Does the Sun Shrink with Increasing Magnetic Activity?

We have analyzed the full set of SOHO/MDI f- and p-mode oscillation frequencies from 1996 to date in a search for evidence of solar radius evolution during the rising phase of the current activity cycle. Like Antia et al. (2000), we find that a significant fraction of the f-mode frequency changes scale with frequency; and that if these are interpreted in terms of a radius change, it implies a shrinking sun. Our inferred rate of shrinkage is about 1.5 km/y, which is somewhat smaller than found by Antia et al. We argue that this rate does not refer to the surface, but rather to a layer extending roughly from 4 to 8 Mm beneath the visible surface. The rate of shrinking may be accounted for by an increasing radial component of the rms random magnetic field at a rate that depends on its radial distribution. If it were uniform, the required field would be ~7 kG. However, if it were inwardly increasing, then a 1 kG field at 8 Mm would suffice. To assess contribution to the solar radius change arising above 4Mm, we analyzed the p-mode data. The evolution of the p-mode frequencies may be explained by a magnetic^M field growing with activity. The implications of the near-surface magnetic field changes depend on the anisotropy of the random magnetic field. If the field change is predominantly radial, then we infer an additional shrinking at a rate between 1.1-1.3 km/y at the photosphere. If on the other hand the increase is isotropic, we find a competing expansion at a rate of 2.3 km/y. In any case, variations in the sun's radius in the activity cycle are at the level of 10^{-5} or less, hence have a negligible contribution to the irradiance variations.Comment: 10 pages (ApJ preprint style), 4 figures; accepted for publication in Ap

Obstacles Faced by Latina Mothers of Children with Autism

The CDC’s most recent autism prevalence estimates document the continued trend of higher prevalence among non-Hispanic white children compared to Hispanic children. The disproportionate underrepresentation of Latino children in the health, education and service systems is measurable, disadvantaging the child and family. This quantitative study identifies support needs and obstacles experienced by 96 Latina mothers of children with autism, active in Spanish-language parent groups in California. Study measures included the Family Needs Survey and the Caring for My Child Survey. To determine the significance of the results on the Family Needs Survey, an item-by-item chi-square analysis compared results to those of to a similar population from a different study that used the same measure. A high proportion of mothers reported substantial levels of unmet needs in their role as primary caregiver using the Family Needs Survey: all 35 survey items were unmet for at least 50% of mothers; 28 items were common needs. The level and number of unmet needs of mothers in the present study in areas such as social support and care services were significantly greater than the comparison group. On the Caring for My Child Survey, mothers identified multiple barriers personally encountered in obtaining assistance for their children including psychosocial, economic, political, and healthcare factors. Findings are relevant to improve access for Latinos in the health, education and service systems, and to establish a baseline for comparison

Obstacles Faced by Latina Mothers of Children with Autism

Abstract The CDC's most recent autism prevalence estimates document the continued trend of higher prevalence among non-Hispanic white children compared to Hispanic children. The disproportionate underrepresentation of Latino children in the health, education and service systems is measurable, disadvantaging the child and family. This quantitative study identifies support needs and obstacles experienced by 96 Latina mothers of children with autism, active in Spanish-language parent groups in California. Study measures included the Family Needs Survey and the Caring for My Child Survey. To determine the significance of the results on the Family Needs Survey, an item-by-item chi-square analysis compared results to those of to a similar population from a different study that used the same measure. A high proportion of mothers reported substantial levels of unmet needs in their role as primary caregiver using the Family Needs Survey: all 35 survey items were unmet for at least 50% of mothers; 28 items were common needs. The level and number of unmet needs of mothers in the present study in areas such as social support and care services were significantly greater than the comparison group. On the Caring for My Child Survey, mothers identified multiple barriers personally encountered in obtaining assistance for their children including psychosocial, economic, political, and healthcare factors. Findings are relevant to improve access for Latinos in the health, education and service systems, and to establish a baseline for comparison

