THE NEW WAVE OF REGIONALISM: DOES OUTSIDER/INSIDER STATUS AFFECT THE COMPETITIVENESS OF U.S. AGRICULTURAL EXPORTS?

The degree to which countries are pursuing regional trade agreements (RTAs) has been nothing short of extraordinary. The topic of regional integration is “breeding concern” among academics and policymakers as to the intra- and extra-regional effects of these agreements. This study constructs and uses an updated database of agricultural trade flows from 1992-2008 to shed light on the degree to which insider and outsiders status affects U.S. agricultural exporters and its competing suppliers. Regarding outsider status, we modify the existing approach by incorporating region-specific extra-bloc trade flow variables to examine the degree to which RTAs divert trade from specific regions of the world. The results are quite illuminating. While RTAs may not be trade diverting on net, all RTAs considered exhibit trade diversion with respect to at least some regions. The results have important policy implications for nations that are not actively participating in the latest wave of regionalism.International Relations/Trade,

NORTH AMERICAN INTEGRATION IN AGRICULTURE: A SURVEY PAPER

This paper surveys the economic literature about North American integration in the agri-food sector. The purpose of this survey is two-fold: it summarizes the lessons learned, and it identifies areas where further research could provide valuable input into policy discussions. As the integration of North American agriculture progresses, the range of agri-food policies with strictly domestic effects becomes increasingly narrow. Thus, policymakers in North America need to consider the effects that their decisions will have on other NAFTA countries, as well as the impact that decisions by other NAFTA governments will have at home. The paper is organized as follows. Section 2 identifies the major factors contributing to integration and comments on their relative importance. Section 3 summarizes research into the indicators of integration. These studies focus on price co-movements and trade flow data. Section 4 outlines the state of current knowledge regarding foreign direct investment in the agri-food sector, while Section 5 assesses the impact of integration on the structure and performance of the sector. Section 6 discusses opportunities for further integration in the sector, and Section 7 concludes the paper. Throughout the paper, gaps in the knowledge base are highlighted, along with suggested areas for further research.Industrial Organization,

The focus of light - linear polarization breaks the rotational symmetry of the focal spot

We experimentally demonstrate for the first time that a linearly polarized beam is focussed to an asymmetric spot when using a high-numerical aperture focussing system. This asymmetry was predicted by Richards and Wolf [Proc.R.Soc.London A, 253, 358 (1959)] and can only be measured when a polarization insensitive sensor is placed in the focal region. We used a specially modified photodiode in a knife edge type set up to obtain highly resolved images of the total electric energy density distribution at the focus. The results are in good agreement with the predictions of a vectorial focussing theory.Comment: to be published in "Journal of Modern Optics

Hierarchical Chain Model of Spider Capture Silk Elasticity

Spider capture silk is a biomaterial with both high strength and high elasticity, but the structural design principle underlying these remarkable properties is still unknown. It was revealed recently by atomic force microscopy that, an exponential force--extension relationship holds both for capture silk mesostructures and for intact capture silk fibers [N. Becker et al., Nature Materials 2, 278 (2003)]. In this Letter a simple hierarchical chain model was proposed to understand and reproduce this striking observation. In the hierarchical chain model, a polymer is composed of many structural motifs which organize into structural modules and supra-modules in a hierarchical manner. Each module in this hierarchy has its own characteristic force. The repetitive patterns in the amino acid sequence of the major flagelliform protein of spider capture silk is in support of this model.Comment: 4 pages, 3 figures. Will be formally published in PR

Prediction of posttraumatic stress in fathers of children with chronic diseases or unintentional injuries: a six-months follow-up study

<p>Abstract</p> <p>Background</p> <p>While fathers were neglected for a long time in research investigating families of pediatric patients, there are now a few studies available on fathers' posttraumatic stress symptoms (PTSS) and posttraumatic stress disorder (PTSD). However, little is known about the course of PTSS and PTSD in fathers of pediatric patients. The present study aimed to compare the prevalence and course of PTSS and PTSD in fathers of children with different chronic and acute conditions and to identify factors that contribute to fathers' PTSS.</p> <p>Methods</p> <p>Sixty-nine fathers of children newly diagnosed with either cancer, type I diabetes mellitus, or epilepsy and 70 fathers of children suffering from an unintentional injury completed questionnaires at 4–6 weeks (Time 1) and six months (Time 2) after diagnosis or injury.</p> <p>Results</p> <p>Noticeable PTSD rates were found in fathers of children with a chronic disease (26% at Time 1 and 21% at Time 2, respectively). These rates were significantly higher than rates found in fathers of children with unintentional injuries (12% at Time 1 and 6% at Time 2, respectively). Within six months after the child's diagnosis or accident a decrease in severity of PTSS was observed in both groups. Significant predictors of PTSS at Time 2 were the father's initial level of PTSS, the child's medical condition (injuries vs. chronic diseases) and functional status, the father's use of dysfunctional coping strategies, and father's level of neuroticism.</p> <p>Conclusion</p> <p>Our findings suggest that fathers with initially high PTSS levels are at greater risk to experience PTSS at follow-up, particularly fathers of children with a chronic disease. Sensitizing health care professionals to the identification of PTSS symptoms but also to indicators of neuroticism and the use of specific coping strategies early in the treatment course is essential for the planning and implementation of adequate intervention strategies.</p

