Conversion from Staple to Cash Crop Production in Mexico After NAFTA: Effects of PROCAMPO and Credit Constraints

In this thesis, I ask whether the Program of Direct Support for the Countryside (PROCAMPO) helped Mexican agricultural producers benefit from the North American Free Trade Agreement (NAFTA). Specifically, I explore the effect of PROCAMPO???s decoupled income payments on producers??? ability to switch to cash crop production, and whether these payments continue to alleviate credit constraints for poorer producers. Given that World Trade Organization (WTO) negotiations are currently stalled in part because of the trade concerns of developing nations, exploring the constraints that small producers face and whether decoupled subsidies can assist those producers in benefiting from new markets is important. Unlike previous studies, which concentrated on specific regions and ejidal lands, I use nation-wide county-level data, allowing me to see the regional distribution of change across Mexico. I use these data to estimate the change in staple crop production as a function of county-level characteristics. This analysis led to several interesting observations. First, I find some evidence to support the hypothesis that an increase in PROCAMPO payments leads to a decrease in the area planted in staples. Second, the implementation of NAFTA is associated with greater cash crop production, and I can see that the creation of new markets is, in general, leading to a reduction in land planted in staples. Third, I find that the effect of PROCAMPO is even larger for ejido producers, implying that the benefits are not constrained to larger producers. Last, I find evidence that areas closest to the United States border have seen a greater movement to cash crop production after NAFTA

Conversion from Staple to Cash Crop Production in Mexico After NAFTA: Effects of PROCAMPO and Credit Constraints

In this paper, we ask whether PROCAMPO helped Mexican agricultural producers benefit from NAFTA. Specifically, we explore the effect of these decoupled income payments (PROCAMPO) on producers’ ability to switch to cash crop production, and whether these payments help alleviate credit constraints for poorer producers. Given that WTO negotiations are currently stalled in part because of the trade concerns of developing nations, exploring the constraints that small producers face and whether decoupled subsidies can assist those producers in benefiting from new markets is important. Unlike previous studies, who concentrated on specific regions and ejidal lands, we use nationwide county-level data, which allows for us to see the regional distribution of change across Mexico. We use these data to estimate the change in staple crop production as a function of county-level characteristics. We find some evidence to support the hypothesis that an increase in PROCAMPO payments leads to a decrease in the area planted in staples. Second, the implementation of NAFTA is associated with greater cash crop production and we can see that the creation of new markets is, in general, leading to a reduction in land planted in staples. Third, we find that the effect of PROCAMPO is even larger for ejido producers, implying that their benefits are not constrained to larger producers. Last, we find evidence that areas closest to the United States border have seen a greater movement to cash crop production after NAFTA.NAFTA, PROCAMPO, Credit Constraint, Mexico, staple production, crop choice, International Relations/Trade,

Application of response surface techniques to helicopter rotor blade optimization procedure

In multidisciplinary optimization problems, response surface techniques can be used to replace the complex analyses that define the objective function and/or constraints with simple functions, typically polynomials. In this work a response surface is applied to the design optimization of a helicopter rotor blade. In previous work, this problem has been formulated with a multilevel approach. Here, the response surface takes advantage of this decomposition and is used to replace the lower level, a structural optimization of the blade. Problems that were encountered and important considerations in applying the response surface are discussed. Preliminary results are also presented that illustrate the benefits of using the response surface

“If I Could in a Small Way Help”: Motivations for and Beliefs About Sample Donation for Genetic Research

Human genome research depends upon participants who donate genetic samples, but few studies have explored in depth the motivations of genetic research donors. This mixed methods study examines telephone interviews with 752 sample donors in a U.S. genetic epidemiology study investigating colorectal cancer. Quantitative and qualitative results indicate that most participants wanted to help society, and that many also wanted information about their own health, even though such information was not promised. Qualitative analysis reveals that donors believed their samples contributed to a scientific “common good”; imagined samples as information rather than tissues; and often blurred distinctions between research and diagnostic testing of samples. Differences between African American and White perspectives were distinct from educational and other possible explanatory factors

High Power Density from a Miniature Microbial Fuel Cell Using \u3ci\u3eShewanella oneidensis\u3c/i\u3e DSP10

A miniature microbial fuel cell (mini-MFC) is described that demonstrates high output power per device crosssection (2.0 cm2) and volume (1.2 cm3). Shewanella oneidensis DSP10 in growth medium with lactate and buffered ferricyanide solutions were used as the anolyte and catholyte, respectively. Maximum power densities of 24 and 10 mW/m2 were measured using the true surface areas of reticulated vitreous carbon (RVC) and graphite felt (GF) electrodes without the addition of exogenous mediators in the anolyte. Current densities at maximum power were measured as 44 and 20 mA/m2 for RVC and GF, while short circuit current densities reached 32 mA/m2 for GF anodes and 100 mA/m2 for RVC. When the power density for GF was calculated using the cross sectional area of the device or the volume of the anode chamber, we found values (3 W/m2, 500 W/m3) similar to the maxima reported in the literature. The addition of electron mediators resulted in current and power increases of 30-100%. These power densities were surprisingly high considering a pure S. oneidensis culture was used. We found that the short diffusion lengths and high surface-area-to-chamber volume ratio utilized in the mini-MFC enhanced power density when compared to output from similar macroscopic MFCs

High Power Density from a Miniature Microbial Fuel Cell Using \u3ci\u3eShewanella oneidensis\u3c/i\u3e DSP10

