ASSESSING THE RELATIVE IMPORTANCE OF DIFFERENT SOURCES OF MORTALITY FROM RECOVERIES OF MARKED ANIMALS

A study of the horizontal and vertical distribution of herbage in grass-dominant swards was made to assess the relative importance of different sources of wastage during grazing. A sward grazed by cattle under two contrasting managements was divided, for the purpose of herbage sampling, into two categories: ‘grazed’ herbage, on ground with no obvious dung contamination, and ‘dung patches’, which were of ungrazed or lightly grazed herbage resulting from the effects of faeces dropped at previous grazings. In each category, samples were cut at two successive heights to provide an estimate of the quantity of herbage in the upper region of the sward (over 2½ in. from ground level) and in the lower region (½-2½ in. from ground level).After grazing, some 35% of the original crop remained in ‘grazed’ areas, and some 20% in ‘dung patches’. In terms of vertical distribution, most of the residue (40% of the original crop) was in the lower region, from ½ to 2½ in. above ground level.Total production as live-weight gain was not significantly different, but the yield of conserved herbage was greater in treatment R (five rotations) than in treatment RR (nineteen rotations). Frequent grazing reduced herbage production, and this effect was not offset by any less intense defoliation of the frequently grazed sward. The average quantity of herbage residue was no higher in treatment RR than in treatment R, although the time of occupation per plot by the cattle in RR was only a quarter of that of the cattle in treatment R.

Download Full-text

Evolutionary relationships among bifidobacteria and their hosts and environments

10.21203/rs.2.16551/v2 ◽

2019 ◽

Author(s):

Cynthia Itzel Rodriguez ◽

Jennifer B.H. Martiny

Keyword(s):

Amino Acid ◽

Genetic Relatedness ◽

Phylogenetic Signal ◽

Amino Acid Biosynthesis ◽

Relative Importance ◽

Accessory Gene ◽

Acid Biosynthesis ◽

Genomic Signatures ◽

Health Promoting ◽

Different Sources

Abstract Background The assembly of animal microbiomes is influenced by multiple environmental factors and host genetics, although the relative importance of these factors remains unclear. Bifidobacteria (genus Bifidobacterium , phylum Actinobacteria) are common first colonizers of gut microbiomes in humans and inhabit other mammals, social insects, food, and sewages. In humans, the presence of bifidobacteria in the gut has been correlated with health-promoting benefits. Here, we compared the genome sequences of a subset of the over 400 Bifidobacterium strains publicly available to investigate the adaptation of bifidobacteria diversity. We tested 1) whether bifidobacteria show a phylogenetic signal with their isolation sources (hosts and environments) and 2) whether key traits encoded by the bifidobacteria genomes depend on the host or environment from which they were isolated. We analyzed Bifidobacterium genomes available in the PATRIC and NCBI repositories and identified the hosts and/or environment from which they were isolated. A multilocus phylogenetic analysis was conducted to compare the genetic relatedness the strains harbored by different hosts and environments. Furthermore, we examined differences in genomic traits and genes related to amino acid biosynthesis and degradation of carbohydrates. Results We found that bifidobacteria diversity appears to have evolved with their hosts as strains isolated from the same host were non-randomly associated with their phylogenetic relatedness. Moreover, bifidobacteria isolated from different sources displayed differences in genomic traits such as genome size and accessory gene composition and on particular traits related to amino acid production and degradation of carbohydrates. In contrast, when analyzing diversity within human-derived bifidobacteria, we observed no phylogenetic signal or differences on specific traits (amino acid biosynthesis genes and CAZymes). Conclusions Overall, our study shows that bifidobacteria diversity is strongly adapted to specific hosts and environments and that several genomic traits were associated with their isolation sources. However, this signal is not observed in human strains alone. Looking into the genomic signatures of bifidobacteria strains in different environments can give insights into how this bacterial group adapts to their environment and what types of traits are important for these adaptations.

Download Full-text

Large herbivorous wildlife and livestock differentially influence the relative importance of different sources of carbon for riverine food webs

10.1101/2021.07.29.454315 ◽

2021 ◽

Author(s):

Frank O. Masese ◽

Thomas Fuss ◽

Lukas Bistarelli ◽

Caroline Buchen-Tschiskale ◽

Gabriel Singer

Keyword(s):

