Equity and efficiency impacts of rural land rental restrictions: Evidence from India

Recognition of the potentially deleterious implications of high inequality of opportunity due to a biased asset distribution has led to increased interest in land reforms. However, little attention has been devoted to the potential longer-term impacts of the measures used to implement such reforms, despite evidence that, the restrictions on land rental in rural areas they imply can have potentially far-reaching consequences. Use of state level data on rental restrictions, in conjunction with a nationally representative survey from India suggests that, contrary to their original intention, rental restrictions significantly reduce supply of land to the rental market, prevent land access by the landless, and by more productive producers. Ways to counter these effects by liberalizing land rental markets are discussed.Land Economics/Use,

Determinants and Consequences of Land Sales Market Participation: Panel Evidence from India

Although opinions on impacts of land market transfers are sharply divided, few studies explore the welfare- and productivity impact of land markets on a larger scale. We use a large Indian panel spanning almost 20 years, together with a climatic shock (rainfall) indicator, to assess the productivity- and equity-impact of market-mediated land transfers (sale and purchase) as compared to non-market ones (inheritance). While frequent shocks increase land market activity, an effect that is mitigated by presence of safety nets and banks- land sales markets improved productivity and helped purchasers, many of them formerly landless, to accumulate non-land assets and significantly enhance their welfare.Land Economics/Use,

Does Land Fragmentation Reduce Efficiency: Micro Evidence from India

Land Economics/Use,

The 30-kW ammonia arcjet technology

The technical results are summarized of a 30 kW class ammonia propellant arcjet technology program. Evaluation of previous arcjet thruster performance, including materials analysis of used thruster components, led to the design of an arcjet with improved performance and thermal characteristics. Tests of the new engine demonstrated that engine performance is relatively insensitive to cathode tip geometry. Other data suggested a maximum sustainable arc length for a given thruster configuration, beyond which the arc may reconfigure in a destructive manner. A flow controller calibration error was identified. This error caused previously reported values of specific impulse and thrust efficiency to be 20 percent higher than the real values. Corrected arcjet performance data are given. Duration tests of 413 and 252 hours, and several tests 100 hours in duration, were performed. The cathode tip erosion rate increased with increasing arc current. Elimination of power source ripple did not affect cathode tip whisker growth. Results of arcjet modeling, diagnostic development and mission analyses are also discussed. The 30 kW ammonia arcjet may now be considered ready for development for a flight demonstration, but widespread application of 30 kW class arcjet will require improved efficiency and lifetime

DNA sequences of Alu elements indicate a recent replacement of the human autosomal genetic complement

DNA sequences of neutral nuclear autosomal loci, compared across diverse human populations, provide a previously untapped perspective into the mode and tempo of the emergence of modern humans and a critical comparison with published clonally inherited mitochondrial DNA and Y chromosome measurements of human diversity. We obtained over 55 kilobases of sequence from three autosomal loci encompassing Alu repeats for representatives of diverse human populations as well as orthologous sequences for other hominoid species at one of these loci. Nucleotide diversity was exceedingly low. Most individuals and populations were identical. Only a single nucleotide difference distinguished presumed ancestral alleles from descendants. These results differ from those expected if alleles from divergent archaic populations were maintained through multiregional continuity. The observed virtual lack of sequence polymorphism is the signature of a recent single origin for modern humans, with general replacement of archaic populations

Identification and Characterization of AES-135, a Hydroxamic Acid-Based HDAC Inhibitor That Prolongs Survival in an Orthotopic Mouse Model of Pancreatic Cancer

Pancreatic ductal adenocarcinoma (PDAC) is an aggressive, incurable cancer with a 20% 1 year survival rate. While standard-of-care therapy can prolong life in a small fraction of cases, PDAC is inherently resistant to current treatments, and novel therapies are urgently required. Histone deacetylase (HDAC) inhibitors are effective in killing pancreatic cancer cells in in vitro PDAC studies, and although there are a few clinical studies investigating combination therapy including HDAC inhibitors, no HDAC drug or combination therapy with an HDAC drug has been approved for the treatment of PDAC. We developed an inhibitor of HDACs, AES-135, that exhibits nanomolar inhibitory activity against HDAC3, HDAC6, and HDAC11 in biochemical assays. In a three-dimensional coculture model, AES-135 kills low-passage patient-derived tumor spheroids selectively over surrounding cancer-associated fibroblasts and has excellent pharmacokinetic properties in vivo. In an orthotopic murine model of pancreatic cancer, AES-135 prolongs survival significantly, therefore representing a candidate for further preclinical testing

