Questions Raised by the Global Warming Hiatus: The Predictability of Tropical Pacific Decadal Variability and Subsurface Warming of the Tropical Atlantic Ocean

This dissertation explores two aspects of interdecadal climate variability: the predictability of variability in the tropical Pacific region on longer-than-interannual timescales, and changes to subsurface heat content in the tropical Atlantic Ocean over a decade. Chapter 1 assesses the ability of a general circulation model (GCM) and an intermediate- complexity model (ICM) to simulate persistent cool states of the Tropical Pacific. These states, which are La Niña-like on average, last from seven to ten years and induce prolonged droughts in many parts of the world. We find that these models produce analogs to real-world examples of these states and that they are modestly predictable in the ICM. We also find some predictability of the interdecadal shifts in the mean state in this model. In Chapter 2, an attractor reconstruction technique is used to investigate the predictability of interdecadal variability in the ICM further. We find that the interdecadal regimes of the ICM emerge as a pair of distinct orbits in a three-dimensional state space, and that the observed system possesses some comparable characteristics. The ICM is found to spend over a third of the time in states from which the regime of the following fifteen years is predictable with high confidence. The implications for developing an interdecadal prediction scheme are discussed. Chapter 3 examines changes in the heat content of the tropical Atlantic below the thermocline during the recent global warming hiatus. We use simulated Lagrangian particles in an ocean reanalysis dataset to analyze the changes to the circulation of the upper tropical Atlantic Ocean that occurred between the hiatus decade and the decade prior to it; and develop a testable hypothesis for how variability in the tropical Pacific region may have influenced the subsurface heat content of the Atlantic

Contract design in soybean production

Although there is considerable interest in component pricing of soybeans from both the industry and the academia, it is not commonly observed in the soybean industry. In this thesis, the Principal Agent model is used to design a contract between a processor and grower. The processor provides incentives to growers to produce soybeans with higher components (protein and oil) in them. Under the assumption that growers are risk neutral, a contract is designed where the grower faces all the risk in the production of components. The contract also compensates the grower for the yield drag as a result of production of soybeans with higher components in them. Since there is significant difference in the production of components across regions and year, a diffe-2000. Data from the Iowa Soybean yield trials show that an expected social surplus of {dollar}0.15/bu and {dollar}8.02/acre can be generated through a contract with incentives for components

Compressive sensing based image processing and energy-efficient hardware implementation with application to MRI and JPG 2000

In the present age of technology, the buzzwords are low-power, energy-efficient and compact systems. This directly leads to the date processing and hardware techniques employed in the core of these devices. One of the most power-hungry and space-consuming schemes is that of image/video processing, due to its high quality requirements. In current design methodologies, a point has nearly been reached in which physical and physiological effects limit the ability to just encode data faster. These limits have led to research into methods to reduce the amount of acquired data without degrading image quality and increasing the energy consumption. Compressive sensing (CS) has emerged as an efficient signal compression and recovery technique, which can be used to efficiently reduce the data acquisition and processing. It exploits the sparsity of a signal in a transform domain to perform sampling and stable recovery. This is an alternative paradigm to conventional data processing and is robust in nature. Unlike the conventional methods, CS provides an information capturing paradigm with both sampling and compression. It permits signals to be sampled below the Nyquist rate, and still allowing optimal reconstruction of the signal. The required measurements are far less than those of conventional methods, and the process is non-adaptive, making the sampling process faster and universal. In this thesis, CS methods are applied to magnetic resonance imaging (MRI) and JPEG 2000, which are popularly used imaging techniques in clinical applications and image compression, respectively. Over the years, MRI has improved dramatically in both imaging quality and speed. This has further revolutionized the field of diagnostic medicine. However, imaging speed, which is essential to many MRI applications still remains a major challenge. The specific challenge addressed in this work is the use of non-Fourier based complex measurement-based data acquisition. This method provides the possibility of reconstructing high quality MRI data with minimal measurements, due to the high incoherence between the two chosen matrices. Similarly, JPEG2000, though providing a high compression, can be further improved upon by using compressive sampling. In addition, the image quality is also improved. Moreover, having a optimized JPEG 2000 architecture reduces the overall processing, and a faster computation when combined with CS. Considering the requirements, this thesis is presented in two parts. In the first part: (1) A complex Hadamard matrix (CHM) based 2D and 3D MRI data acquisition with recovery using a greedy algorithm is proposed. The CHM measurement matrix is shown to satisfy the necessary condition for CS, known as restricted isometry property (RIP). The sparse recovery is done using compressive sampling matching pursuit (CoSaMP); (2) An optimized matrix and modified CoSaMP is presented, which enhances the MRI performance when compared with the conventional sampling; (3) An energy-efficient, cost-efficient hardware design based on field programmable gate array (FPGA) is proposed, to provide a platform for low-cost MRI processing hardware. At every stage, the design is proven to be superior with other commonly used MRI-CS methods and is comparable with the conventional MRI sampling. In the second part, CS techniques are applied to image processing and is combined with JPEG 2000 coder. While CS can reduce the encoding time, the effect on the overall JPEG 2000 encoder is not very significant due to some complex JPEG 2000 algorithms. One problem encountered is the big-level operations in JPEG 2000 arithmetic encoding (AE), which is completely based on bit-level operations. In this work, this problem is tackled by proposing a two-symbol AE with an efficient FPGA based hardware design. Furthermore, this design is energy-efficient, fast and has lower complexity when compared to conventional JPEG 2000 encoding