Organic Matter ◽

Food Webs ◽

Aquatic Ecosystems ◽

Carbon Sources ◽

Large River ◽

Livestock Grazing ◽

Relative Importance ◽

River Continuum ◽

Aquatic Food ◽

Different Sources

In many regions around the world, large populations of native wildlife have declined or been replaced by livestock grazing areas and farmlands, with consequences on terrestrial-aquatic ecosystems connectivity and trophic resources supporting food webs in aquatic ecosystems. The river continuum concept (RCC) and the riverine productivity model (RPM) predict a shift of carbon supplying aquatic food webs along the river: from terrestrial inputs in low-order streams to autochthonous production in mid-sized rivers. Here, we studied the influence of replacing large wildlife (mainly hippos) with livestock on the relative importance of C3 vegetation, C4 grasses and periphyton on macroinvertebrates in the Mara River, which is an African montane-savanna river known to receive large subsidy fluxes of terrestrial carbon and nutrients mediated by LMH, both wildlife and livestock. Using stable carbon (δ13C) and nitrogen (δ15N) isotopes, we identified spatial patterns of the relative importance of allochthonous carbon from C3 and C4 plants (woody vegetation and grasses, respectively) and autochthonous carbon from periphyton for macroinvertebrates at various sites of the Mara River and its tributaries. Potential organic carbon sources and invertebrates were sampled at 80 sites spanning stream orders 1 to 7, various catchment land uses (forest, agriculture and grasslands) and different loading rates of organic matter and nutrients by LMH (livestock and wildlife, i.e., hippopotamus). The importance of different sources of carbon along the river did not follow predictions of RCC and RPM. First, the importance of C3 and C4 carbon was not related to river order or location along the fluvial continuum but to the loading of organic matter (dung) by both wildlife and livestock. Notably, C4 carbon was important for macroinvertebrates even in large river sections inhabited by hippos. Second, even in small 1st -3rd order forested streams, autochthonous carbon was a major source of energy for macroinvertebrates, and this was fostered by livestock inputs fuelling aquatic primary production throughout the river network. Importantly, our results show that replacing wildlife (hippos) with livestock shifts river systems towards greater reliance on autochthonous carbon through an algae-grazer pathway as opposed to reliance on allochthonous inputs of C4 carbon through a detrital pathway.

Download Full-text

Quantifying the Sources of Slaves in the Early Roman Empire

The Journal of Roman Studies ◽

10.2307/301373 ◽

1997 ◽

Vol 87 ◽

pp. 156-169 ◽

Cited By ~ 16

Author(s):

Walter Scheidel

Keyword(s):

Roman Empire ◽

Sexual Reproduction ◽

Slave Trade ◽

Relative Importance ◽

Single Source ◽

Child Exposure ◽

Demographic Models ◽

Natural Reproduction ◽

Different Sources ◽

Ancient Texts

The relative importance of different sources of slaves in the Roman Empire during the Principate cannot be gauged from ancient texts. However, simple demographic models show that, for purely statistical reasons, natural reproduction made a greater contribution to the Roman slave supply than child exposure, warfare, and the slave trade taken together and was in all probability several times as important as any other single source. The most plausible projections also suggest that on average the incidence of manumission was rather low. By implication, overall fertility of ex-slaves in general and of freedwomen in particular would be low as well, which must have reduced their chances of acquiring legal privileges that accrued from sexual reproduction.

Download Full-text

Evolutionary relationships among bifidobacteria and their hosts and environments

10.21203/rs.2.16551/v1 ◽

2019 ◽

Author(s):

Cynthia Itzel Rodriguez ◽

Jennifer B.H. Martiny

Keyword(s):

Amino Acid ◽

Genetic Relatedness ◽

Phylogenetic Signal ◽

Amino Acid Biosynthesis ◽

Relative Importance ◽

Accessory Gene ◽

Acid Biosynthesis ◽

Genomic Signatures ◽

Health Promoting ◽

Different Sources

Abstract Background The assembly of animal microbiomes is influenced by multiple environmental factors and host genetics, although the relative importance of these factors remains unclear. Bifidobacteria (genus Bifidobacterium , phylum Actinobacteria) are common first colonizers of gut microbiomes in humans and inhabit other mammals, social insects, food, and sewages. In humans, the presence of bifidobacteria in the gut has been correlated with health-promoting benefits. Here, we compared the genome sequences of a subset of the over 400 Bifidobacterium strains publicly available to investigate the adaptation of bifidobacteria diversity. We tested 1) whether bifidobacteria show a phylogenetic signal with their isolation sources (hosts and environments) and 2) whether key traits encoded by the bifidobacteria genomes depend on the host or environment from which they were isolated. We analyzed Bifidobacterium genomes available in the PATRIC and NCBI repositories and identified the hosts and/or environment from which they were isolated. A multilocus phylogenetic analysis was conducted to compare the genetic relatedness the strains harbored by different hosts and environments. Furthermore, we examined differences in genomic traits and genes related to amino acid biosynthesis and degradation of carbohydrates. Results We found that bifidobacteria diversity appears to have evolved with their hosts as strains isolated from the same host were non-randomly associated with their phylogenetic relatedness. Moreover, bifidobacteria isolated from different sources displayed differences in genomic traits such as genome size and accessory gene composition and on particular traits related to amino acid production and degradation of carbohydrates. In contrast, when analyzing diversity within human-derived bifidobacteria, we observed no phylogenetic signal or differences on specific traits (amino acid biosynthesis genes and CAZymes). Conclusions Overall, our study shows that bifidobacteria diversity is strongly adapted to specific hosts and environments and that several genomic traits were associated with their isolation sources. However, this signal is not observed in human strains alone. Looking into the genomic signatures of bifidobacteria strains in different environments can give insights into how this bacterial group adapts to their environment and what types of traits are important for these adaptations.

