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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
531

Compositional gradients in photopolymer films utilizing kinetic driving forces

Cook, Clinton John 01 July 2014 (has links)
Independent control of the surface and bulk properties is advantageous for many applications such as adhesives, release coatings, and antimicrobial films. Traditional methods for achieving independent control typically require multiple processing steps such as wet-on-wet or wet-on-dry coating methods. Independent control over the surface properties can achieved in a single step utilizing the temporal and spatial control inherent to photopolymerization. Specifically, a co-photopolymerization of monomers with different reactivities in the presence of a light gradient is capable of producing a polymer film with a surface chemistry that differs from the bulk chemistry. The light gradient, produced via the concentration of photoinitiator in the formulation, results in a reaction gradient through the film with the higher rates of reaction occurring in the high light intensity regions of the film. The preferentially reacting monomer adds at a greater rate in the high light intensity regions resulting in non-uniform consumption yielding a concentration gradient. Consequently, diffusion of the preferentially reacting monomer from the bulk to the surface of the film and a counter-diffusion of the other monomer from the surface to the bulk of the film occurs from the non-uniform monomer consumption thus producing a film with a concentration gradient through the depth of the film with the preferentially reacting monomer enriching the high light intensity regions. A variety of kinetic differences capable of producing a stratified film will be presented including inherent monomer reactivity, number of functional groups per monomer, oxygen inhibition, thiol-ene chemistry, and Norrish type two initiation. Additionally, parameters that control the degree of stratification, such as methods of varying polymerization rate and the light gradient, will be examined. Changes in surface properties (such as contact angle, surface hardness, adhesion) and bulk properties (such as mechanical properties measured by dynamic mechanical analysis and polymer swelling) are studied as a function of stratification. Finally, a mathematical model which describes and predicts the production of stratified films via photopolymerization is presented. Photopolymerization allows for a facile, single step method of generating stratified films with controllable surface chemistries.
532

Impact of imbalanced graft-to-spleen volume ratio on outcomes following living donor liver transplantation in an era when simultaneous splenectomy is not typically indicated / 同時性脾臓摘出術が標準的ではない時代における、不均衡なグラフト/脾臓容積比が生体肝移植後のアウトカムに与える影響

Yao, Siyuan 23 March 2020 (has links)
京都大学 / 0048 / 新制・課程博士 / 博士(医学) / 甲第22303号 / 医博第4544号 / 新制||医||1040(附属図書館) / 京都大学大学院医学研究科医学専攻 / (主査)教授 福原 俊一, 教授 川口 義弥, 教授 松村 由美 / 学位規則第4条第1項該当 / Doctor of Medical Science / Kyoto University / DFAM
533

Stigma in Class: Mental Illness, Social Status, and Tokenism in Elite College Culture

Billings, Katie R 02 July 2019 (has links)
The majority of mental illness on college campuses remains untreated, and mental illness stigma is the most cited explanation for not seeking mental health treatment. Working-class college students are not only at greater risk of mental illness, but also are less likely to seek mental health treatment and hold more stigmatized views toward people with mental illness compared to affluent college students. Research on college culture suggests that elite college contexts may be associated with greater stigmatization of mental illness. This study bridges the social status and college culture literatures by asking—does social status and college context together predict students’ mental health attitudes? By surveying 757 undergraduates at an Ivy League university and a Non-Ivy League university, I found that 1) elite college students had greater mental illness stigma than non-elite students, 2) social status was positively related to personal stigma and negatively related to perceived stigma, and 3) low social status students at the Ivy League university had greater personal mental illness stigma compared to their counterparts at the Non-Ivy League university. Low social status students’ perceptions of themselves as social status minorities may be responsible for their greater stigmatization of mental illness in the elite college context. These findings suggest that increasing socioeconomic diversity on college campuses may improve lower social status students’ mental health attitudes.
534

Klasické koncepty stratifikace a jejich srovnání se situací v soudobé společnosti. Subjektivní a objektivní pozice ve společenské struktuře / Classical concepts of stratification and their comparison with the situation in contemporary society. Subjective and objective position in the social structure

