Time Dependence of Magnetic Susceptibility of Soil Chronosequences on the California Coast

1992 ◽  
Vol 37 (3) ◽  
pp. 323-332 ◽  
Author(s):  
M. J. Singer ◽  
P. Fine ◽  
K. L. Verosub ◽  
O. A. Chadwick
Keyword(s):  
Magnetic Susceptibility ◽  
Time Dependence ◽  
Annual Precipitation ◽  
Mean Annual Precipitation ◽  
Magnetic Minerals ◽  
California Coast ◽  
Preferential Accumulation ◽  
Soil Age ◽  
The Difference ◽  
Over Time

AbstractAs the age of the soils in a chronosequence on the California coast increases, the difference between the magnetic susceptibility of eluvial and illuvial horizons increases, and the residual susceptibility after extraction with citrate-bicarbonate-dithionite (CBD) decreases. Enhanced susceptibility results from the conversion of nonferrimagnetic minerals to secondary ferrimagnetic forms (most likely maghemite) and the preferential accumulation of inherited and pedogenic magnetic minerals. Little enhancement occurs for pedons younger than 40,000 yr. By 124,000 yr, most of the magnetic susceptibility can be attributed to forms soluble in CBD. Magnetic susceptibility appears to vary systematically over time for three chronosequences from areas with mean annual precipitation ranging from 650 to 1500 mm yr−1. Magnetic susceptibility enhancement may be a useful parameter for estimating soil age in certain climates.

Outcomes of a quantitative analysis of 46 soil chronosequence studies: Vegetation plays the key role for rates of podzolization in most environments.

2020 ◽  
Author(s):  
Lisa Zwanzig ◽  
Martin Zwanzig ◽  
Daniela Sauer
Keyword(s):  
Continuous Distribution ◽  
Annual Precipitation ◽  
Mean Annual Precipitation ◽  
Annual Number ◽  
Published Data ◽  
Mean Annual Temperature ◽  
Relative Importance ◽  
Sand Content ◽  
Soil Chronosequence ◽  
Soil Age

<p>Soil formation is controlled by climate, vegetation, organisms, topography, parent material and time. There are various hypotheses on the relative importance of these individual soil-forming factors. The quantitative influence of each soil-forming factor on the expression and rates of soil-forming processes, and in particular the influence of the different factors in combination, have not yet been sufficiently analyzed. The aim of this study was to quantify the influence of the soil-forming factors on the rates of podzolization. For this purpose, we compiled published data from 46 soil chronosequence studies in a database. These studies contained altogether 231 soil profiles of known age, on which we tested existing hypotheses on the influence of different soil-forming factors. The formation of an E horizon and its increase in thickness over time is one of the characteristic features of Podzol formation. As it is one of the few features that was described in all 46 studies, we used it as an indicator of progressive podzolization. Through statistical analysis, we investigated how E horizon thickness is affected by latitude, longitude, mean annual precipitation, mean annual temperature, range between minimum and maximum monthly temperature, annual number of days with frost, vegetation class (pioneer, deciduous and coniferous), sand content, clay content, and soil age.</p><p>Since E horizon thickness exhibited a zero-inflated (semi-)continuous distribution, we opted for a zero-altered gamma (ZAG) model, consisting of a Bernoulli and a Gamma part. The Bernoulli part shows, how the probability of the presence of an E horizon changes with soil age and environmental conditions. The Gamma part of the ZAG model allows for capturing the effects of the covariates on E horizon thickness. Our results indicate that vegetation is the most important factor for both (1) the soil age at which podzolization starts (used indicator: first occurrence of an E horizon), and (2) the rates of podzolization thereafter (used measure: increase of E horizon thickness with soil age). Climatic factors such as mean annual precipitation and range of temperature play subordinate roles. They are important for the soil age at which podzolization starts but less important for the rates of podzolization. We did not identify a significant influence of sand content, neither on the start nor the rates of podzolization. Thus, this statistical assessment of global data provides new insights into the relative importance of the individual soil-forming factors on the onset and temporal course of podzolization.</p>

Dependence of Near-Surface Magnetic Susceptibility on Dust Accumulation Rate and Precipitation on the Chinese Loess Plateau

2001 ◽  
Vol 55 (3) ◽  
pp. 271-283 ◽  
Author(s):  
Stephen C. Porter ◽  
Bernard Hallet ◽  
Xihao Wu ◽  
Zhisheng An
Keyword(s):  
Grain Size ◽  
Magnetic Susceptibility ◽  
Loess Plateau ◽  
Surface Sediment ◽  
Accumulation Rate ◽  
Central China ◽  
Mean Annual Precipitation ◽  
Magnetic Minerals ◽  
Near Surface ◽  
Dust Accumulation