Predictability and prediction of persistent cool states of the Tropical Pacific Ocean

The Tropical Pacific Ocean displays persistently cool sea surface temperature (SST) anomalies that last several years to a decade, with either no El Niño events or a few weak El Niño events. These cause largescale droughts in the extratropics, including major North American droughts such as the 1930s Dust Bowl, and also modulate the global mean surface temperature. Here we show that two models with different levels of complexity— the Zebiak–Cane intermediate model and the Geophysical Fluid Dynamics Laboratory Coupled Model version 2.1— are able to produce such periods in a realistic manner. We then test the predictability of these periods in the Zebiak– Cane model using an ensemble of experiments with perturbed initial states. Our results show that in most cases the cool mean state is predictable. We then apply this method to make retrospective forecasts of shifts in the decadal mean state and to forecast the mean state of the Tropical Pacific Ocean for the upcoming decade. Our results suggest that the Pacific will undergo a shift to a warmer mean state after the 2015–2016 El Niño. This could imply the cessation of the drier than normal conditions that have generally afflicted southwest North America since the 1997–1998 El Niño, as well as the twenty-first-century pause in global warming. Implications for our understanding of the origins of such persistent cool states and the possibility of improving predictions of large-scale droughts are discussed

Preliminary Phytochemical Analysis and Antioxidants Activities of Ethanolic Extract from Gomphrena serrata Whole Plant

The present study was designed to investigate the phytochemical analysis and antioxidant activities of the whole plant of Gomphrena serrata. Gomphrena serrata widely distributed in South America, North America, and India. These plant parts are used as traditional medicine for the treatment of several ailments. This study aims to assess the phytochemical and free radical scavenging of ethanolic extract of G. serrata present in the plant. The preliminary phytochemical study was performed by standard method. The whole plant of G. serrata proved the presence of bioactive constituents such as carbohydrates, alkaloids, steroids, glycosides, triterpenoids, protein and amino acids, saponins, as well as flavonoids. The in-vitro antioxidant study was performed on the ethanolic extract of shade-dried of the whole plant, which determined by hydrogen peroxide, hydroxyl radical, and 1,1-diphenyl-2-picrylhydrazyl (DPPH) 100 µg/ml assay and was compared to ascorbic acid. The ethanolic extract of the whole plant of G. serrata shows the strong free radical scavenging activity. The present study was the proof for ethanol extract of G. serrata which have medicinally significant and bioactive compounds since these plant species are used as traditional medicine for the treatment of various diseases

The small world of global marine fisheries: the cross-boundary consequences of larval dispersal

Fish stocks are managed within national boundaries and by regional organizations, but the interdependence of stocks between these jurisdictions, especially as a result of larval dispersal, remains poorly explored. We examined the international connectivity of 747 commercially fished taxonomic groups by building a global network of fish larval dispersal. We found that the world’s fisheries are highly interconnected, forming a small-world network, emphasizing the need for international cooperation. We quantify each country’s dependence on its neighbors in terms of landed value, food security, and jobs. We estimate that more than $10 billion in annual catch from 2005 to 2014 is attributable to these international flows of larvae. The economic risks associated with these dependencies is greatest in the tropics

High prevalence of alpha thalassemia in the tribal community of the western part of India! Reality or myth? Can simple hematology parameters; MCV and MCH act as screening tools at birth?

Background: The majority of adult tribal subjects in the western part of India, show microcytic hypochromic red cells, and borderline anemia with a normal iron profile, suggesting a high prevalence of thalassemia in this population. Methods: The current study was designed to perform qualitative (to screen for Hb Bart’s) and quantitative (to estimate percentage of Hb Bart’s) hemoglobin electrophoresis with modification of the method, to evaluate the prevalence of α thalassemia and to determine gene frequency of α+ thal gene. Furthermore, the present study also aimed to evaluate common hematology parameters like MCV and MCH as screening tools to suspect α thalassemia at birth. Results: Based on hemoglobin electrophoresis, the prevalence of α thalassemia in all its forms was found to be 66.66%. The estimated gene frequency for α+ thal was found to be 0.7453 and based on that, the extrapolated prevalence of α thalassemia was 93.52% (55.55% homozygous and 37.97% heterozygous). MCV<100 fl and MCH<31 pg were found to be reliable screening tools to predict α thalassemia at birth in full-term uncomplicated pregnancy. Conclusions: Tribal community in the western part of India bears a very high prevalence of α thalassemia, it’s a reality and not a myth. Simple hematological parameters like MCV (<100 fl) and MCH (<31 pg) measured at birth can prove to be cost-effective surrogate markers for α thalassemia. Large scale study using confirmatory genetic analysis is required to validate the findings.

