A VEGETATIVELY PROPAGATED STRAIN OF LARVAL ECHINOCOCCUS MULTILOCULARIS

1960 ◽  
Vol 38 (6) ◽  
pp. 1117-1125 ◽  
Author(s):  
G. Lubinsky
Keyword(s):  
Growth Rate ◽  
Echinococcus Multilocularis ◽  
Fast Growth ◽  
Total Weight ◽  
Cotton Rats

Quantitative observations on the growth rate of vegetatively propagated strains of larval Echinococcus multilocularis sibiricensis in cotton rats and white mice are reported, and some peculiarities of growth in these animals are discussed. It is shown that the weight of 70-day-old cysts of the seventh transfer in cotton rats was about 25% of the total weight of the host animals, and that the fast growth and the elimination of the hazardous work with definitive hosts make this strain suitable for chemotherapeutic studies.

Echinococcus multilocularis in the cotton rat. The effect of preexisting subcutaneous cysts on the development of a subsequent intraperitoneal inoculum of protoscolices

1973 ◽  
Vol 51 (1) ◽  
pp. 55-59 ◽  
Author(s):  
M. E. Rau ◽  
C. E. Tanner
Keyword(s):  
Echinococcus Multilocularis ◽  
Total Weight ◽  
Small Vesicle ◽  
Cotton Rat ◽  
Cotton Rats

Cotton rats were inoculated subcutaneousîy with small cysts of Echinococcus multilocularis and challenged intraperitoneally with 100 protoscolices 40 days later. Subcutaneous cysts which attained weights of more than about 5 g effectively suppressed the establishment, growth, and transperitoneal dissemination of the challenging infection. Normal cotton rats, inoculated intraperitoneally with 100 protoscolices, characteristically developed massive cysts which weighed, on the average, 31 g and consisted of about 31 cyst clusters. In contrast, animals which already harbored large, subcutaneous cysts developed only very mild infections following intraperitoneal reinoculation. Such hosts supported never more than two small, intraperitoneal cysts with a mean total weight of less than 1 g. The intensity of this suppression was underscored by the fact that even a single protoscolex or a small vesicle of E. multilocularis inoculated intraperitoneally into normal cotton rats could give rise to 11 g of cyst material distributed among as many as 87 cyst clusters.

scholarly journals Comparative genomics reveals the molecular determinants of rapid growth of the cyanobacteriumSynechococcus elongatusUTEX 2973

2018 ◽  
Vol 115 (50) ◽  
pp. E11761-E11770 ◽  
Author(s):  
Justin Ungerer ◽  
Kristen E. Wendt ◽  
John I. Hendry ◽  
Costas D. Maranas ◽  
Himadri B. Pakrasi
Keyword(s):  
Growth Rate ◽  
Photosynthetic Rate ◽  
Rapid Growth ◽  
Mutational Analysis ◽  
Specific Activity ◽  
Synechococcus Elongatus ◽  
Fast Growth ◽  
Close Relative ◽  
Genetic Changes ◽  
Photosynthetic Productivity

Cyanobacteria are emerging as attractive organisms for sustainable bioproduction. We previously describedSynechococcus elongatusUTEX 2973 as the fastest growing cyanobacterium known.Synechococcus2973 exhibits high light tolerance and an increased photosynthetic rate and produces biomass at three times the rate of its close relative, the model strainSynechococcus elongatus7942. The two strains differ at 55 genetic loci, andsome of these loci must contain the genetic determinants of rapid photoautotrophic growth and improved photosynthetic rate. Using CRISPR/Cpf1, we performed a comprehensive mutational analysis ofSynechococcus2973 and identified three specific genes,atpA,ppnK, andrpaA, with SNPs that confer rapid growth. The fast-growth–associated allele of each gene was then used to replace the wild-type alleles inSynechococcus7942. Upon incorporation, each allele successively increased the growth rate ofSynechococcus7942; remarkably, inclusion of all three alleles drastically reduced the doubling time from 6.8 to 2.3 hours. Further analysis revealed that our engineering effort doubled the photosynthetic productivity ofSynechococcus7942. We also determined that the fast-growth–associated allele ofatpAyielded an ATP synthase with higher specific activity, while that ofppnKencoded a NAD+kinase with significantly improved kinetics. TherpaASNPs cause broad changes in the transcriptional profile, as this gene is the master output regulator of the circadian clock. This pioneering study has revealed the molecular basis for rapid growth, demonstrating that limited genetic changes can dramatically improve the growth rate of a microbe by as much as threefold.

scholarly journals Effects of feed restriction on metabolic disorders in broiler chickens: A review

2014 ◽  
Vol 30 (1) ◽  
pp. 1-13 ◽  
Author(s):  
M. Sahraei
Keyword(s):  
Growth Rate ◽  
Broiler Chickens ◽  
Broiler Chicken ◽  
Metabolic Disorders ◽  
Production Efficiency ◽  
Early Growth ◽  
Fast Growth ◽  
Feed Consumption ◽  
Feed Restriction ◽  
Fast Growth Rate