A flexible and efficient template format for circular consensus sequencing and SNP detection

A novel template design for single-molecule sequencing is introduced, a structure we refer to as a SMRTbell™ template. This structure consists of a double-stranded portion, containing the insert of interest, and a single-stranded hairpin loop on either end, which provides a site for primer binding. Structurally, this format resembles a linear double-stranded molecule, and yet it is topologically circular. When placed into a single-molecule sequencing reaction, the SMRTbell template format enables a consensus sequence to be obtained from multiple passes on a single molecule. Furthermore, this consensus sequence is obtained from both the sense and antisense strands of the insert region. In this article, we present a universal method for constructing these templates, as well as an application of their use. We demonstrate the generation of high-quality consensus accuracy from single molecules, as well as the use of SMRTbell templates in the identification of rare sequence variants

Quantitative assay for the detection of the V617F variant in the Janus kinase 2 (JAK2) gene using the Luminex xMAP technology

<p>Abstract</p> <p>Background</p> <p>The availability of clinically valid biomarkers contribute to improve the diagnosis and clinical management of diseases. A valine-to-phenylalanine substitution at position 617 (V617F) in the Janus kinase 2 (JAK2) gene has been recently associated with key signaling abnormalities in the transduction of haemopoietic growth-factor receptors and is now considered as a useful clinical marker of myeloproliferative neoplasms. Several methods have recently been reported to detect the JAK2 V617F point mutation and show variable sensitivity.</p> <p>Methods</p> <p>Using the Luminex xMAP technology, we developed a quantitative assay to detect the JAK2V617F variant. The method was based on polymerase chain reaction (PCR) followed by hybridization to specific probes coupled with internally dyed microspheres. The assay comprises 3 steps: genomic DNA extraction, end point PCR reaction, direct hybridization of PCR fragments and quantification. It has been tested with different sources of nucleic acid.</p> <p>Results</p> <p>Applied to whole blood samples, this quantitative assay showed a limit of detection of 2%. A highly sensitive allele-specific primer extension reaction performed in parallel allowed to validate the results and to identify the specimens with values below 2%.</p> <p>Conclusion</p> <p>Direct hybridization assay using the Luminex xMAP technology allows sensitive quantification of JAK2V617F from blood spots. It is simple and can be easily performed in a clinical setting.</p

Environmental Costs of Government-Sponsored Agrarian Settlements in Brazilian Amazonia

Brazil has presided over the most comprehensive agrarian reform frontier colonization program on Earth, in which ~1.2 million settlers have been translocated by successive governments since the 1970's, mostly into forested hinterlands of Brazilian Amazonia. These settlements encompass 5.3% of this ~5 million km2 region, but have contributed with 13.5% of all land conversion into agropastoral land uses. The Brazilian Federal Agrarian Agency (INCRA) has repeatedly claimed that deforestation in these areas largely predates the sanctioned arrival of new settlers. Here, we quantify rates of natural vegetation conversion across 1911 agrarian settlements allocated to 568 Amazonian counties and compare fire incidence and deforestation rates before and after the official occupation of settlements by migrant farmers. The timing and spatial distribution of deforestation and fires in our analysis provides irrefutable chronological and spatially explicit evidence of agropastoral conversion both inside and immediately outside agrarian settlements over the last decade. Deforestation rates are strongly related to local human population density and road access to regional markets. Agrarian settlements consistently accelerated rates of deforestation and fires, compared to neighboring areas outside settlements, but within the same counties. Relocated smallholders allocated to forest areas undoubtedly operate as pivotal agents of deforestation, and most of the forest clearance occurs in the aftermath of government-induced migration

Characteristics of transposable element exonization within human and mouse

Insertion of transposed elements within mammalian genes is thought to be an important contributor to mammalian evolution and speciation. Insertion of transposed elements into introns can lead to their activation as alternatively spliced cassette exons, an event called exonization. Elucidation of the evolutionary constraints that have shaped fixation of transposed elements within human and mouse protein coding genes and subsequent exonization is important for understanding of how the exonization process has affected transcriptome and proteome complexities. Here we show that exonization of transposed elements is biased towards the beginning of the coding sequence in both human and mouse genes. Analysis of single nucleotide polymorphisms (SNPs) revealed that exonization of transposed elements can be population-specific, implying that exonizations may enhance divergence and lead to speciation. SNP density analysis revealed differences between Alu and other transposed elements. Finally, we identified cases of primate-specific Alu elements that depend on RNA editing for their exonization. These results shed light on TE fixation and the exonization process within human and mouse genes.Comment: 11 pages, 4 figure