Download Full-text

Expenditure-Growth Nexus:Does the Source of Finance Matter? Empirical Evidence from Selected South Asian Countries

The Pakistan Development Review ◽

10.30541/v49i4iipp.631-640 ◽

2010 ◽

Vol 49 (4II) ◽

pp. 631-640 ◽

Cited By ~ 1

Author(s):

Muhammad Iftikhar Ul Husnain

Keyword(s):

Economic Growth ◽

South Asian ◽

Public Expenditure ◽

Government Expenditure ◽

Relative Importance ◽

Consumption Expenditure ◽

Asian Countries ◽

Government Consumption ◽

Endogenous Growth Model ◽

Different Sources

Government can generate revenues to finance its expenditure in three major ways i.e., taxes, bonds and seigniorage.1 Interestingly, public expenditure financed through different sources affect growth differently. Which source of finance is less distortionary? is a question that has attracted great attention over the years. However, no consensus is available on the relative importance of the financing source. The prominent work on this issue relates to Miller and Russek (1997) who provide a detailed discussion over the relative importance of tax financed and debt financed increases in government expenditure in terms of economic growth and report that the results vary considerably as the source of finance differs.2 Similarly, Bose, Holman and Neanidis (2005) compare the effect of tax financed and seigniorage financed increases in public expenditure on economic growth.3 Likewise, Palivos and Yip (1995) analyse the effects of tax financed and money financed government consumption expenditure on economic growth and social welfare within a framework of endogenous growth model. Latter, in another study Espinosa-Vega and Yip (1999) study the effects of money financed and tax financed increases in government consumption expenditure on inflation and economic growth.

Download Full-text

Uncertainty quantification and attribution in flood risk assessment using Global Flood Models: an application to the river Rhine basin

10.5194/egusphere-egu21-3488 ◽

2021 ◽

Author(s):

Georgios Sarailidis ◽

Francesca Pianosi ◽

Thorsten Wagener ◽

Kirsty Styles ◽

Stephen Hutchings ◽

...

Keyword(s):

Flood Risk ◽

Methodological Approach ◽

Model Parameters ◽

River Rhine ◽

Relative Importance ◽

Risk Models ◽

Sources Of Uncertainty ◽

Daunting Task ◽

Flood Losses ◽

Different Sources

<p>Floods are extreme hydro-meteorological hazards that pose significant risks to the economy and society. Reducing the risk associated with floods and better adapting to them is a daunting task because flood risk dynamics are influenced by different factors. Flood risk is usually defined as the product of three components: hazard, exposure and vulnerability. Global Flood Risk Models (GFRM) represent the underlying physical hazard, the exposure of people, properties or other assets to the hazard, and the losses that may occur following a flood event. &#160;Consequently, they are used by governmental agencies, risk reduction organisations, global investors and the (re)insurance industry to help manage the societal and financial risks associated with floods. GFRMs are subject to many sources of uncertainty, including uncertainty in processes representation, model parameters and input data; however, the relative importance of these different sources is poorly understood. Currently, no evidence exists on which uncertain input factor mostly control the final uncertainty in predicted losses in different places and circumstances. In this project, we use JBA&#8217;s (a leading flood risk modelling company) Global Flood Model and Open Exposure Data (OED) to develop an appropriate methodological approach to analyse the sensitivity of loss predictions in a structured way. This is particularly challenging as input uncertainties exhibit complex spatially distributed and spatially-structured (correlated) patterns. We apply the methodology to the Rhine river basin, covering regions with different physical and socio-economic characteristics. We pursue the following objectives; (1) Identify and quantify the various sources of uncertainty e.g. associated to rainfall data, extraction of flood events sets, defence database, vulnerability curves, exposure portfolios (2) Analyse their relative importance on flood losses predictions across places along the river (3) Understand which of them are most important at each place. We aim to produce scientifically robust evidence about the importance of different sources of uncertainty across places with different climate, hydrology and socio-economic characteristics and try to address questions related to exposure and vulnerability dynamics, flood losses modelling and adaptation strategies. Such evidence base will help prioritise efforts for uncertainty reduction of the case study model, as well as other flood risk models used by (re)insurers and government agencies, ultimately contributing to more informed decisions for flood risk mitigation.</p>

Download Full-text

Obsidian as an indicator of inter-regional contacts and exchange: three case-studies from the Halaf period