Flying Drones Beyond Visual Line of Sight Using 4G LTE: Issues and Concerns

The purpose of this paper is to address the extent in which 4G LTE can be used for air traffic management of small Unmanned Air Vehicles (sUAVs) and the limitations and enhancements that may be necessary. We provide a brief overview of the communications aspects of the Unmanned Aerial System (UAS) Traffic Management Project followed by the evolving trends in air traffic management including beyond visual line of sight (BVLOS) operations concepts and current BVLOS operational systems. Issues and Concerns are addressed including the rapidly evolving global regulations and the resulting communications requirements as well LTE downlink and uplink interference at altitude and how that interference affects command and control reliability as well as application data capabilities and mobility performance

Space Link Extension (SLE) Emulation for High-Throughput Network Communication

As the data rate requirements for space communications increases, significant stress is placed not only on the wireless satellite communication links, but also on the ground networks which forward data from end-users to remote ground stations. These wide area network (WAN) connections add delay and jitter to the end-to-end satellite communication link, effects which can have significant impacts on the wireless communication link. It is imperative that any ground communication protocol can react to these effects such that the ground network does not become a bottleneck in the communication path to the satellite. In this paper, we present our SCENIC Emulation Lab testbed which was developed to test the CCSDS SLE protocol implementations proposed for use on future NASA communication networks. Our results show that in the presence of realistic levels of network delay, high-throughput SLE communication links can experience significant data rate throttling. Based on our observations, we present some insight into why this data throttling happens, and trace the probable issue back to non-optimal blocking communication which is sup-ported by the CCSDS SLE API recommended practices. These issues were presented as well to the SLE implementation developers which, based on our reports, developed a new release for SLE which we show fixes the SLE blocking issue and greatly improves the protocol throughput. In this paper, we also discuss future developments for our end-to-end emulation lab and how these improvements can be used to develop and test future space communication technologies

Vesicoureteral Reflux and Other Urinary Tract Malformations in Mice Compound Heterozygous for Pax2 and Emx2

Congenital anomalies of the kidney and urinary tract (CAKUT) are the most common cause of chronic kidney disease in children. This disease group includes a spectrum of urinary tract defects including vesicoureteral reflux, duplex kidneys and other developmental defects that can be found alone or in combination. To identify new regulators of CAKUT, we tested the genetic cooperativity between several key regulators of urogenital system development in mice. We found a high incidence of urinary tract anomalies in Pax2;Emx2 compound heterozygous mice that are not found in single heterozygous mice. Pax2+/−;Emx2+/− mice harbor duplex systems associated with urinary tract obstruction, bifid ureter and a high penetrance of vesicoureteral reflux. Remarkably, most compound heterozygous mice refluxed at low intravesical pressure. Early analysis of Pax2+/−;Emx2+/− embryos point to ureter budding defects as the primary cause of urinary tract anomalies. We additionally establish Pax2 as a direct regulator of Emx2 expression in the Wolffian duct. Together, these results identify a haploinsufficient genetic combination resulting in CAKUT-like phenotype, including a high sensitivity to vesicoureteral reflux. As both genes are located on human chromosome 10q, which is lost in a proportion of VUR patients, these findings may help understand VUR and CAKUT in humans

Controlled comparison of hemodialysis and peritoneal dialysis: Veterans Administration multicenter study

