scholarly journals Emergent evolutionary forces in spatial models of luminal growth in the human gut microbiota

2021 ◽  
Author(s):  
Olivia M Ghosh ◽  
Benjamin H Good
Keyword(s):  
Growth Rate ◽  
Fluid Flow ◽  
Gut Microbiota ◽  
Intestinal Lumen ◽  
Mathematical Framework ◽  
Average Growth ◽  
Evolutionary Forces ◽  
Generation Times ◽  
Starting Point ◽  
Effective Generation

The genetic composition of the gut microbiota is constantly reshaped by ecological and evolutionary forces. These strain-level dynamics can be challenging to understand because they emerge from complex spatial growth processes that take place within a host. Here we introduce a mathematical framework to predict how stochastic evolutionary forces emerge from simple models of microbial growth in the intestinal lumen. Our framework shows how fluid flow and longitudinal variation in growth rate combine to shape the frequencies of genetic variants in sequenced fecal samples, yielding analytical expressions for the effective generation times, selection coefficients, and rates of genetic drift. We find that the emergent evolutionary dynamics can often be captured by well-mixed models that lack explicit spatial structure, even when there is substantial spatial variation in species-level composition. By applying these results to the human colon, we find that continuous fluid flow is unlikely to create sufficient bottlenecks to allow large fluctuations in mutant frequencies within a host, while the effective generation times may be significantly shorter than expected from traditional average growth rate estimates. Our results provide a starting point for quantifying genetic turnover in the gut microbiota, and may be relevant for other microbial ecosystems where unidirectional fluid flow plays an important role.

Competitiveness in the Serbian growth strategy

2021 ◽  
Vol 71 (2) ◽  
pp. 309-326
Author(s):  
Enes Ćorović ◽  
Živorad Gligorijević
Keyword(s):  
Growth Rate ◽  
International Trade ◽  
Growth Model ◽  
Manufacturing Industry ◽  
Growth Strategy ◽  
Average Growth Rate ◽  
Average Growth ◽  
Investment Volume ◽  
Starting Point ◽  
Analytical Tools

AbstractThe paper focuses on the effects of the reformed growth strategy on the competitiveness of the Serbian manufacturing industry during the period of 2007–2016. The paper applies the analytical tools devised by the International Trade Centre, as well as Balassa's RCA Index and some other methodologies. All indicators point to similar conclusion: the reformed growth model would significantly contribute to the improvement of Serbian competitiveness. The starting point of Serbia is also clear: small gross investment volume and a low average growth rate.

scholarly journals The Two Growth Rates of the Economy

2020 ◽  
Author(s):  
Alexander Adamou ◽  
Yonatan Berman ◽  
Ole Peters
Keyword(s):  
Growth Rate ◽  
Growth Rates ◽  
The United States ◽  
Ensemble Average ◽  
Gdp Per Capita ◽  
Average Growth Rate ◽  
Average Growth ◽  
Starting Point ◽  
Time Average ◽  
Per Capita

Economic growth is measured as the rate of relative change in gross domestic product (GDP) per capita. Yet, when incomes follow random multiplicative growth, the ensemble-average (GDP per capita) growth rate is higher than the time-average growth rate achieved by each individual in the long run. This mathematical fact is the starting point of ergodicity economics. Using the atypically high ensemble-average growth rate as the principal growth measure creates an incomplete picture. Policymaking would be better informed by reporting both ensemble-average and time-average growth rates. We analyse rigorously these growth rates and describe their evolution in the United States and France over the last fifty years. The difference between the two growth rates gives rise to a natural measure of income inequality, equal to the mean logarithmic deviation. Despite being estimated as the average of individual income growth rates, the time-average growth rate is independent of income mobility. (Stone Center on Socio-Economic Inequality Working Paper)

SUBSTITUSI FERMENTASI BUNGKIL KELAPA SAWIT DALAM PAKAN BUATAN TERHADAP PERTUMBUHAN DAN KELANGSUNGAN HIDUP BENIH IKAN GURAMI (OSPHRONEMUS GOURAMY)