Continuous genetic selection and improvement in nutrition have led to a very fast growth rate in modern strains of broiler chickens. Metabolic disorders such as ascits, sudden death syndrome and leg problems are related to a rapid early growth rate in poultry, especially in broilers, and their incidence can be decreased by slowing early growth. The use of management tools to reduce metabolic disorders that rely primarily on decreasing feed consumption, The feed restriction programs is on of the main techniques in growth curve manipulation for increasing production efficiency in broiler chicken in alleviate the incidence of some metabolic disorders and can be used to reduction the unfavorable effects of fast growth rate in broiler chicken production industry, and could be profitable in broiler chickens production efficiency. This article implicated on new findings in about different feed restriction programs effects on these problems in broiler chickens.

scholarly journals Adaptive laboratory evolution and reverse engineering of single-vitamin prototrophies in Saccharomyces cerevisiae

2020 ◽  
Author(s):  
Thomas Perli ◽  
Dewi P.I. Moonen ◽  
Marcel van den Broek ◽  
Jack T. Pronk ◽  
Jean-Marc Daran
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Growth Rate ◽  
Nicotinic Acid ◽  
Specific Growth ◽  
Pantothenic Acid ◽  
B Vitamins ◽  
Fast Growth ◽  
Adaptive Laboratory Evolution ◽  
Laboratory Evolution ◽  
B Vitamin

AbstractQuantitative physiological studies on Saccharomyces cerevisiae commonly use synthetic media (SM) that contain a set of water-soluble growth factors that, based on their roles in human nutrition, are referred to as B-vitamins. Previous work demonstrated that, in S. cerevisiae CEN.PK113-7D, requirements for biotin could be eliminated by laboratory evolution. In the present study, this laboratory strain was shown to exhibit suboptimal specific growth rates when either inositol, nicotinic acid, pyridoxine, pantothenic acid, para-aminobenzoic acid (pABA) or thiamine were omitted from SM. Subsequently, this strain was evolved in parallel serial-transfer experiments for fast aerobic growth on glucose in the absence of individual B-vitamins. In all evolution lines, specific growth rates reached at least 90 % of the growth rate observed in SM supplemented with a complete B-vitamin mixture. Fast growth was already observed after a few transfers on SM without myo-inositol, nicotinic acid or pABA. Reaching similar results in SM lacking thiamine, pyridoxine or pantothenate required over 300 generations of selective growth. The genomes of evolved single-colony isolates were re-sequenced and, for each B-vitamin, a subset of non-synonymous mutations associated with fast vitamin-independent growth were selected. These mutations were introduced in a non-evolved reference strain using CRISPR/Cas9-based genome editing. For each B-vitamin, introduction of a small number of mutations sufficed to achieve substantially a increased specific growth rate in non-supplemented SM that represented at least 87% of the specific growth rate observed in fully supplemented complete SM.ImportanceMany strains of Saccharomyces cerevisiae, a popular platform organism in industrial biotechnology, carry the genetic information required for synthesis of biotin, thiamine, pyridoxine, para-aminobenzoic acid, pantothenic acid, nicotinic acid and inositol. However, omission of these B-vitamins typically leads to suboptimal growth. This study demonstrates that, for each individual B-vitamin, it is possible to achieve fast vitamin-independent growth by adaptive laboratory evolution (ALE). Identification of mutations responsible for these fast-growing phenotype by whole-genome sequencing and reverse engineering showed that, for each compound, a small number of mutations sufficed to achieve fast growth in its absence. These results form an important first step towards development of S. cerevisiae strains that exhibit fast growth on cheap, fully mineral media that only require complementation with a carbon source, thereby reducing costs, complexity and contamination risks in industrial yeast fermentation processes.

scholarly journals Genome-Wide Detection of Selection Signatures in Duroc Revealed Candidate Genes Relating to Growth and Meat Quality

2020 ◽  
Vol 10 (10) ◽  
pp. 3765-3773
Author(s):  
Jian Yu ◽  
Pengju Zhao ◽  
Xianrui Zheng ◽  
Lei Zhou ◽  
Chuduan Wang ◽  
...  
Keyword(s):  
Growth Rate ◽  
Artificial Selection ◽  
Fast Growth ◽  
Phenotypic Traits ◽  
Sequencing Data ◽  
Selection Signatures ◽  
Protein Coding ◽  
Pig Genome ◽  
The Difference ◽  
Fast Growth Rate

With the development of high-throughput genotyping techniques, selection signatures in the genome of domestic pigs have been extensively interrogated in the last decade. The Duroc, a major commercial pig breed famous for its fast growth rate and high lean ratio, has not been extensively studied focusing on footprints of intensively artificial selection in their genomes by a lot of re-sequencing data. The goal of this study was to investigate genomic regions under artificial selection and their contribution to the unique phenotypic traits of the Duroc using whole-genome resequencing data from 97 pigs. Three complementary methods (di, CLR, and iHH12) were implemented for selection signature detection. In Total, 464 significant candidate regions were identified, which covered 46.4 Mb of the pig genome. Within the identified regions, 709 genes were annotated, including 600 candidate protein-coding genes (486 functionally annotated genes) and 109 lncRNA genes. Genes undergoing selective pressure were significantly enriched in the insulin resistance signaling pathway, which may partly explain the difference between the Duroc and other breeds in terms of growth rate. The selection signatures identified in the Duroc population demonstrated positive pressures on a set of important genes with potential functions that are involved in many biological processes. The results provide new insights into the genetic mechanisms of fast growth rate and high lean mass, and further facilitate follow-up studies on functional genes that contribute to the Duroc’s excellent phenotypic traits.