Rádl, Michael January 2016 (has links)
The central theme of the thesis is the current conceptualization of social classes and the issue of stratification in the Czech Republic in the period after 1989. In the first part I confront key theses of classical stratification concepts and follow their transformations in the history of exploration of the social structure. In the second part, by secondary analysis of quantitative data, I am trying to find the key factors of self- classification into social structures and to determine how this subjective self- classification correlates with objective (sociological) classification. An important part of the research is also the question of to what extent and in what sense people perceive the contemporary Czech society as a social-stratified. In the conclusion, on the basis of the results of analysis, I am trying to suggest which of the classical concepts of stratification best reflects the situation in contemporary Czech society. Key words: subjective and objective position, stratification, class, stratum, status, society, social structure
535

Dětská porozumění sociální stratifikaci s ohledem na profese / Children's understanding of social stratification regarding occupation

Czafíková, Kateřina January 2020 (has links)
The thesis is focused on research for children's understanding of social stratification on primary school. The main topic are children's representations of the structure of society regarding occupations. The aim is the diagnoses of children's understanding reflecting the structure of society. It tries to reveal if children on primary school percieve invisible network of statuses and roles that result from the structure of our society and carry social rules and agreements. The theoretical part defines socialogical terms, deals with topics concerning the structure of society and describes past and current theories of social stratification. It also presents home and foreign research of children's understanding. Considering a little amount of research on this topic, the thesis draws inspiration from another theses focused on the same topic, yet aimed at children on secondary school. The practical part describes the qualitative research of the thesis. The major issue is How and on which basis a child thinks about the structure of society regarding occupations?. Qualitative research using the method of the depth semi-structured interview studies criteria taken into consideration by children thinking about this topic. The results are analysed by the method of process coding and presented by...
536

Změny reprodukčního chování obyvatelstva na počátku demografické revoluce (na příkladu Staňkova) / Changes in reproductive behaviour in the beginning of the demographic revolution (example of Staňkov)

Bozděch, Lukáš January 2019 (has links)
Changes in reproductive behaviour in the beginning of the demographic revolution (example of Staňkov) Abstract The aim of this study is to analyse reproductive behaviour of population in the Czech lands in the 19th century, a period in which demographic revolution began. The research is based on data from Staňkov, a town in southwestern Bohemia, which, unlike the majority of adjacent region, experienced a substantial industrialization in the 19th century. This resulted in a significant population growth during the analysed period. Family lists were compiled from the registers of births, marriages and deaths using the method of family reconstitution. Nuptiality, marital fertility and infant mortality were the main analysed topics. Population was also divided into groups based on social stratification and these groups were analysed to determine, whether their reproductive behaviour differed from each other. The results from Staňkov were compared to other previously studied localities in the Czech lands. This study revealed that in the 19th century changes in reproductive behaviour within social groups were quite small or negligible. Big changes in nuptiality, fertility or infant mortality in the beginning of demographic revolution can therefore be mainly attributed to the shifts in the social structure of the...
537

Antropogenní transformace přírodní sféry Afriky / An anthropogenic transformation of the natural sphere of Africa

Píšová, Šárka January 2019 (has links)
Africa is a heterogeneous environment that is affected by natural and anthropogenic processes. This thesis uses a review method to characterize the natural environment of the continent, present possible classifications of natural conditions and to describe the transformation of this environment. The main methodological aim of the thesis was to determine areas threatened by biodiversity loss due to anthropogenic pressures based on a new classification of the natural environment on a continental level. This was executed by methods of environmental stratification and subsequent environmental classification. Thus, this thesis presents a classification of the natural environment on the basis of homogenous units determined by bioclimatic variables and terrain, which are subsequently related to the biodiversity of birds, amphibians and mammals and to an anthropogenic influence represented by anthropogenic biomes. Finally, the share of protected areas is executed in relation to this anthropogenic transformation of the natural environment. Therefore, the thesis is quite a unique approach, as it takes into account a combination of both physical and socio-economic factors at a continental level. The final output consists of a map of the anthropogenic transformation of Africa's natural environment in the...
538

Our Bodies, Our Stories: Mental and Physical Self Connection as a Protective Factor in Sexual and Gender Minorities

Todd, Emerson A 01 August 2022 (has links)
The mind and body connection has been actively examined in neuroscience and developmental psychology backgrounds. Sociological theorists posit ways that individuals develop a sense of self through mind, body, and the social world. While research on the connection between the mind and body in disabled and aging populations is common, less is known of the everyday impact of these connections for other minority populations. The present study uses mixed-methods research to explore the relationship between mind and body and the impacts on internal and social life. The quantitative aspect of the study found significant relationships between physical and mental health for sexual and gender minorities (N = 788). The qualitative portion of the research consisted of interviews with sexual and/or gender minorities (N = 20). Interviews revealed central themes of ownership, oppression, and disconnection as a coping mechanism for external and internal body dissatisfaction.
539