Anatolian Studies ◽

10.1017/s0066154600008590 ◽

2007 ◽

Vol 57 ◽

pp. 171-189 ◽

Cited By ~ 5

Author(s):

Elizabeth Healey

Keyword(s):

Case Studies ◽

Near East ◽

Physical Characteristics ◽

Geochemical Analysis ◽

Relative Importance ◽

Provenance Analysis ◽

Spatial Studies ◽

Specific Detail ◽

Halaf Period ◽

Different Sources

AbstractObsidian was used to make tools and luxury items which were widely distributed in the ancient Near East. At most sites it is an imported material and, as such, has been used as an indicator of exchange, although little specific detail of the nature of that exchange is available. Even though methods of provenance analysis for obsidian are well established, often only a few samples per site have been analysed. This means there is not enough information to indicate the relative importance of the obsidian from each source, or to establish whether source preference changed through time or whether obsidians from different sources were treated differently. The restriction in numbers analysed is, at least in part, due to the expense and the destructive nature of provenance analysis and problems associated with obtaining sufficient samples. In an attempt to address these problems case-studies examining the obsidian assemblages from three sites of Halaf date will be used to demonstrate the potential of a method of grouping obsidians based on their physical characteristics, including colour; these groupings are confirmed by geochemical analysis. This allows the entire assemblage to be grouped quickly and cost effectively and, if used alongside techno-typological and spatial studies, enables us to begin to confront some of the issues outlined above.

Download Full-text

The relative importance of some different sources of plant-weight variation in drilled and transplanted leeks

The Journal of Agricultural Science ◽

10.1017/s002185960004363x ◽

1984 ◽

Vol 103 (3) ◽

pp. 527-537 ◽

Cited By ~ 11

Author(s):

L. R. Benjamin

Keyword(s):

Seedling Emergence ◽

Plant Size ◽

Row Spacing ◽

Relative Importance ◽

Plant Weight ◽

Sowing Depth ◽

Weight Variation ◽

The Mean ◽

Shoot Weight ◽

Different Sources

SummaryIn six experiments the effects of various factors on plant-weight variation (sum of squares of deviation from the mean shoot weight) at harvest were examined. These factors were seed size, sowing depth, time of seedling emergence, size at different stages of development, within-row spacing, density and row position within a bed.In a drilled experiment, up to 25% of the variation in mature leek size could be attributed to variation in time of seedling emergence. Similarly, in the experiments which used transplants, 15% of the variation in the mature crop could be associated with variation in size shortly after seedling emergence from peat blocks.Variation in row position within a 4-row bed never accounted for more than 11% of the weight variation at harvest, and variation in within-row spacing never accounted for more than 4% of weight variation. However, the coefficient of variation (c.v.) of leeks growing at 22 plants/m2 was 44% whereas the c.v. of those growing at 50 plants/m2 was 61%.Using large seeds or sowing deeply gave a quicker emergence and a higher percentage emergence than using small seeds or sowing shallowly. However, these factors each never accounted for more than 7% of the weight variation in mature leeks.Most of the plant-weight variation could not be attributed to any of the measured factors in any of the experiments. The c.v. of leeks which had emerged on a specific day and had been grown in a uniform environment, was between 50 and 66%, which was similar to the c.v.s observed in the transplant and drilled experiments. However, selecting for large transplants reduced the c.v. to 28% in one experiment; this effect was only partly attributable to the greater mean plant size resulting from this treatment.

Download Full-text

The relative importance of cluster size, sowing depth, time of seedling emergence and between-plant spacing on variation in plant size in red beet (Beta vulgaris L.) crops

The Journal of Agricultural Science ◽

10.1017/s0021859600064297 ◽

1987 ◽

Vol 108 (1) ◽

pp. 221-230 ◽

Cited By ~ 5

Author(s):

L. R. Benjamin

Keyword(s):

Cluster Size ◽

Seedling Emergence ◽

Plant Size ◽

Root Weight ◽

Relative Importance ◽

Plant Spacing ◽

Sowing Depth ◽

A Value ◽

Sources Of Variation ◽

Different Sources

SummaryBeets with a coefficient of variation (c.v.) of weight of only 36–46% were produced by reducing the variation in cluster size, sowing depth, time of seedling emergence, proximity and size of neighbours to as low a value as practicable. The relative importance of these different sources of variation in plant size was examined in two experiments sown in contrasting conditions.Variation in time of seedling emergence was a major source of variation in plant size and was partially caused by variation in the environment around the clusters. Variation in true seed size and between-plant spacing was achieved by use of clusters of different sizes, but these factors were associated with only a negligible variation in root size. Similarly, local interactions between plants, brought about by variation in plant-to-plant spacing, accounted for only a small proportion of the variation in root weight.

Download Full-text