The Biology of Laminaria Hyperborea. VIII. Growth on Cleared Areas

1976 ◽  
Vol 56 (2) ◽  
pp. 267-290 ◽  
Author(s):  
Joanna M. Kain ◽  
N. S. Jones
Keyword(s):  
Growth Rate ◽  
Shallow Water ◽  
Personal Communication ◽  
Fast Growth ◽  
Depth Range ◽  
Laminaria Hyperborea ◽  
Isle Of Man ◽  
Rocky Subtidal ◽  
Small Depth

INTRODUCTIONStudies of established populations of Laminaria hyperborea (Gunn.) Fosl. have indicated that there is often less change of growth rate with depth than might be expected to result from the decrease in irradiance (Kain, 1967; Lüming, 1969; Jupp & Drew, 1974). This has been attributed to self-limitation by the canopy of Laminaria fronds (Lüning, 1969; Kain et al. 1976). The removal of this canopy can result in fast growth in shallow water (Kitching, 1941; Svendsen, 1972) and a marked differential in growth rate over a small depth range (Svendsen, personal communication). A series of rocky subtidal areas at two depths off the Isle of Man was cleared of vegetation at various times (Kain, 1975a). This provided an opportunity to make growth measurements on individuals of known age in the absence of a canopy formed by older plants.

scholarly journals Different Transcriptional Responses from Slow and Fast Growth Rate Strains of Listeria monocytogenes Adapted to Low Temperature

2016 ◽  
Vol 7 ◽  
Author(s):  
Ninoska Cordero ◽  
Felipe Maza ◽  
Helen Navea-Perez ◽  
Andrés Aravena ◽  
Bárbara Marquez-Fontt ◽  
...  
Keyword(s):  
Growth Rate ◽  
Listeria Monocytogenes ◽  
Low Temperature ◽  
Fast Growth ◽  
Transcriptional Responses ◽  
Fast Growth Rate

ℵ0-categorical structures with arbitrarily fast growth of algebraic closure

2002 ◽  
Vol 67 (3) ◽  
pp. 897-909
Author(s):  
David M. Evans ◽  
M. E. Pantano
Keyword(s):  
Growth Rate ◽  
Automorphism Group ◽  
Finite Subset ◽  
Growth Rates ◽  
Algebraic Closure ◽  
Fast Growth ◽  
Permutation Groups ◽  
Natural Numbers ◽  
Categorical Structure ◽  
Image Position

Various results have been proved about growth rates of certain sequences of integers associated with infinite permutation groups. Most of these concern the number of orbits of the automorphism group of an ℵ0-categorical structure on the set of unordered n-subsets or on the set of n-tuples of elements of . (Recall that by the Ryll-Nardzewski Theorem, if is countable and ℵ0-categorical, the number of the orbits of its automorphism group Aut() on the set of n-tuples from is finite and equals the number of complete n-types consistent with the theory of .) The book [Ca90] is a convenient reference for these results. One of the oldest (in the realms of ‘folklore’) is that for any sequence (Kn)n∈ℕ of natural numbers there is a countable ℵ0-categorical structure such that the number of orbits of Aut() on the set of n-tuples from is greater than kn for all n.These investigations suggested the study of the growth rate of another sequence. Let be an ℵ0-categorical structure and X be a finite subset of . Let acl(X) be the algebraic closure of X, that is, the union of the finite X-definable subsets of . Equivalently, this is the union of the finite orbits on of Aut()(X), the pointwise stabiliser of X in Aut(). Define

Oxidation of Strained Si-Ge Layers Grown by MBE

1987 ◽  
Vol 102 ◽  
Author(s):  
G.L. Patton ◽  
S.S. Iyer ◽  
S.L. Delage ◽  
E. Ganin ◽  
R.C. Mcintosh
Keyword(s):  
Growth Rate ◽  
Molecular Beam Epitaxy ◽  
Epitaxial Layer ◽  
Molecular Beam ◽  
Fast Growth ◽  
Strained Si ◽  
Substrate Interface ◽  
Growth Regime ◽  
Oxide Substrate ◽  
Strained Sige

ABSTRACTThe oxidation of strained SiGe alloy layers grown by Molecular Beam Epitaxy (MBE) was studied. An initial fast growth regime was identified for 800°C steam oxidations, where the growth rate is 2.5 times that of silicon. The oxides formed on SiGe were found to be essentially Ge-free: Ge present in the material is rejected by the oxide, resulting in the formation of a Ge-rich epitaxial layer at the oxide/substrate interface.

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