LAND TITLING IN PERU: IS IT FULFILLING ITS PROMISE?

The objective of this paper is to determine the impact of land titling in coastal Peru on the beneficiaries of this program. The paper examines the effects of land titling on access to credit, on-farm investment, the use of conservation techniques and the functioning of land markets.Land Economics/Use,

Asian Americans and Party Affiliation

This issue brief explores Asian Americans and Party Affiliation in the United States. It discusses whether or not Asian Americans identify with a particular political party and the significance of the Asian American vote in elections

African Americans and Native Americans

This issue brief examines the relationship between African Americans and Native Americans in the United States. It discusses the implementation of a blood quantification system whereby persons of African American and Native American heritage are denied not only the benefits but more importantly membership to these Native American groups

Qualitative Analysis of Loss of Control Aircraft Accidents Using Text Mining Techniques

The purpose of this study was to analyze the narrative National Transportation Safety Board (NTSB) accident cause descriptions for general aviation (GA) Loss of Control (LOC) accident reports by the different certification categories: Federal Aviation Regulations Part 23 (Part 23), Civil Air Regulations 3 (CAR 3), Light Sport Aircraft (LSA), and Experimental-Amateur Built (E-AB). Airworthiness certification categories represent a wide diversity of government oversight. Part 23 rules have evolved from the initial set of simpler design standards and have progressed into a comprehensive and strict set of rules to address the safety issues of the more complex airplanes within the category. E-AB airplanes have the least amount of government oversight and are the fastest-growing segment. The LSA category is a more recent certification category that utilizes consensus standards in the approval process. CAR 3 airplanes were designed and manufactured under simpler rules, but modifying these airplanes has become lengthy and expensive. The qualitative analysis involved the use of text mining techniques for the analysis of the narrative cause descriptions contained within the accident reports. The text mining analysis of the narrative causes of LOC accidents indicated that only the CAR 3 category airplanes had clusters of words associated with visual flight into instrument meteorological conditions. CAR 3 airplanes were designed and manufactured prior to the 1960s, and in most cases have not been retrofitted to take advantage of newer technologies that could help prevent LOC accidents. According to the literature, government oversight could have become an obstacle in the implementation of safety enhancing equipment that could reduce LOC accidents

Subwavelength resolution for horizontal and vertical polarization by coupled arrays of oblate nanoellipsoids

A structure comprising a coupled pair of two-dimensional arrays of oblate plasmonic nanoellipsoids in a dielectric host medium is proposed as a superlens in the optical domain for both horizontal and vertical polarizations. By means of simulations it is demonstrated that a structure formed by silver nanoellipsoids is capable of restoring subwavelength features of the object for both polarizations at distances larger than half-wavelength. The bandwidth of subwavelength resolution is in all cases very large (above 13%).Comment: 3 pages with 6 figure

The colour and golden shine of early silver Islamic lustre

A selection of lustres including 9th century AD polychrome and 10th century AD monochrome Abbasid lustres from Iraq, and 10th to 12th centuries AD Fatimid lustres from Egypt and Syria is studied in the present paper. The selection is based on previous studies that demonstrated that all of them contain metal silver nanoparticles and copper, which, when present, appears either as Cuþ or Cu2þ dissolved in the glaze. They show different colours, green, yellow, amber, and brown, and may also show or lack a golden-like reflectivity, which results mainly from average size and concentration in the layer of the silver nanoparticles. In this paper, a depth profile composition of the lustre layers is determined using Rutheford Backscattering Spectroscopy, allowing the determination of the total silver content, concentration of silver, copper to silver ratio, and thickness of the lustre layers. We show that the enhanced golden-like reflectivity occurs only for layers with a high concentration of silver, and that the addition of PbO to the alkaline glaze helps the formation of more concentrated layers. The results obtained provide new hints concerning the lead enrichment of the glazes during this period.Peer ReviewedPostprint (published version

Human urinary mutagenicity after wood smoke exposure during traditional temazcal use.

