<p>U ovoj doktorskoj disertaciji dat je predlog dizajna algoritma i metodologije za procenu indikatora suše &ndash; MEPIS. Istraživanje metoda praćenja suše obuhvatilo je tri tradicionalna indikatora i jedan novo formirani. Sve ukupno analizirano je 16 varijacija četiri odabrana indeksa suše period istraživanja obuhvatio je 62 godine, 1951-2012. Analize indikatora ukazale su na opravdanost menjanja pristupa pristupa problematici suše i odstupanja od stohastičkog razmatranja njene pojave i pristupanja termodinamičkim osnovama suše. Modelovanje suše po analogiji sa procesom sušenja vazduhom pokazalo je zadovoljavajuće rezultate i kao agregat ovog pristupa dobijen je IDEA indeks za praćenje uslova koji pogoduju suši. Kao indeks suše koji se striktno bazira na simulaciji fizičkih procesa ukazuje na mogućnost definisanja fizičkog stanja atmosfere koji odgovara stanju suše i korak je ka uniformnoj fizičkoj definiciji suše na osnovu uslova koji je uzrokuju. MEPIS u svojoj punoj formi bi dao dovoljno argumenata da se određeni indeksi koriste operativno i mogao bi opravdati neophodne investicije u tehničke i ljudske resurse.</p> / <p>In this doctoral dissertation have been proposed the designs of the algorithm and<br />methodology for drought indicator assessment &ndash;MEPIS. Methods of drought<br />monitoring were assessed. Three traditional drought indicators and one newly<br />developed were investigated. In total 16 variations of four selected drought indicators<br />were analyzed. Research covered period of 62 years, from 1951-2012. Analyses have<br />resulted with justification that approach to the drought problem should be changed<br />from stochastic to the one based on thermodynamics of drought. Modelling of drought<br />in analogy with air drying has shown satisfactory results and as an aggregate of this<br />approach was obtained IDEA drought indicator. Developed indicator showed<br />significant progress in identifying meteorological conditions that favor the development<br />of drought. It proves it is possible to define physical conditions that correspond to the<br />state of drought. It is step forward to uniform definition of drought phenomena. MEPIS<br />in its full form would give enough arguments to make decision about usage of tested<br />drought indicators and could justify the necessary investments in the technical and<br />human resources.</p>

LD2668 .T4 1954 S25 / Master of Science

Call number: LD2668 .T4 1955 H34 / Master of Science

Call number: LD2668 .T4 1966 S761 / Master of Science

Polyribosome aggregation state in growing tissues of barley and wheat leaf or stems of pea and squash was studied in relation to seedling growth and water status of the growing tissue in plants at various levels of osmotic stress. It was found to be highly correlated with water potential and osmotic potential of the growing tissue and with leaf or stem elongation rate. Stress rapidly reduced polyribosome content and water status in growing tissues of barley leaves; changes were slow and slight in the non-growing leaf blade. Membrane-bound and free polyribosomes were equally sensitive to stress-induced disaggregation. Incorporation of ³²PO₄³⁻ into ribosomal RNA was rapidly inhibited by stress, but stability of poly(A) ⁺RNA relative to ribosomal RNA was similar in stressed and unstressed tissues, with a half-life of about 12 hours. Stress also caused progressive loss of poly(A) ⁺RNA from these tissues. Quantitation of poly(A) and in vitro messenger template activity in polysome gradient fractions showed a shift of activity from the polysomal region to the region of 20-60 S in stressed plants. Messenger RNA in the 20-60 S region coded for the same peptides as mRNA found in the polysomal fraction. Nonpolysomal and polysome-derived messenger ribonucleoprotein complexes (mRNP) were isolated, and characteristic proteins were found associated with either fraction. Polysomal mRNP from stressed or unstressed plants were translated with similar efficiency in a wheat germ cell-free system; activity of nonpolysomal mRNP was variable, but usually less than that of polysomal mRNP. Deproteinization of mRNP failed to improve its activity. No inhibition of translation of poly(A) ⁺RNA by nonpolysomal mRNP was observed in mixing experiments with the wheat germ cell-free system. It was concluded that no translational inhibitory activity was associated with nonpolysomal mRNP from barley prepared as described.

Master of Science / Department of Agronomy / P. V. Vara Prasad / Drought is the single most limiting factor in crop production. This study was conducted to investigate if a cell viability assay could serve as an effective, efficient screen to determine post-anthesis drought tolerance in sorghum (Sorghum bicolor [L.] Moench) and maize (Zea mays [L]). The assay measured decline in chlorophyll fluorescence (Fv/Fm) over time from leaf punches collected from plants grown under optimum environmental conditions and placed in an incubator under high respiratory demand. A total of 300 lines of sorghum and 197 lines of maize were screened using this assay and potential post flowering drought tolerant staygreen lines and non-stay green lines were identified. Further testing of potential lines was done in both controlled and field environments, under drought conditions, to evaluate genotype performance for physiological, yield, and staygreen traits. Standard known staygreen and non-staygreen checks were also included in these studies for comparisons. Some relationships existed between results from the cell viability assay and performance measures under controlled environment and field conditions for both sorghum and corn. However, controlled experiments were limited due to space and time constraints, and field experiments were limited due to an absence of drought during the growing season. These studies showed that the staygreen trait was not clear in the known standards under controlled environment conditions. Few of the selected lines performed better under field condition. Further testing needs to be conducted to investigate the effectiveness of a cell viability assay as a feasible indicator of drought tolerance. Experiments under field conditions at different locations and with more replications would be necessary to evaluate relations between cell viability assay and expression of drought tolerance in field conditions.

