to totally suppress the response to PTH. Cyclic AMP generation in response to PTH, determined both in vivo and in vitro, was not measurably altered in fasting. However, the phosphaturic response to cyclic AMP was decreased in fasting, suggesting that the mechanism of partial resistance to PTH is probably not at but after cyclic AMP generation.

Adulticide Resistance Status of Aedes albopictus (Diptera: Culicidae) in Sabah, Malaysia: A Statewide Assessment

2019 ◽  
Vol 56 (6) ◽  
pp. 1715-1725
Author(s):  
N M R Elia-Amira ◽  
C D Chen ◽  
V L Low ◽  
K W Lau ◽  
A Haziqah-Rashid ◽  
...  
Keyword(s):  
Mortality Rate ◽  
Correlation Analysis ◽  
Aedes Albopictus ◽  
Mortality Rates ◽  
The Other ◽  
Cross Resistance ◽  
Lambda Cyhalothrin ◽  
East Malaysia ◽  
Statewide Assessment ◽  
Susceptibility Status

Abstract Resistance status of Aedes albopictus (Diptera: Culicidae) collected from Sabah, East Malaysia, was evaluated against four major classes of adulticides, namely pyrethroid, carbamate, organochlorine, and organophosphate. Adult bioassays conforming to WHO standard protocols were conducted to assess knockdown and mortality rates of Ae. albopictus. Among tested pyrethroid adulticides, only cyfluthrin, lambda-cyaholthrin, and deltamethrin were able to inflict total knockdown. The other adulticide classes mostly failed to cause any knockdown; the highest knockdown rate was only 18.33% for propoxur. With regards to mortality rate, Ae. albopictus was unanimously susceptible toward all pyrethroids, dieldrin, and malathion, but exhibited resistance toward bendiocarb, propoxur, dichlorodiphenyltrichloroethane, and fenitrothion. Additionally, correlation analysis demonstrated cross-resistance between bendiocarb and propoxur, and malathion and propoxur. In conclusion, this study has disclosed that pyrethroids are still generally effective for Aedes control in Sabah, Malaysia. The susceptibility status of Ae. albopictus against pyrethroids in descending order was cyfluthrin > lambda-cyhalothrin > deltamethrin > etofenprox > permethrin.

Immunological variation between two strains of Eimeria acervulina

Parasitology ◽  
1969 ◽  
Vol 59 (3) ◽  
pp. 725-732 ◽  
Author(s):  
L. P. Joyner
Keyword(s):  
Experimental Data ◽  
Technical Assistance ◽  
Reproductive Potential ◽  
The Other ◽  
Eimeria Acervulina

Two strains of Eimeria acervulina were compared. The more recently isolated strain had a higher reproductive potential and produced slightly longer oocysts. Otherwise both strains conformed to the characteristics of the species.The two strains were not immunologically identical and birds which were solidly immune to one strain would support a degree of infection with the other.Acknowledgements are due to Mr C. C. Norton for technical assistance and to Dr Helen Hein who provided access to experimental data prior to publication and discussed some aspects of the results. The statistical calculations were carried out by Miss N. Hebert.

scholarly journals An Enhanced Supervisory Control Strategy for Periodicity Mutual Exclusions in Discrete Event Systems Based on Petri Nets

2017 ◽  
Vol 2017 ◽  
pp. 1-14 ◽  
Author(s):  
Zhongyuan Jiang ◽  
Huan Wang ◽  
Xiaoliang Chen ◽  
Mingwei Tang ◽  
Jianhong Ye
Keyword(s):  
Control Strategy ◽  
Supervisory Control ◽  
Discrete Event Systems ◽  
Discrete Event ◽  
Mutual Exclusion ◽  
The Other ◽  
Structural Conversion ◽  
Event Systems ◽  
Common Resource ◽  
The Common

Mutual exclusion problems widely exist in discrete event systems in which several processes will compete for the common resource for maintaining their normal running. This competition is mutually exclusive. However, a special behavior, that is, periodic mutual exclusion behavior, is important for many discrete event systems. Once a process obtains the common resource, it will consecutively obtain the common resource in the following several competitions. The other processes should wait for the release of the common resource. All processes will compete for the common resource again after the common resource is released. These competitions have obvious periodicity. In this paper, a methodology is proposed to design periodic mutual exclusion supervisors to control the periodic mutual exclusion behavior in discrete event systems. Moreover, two original structural conversion concepts, calledk-derivation andk-convergence processes, are proposed to construct the periodic mutual exclusion supervisors. The discussion results show that many undesirable execution sequences are forbidden since the periodic mutual exclusion behavior is controlled by the proposed periodic mutual exclusion supervisors. Finally, an example is used to illustrate the proposed methodology.

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