AN ECONOMIC ASSESSMENT OF REMOVING THE PARTIAL U.S. IMPORT BAN ON FRESH MEXICAN HASS AVOCADOS

The importation of fresh Hass avocados from Mexico into the United States has been restricted, totally or partially, since 1914 on grounds of the potential risk of pest infestation. This quarantine has been a cause of dispute between the Mexican and U.S. governments. In 1997, Hass avocados from approved orchards in the State of Michoacán, Mexico, were permitted to be imported during the months of November through February into 19 northeastern states plus the District of Columbia. In 2001, the import period was extended to October 15 through April 15, and access was granted to 12 additional states. Currently there is a proposal to remove all seasonal and geographic restrictions on the importation of fresh Hass avocados from Mexico. The purpose of this research is to assess the potential economic impacts of removing the partial import ban. A static, partial equilibrium model is constructed to analyze impacts of removing the partial import ban on Mexican avocados. Two scenarios are considered: one with population and real per-capita income held constant (short run) and one that allows growth in population and real per-capita income over five years (long run). When population and real income are held constant, removal of the partial import ban leads to an increase in avocado imports from Mexico of 102.72 million pounds (267% increase). The increased competition from Mexican avocados results in welfare losses for both Californian and Chilean avocado producers of $84.5 million and$8.5 million respectively. Conversely, consumers in the United States gain from greater availability of avocados and lower prices. The gain in equivalent variation for US consumers is $115.3 million resulting in a net welfare gain of$30.8 million for the US. For the long-run scenario, population and real per-capita income are allowed to grow at their recent historical annual averages for five years. A five-year period is chosen to match the biological lag between planting and fruit bearing for avocados and is assumed to be the time period required for avocado producers to fully adjust to any price changes. The resulting increase in the aggregate demand for avocados significantly reduces the impact on Californian and Chilean producers of removing the partial import ban on Mexican avocados. While imports from Mexico increase by 161.4 million pounds, Californian avocado production decreases by only 14.4 million pounds and exports from Chile increase by 2.5 million pounds. The loss in producer surplus for Californian producers is $9.4 million, while the net US welfare gain is$33.2 million. While it appears likely that the removal of the partial import ban on Mexican avocados will hurt Californian producers, growth in demand for avocados will mitigate a great deal of the potential losses. Regardless of the magnitude of the growth in demand, consumers in the United States will benefit from a greater availability of avocados at lower prices. The gain in consumer welfare more than offsets the loss in producer welfare.International Relations/Trade,

Locus-specific DNA methylation analysis of retrotransposons in ES, somatic and cancer cells using High-Throughput Targeted Repeat Element Bisulfite Sequencing

© 2014. DNA methylation is a major epigenetic mark associated with multiple aspects of retrotransposons within the mammalian genome. In order to study DNA methylation of a large number of retrotransposons on an individual-locus basis, we have developed a new protocol termed High-Throughput Targeted Repeat Element Bisulfite Sequencing (HT-TREBS) (Ekram and Kim, 2014 [1]). We have used this technique to characterize the locus-specific patterns of DNA methylation of 4799 members of the mouse IAP LTR (Intracisternal A Particle Long Terminal Repeat) retrotransposon family in embryonic stem, somatic and Neuro2A cells (Bakshi and Kim, 2014 [2]). Here we describe in detail the sample preparation and bioinformatics analyses used for these studies. The somatic cell data may be accessed under GEO accession number GSE49222. The ES and Neuro2A data are deposited under GEO accession number GSE60007

Is Our Model for Contention Resolution Wrong?

Randomized binary exponential backoff (BEB) is a popular algorithm for coordinating access to a shared channel. With an operational history exceeding four decades, BEB is currently an important component of several wireless standards. Despite this track record, prior theoretical results indicate that under bursty traffic (1) BEB yields poor makespan and (2) superior algorithms are possible. To date, the degree to which these findings manifest in practice has not been resolved. To address this issue, we examine one of the strongest cases against BEB: $n$ packets that simultaneously begin contending for the wireless channel. Using Network Simulator 3, we compare against more recent algorithms that are inspired by BEB, but whose makespan guarantees are superior. Surprisingly, we discover that these newer algorithms significantly underperform. Through further investigation, we identify as the culprit a flawed but common abstraction regarding the cost of collisions. Our experimental results are complemented by analytical arguments that the number of collisions -- and not solely makespan -- is an important metric to optimize. We believe that these findings have implications for the design of contention-resolution algorithms.Comment: Accepted to the 29th ACM Symposium on Parallelism in Algorithms and Architectures (SPAA 2017

Parallel algorithm with spectral convergence for nonlinear integro-differential equations

We discuss a numerical algorithm for solving nonlinear integro-differential equations, and illustrate our findings for the particular case of Volterra type equations. The algorithm combines a perturbation approach meant to render a linearized version of the problem and a spectral method where unknown functions are expanded in terms of Chebyshev polynomials (El-gendi's method). This approach is shown to be suitable for the calculation of two-point Green functions required in next to leading order studies of time-dependent quantum field theory.Comment: 15 pages, 9 figure