A miniature microbial fuel cell (mini-MFC) is described that demonstrates high output power per device crosssection (2.0 cm2) and volume (1.2 cm3). Shewanella oneidensis DSP10 in growth medium with lactate and buffered ferricyanide solutions were used as the anolyte and catholyte, respectively. Maximum power densities of 24 and 10 mW/m2 were measured using the true surface areas of reticulated vitreous carbon (RVC) and graphite felt (GF) electrodes without the addition of exogenous mediators in the anolyte. Current densities at maximum power were measured as 44 and 20 mA/m2 for RVC and GF, while short circuit current densities reached 32 mA/m2 for GF anodes and 100 mA/m2 for RVC. When the power density for GF was calculated using the cross sectional area of the device or the volume of the anode chamber, we found values (3 W/m2, 500 W/m3) similar to the maxima reported in the literature. The addition of electron mediators resulted in current and power increases of 30-100%. These power densities were surprisingly high considering a pure S. oneidensis culture was used. We found that the short diffusion lengths and high surface-area-to-chamber volume ratio utilized in the mini-MFC enhanced power density when compared to output from similar macroscopic MFCs

Transcriptional dynamics of pluripotent stem cell-derived endothelial cell differentiation revealed by single-cell RNA sequencing

Aims Pluripotent stem cell-derived endothelial cell products possess therapeutic potential in ischaemic vascular disease. However, the factors that drive endothelial differentiation from pluripotency and cellular specification are largely unknown. The aims of this study were to use single-cell RNA sequencing (scRNA-seq) to map the transcriptional landscape and cellular dynamics of directed differentiation of human embryonic stem cell-derived endothelial cells (hESC-EC) and to compare these cells to mature endothelial cells from diverse vascular beds. Methods and results A highly efficient directed 8-day differentiation protocol was used to generate a hESC-derived endothelial cell product (hESC-ECP), in which 66% of cells co-expressed CD31 and CD144. We observed largely homogeneous hESC and mesodermal populations at Days 0 and 4, respectively, followed by a rapid emergence of distinct endothelial and mesenchymal populations. Pseudotime trajectory identified transcriptional signatures of endothelial commitment and maturation during the differentiation process. Concordance in transcriptional signatures was verified by scRNA-seq analysis using both a second hESC line RC11, and an alternative hESC-EC differentiation protocol. In total, 105 727 cells were subjected to scRNA-seq analysis. Global transcriptional comparison revealed a transcriptional architecture of hESC-EC that differs from freshly isolated and cultured human endothelial cells and from organ-specific endothelial cells. Conclusion A transcriptional bifurcation into endothelial and mesenchymal lineages was identified, as well as novel transcriptional signatures underpinning commitment and maturation. The transcriptional architecture of hESC-ECP was distinct from mature and foetal human EC.This work was supported by the Medical Research Council [MRC Precision Medicine Doctoral Training Programme to I.R.M. and both the MRC Discovery Award and Programme grant (MC_PC_15075) and MRC Programme: Computational and Disease Genomics (MC_UU_00007/15) to C.P.P.], the Wellcome Trust [Wellcome Trust Senior Research Fellowship in Clinical Science (ref. 103749) to N.C.H.], the European Research Council [Advanced Grant VASCMIR (RE7644) to A.H.B.], and the British Heart Foundation [BHF CVR grant (RM/17/3/ 33381) and BHF Chair of Translational Cardiovascular Sciences to A.H.B.]

The interactive effects of post-traumatic stress symptoms and breathlessness on fatigue severity in post-COVID-19 syndrome

Background: Post-traumatic stress symptoms (PTSS) and breathlessness have been well documented in the acute phase of COVID-19 as well as in Post-COVID-19 Syndrome (PCS), commonly known as Long-COVID. The present study aimed to explore whether PTSS and breathlessness interact to exacerbate fatigue among individuals recovering from PCS, similar to the effects evidenced in other health conditions that feature respiratory distress.. Methods: Outcome measures were collected from 154 participants reporting persistent fatigue following acute COVID-19 infection who were enrolled in a 7-week rehabilitation course provided by the Primary Care Wellbeing Service (PCWBS) in Bradford District Care NHS Foundation Trust (BDCFT). Results: Hierarchical multiple linear regression revealed that fatigue severity was associated with a significant interaction between PTSS and breathlessness, even when controlling for pre-COVID health related quality of life (HRQoL), age, symptom duration and hospital admittance during the acute phase. Furthermore, improvements in fatigue following rehabilitation were significantly associated with improvements in PTSS. Conclusions: PTSS may be an important therapeutic target in multidisciplinary rehabilitation for reducing fatigue in the recovery from PCS. It is therefore important that treatment for PCS takes a biopsychosocial approach to recovery, putting emphasis on direct and indirect psychological factors which may facilitate or disrupt physical recovery. This highlights the need for all PCS clinics to screen for PTSD and if present, target as a priority in treatment to maximise the potential for successful rehabilitation

The role of race and trust in tissue/blood donation for genetic research

Public willingness to donate tissue samples is critical to genetic research. Prior work has linked minority status and mistrust with less willingness to provide specimens. Some have suggested recruitment of prior research participants to address these barriers. We present data from a genetic epidemiology study with a request for blood and/or saliva specimens to: 1) measure willingness to donate tissue/blood samples, 2) identify demographic, trust, and other factors associated with willingness to donate samples, and 3) measure willingness to participate in future genetic research