2016 ◽  
Vol 4 (1) ◽  
Author(s):  
Farida . ◽  
Eka Indah Raharjo ◽  
Arnis Maylinda Sari
Keyword(s):  
Growth Rate ◽  
Palm Oil ◽  
Palm Kernel ◽  
Specific Weight ◽  
Feed Conversion ◽  
Daily Growth Rate ◽  
Daily Growth ◽  
Average Growth ◽  
Fermentation Residue ◽  
Average Average

ABSTRAKPenelitian bertujuan untuk mengetahui penggunaan fermentasi bungkil kelapa sawit dalam pakan buatan.Penelitian menggunakan Rancangan Acak Lengkap (RAL) yang terdiri dari 4 perlakuan 3 ulangan.Susunan perlakuan adalah Perlakuan A : bungkil kelapa sawit 12%, Perlakuan B : fermentasi bungkil kelapa sawit 15%, Perlakuan C : fermentasi bungkil kelapa sawit 18%, Perlakuan D : fermentasi bungkil kelapa sawit 21%. Penelitian ini dilakukan selama 60 hari untuk mengetahui laju pertumbuhan spesifikberat, laju pertumbuhan harianpanjang, konversi pakan, kelangsungan hidup dan kualitas air sebagai penunjang.Hasil penelitian menunjukkan pemberian pakan buatan dengan fermentasi bungkil kelapa sawit menghasilkan respon yang baik terhadap pertumbuhan ikan gurami. Pemberian pakan buatan dengan fermentasi bungkil kelapa sawit 18% (perlakuan C), memberikan hasil terbaik dengan laju pertumbuhan dengan rata – rata laju pertumbuhan spesifik berat 1.502%, laju pertumbuhan harian panjang 4.06%, nilai konversi pakan rata – rata 3.48 dan kelangsungan hidup rata – rata 90%.Kata Kunci : Fermentasi Bungkil Kelapa Sawit, Ikan Gurami, Laju PertumbuhanThe study aims to determine the use of fermentation residue oil palm in artificial feed .Research using a completely randomized design ( CRD ), which consists of 4 treatment three replications.The composition of the treatment is the treatment  A : 12 % of palm oil cake , Treatment B : fermented palm oil cake 15 % , Treatment C : fermented palm oil cake 18 % , Treatment D : fermentation residue palm oil 21 %.This research was conducted for 60 days to determine the specific growth rate of heavy , long daily growth rate , feed conversion , survival and quality of water as a supporter.The results showed the artificial feeding with fermented palm cake to produce a good response to the growth of carp.Feeding artificially by fermentation cake palm oil 18 % ( treatment C ) , gives the best results with a growth rate with the average - average growth rate of the specific weight of 1.502 % daily growth rate long- 4:06 % , the value of feed conversion average - average 3:48 and median survival - average of 90 % .Keywords : Fermentation Palm Kernel Oil, Fish carp, Growth Rate

The United States as the Trade Partner of Poland in te Context of the Transatlantic Trade and Investment Partnership (TTIP)

2014 ◽  
Vol 9 (3) ◽  
pp. 201-213
Author(s):  
Renata Marks-Bielska ◽  
Wiesława Lizińska ◽  
Izabela Serocka
Keyword(s):  
Growth Rate ◽  
Foreign Trade ◽  
The United States ◽  
Average Growth ◽  
Transatlantic Trade ◽  
Central Statistical ◽  
The Usa ◽  
Central Statistical Office ◽  
Trade Partner ◽  
Structure Of Trade

Evaluation of the importance of the USA as the trade partner of Poland is the main objective of the paper, based on the changes in the value of trade during the years 2000-2012 and changes in the structure of trade during the years 2008-2012. The data from the Statistical Yearbooks of Foreign Trade published by the Central Statistical Office was used. The potential for foreign trade growth was illustrated using the simplified analysis based on the gravity model of foreign trade concept. Gradually increasing value of Polish trade with the USA (the average growth rate 9.8%, EU-15 countries 13.1%). Polish exports are characterised by a higher than imports growth rate (USA - exports growth by 12.5%, imports 9.2%, EU-15 - exports 15.1%, imports 11.6%). Trade is strongly dominated by position of one group of products (over 30% share in both exports and imports). The potential of trade is poorly exploited currently. Trade was focused mainly on the countries situated in the close neighbourhood (mainly the EU countries with the domination of Germany).