AEBP2 as a transcriptional activator and its role in cell migration

© 2014 Elsevier Inc. Aebp2 encodes an evolutionarily conserved zinc finger protein that has not been well studied so far, yet recent studies indicated that this gene is closely associated with the Polycomb Repressive Complex 2 (PRC2). Thus, the current study characterized the basic aspects of this gene, including alternative promoters and protein isoforms. According to the results, Aebp2 is controlled through three alternative promoters, deriving three different transcripts encoding the embryonic (32. kDa) and somatic (52. kDa) forms. Chromatin Immuno-Precipitation (ChIP) experiments revealed that AEBP2 binds to its own promoter as well as the promoters of Jarid2 and Snai2. While the embryonic form acts as a transcriptional repressor for Snai2, the somatic form functions as a transcriptional activator for Jarid2, Aebp2 and Snai2. Cell migration assays also demonstrated that the Aebp2 somatic form has an enhancing activity in cell migration. This is consistent with the functional association of Aebp2 with migratory neural crest cells. These results suggest that the two protein isoforms of AEBP2 may have opposite functions for the PcG target genes, and may play significant roles in cell migration during development

Study of biochemical markers in iron deficiency anemia

Background: The present study was aimed to study alterations in levels of oxidants and antioxidants in iron deficiency anemia (IDA).Methods: 30 patients of IDA in age group of 20-50 and 30 healthy subjects were included for study. Serum Iron, TIBC & Hb% were estimated to diagnose IDA. Serum Malondialdehyde (MDA), Nitric oxide (NO) as an oxidants & Superoxide dismutase (SOD), vitamin E, vitamin C, Zinc (Zn) levels as antioxidants were estimated.Results: Significant decreased levels of Hb%, serum iron, SOD, Vitamin C, vitamin E, Zn were found. TIBC, MDA, NO were significantly increased as compared to controls.Conclusion: The normal adult erythrocytes can resist oxidative stress by several antioxidant defense systems. In IDA, oxidative stress causes lipid peroxidation and membrane damage. So antioxidants can be used as a marker for prevention of membrane damage due to oxidative stress

Numerical Approximations Using Chebyshev Polynomial Expansions

We present numerical solutions for differential equations by expanding the unknown function in terms of Chebyshev polynomials and solving a system of linear equations directly for the values of the function at the extrema (or zeros) of the Chebyshev polynomial of order N (El-gendi's method). The solutions are exact at these points, apart from round-off computer errors and the convergence of other numerical methods used in connection to solving the linear system of equations. Applications to initial value problems in time-dependent quantum field theory, and second order boundary value problems in fluid dynamics are presented.Comment: minor wording changes, some typos have been eliminate

Antioxidants deficiency: a sensitive indicator of cardiometabolic risk in chronic renal failure?

Background: Antioxidant depletion occurring in chronic renal failure patients is an important cause of associated morbidity & mortality, which in turn imposes a great socioeconomic burden of health care. Early diagnosis & targeted management of this preventable deficiency may have a positive impact on the management of co morbidities associated with chronic renal failure.Aims & Objectives: To evaluate the status of antioxidants as an early indicator of cardiometabolic risk in chronic renal failure patients.Settings & Design: This was a randomised case Control study including 10 controls of either sex with normal renal function between age group 20-60 years and 15 patients of chronic renal failure on dialysis between the age group of 16 - 60 years.Methods: 12 hour fasting venous blood samples were collected from all the participants and were assayed for various antioxidants.Statistical analysis: Results were analyzed by unpaired t test, p value was determined & Correlation coefficient was calculated amongst various parameters.Results: In the present study, significantly low levels of vitamin C ( Cases: 0.367 ± 0.13 mg/dl controls: 1.324 ± 0.61 mg/dl; p < 0.01) & vitamin E  (cases: 0.235 ± 0.102 mg/dl, controls (0.854 ± 0.28 mg/dl; p < 0.01) were observed in chronic renal failure patients as compared to controls.Conclusion: Diminished levels of Vitamin C & E in our study may be an indicator of increased oxidative stress which can be a responsible factor for increased incidence of cardiovascular complications. Supplementing these patients with recommended dosage of these vitamins may provide an essential tool to reduce the burden of suffering

Study of serum sodium and potassium concentration in cataract patients

Background: The present study was aimed to study alterations in levels of sodium and potassium in age-related cataract patients.Methods: 50 senile cataract patients in age group of 50 to 80 years and 50 control group were included for the study. Serum sodium and potassium levels were determined by flame photometry.Results: Significant (<0.0001)  increased levels of plasma Na+ in cataract patients (145.06 ± 5.84mEq/lit) were found as compared with controls (141.18 ± 2.67mEq/lit). While Plasma K+ the conc. in cataract patients (4.18 ± 0.34mEq/lit) was not significantly (P = 0.002) increased when compared with controls (4.13 ± 0.32mEq/lit).Conclusion: Na, K-ATPase is responsible for maintaining the correct concentrations of sodium and potassium in lens cells. In ageing, lens fibers undergoes oxidation, and glycation may decrease Na, K-ATPase activity. The asymmetrical distribution of Na, K-ATPase activity in the epithelium and fibers may contribute to ionic currents that flow in and around the lens. So, abnormal elevation of lens sodium can be used as a marker in the opacification of the lens cortex in age-related human cataract