Validierung des CRB-65- und des qSOFA-Scores bei Patienten mit ambulant erworbener Pneumonie und schwerer Immunsuppression

Frantz, Sophie 23 April 2021 (has links)
Hintergrund: Die ambulant erworbene Pneumonie (CAP) ist bei Patienten mit schwerer Immunsuppression häufig und mit einer schlechten Prognose assoziiert. Scores zur Risikoprädiktion bei Sepsis oder CAP sind bei diesen Patienten kaum untersucht. Fragestellung: Ziel der Studie war die Evaluation der prognostischen Prädiktion der qSOFA- und CRB-65-Scores bei Patienten mit Pneumonie und schwerer Immunsuppression. Methoden: Es handelt sich um eine retrospektive Kohortenstudie am Uniklinikum Dresden zwischen 2014 und 2017 mit Einschluss konsekutiver Patienten mit CAP und schwerer Immunsuppression (u.a. Neutropenie, aktive hämatologische Neoplasie, Z.n. allogener Stammzell- oder Organtransplantation, HIV–Infektion mit CD4-Zellen < 200/µl, zytostatische oder rheumatologische immunsuppressive Therapie innerhalb der letzten 3 Monate, Prednisolon-Äquivalent >10mg/d > 3 Monate). Patienten mit dokumentierter Therapielimitation oder direkter Aufnahme auf die Intensivstation wurden ausgeschlossen. Die CRB-65- und qSOFA-Kriterien wurden bei Erstvorstellung dokumentiert. Der primäre Endpunkt war definiert als Notwendigkeit mechanischer Beatmung oder von Vasopressoren (MVVS) und/oder Krankenhausletalität. Um die prognostischen Eigenschaften der Scores, der einzelnen Score- Parameter, sowie der darüber hinaus erhobenen Parameter zu untersuchen, wurden univariate und multivariate Regressionsanalysen sowie ROC-Kurvenanalysen durchgeführt. Ergebnisse: Von 198 eingeschlossenen Patienten erfüllten 41 (21%) den primären Endpunkt, 19 (10%) verstarben. Das Alter war kein unabhängiger Prädiktor, dagegen waren sowohl der CRB- als auch der qSOFA-Score in der Kaplan-Meier-Analyse sowie in der multivariaten Analyse unabhängig von anderen Prädiktoren mit dem primären Endpunkt assoziiert (jeweils p < 0.001). In der ROC-Analyse erreichten beide Scores eine moderate Prädiktion (AUC 0,70 bzw. 0,69), bei 0 vorliegenden Kriterien zeigte sich ein NPV von jeweils 89% (13/120 bzw. 12/105 Patienten „übersehen“). Bei ≥ 2 Kriterien resultierten PPVs von 44 bzw. 58%. Diskussion: Sowohl die CRB- als auch die qSOFA-Kriterien zeigten eine moderate, aber signifikante prognostische Aussagekraft. Das Alter ist dagegen in dieser Population kein geeigneter prädiktiver Parameter. Auch bei den Scores ohne Alterskriterium ist der NPV jedoch nicht ausreichend zum Ausschluss von Komplikationen. Daher sollten alle schwer immunsupprimierten Patienten mit Pneumonie zumindest initial stationär, bei > 1 positivem Score-Kriterium auch intensiv hinsichtlich einer akuten Organdysfunktion, überwacht werden.:ABBILDUNGSVERZEICHNIS V TABELLENVERZEICHNIS VI ABKÜRZUNGS- UND SYMBOLVERZEICHNIS VIII 1 EINLEITUNG 1 1.1 DIE AMBULANT ERWORBENE PNEUMONIE 1 1.1.1 Definition und Einteilung 1 1.1.2 Epidemiologie 2 1.1.3 Diagnosestellung 3 1.1.4 Erregerspektrum bei CAP ohne Immunsuppression 4 1.1.5 Therapie der CAP ohne Immunsuppression 5 1.1.6 Verlauf, klinische Stabilitätskriterien und Therapiedauer 6 1.2 RISIKOSTRATIFIZIERUNG DER CAP OHNE IMMUNSUPPRESSION 7 1.2.1 Bedeutung der korrekten und schnellen Risikostratifizierung 7 1.2.2 Risikostratifizierung der CAP ohne