Anterior knee pain from the evolutionary perspective

Background This paper describes the evolutionary changes in morphology and orientation of the PFJ using species present through our ancestry over 340 million years. Methods 37 specimens from the Devonian period to modern day were scanned using a 64-slice CT scanner. 3D geometries were created following routine segmentation and anatomical measurements taken from standardised bony landmarks. Results Findings are described according to gait strategy and age. The adoption of an upright bi-pedal stance caused a dramatic change in the loading of the PFJ which has subsequently led to changes in the arrangement of the PFJ. From Devonian to Miocene periods, our sprawling and climbing ancestors possessed a broad knee with a shallow, centrally located trochlea. A more rounded knee was present from the Paleolithic period onwards in erect and bipedal gait types (aspect ratio 0.93 vs 1.2 in late Devonian), with the PFJ being placed lateral to the midline compared to the medial position in quadrapeds. The depth of the trochlea groove was maximal in the Miocene period of the African ground apes with associated acute sulcus angles in Gorilla (117°) becoming more flattened towards the modern human (138°). Conclusions The evolving bipedal gait lead to anteriorisation of the patellofemoral joint, flattening of the trochlea sulcus, in a more lateral, dislocation prone arrangement. Ancestral developments might help explain the variety of presentations of anterior knee pain and patellofemoral instability

Active zone proteins are dynamically associated with synaptic ribbons in rat pinealocytes

Synaptic ribbons (SRs) are prominent organelles that are abundant in the ribbon synapses of sensory neurons where they represent a specialization of the cytomatrix at the active zone (CAZ). SRs occur not only in neurons, but also in neuroendocrine pinealocytes where their function is still obscure. In this study, we report that pinealocyte SRs are associated with CAZ proteins such as Bassoon, Piccolo, CtBP1, Munc13–1, and the motorprotein KIF3A and, therefore, consist of a protein complex that resembles the ribbon complex of retinal and other sensory ribbon synapses. The pinealocyte ribbon complex is biochemically dynamic. Its protein composition changes in favor of Bassoon, Piccolo, and Munc13–1 at night and in favor of KIF3A during the day, whereas CtBP1 is equally present during the night and day. The diurnal dynamics of the ribbon complex persist under constant darkness and decrease after stimulus deprivation of the pineal gland by constant light. Our findings indicate that neuroendocrine pinealocytes possess a protein complex that resembles the CAZ of ribbon synapses in sensory organs and whose dynamics are under circadian regulation

An RCS-Like Retinal Dystrophy Phenotype in Mer Knockout Mice

PURPOSE. To determine whether mice that are homozygous for a targeted disruption of the Mer receptor tyrosine kinase gene (merkd) manifest a retinal dystrophy phenotype similar to RCS rats, which carry a mutation in the orthologous gene Mertk. METHODS. Eyes of merkdand C57BL/6 wild-type (WT) mice were examined by light and electron microscopy, whole-eye rhodopsin measurement, and Ganzfeld electroretinography (ERG). RESULTS. The merkdmice showed rapid, progressive degeneration of the photoreceptors (PRs). Features of the phenotype common to metkdmice and RCS rats included the absence or near absence of phagosomes in the retinal pigment epithelium (RPE) at the peak of outer segment (OS) disc shedding, accumulation of debris and whorls of membranes at the RPE-OS interface, transient supernormal rhodopsin content and OS lengths, the presence of OS vacuoles beginning at early ages, and a relatively slow removal of pyknotic PR nuclei. Most PRs were missing, and OS debris was removed by approximately postnatal day (P)45. Scotopic ERG responses were lower than age-matched WT responses and declined with PR loss. Photopic responses were preserved better than scotopic responses, corresponding with preferential cone preservation as judged histologically. ERG amplitudes were usually unmeasurable beyond P40, although a small-amplitude scotopic threshold response (STR) could still be elicited at P253 in some mice when only scattered PR nuclei remained. CONCLUSIONS. Ablation of Mer function in merkdmice results in a retinal phenotype almost identical with that of RCS rats. The similarity in phenotypes between the two rodent models suggests that an RPE phagocytic defect is a feature of all types of retinal degeneration caused by loss of function of Mer tyrosine kinase, perhaps including mutations in human MERTK

Exploring causal pathways of child behavior and maternal mental health in families with a child with congenital heart disease: a longitudinal study

BACKGROUND: A congenital heart defect (CHD) can increase the risk of mental health problems in affected children and their parents. The extent to which risk factors for these problems are shared in families or are specific to the individual family member is unclear. METHOD: Prospective data from the Norwegian Mother and Child Cohort Study (MoBa; n=93009) were linked with a nationwide CHD registry, and 408 children with CHD were identified. Mothers' reports on child internalizing problems and their own distress were assessed by questionnaires at child ages 6, 18 and 36 months. A structural model was applied to distinguish between familial (shared) factors and individual-specific factors for mental health problems. RESULTS: CHD was a substantial risk factor for problems in children and their mothers at all time points. CHD contributed on average 31% and 39% to the variance in children's and mothers' problems respectively. Both shared familial and individual-specific factors unique to CHD families contributed to risk for mental health problems. Whereas individual-specific risk factors contributed to the stability of problems in mothers, the effect of these factors lasted only a short time in children. Mutual influences over time were found between the mother's and the child's mental health at 18 and 36 months. CONCLUSIONS: The burden of CHD in a child is shared between family members but is also specific to the individual. This study points to a need for both an individual and a family-based approach to provide psychological support to children with CHD and their parent