In Central America, the traditional temazcales or wood-fired steam baths, commonly used by many Native American populations, are often heated by wood fires with little ventilation, and this use results in high wood smoke exposure. Urinary mutagenicity has been previously employed as a non-invasive biomarker of human exposure to combustion emissions. This study examined the urinary mutagenicity in 19 indigenous Mayan families from the highlands of Guatemala who regularly use temazcales (N = 32), as well as control (unexposed) individuals from the same population (N = 9). Urine samples collected before and after temazcal exposure were enzymatically deconjugated and extracted using solid-phase extraction. The creatinine-adjusted mutagenic potency of urine extracts was assessed using the plate-incorporation version of the Salmonella mutagenicity assay with strain YG1041 in the presence of exogenous metabolic activation. The post-exposure mutagenic potency of urine extracts were, on average, 1.7-fold higher than pre-exposure samples (P < 0.005) and also significantly more mutagenic than the control samples (P < 0.05). Exhaled carbon monoxide (CO) was ~10 times higher following temazcal use (P < 0.0001), and both CO level and time spent in temazcal were positively associated with urinary mutagenic potency (i.e. P < 0.0001 and P = 0.01, respectively). Thus, the wood smoke exposure associated with temazcal use contributes to increased excretion of conjugated mutagenic metabolites. Moreover, urinary mutagenic potency is correlated with other metrics of exposure (i.e. exhaled CO, duration of exposure). Since urinary mutagenicity is a biomarker associated with genetic damage, temazcal use may therefore be expected to contribute to an increased risk of DNA damage and mutation, effects associated with the initiation of cancer

Effects of Dry‐Season Irrigation on Leaf Physiology and Biomass Allocation in Tropical Lianas and Trees

Lianas are more abundant in seasonal forests than in wetter forests and are thought to perform better than trees when light is abundant and water is limited. We tested the hypothesis that lianas perform better than trees during seasonal drought using a common garden experiment with 12 taxonomically diverse species (six liana and six tree species) in 12 replicated plots. We irrigated six of the plots during the dry season for four years, while the remaining six control plots received only ambient rainfall. In year 5, we measured stem diameters for all individuals and harvested above‐ and belowground biomass for a subset of individuals to quantify absolute growth and biomass allocation to roots, stems, and leaves, as well as total root length and maximum rooting depth. We also measured rate of photosynthesis, intrinsic water use efficiency (iWUE), pre‐dawn and midday water potential, and a set of functional and hydraulic traits. During the peak of the dry season, lianas in control plots had 54% higher predawn leaf water potentials (ΨPD), and 45% higher photosynthetic rates than trees in control plots. By contrast, during the peak of the wet season, these physiological differences between lianas and trees become less pronounced and, in some cases, even disappeared. Trees had higher specific leaf area (SLA) than lianas; however, no other functional trait differed between growth forms. Trees responded to the irrigation treatment with 15% larger diameters and 119% greater biomass than trees in control plots. Liana growth, however, did not respond to irrigation; liana diameter and biomass were similar in control and irrigation plots, suggesting that lianas were far less limited by soil moisture than were trees. Contrary to previous hypotheses, lianas did not have deeper roots than trees; however, lianas had longer roots per stem diameter than did trees. Our results support the hypothesis that lianas perform better and experience less physiological stress than trees during seasonal drought, suggesting clear differences between growth forms in response to altered rainfall regimes. Ultimately, better dry‐season performance may explain why liana abundance peaks in seasonal forests compared to trees, which peak in abundance in less seasonal, wetter forests

Samuel Roberts Owens to Frances Owens, January 28, 1942

This letter was written by Samuel Roberts Owens to his mother, Mrs. S.J. Owens. He sends greetings to his family, especially his father, to whom he wishes a happy birthday. Owens tells his mother not to write for a while, and assures her he will write her as often as he can. He tells her not to worry, that “no news is good news” since she would hear if anything bad happened to him. He tells her he expects to get leave soon to come home, and sends his love