Immunsuppression 8 1.2.3 Aktuelle Studien zur Risikostratifizierung mittels CRB-65/qSOFA 13 1.3 CAP BEI IMMUNSUPPRESSION 15 1.3.1 Aufbau des Immunsystems 15 1.3.2 Immunsuppression 16 1.3.3 Ursachen der Immunsuppression 17 1.3.4 Bedeutung der CAP bei Immunsuppression 19 1.3.5 Verändertes Erregerspektrum und Therapie bei CAP-Patienten mit Immunsuppression 20 1.3.6 Risikostratifizierung bei CAP und Immunsuppression 23 1.4 RATIONALE UND STUDIENZIEL 26 2 METHODEN 28 2.1 ÜBERBLICK 28 2.2 STUDIENDESIGN 28 2.3 SELEKTION DER STUDIENPOPULATION 28 2.3.1 Datenbasis 28 2.3.2 Einschlusskriterien 29 2.3.3 Ausschlusskriterien 30 2.3.4 Studienpopulation 31 2.4 ENDPUNKTE 33 2.5 DATENERFASSUNG 33 2.5.1 Erhobene Parameter 33 2.5.2 Berechnete Scores und Parameter 34 2.6 FALLZAHLSCHÄTZUNG 34 2.7 STATISTISCHE ANALYSE 34 3 ERGEBNISSE 36 3.1 PATIENTENCHARAKTERISTIKA 36 3.2 MIKROBIOLOGIE 39 3.3 UNIVARIATE ANALYSEN 41 3.3.1 Primärer Endpunkt 41 3.3.2 Sekundärer Endpunkt 45 3.4 MULTIVARIATE ANALYSEN 48 3.5 KAPLAN-MEIER-ANALYSE 54 3.6 ROC-KURVENANALYSE FÜR QSOFA-, CRB-65-, QSOFA-65- UND CRB- SCORE 56 4 DISKUSSION 61 4.1 WICHTIGSTE ERGEBNISSE DER ARBEIT 61 4.2 REPRÄSENTATIVITÄT DER PATIENTENKOHORTE 61 4.2.1 Patientencharakteristika 61 4.2.2 Mikrobiologie 65 4.2.3 Endpunkte 66 4.3 PRÄDIKTIVE PARAMETER 67 4.3.1 CRB-65-Einzelkriterien und -Score 67 4.3.2 qSOFA-Einzelkriterien und -Score 69 4.3.3 Neuer Score 70 4.3.4 qSOFA-Score und CRB-65-Score im direkten Vergleich 70 4.3.5 Komorbiditäten 71 4.3.6 Laborchemische Prognoseparameter 72 4.3.7 Weitere Prognoseparameter 73 4.4 LIMITATIONEN 75 4.5 SCHLUSSFOLGERUNG UND KLINISCHE BEDEUTUNG 75 4.6 AUSBLICK 77 5 ZUSAMMENFASSUNG 78 6 SUMMARY 79 7 LITERATURVERZEICHNIS 80 8 ANHANG 93 9 DANKSAGUNG 101 10 SELBSTSTÄNDIGKEITSERKLÄRUNG 102 / Background: Community-acquired pneumonia (CAP) in immunocompromised patients is a common issue and often associated with poor prognosis. Scores for risk prediction used in immunocompetent patients with sepsis or CAP are poorly evaluated for these patients. Aim: The purpose of the study was to evaluate the prognostic value of the qSOFA- and CRB-65-criteria for risk stratification of immunocompromised patients with CAP. Methods: The retrospective cohort study including 198 consecutive patients hospitalized in the university hospital of Dresden with CAP and severe immunosuppression (neutropenia, active haematological neoplasia, stem cell transplantation, solid organ transplantation, HIV-infection with CD4-cells < 200/µl, immunosuppressive treatment within the last 3 months, prednisolone equivalent > 10 mg/d > 3 months) was conducted between 2014 and 2017. Patients that were admitted directly to the intensive care unit and those with treatment restrictions were excluded. The CRB- and qSOFA-criteria were documented when patients entered the emergency department. Primary outcome was defined as need of mechanical ventilation (MV) or vasopressor support (VS) and/or hospital-mortality. Univariate and multivariate regression analysis as well as ROC curve analysis were performed to investigate the prognostic properties of all scores, the single score parameters and other predictive parameters. Results: 41 (21 %) of 198 included patients reached the primary endpoint and 19 (10 %) of the patients died. Age was not an independent