AbstractMagnetic susceptibility (MS) of surface sediment varies systematically across the Loess Plateau in central China, decreasing exponentially from >200×10−8 m3/kg at the northern margin of the Qinling Shan to ≤30×10−8 m3/kg near the southern margin of the Mu Us Desert. MS correlates highly with loess median grain size (r2=0.79), which decreases south-southeastward across the plateau. It also correlates with mean annual temperature (MAT) and mean annual precipitation (MAP) (r2=0.58 and 0.60, respectively), and with their product MAT×MAP (r2=0.83), which is considered a measure of potential pedogenic activity. Because regional isopleths depicting grain size and the primary meteorological parameters are nearly parallel, it is difficult to determine their relative influence on MS. A simple MS model, based on the observed spatial variation in loess thickness, permits quantitative assessment of the effect of the dust accumulation rate on the MS signal of surface sediment and isolates the likely role of climate in the production of magnetic minerals. The model suggests that 84% of the loess MS variance is dictated by the diluting effect of dust and 10–11% is associated with meteorological factors, primarily precipitation. The observed and modeled relationships support hypotheses that attribute variations in MS in the loess-paleosol succession to varying rates of dust deposition and in situ production of magnetic minerals in the accretionary soils, both of which are controlled by monsoon climate.

The Distinction between [P] and [S]

2017 ◽  
Author(s):  
Galen Strawson
Keyword(s):  
Personal Identity ◽  
Radical Change ◽  
Legal Responsibility ◽  
The Difference ◽  
Definition Of ◽  
Over Time

This chapter examines the difference between John Locke's definition of a person [P], considered as a kind of thing, and his definition of a subject of experience of a certain sophisticated sort [S]. It first discusses the equation [P] = [S], where [S] is assumed to be a continuing thing that is able to survive radical change of substantial realization, as well as Locke's position about consciousness in relation to [P]'s identity or existence over time as [S]. It argues that Locke is not guilty of circularity because he is not proposing consciousness as the determinant of [S]'s identity over time, but only of [S]'s moral and legal responsibility over time. Finally, it suggests that the terms “Person” and “Personal identity” pull apart, in Locke's scheme of things, but in a perfectly coherent way.

ANALISIS KOMPARATIF TUTURAN BAHASA INDONESIA PADA MAHASISWA UNIVERSITAS IQRA BURU

2020 ◽  
Author(s):  
HARZIKO
Keyword(s):  
Historical Development ◽  
Qualitative Approach ◽  
Data Selection ◽  
Communication Tool ◽  
Comparative Linguistics ◽  
Data Presentation ◽  
Vocal System ◽  
The Difference ◽  
Bahasa Indonesia ◽  
Over Time

Language is a tool used to convey ideas, ideas, feelings, and thoughts to others. Language, which is an arbiter sound symbol system that is used by members of one community to work together, interact, and identify themselves. In other words, language can be a means to convey intent or purpose so that the desired thing is achieved. As a communication tool, language develops over time. Therefore, language will never die if its speakers still care and love for the language comparative linguistics as a study or study of language which includes the comparison of cognate languages or the historical development of a language. This research aims to elucidate the use of Indonesian language at students of Iqra Buru University with Comparative Analysis. The method used in this research is descriptive with a qualitative approach. Data collected by observation, interview, and documentation techniques. Sources of data in this study were 5 speakers 5 speakers language Analyzing the data by means of data selection, data classification, and data presentation. The results of the study stated that there were phonological differences, namely the Jamee vowel system contained / ɛ / and / ɔ /, while the vocal system was / a / and the consonant system was Jamee / ɣ / or / R /, while the language / r /, then the difference pronunciations include single vowels, for example makɛn, bɔRa in Jamee and eating, bara in Language used by iqra Rush university students. Keywords

scholarly journals Herd-Level and Individual Differences in Fecal Lactobacilli Dynamics of Growing Pigs

Animals ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 113
Author(s):  
Emilia König ◽  
Virpi Sali ◽  
Paulina Heponiemi ◽  
Seppo Salminen ◽  
Anna Valros ◽  
...  
Keyword(s):  
Species Diversity ◽  
Growing Pigs ◽  
General Management ◽  
Immune Parameters ◽  
Sampling Points ◽  
Sequencing Technique ◽  
Piglet Serum ◽  
The Difference ◽  
Over Time ◽  
Fecal Sampling

We studied the fecal lactobacilli count and species diversity of growing pigs along with immune parameters associated with intestinal lactobacilli. Thirty pigs categorized as small (S, n = 12) or large (L, n = 18) at birth were followed from birth to slaughter in two commercial herds, H1 and H2. Herds differed in terms of their general management. We determined sow colostrum quality, colostrum intake, piglet serum immunoglobulins, and pig growth. We took individual fecal samples from pigs in the weaning and finishing units. We studied lactobacilli count and identified their diversity with 16S PCR. Total lactobacilli count increased in H1 and decreased in H2 between samplings. Lactobacilli species diversity was higher in H1 in both fecal sampling points, whereas diversity decreased over time in both herds. We identified altogether seven lactobacilli species with a maximum of five (one to five) species in one herd. However, a relatively large proportion of lactobacilli remained unidentified with the used sequencing technique. Small pigs had higher lactobacilli counts in both herds but the difference was significant only in H2 (p = 0.01). Colostrum quality was numerically better in H1 than in H2, where colostrum intake tended to be associated with total lactobacilli count (p = 0.05).