Controlled comparison of hemodialysis and peritoneal dialysis: Veterans Administration multicenter study. We measured mortality and morbidity among 114 patients assigned randomly to home hemodialysis (HD) and home intermittent peritoneal dialysis (IPD). Data were collected during the time of home training and for 12 months after initiation of home dialysis. Training time was shorter for the IPD than for the HD patients (P < 0.001) with median time 1.8 months for IPD and 3.9 months for HD. Switching to the alternative mode of treatment was more frequent for the IPD group (29/59 vs. 5/55, P < 0.001). Survival time was not different, perhaps because of the modality change. More IPD patients were hospitalized in the first 6 months (20 for IPD vs. 9 for HD, P = 0.02), but they had fewer troublesome cardiovascular events in the first year (0 vs. 12, P < 0.001). The HD patients maintained better nutritional status as reflected in body weight and arm muscle circumference and possibly in urea appearance rate. Thus, these data suggest that for most patients, IPD is a less satisfactory form of therapy than HD, but certain advantages of IPD did emerge. Applications of this information to the currently more popular mode of CAPD await further study.Comparaison contrôlée entre l'hémodialyse et la dialyse péritonéale: Étude multicentrique de l'Administration des Veterans. Nous avons mesuré la mortalité et la morbidité chez 114 malades, pris au hasard, en hémodialyse à domicile (HD) ou en dialyse péritonéale intermittente à domicile (IPD). Les données ont été recueillies pendant l'entrainement à domicile et pendant les 12 mois suivant le début de la dialyse à domicile. La durée d'entrainement était plus brève pour les malades en IPD que pour ceux en HD (P < 0,001), avec un temps médian de 1,8 mois pour l'IPD et de 3,9 mois pour l'HD. Le changement pour l'autre mode de traitement était plus fréquent pour le groupe IPD (29/59 contre 5/55, P < 0,001). La durée de suivi n'était pas différente, peut-être à cause du changement de modalité. Plus de malades en IPD ont été hospitalisés dans les 6 premiers mois (20 en IPD, contre 9 en HD, P = 0,02), mais ils ont eu moins d'ennuis cardiovasculaires gênants au cours de la première année (0 contre 12, P < 0,001). Les malades HD conservaient un meilleur état nutritionnel, reflété par le poids corporel, la circonférence musculaire du bras, et probablement la vitesse d'apparition de l'urée. Ainsi ces données suggèrent que pour la plupart des malades, l'IPD est une forme de traitement moins satisfaisante que l'HD, mais certains avantages de l'IPD sont apparus. Les applications de cette information au mode actuellement le plus répandu de CAPD requièrent d'autres études

Flying Drones Beyond Visual Line of Sight Using 4G LTE: Issues and Concerns

The purpose of this paper is to address the extent in which 4G LTE can be used for air traffic management of small Unmanned Air Vehicles (sUAVs) and the limitations and enhancements that may be necessary. We provide a brief overview of the communications aspects of the Unmanned Aerial System (UAS) Traffic Management Project followed by the evolving trends in air traffic management including beyond visual line of sight (BVLOS) operations concepts and current BVLOS operational systems. Issues and Concerns are addressed including the rapidly evolving global regulations and the resulting communications requirements as well LTE downlink and uplink interference at altitude and how that interference affects command and control reliability as well as application data capabilities and mobility performance

On-disk coronal rain

Small and elongated, cool and dense blob-like structures are being reported with high resolution telescopes in physically different regions throughout the solar atmosphere. Their detection and the understanding of their formation, morphology and thermodynamical characteristics can provide important information on their hosting environment, especially concerning the magnetic field, whose understanding constitutes a major problem in solar physics. An example of such blobs is coronal rain, a phenomenon of thermal non- equilibrium observed in active region loops, which consists of cool and dense chromospheric blobs falling along loop-like paths from coronal heights. So far, only off-limb coronal rain has been observed and few reports on the phenomenon exist. In the present work, several datasets of on-disk H{\alpha} observations with the CRisp Imaging SpectroPolarimeter (CRISP) at the Swedish 1-m Solar Telescope (SST) are analyzed. A special family of on-disk blobs is selected for each dataset and a statistical analysis is carried out on their dynamics, morphology and temperatures. All characteristics present distributions which are very similar to reported coronal rain statistics. We discuss possible interpretations considering other similar blob-like structures reported so far and show that a coronal rain interpretation is the most likely one. Their chromospheric nature and the projection effects (which eliminate all direct possibility of height estimation) on one side, and their small sizes, fast dynamics, and especially, their faint character (offering low contrast with the background intensity) on the other side, are found as the main causes for the absence until now of the detection of this on-disk coronal rain counterpart.Comment: 18 pages, 10 figures. Accepted for Solar Physic