predictive parameter. Using Kaplan-Meier and multivariate logistic regression analysis, both the CRB- and qSOFA-scores were independently associated with the primary endpoint (each p < 0,001). However, after ROC curve analysis both scores only showed moderate prediction (AUC 0,70 and 0,69). With a score of 0, the negative predictive value (NVP) was about 89% in both scores (13/120 and 12/105 missed patients, respectively). When 2 or more parameters were positive the positive predictive values (PPV) were 44 and 58%, respectively. Conclusion: Both, the qSOFA as well as the CRB score, showed moderate but significant prognostic properties. In this population, age was an inappropriate predictive parameter. Even without the age criterion the NPV was inadequate to exclude the possibility of organ failure and complications. Therefore, all immunocompromised patients, especially those with a score > 1, should be monitored intensively concerning organ failure when having a CAP.:ABBILDUNGSVERZEICHNIS V TABELLENVERZEICHNIS VI ABKÜRZUNGS- UND SYMBOLVERZEICHNIS VIII 1 EINLEITUNG 1 1.1 DIE AMBULANT ERWORBENE PNEUMONIE 1 1.1.1 Definition und Einteilung 1 1.1.2 Epidemiologie 2 1.1.3 Diagnosestellung 3 1.1.4 Erregerspektrum bei CAP ohne Immunsuppression 4 1.1.5 Therapie der CAP ohne Immunsuppression 5 1.1.6 Verlauf, klinische Stabilitätskriterien und Therapiedauer 6 1.2 RISIKOSTRATIFIZIERUNG DER CAP OHNE IMMUNSUPPRESSION 7 1.2.1 Bedeutung der korrekten und schnellen Risikostratifizierung 7 1.2.2 Risikostratifizierung der CAP ohne Immunsuppression 8 1.2.3 Aktuelle Studien zur Risikostratifizierung mittels CRB-65/qSOFA 13 1.3 CAP BEI IMMUNSUPPRESSION 15 1.3.1 Aufbau des Immunsystems 15 1.3.2 Immunsuppression 16 1.3.3 Ursachen der Immunsuppression 17 1.3.4 Bedeutung der CAP bei Immunsuppression 19 1.3.5 Verändertes Erregerspektrum und Therapie bei CAP-Patienten mit Immunsuppression 20 1.3.6 Risikostratifizierung bei CAP und Immunsuppression 23 1.4 RATIONALE UND STUDIENZIEL 26 2 METHODEN 28 2.1 ÜBERBLICK 28 2.2 STUDIENDESIGN 28 2.3 SELEKTION DER STUDIENPOPULATION 28 2.3.1 Datenbasis 28 2.3.2 Einschlusskriterien 29 2.3.3 Ausschlusskriterien 30 2.3.4 Studienpopulation 31 2.4 ENDPUNKTE 33 2.5 DATENERFASSUNG 33 2.5.1 Erhobene Parameter 33 2.5.2 Berechnete Scores und Parameter 34 2.6 FALLZAHLSCHÄTZUNG 34 2.7 STATISTISCHE ANALYSE 34 3 ERGEBNISSE 36 3.1 PATIENTENCHARAKTERISTIKA 36 3.2 MIKROBIOLOGIE 39 3.3 UNIVARIATE ANALYSEN 41 3.3.1 Primärer Endpunkt 41 3.3.2 Sekundärer Endpunkt 45 3.4 MULTIVARIATE ANALYSEN 48 3.5 KAPLAN-MEIER-ANALYSE 54 3.6 ROC-KURVENANALYSE FÜR QSOFA-, CRB-65-, QSOFA-65- UND CRB- SCORE 56 4 DISKUSSION 61 4.1 WICHTIGSTE ERGEBNISSE DER ARBEIT 61 4.2 REPRÄSENTATIVITÄT DER PATIENTENKOHORTE 61 4.2.1 Patientencharakteristika 61 4.2.2 Mikrobiologie 65 4.2.3 Endpunkte 66 4.3 PRÄDIKTIVE PARAMETER 67 4.3.1 CRB-65-Einzelkriterien und -Score 67 4.3.2 qSOFA-Einzelkriterien und -Score 69 4.3.3 Neuer Score 70 4.3.4 qSOFA-Score und CRB-65-Score im direkten Vergleich 70 4.3.5 Komorbiditäten 71 4.3.6 Laborchemische Prognoseparameter 72 4.3.7 Weitere Prognoseparameter 73 4.4 LIMITATIONEN 75 4.5 SCHLUSSFOLGERUNG UND KLINISCHE BEDEUTUNG 75 4.6 AUSBLICK 77 5 ZUSAMMENFASSUNG 78 6 SUMMARY 79 7 LITERATURVERZEICHNIS 80 8 ANHANG 93 9 DANKSAGUNG 101 10 SELBSTSTÄNDIGKEITSERKLÄRUNG 102
540