Tetanus vaccination is associated with differential DNA-methylation: Reduces the risk of asthma in adolescence

BackgroundVaccinations have been suggested to be associated with increased risk of allergic diseases. Tetanus vaccination is one of the most frequently administered vaccines as a part of wound management and was also found to be associated with increased serum IgE levels. We hypothesized that the vaccination modifies the risk of allergic diseases through epigenetic changes such as DNA methylation.MethodData on tetanus vaccination between 10 and 18 years of age was collected from a birth cohort established on the Isle of Wight UK in 1989. DNA methylation data were collected from individuals at different ages (at birth [n = 30], age 10 [n = 34], age 18 [n = 245] and during pregnancy [n = 121]) using the Illumina Infinium HumanMethylation450 K array. Firstly, we performed an epigenome-wide screening to identify cytosine-phosphate-guanine sites (CpGs) associated with tetanus vaccination in 18-year-olds. Secondly, we tested their association with asthma, allergic sensitization, eczema, serum IgE and pulmonary lung function (FVC, FEV1, FEV1/FVC, and FEF25-75%). We then described changes in the methylation of the selected CpG sites over age, and by vaccination status.ResultsTetanus vaccination was found to be associated with decreased methylation of cg14472551 (p value 0.5 × 10?5, FDR-adjusted p value 2.1 × 10?4) and increased methylation of cg01669161 (p value 0.0007, FDR-adjusted p value 0.014). Both CpGs, in turn, were associated with decreased risk of asthma at 18 years of age. Cg14472551 is located in an intron of KIAA1549L, whose protein binds to a B-cell commitment transcription factor; cg01669161 is located between an antisense regulator of the proteasome assembly chaperone PSMG3, and TFAMP1, a pseudogene. Increased methylation of cg01669161 was also associated with decreased serum IgE levels.ConclusionDNA methylation changes following tetanus vaccination may offer a novel prospect to explain a differential occurrence of asthma in adolescence

The chaperone HSPB8 reduces the accumulation of truncated TDP-43 species in cells and protects against TDP-43-mediated toxicity

Aggregation of TAR-DNA-binding protein 43 (TDP-43) and of its fragments TDP-25 and TDP-35 occurs in amyotrophic lateral sclerosis (ALS). TDP-25 and TDP-35 act as seeds for TDP-43 aggregation, altering its function and exerting toxicity. Thus, inhibition of TDP-25 and TDP-35 aggregation and promotion of their degradation may protect against cellular damage. Upregulation of HSPB8 is one possible approach for this purpose, since this chaperone promotes the clearance of an ALS associated fragments of TDP-43 and is upregulated in the surviving motor neurones of transgenic ALS mice and human patients. We report that overexpression of HSPB8 in immortalized motor neurones decreased the accumulation of TDP-25 and TDP-35 and that protection against mislocalized/truncated TDP-43 was observed for HSPB8 in Drosophila melanogaster. Overexpression of HSP67Bc, the functional ortholog of human HSPB8, suppressed the eye degeneration caused by the cytoplasmic accumulation of a TDP-43 variant with a mutation in the nuclear localization signal (TDP-43-NLS). TDP-43-NLS accumulation in retinal cells was counteracted by HSP67Bc overexpression. According with this finding, downregulation of HSP67Bc increased eye degeneration, an effect that is consistent with the accumulation of high molecular weight TDP-43 species and ubiquitinated proteins. Moreover, we report a novel Drosophila model expressing TDP-35, and show that while TDP-43 and TDP-25 expression in the fly eyes causes a mild degeneration, TDP-35 expression leads to severe neurodegeneration as revealed by pupae lethality; the latter effect could be rescued by HSP67Bc overexpression. Collectively, our data demonstrate that HSPB8 upregulation mitigates TDP-43 fragment mediated toxicity, in mammalian neuronal cells and flies

Mutations in TGM6 induce the unfolded protein response in SCA35

Spinocerebellar ataxia type 35 (SCA35) is a rare autosomal-dominant neurodegenerative disease caused by mutations in the TGM6 gene, which codes for transglutaminase 6 (TG6). Mutations in TG6 induce cerebellar degeneration by an unknown mechanism. We identified seven patients bearing new mutations in TGM6. To gain insights into the molecular basis of mutant TG6-induced neurotoxicity, we analyzed all of the seven new TG6 mutants and the five TG6 mutants previously linked to SCA35. We found that wild-type (TG6-WT) mainly localized to the nucleus and perinuclear area, whereas five TG6 mutations showed nuclear depletion, increased accumulation in the perinuclear area, insolubility and loss of enzymatic function. Aberrant accumulation of these TG6 mutants in the perinuclear area led to activation of the unfolded protein response (UPR), suggesting that specific TG6 mutants elicit an endoplasmic reticulum (ER) stress response. Mutations associated with activation of the UPR caused death of primary neurons and reduced the survival of novel D. melanogaster models of SCA35. These results indicate that mutations differently impacting on TG6 function cause neuronal dysfunction and death through diverse mechanisms and highlight the UPR as a potential therapeutic target for patient treatment