scholarly journals Oral Iron Supplementation—Gastrointestinal Side Effects and the Impact on the Gut Microbiota

2021 ◽  
Vol 12 (2) ◽  
pp. 491-502
Author(s):  
Sarah R. Bloor ◽  
Rudolph Schutte ◽  
Anthony R. Hobson
Keyword(s):  
Side Effects ◽  
Gut Microbiota ◽  
Iron Supplementation ◽  
Methanogenic Archaea ◽  
Intravenous Iron ◽  
Oral Iron ◽  
Intestinal Lumen ◽  
Gastrointestinal Side Effects ◽  
Potential Link ◽  
The Impact

Iron deficiency anaemia (IDA) is a worldwide healthcare problem affecting approximately 25% of the global population. The most common IDA treatment is oral iron supplementation, which has been associated with gastrointestinal (GI) side effects such as constipation and bloating. These can result in treatment non-adherence and the persistence of IDA. Intravenous iron does not cause GI side effects, which may be due to the lack of exposure to the intestinal lumen. Luminal iron can cause changes to the gut microbiota, aiding the promotion of pathogenic species and decreasing beneficial protective species. Iron is vital for methanogenic archaea, which rely on iron for growth and metabolism. Increased intestinal methane has been associated with slowing of intestinal transit, constipation, and bloating. Here we explore the literature to understand a potential link between iron and methanogenesis as a novel way to understand the mechanism of oral iron supplementation induced GI side effects.

Crystal-growth kinetics of protein single crystals along capillary tubes in the gel-acupuncture technique

1999 ◽  
Vol 55 (2) ◽  
pp. 577-580 ◽  
Author(s):  
Abel Moreno ◽  
Manuel Soriano-García
Keyword(s):  
Growth Rate ◽  
Crystal Growth ◽  
Capillary Tube ◽  
Crystal Growth Rate ◽  
Equilibrium Studies ◽  
Acta Cryst ◽  
Average Growth ◽  
X Ray Crystallography ◽  
Growing Cell ◽  
Kinetics Of

In attempts to obtain protein crystals of a sufficient size for structural studies, lack of knowledge of the physicochemical properties of protein solutions and of their crystal-growth behaviour lead to a bottleneck for drug design as well as for X-ray crystallography. Most formal investigations on crystal-growth phenomena have been focused on equilibrium studies, where the protein is soluble, and on the kinetics of crystal growth, which is related to both nucleation and crystal-growth phenomena. The aim of this work is to measure the crystal-growth rate along a capillary tube used as a growing cell. These experiments were carried out using the gel-acupuncture technique [García-Ruiz et al. (1993). Mater. Res. Bull. 28, 541–546; García-Ruiz & Moreno (1994). Acta Cryst. D50, 484–490; García-Ruiz & Moreno (1997). J. Cryst. Growth, 178, 393–401]. Crystal-growth investigations took place using lysozyme and thaumatin I as standard proteins. The maximum average growth rate obtained in the lower part of the capillary tube was about 35 Å s−1 and the minimum average growing rate in the upper part of the capillary tube was about 8 Å s−1. The crystal-growth rate as a function of the supersaturation was experimentally estimated at a constant height along the capillary tube.

scholarly journals Differences in the gut microbiomes of distinct ethnicities within the same geographic area are linked to host metabolic health

2021 ◽  
Author(s):  
Qi Yan Ang ◽  
Diana L. Alba ◽  
Vaibhav Upadhyay ◽  
Jordan E. Bisanz ◽  
Jingwei Cai ◽  
...  
Keyword(s):  
Community Structure ◽  
Gut Microbiota ◽  
Dietary Intake ◽  
Ethnic Groups ◽  
San Francisco ◽  
East Asian ◽  
Geographical Location ◽  
Rrna Gene ◽  
Bacterial Phyla ◽  
Starting Point