scholarly journals 152. Applying A Difference-in-Difference Analysis to Assess Effect of Antimicrobial Stewardship Strategies on Changes in Antimicrobial Use

2020 ◽  
Vol 7 (Supplement_1) ◽  
pp. S86-S86
Author(s):  
Ann F Chou ◽  
Yue Zhang ◽  
Makoto M Jones ◽  
Christopher J Graber ◽  
Matthew B Goetz ◽  
...  
Keyword(s):  
Antimicrobial Stewardship ◽  
Clinical Pharmacist ◽  
Antibiotic Use ◽  
Feedback Mechanism ◽  
Health Care Facilities ◽  
Antimicrobial Use ◽  
Time Points ◽  
The Difference ◽  
The Impact ◽  
Over Time

Abstract Background About 30–50% of inpatient antimicrobial therapy is sub-optimal. Health care facilities have utilized various antimicrobial stewardship (AS) strategies to optimize appropriate antimicrobial use, improve health outcomes, and promote patient safety. However, little evidence exists to assess relationships between AS strategies and antimicrobial use. This study examined the impact of changes in AS strategies on antimicrobial use over time. Methods This study used data from the Veterans Affairs (VA) Healthcare Analysis & Informatics Group (HAIG) AS survey, administered at 130 VA facilities in 2012 and 2015, and antimicrobial utilization from VA Corporate Data Warehouse. Four AS strategies were examined: having an AS team, feedback mechanism on antimicrobial use, infectious diseases (ID) attending physicians, and clinical pharmacist on wards. Change in AS strategies were computed by taking the difference in the presence of a given strategy in a facility between 2012–2015. The outcome was the difference between antimicrobial use per 1000 patient days in 2012–2013 and 2015–2016. Employing multiple regression analysis, changes in antimicrobial use was estimated as a function of changes in AS strategies, controlling for ID human resources in and organizational complexity. Results Of the 4 strategies, only change in availability of AS teams had an impact on antimicrobial use. Compared to facilities with no AS teams at both time points, antibiotic use decreased by 63.9 uses per 1000 patient days in facilities that did not have a AS team in 2012 but implemented one in 2015 (p=0.0183). Facilities that had an AS team at both time points decreased use by 62.2 per 1000 patient days (p=0.0324). Conclusion The findings showed that AS teams reduced inpatient antibiotic use over time. While changes in having feedback on antimicrobial use and clinical pharmacist on wards showed reduced antimicrobial use between 2012–2015, the differences were not statistically significant. These strategies may already be a part of a comprehensive AS program and employed by AS teams. In further development of stewardship programs within healthcare organizations, the association between AS teams and antibiotic use should inform program design and implementation. Disclosures All Authors: No reported disclosures

Ecological Niche Modeling Predicting the Potential Distribution of African Horse Sickness Virus from 2020 - 2060

2021 ◽  
Author(s):  
Ayalew Assefa ◽  
Abebe Tibebu ◽  
Amare Bihon ◽  
Alemu Dagnachew ◽  
Yimer Muktar
Keyword(s):  
Solar Radiation ◽  
Ecological Niche ◽  
Annual Precipitation ◽  
Maximum Temperature ◽  
Mean Annual Precipitation ◽  
African Horse Sickness ◽  
Diurnal Range ◽  
Annual Minimum Temperature ◽  
Precipitation Seasonality ◽  
Vector Borne

Abstract African horse sickness is a vector-borne, non-contagious and highly infectious disease of equines caused by African Horse Sickness viruses (AHSv) that mainly affect horses. The occurrence of the disease causes huge economic impacts because of its fatality rate is high, trade ban and disease control costs. In planning of vectors and vector borne diseases, the application of Ecological niche models (ENM) used an enormous contribution in exactly delineating the suitable habitats of the vector. We developed an ENM with the objective of delineating the global suitability of AHSv outbreaks retrospective based on data records from 2005–2019. The model was developed in R software program using Biomod2 package with an Ensemble modeling technique. Predictive environmental variables like mean diurnal range, mean precipitation of driest month(mm), precipitation seasonality (cv), mean annual maximum temperature (oc), mean annual minimum temperature (oc) mean precipitation of warmest quarter(mm), mean precipitation of coldest quarter (mm) mean annual precipitation (mm), solar radiation (kj /day), elevation/altitude (m), wind speed (m/s) were used to develop the model. From these variables, solar radiation, mean maximum temperature, average annual precipitation, altitude and precipitation seasonality contributed 36.83%, 17.1%, 14.34%, 7.61%, and 6.4%, respectively. The model depicted the sub-Sahara African continent as the most suitable area for the virus. Mainly Senegal, Burkina Faso, Niger, Nigeria, Ethiopia, Sudan, Somalia, South Africa, Zimbabwe, Madagascar and Malawi are African countries identified as highly suitable countries for the virus. Besides, OIE-listed disease-free countries like India, Australia, Brazil, Paraguay and Bolivia have been found suitable for the virusThis model can be used as an epidemiological tool in planning control and surveillance of diseases nationally or internationally.

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