This dissertation interprets gender-differentiated vulnerability to drought within a rural community located in the dry zone, la zona seca, of Nicaragua, a region that has been identified by the government and NGO sector as suffering from prolonged and, since the 1970s, more frequent droughts.  A combination of gender, capitals, and vulnerability demonstrates the value in using a multidimensional perspective to look at the socioeconomic and cultural contexts that form the capacity individuals have had to reduce their long-term vulnerability to drought in Nicaragua.  Due to the place-based characteristics of gender as well as vulnerability the analysis is mainly based on people’s stories about the history of their lives.  Based on these stories a local level picture is created of the households’ situation over time, how their work strategies and management of resources have varied, and how they perceived changes in capacity and vulnerability in relation to continuity and change in the climate.  The issue of adaptive capacity, which currently is less covered in research on gender and vulnerability and recognized in the literature as in need of more attention, and how it distinguishes itself from coping capacity in relation to vulnerability, is placed at the center of analysis.  In an additional analysis of how Nicaragua’s hazard management policies look upon the role and importance of interaction among societal levels and actors in reducing hazard vulnerability I show how the discourse has moved from emergency response to risk management with an increased emphasis on capacity building.  However, the recognition to differentiated vulnerability is lacking which risks hampering a successful vulnerability reduction. / <p>At the time of the doctoral defense, the following papers were unpublished and had a status as follows: Paper 2: Accepted. Paper 3: Manuscript.</p>

Levisticum officinale Koch is one of the most important plants producing essential oil. An experiment was conducted to determine the effect of drought stress on growth, total protein and essential oil content of Levisticum officinale. The experiment was conducted in a greenhouse, in a completely randomized design using 5 replications. Aridity levels of field capacity irrigation (as control), −0.6 and −1.0 MPa were applied. There was significant effect of aridity on leaf area in Levisticum officinale. The highest leaf area values were found in the lowest aridity (FC) level. The root weight and root length in the −0.6 MPa aridity level were more than that of the control aridity level, but, shoot height and shoot weight were highest in the control treatment. Total soluble protein contents under −0.6 MPa drought stress was numerically lower than that in the control treatment, but statistically there was no significant difference between protein contents in the −0.6 MPa and the control treatment. Compared to the control treatment, total soluble protein contents of Levisticum officinale were significantly decreased in the −1.0 MPa drought treatment. Essential oil content of Levisticum officinale was significantly increased in the −0.6 MPa drought treatment compared to the control. Compared to control treatment, there was a significant reduction found in essential oil content of Levisticum officinale in the −1.0 MPa aridity treatment. The results suggest that in the drought levels between −0.6 to −1.0 MPa, Levisticum officinale could be used for arid and semi-arid lands economical use.

The 2008-2009 Texas drought rivals the 1950s drought, known as the “drought of record,” as one of the state’s worst droughts in recent memory. Prolonged periods of little to no precipitation combined with high temperatures and the strain of population growth have created disastrous conditions especially across the southern and central regions of the state, which have been hardest and longest. At one point, more than 83 percent of the entire state was in some form of drought and the United States Department of Agriculture declared more than half the state as a primary natural disaster area due to losses from drought, above-normal temperatures and associated wildfires. More than $4 billion in agricultural losses have been predicted as a result of the drought. Even after heavy rains have lifted nearly all of Texas out of drought, there are still counties in extreme and exceptional drought. It is clear that water issues will continue to impact the state socially, economically and ecologically, so it is crucial for all Texans to have a better understanding of the myriad ramifications drought can have on various industries and communities throughout the state. / text

Electricity generation has significant environmental impacts, including on regional air quality, greenhouse gas emissions, and water availability. Modeling the overall environmental impact of electricity generation requires linked simulations of power generation, air pollution physics and chemistry, greenhouse gas emissions, and water use. Tools for performing these analyses in an integrated manner are just beginning to emerge. This work expands on the development of linked models for electricity generation, air quality, and water use that have provided single-day snapshots of these environmental impacts. The original model used a non-linear optimization model for power generation, a regional photochemical model for air quality impacts, and self-contained modules for greenhouse gas emissions and water usage at power plants in Texas. The new model includes life cycle scenarios for the power sector (including changes in both the fuel production and electricity generation stages) and expands the temporal scale of the modeling framework to include impacts on monthly, seasonal, and annual time scales instead of on single days. In addition, the air quality framework has been expanded to include atmospheric particulate matter as an air quality impact. This modeling framework will be used to assess the air quality impacts of new natural gas developments in the Barnett and Eagle Ford shale regions in Texas, the consumptive water impact of new natural gas development in Texas, the impact of seasonal versus ozone forecast-based pricing for power plant NOx emissions in the state of Texas, and the potential cost and air quality impacts of drought-based operation of the power grid in Texas. / text