Abstract Background: The human gut microbiota exhibits marked variation around the world, which has been attributed to dietary intake and other environmental factors. However, the degree to which ethnicity-associated differences in gut microbial community structure and function are maintained following immigration or in the context of metabolic disease is poorly understood.Results: We conducted a multi-omic study of 46 lean and obese East Asian and White participants living in the San Francisco Bay Area. 16S rRNA gene sequencing revealed significant differences between ethnic groups in bacterial richness and community structure. White individuals were enriched for the mucin-degrading Akkermansia muciniphila. East Asian participants had increased levels of multiple bacterial phyla, fermentative pathways detected by metagenomics, and the short-chain fatty acid end products acetate, propionate, and isobutyrate. Differences in the gut microbiota between the East Asian and White groups could not be explained by reported dietary intake, were more pronounced in lean individuals, and were associated with current geographical location. Microbiome transplantations into germ-free mice confirmed that the differences in the gut microbiota of the East Asian and White individuals we analyzed are independent of diet and that they differentially impact host body weight and adiposity in genetically identical mouse recipients.Conclusions: The reported findings emphasize the utility of studying diverse ethnic groups within a defined geographical location and provide a starting point for dissecting the mechanisms contributing to the complex interactions between the gut microbiome and ethnicity-associated lifestyle, demographic, metabolic, and genetic factors.

scholarly journals Growth rate of african catfish (Clarias gariepinus) and plankton diversity in ponds under organic and inorganic fertilization

2021 ◽  
Vol 21 (02) ◽  
pp. 17545-17559
Author(s):  
PA Otieno ◽  
◽  
DO Owiti ◽  
PO Onyango ◽  
◽  
...  
Keyword(s):  
Growth Rate ◽  
Clarias Gariepinus ◽  
Chicken Manure ◽  
Average Weight ◽  
African Catfish ◽  
Phytoplankton Species ◽  
Inorganic Fertilizers ◽  
Average Growth ◽  
Plankton Diversity ◽  
And Control

Aquaculture offers the opportunity for safeguarding local and global food security in the face of declining capture fisheries. However, the form of aquaculture that is commonly practiced in Kenya is characterized by the use of agrochemicals such as fertilizers that negatively impact biodiversity especially when effluents from fish ponds drain into water bodies. This study aimed to determine differences in the growth rate of Clarias gariepinus, an important aquaculture fish in Kenya, to assess plankton diversity, and to identify phytoplankton species associated with pollution under organic and inorganic fertilization regimens using chicken manure, Diammonium phosphate, and urea, respectively. Average growth rate calculated per day was higher in the organically-fertilized ponds at 0.06 cm/day, followed by inorganically-fertilized ponds at 0.05cm/day and then, the control at 0.04 cm/day. Average weight gain was higher in organically-fertilized ponds at 0.08 g/day followed by ponds fertilized with inorganic fertilizer at 0.07 g/day and the control, at 0.06g/day. There were significant differences in growth rate across fertilization regimens (length: F2, 264= 24.06, p = 0.0399; weight: F2, 264 = 20.89, p = 0. 0457). Specifically, although differences in growth rate of fish in organically and inorganically fertilized ponds were not significant, fish in fertilized ponds were on average, longer and weighed more than those in the control pond. Jaccard’s similarity index for phytoplankton was highest (0.38) between organically-fertilized ponds and control but lowest (0.25) between inorganically-fertilized ponds and control. Use of chicken manure produced the highest diversity of zooplankton (Shannon-Weiner’s H in organically-fertilized pond = 1.886; inorganic = 1.044, and control = 0.935). The use of DAP and urea produced the highest proportion of phytoplankton species associated with pollution. These results do not support the commonly reported notion that ponds fertilized using inorganic fertilizers are more productive. Findings suggest that the use of inorganic fertilizers may threaten biodiversity in aquatic ecosystems through the production of toxic algae.

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