Effect of Conservation Agriculture on Organic Matter Stratification and Hydro-Physical Properties of Soil Under Intensive Cereal-based Cropping Systems

Patra, Sridhar 13 May 2022 (has links)
Although, the potential of management induced changes of soil organic matter, soil hydraulic properties (SHPs) and soil physical quality has been studied particularly in relation to tillage, few studies have evaluated combined effect of tillage, crop residue retention and cropping sequence, which are essential components of conservation agriculture (CA), on stratification and storage of soil organic matter, its effect on near-saturated soil hydraulic properties and soil physical quality in intensive cereal based irrigated cropping systems. Hence, the present study critically analyses the effects of CA on organic matter and hydro-physical properties of soil in a long-term CA field trial in NWIGP, India, which is one of the most fragile agro-ecosystems in the world. The objectives were (I) to investigate the stratification of soil organic carbon (SOC), total nitrogen (TN), C/N ratio and evaluate SR as an indicator of storage of SOC and TN and soil quality for different CA practices, (II) to assess the long-term effect of CA practices and short-term effect of crops on near-saturated soil hydraulic conductivity and water transmission properties, and (III) to assess the effect of CA practices on soil physical quality using capacitive and dynamic indicators. There were four treatments: (1) conventionally tilled rice-wheat cropping system (CT-RW), (2) reduced till CA-based rice-wheat-mungbean system (RT-RWMB), (3) no-till CA-based rice-wheat-mungbean system (NT-RWMB), and (4) no-till CA-based maize-wheat-mungbean system (NT-MWMB). To achieve these objectives, soil bulk density, SOC and TN were measured in an increment of 5 cm up to 30 cm soil depth. Furthermore, the effects of CA were also evaluated in terms of soil hydro-physical properties. Soil physical properties such as bulk density and soil aggregate distribution were evaluated in two cropping seasons along with near saturated hydraulic properties. Steady state infiltration rates were obtained at four pressure heads by hood infiltrometer consecutively over two cropping seasons, i.e. during harvest season of rice/maize (October 2017) and maximum crop growth stage of wheat (February 2018). Data were analysed in terms of soil hydraulic conductivity, k(h), flow weighted mean pore radius (r0), hydraulically active porosity (ε) and threshold pore radius (rbp), a new pore measure indicative of macropore stability derived by substituting soil’s bubble pressure in the capillary equation. Finally, the effects of CA on soil physical quality in terms of both capacitive and dynamic indicators, derived from soil moisture retention curve and field measured hydraulic conductivity, respectively, were assessed and related with crop yield to infer which indicator better represented the soil physical quality and its effect on crop yield under irrigated intensive cereal based cropping systems. Results showed that CA had profound impacts on distribution of SOC and TN in the soil profile. Significantly higher proportion of both SOC and TN were observed in the top soil in the CA-based treatments as compared with conventional intensive tillage-based treatment. The mean stratification ratio of both SOC and TN were found > 2 in CA-based treatments whereas the same was < 2 in intensive tillage-based treatment. Storage of SOC and TN in the 0-30 cm were found higher in CA-based treatments as compared with the intensive tillage-based treatment. These results on vertical distribution and storage of SOC and TN indicated a relatively better soil carbon sequestration and soil quality in CA-based treatment. The higher concentrations and storage of soil organic matter in CA-based treatments were, however, not translated into significantly (p < 0.05) lower bulk density due to probable compaction effect of no-tillage and harvest machinery and hydraulic pressure exerted by the flooded irrigation water. However, the increased soil organic matter in the top soil in CA-based treatments improved the soil aggregation significantly which helped in enhancing soil structural quality. Improvement in soil structure was reflected in relatively higher near saturated hydraulic conductivity in CA-based treatments. Irrespective of crop seasons, higher k(h) was observed under CA due to formation of macropores with better continuity, greater size and numbers as compared with conventional intensive tillage treatment. Moreover, higher r0 values were observed for a given k(h) for CA treatments suggesting that interaggregate pores are the dominant pathways of infiltration in CA. A relatively smaller temporal variation of rbp was indicative of a more stable macropore system established by rice-based CA as compared with maize-based CA. CA also enhanced hydraulically active macropores as compared with intensive tillage based conventional agriculture. Results also indicated that crops play an important role in relative distribution of the hydraulically active macropores in the root zone. The impact of CA on soil organic matter stratification and soil hydraulic properties were found to be expressed in terms of changes in soil physical quality. Soil moisture retention curves and pore size distributions under different treatments suggested higher soil water storage in structural pores in CA as compared with intensive tillage-based conventional agriculture. The impact of CA on soil physical quality and consequent effect on crop yield was found to be more expressed through dynamic indicators such as hydraulically active porosity rather than capacitive indicators derived from soil moisture retention curve. Overall, this study reveals that conservation agriculture has great potentials to reverse the intensive tillage induced degradation of soil resources in Indo-Gangetic Plains of India by improving the soil hydro-physical properties and soil physical quality.:Table of Contents Declaration i Declaration of Conformity ii Acknowledgements iii Table of Contents v List of Figures vii List of Tables xi List of Symbols, Abbreviations and Acronyms xiv Abstract xvii 1 Introduction and Background 1 1.1 General Overview 1 1.2 Statement of the Research Problem 5 1.3 Objectives 6 1.4 Research Flow and Chapter Description 7 2 Materials and Methods 9 2.1 Study Area Description 9 2.1.1 Study site 9 2.1.2 Climate 9 2.1.3 Soil 10 2.1.4 Treatments 10 2.1.5 Field Campaigns and Measurement/Analysis 14 2.2 Methods and Theoretical Considerations 14 2.2.1 Soil Sampling and Analysis 14 2.2.1.1 Calculation of Stratification Ratio 15 2.2.1.2 Calculation of SOC and TN Storage 15 2.2.1.3 Aggregate Size Distribution 16 2.2.2 Infiltration Measurements 16 2.2.3 Soil Moisture Retention Experiments 17 2.2.4 Derivation of Hydraulic Properties from Steady State Infiltration Rates 18 2.2.4.1 Near-Saturated Hydraulic Conductivity 18 2.2.4.2 Flow Weighted Mean Pore Radius 20 2.2.4.3 Equivalent Threshold pore Radius 21 2.2.4.4 Hydraulically Active Porosity 21 2.2.5 Determiation of Soil Moisture Charachtristics and Pore Size Distribution 22 2.2.6 Derivation of Soil Physical Quality Indicators 23 2.3 Statistics 25 3 Results and Discussion 26 3.1 Stratification and Storage of Soil Organic Matter 26 3.1.1 Bulk Density 26 3.1.2 Concenrations of SOC 27 3.1.3 Concentrations of TN 28 3.1.4 C/N Ratio 29 3.1.5 Stratification Ratio of SOC, TN and C/N Ratio 30 3.1.6 Storage of SOC and TN 33 3.1.7 Discussion 34 3.1.8 Summary of Results 39 3.2 Soil Hydro-Physical Properties 40 3.2.1 Soil Physical Properties 40 3.2.2 Near-Saturated Hydraulic Conductivity 43 3.2.3 Soil Pore Characteristics-Conductivity Relationship 47 3.2.4 Hydrailically active Porosity 51 3.2.5 Summary of Results 54 3.3 Soil Physical Quality (SPQ) 56 3.3.1 Soil Moisture Retention Curve (SMRC) 56 3.3.2 Soil Pore Size Distribution (SPSD) 58 3.3.3 Capacitive Indicators 59 3.3.4 Dynamic Indicators 60 3.3.5 Relationship between capacitive indicators of SPQ with dynamic indicators of SPQ and long-term crop yield 60 3.3.6 Relationship between dynamic indicator of SPQ (hydraulically active porosity) and Long-term Crop Yield 62 3.3.7 Summary of Results 64 4 Synthesis and Conclusions 65 5 Implications and Outlook 69 References 71

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