Background: Socio-environmental conditions vary across rural Honduras. As medical relief missions target rural communities, planning should focus on highly prevalent concerns. We assessed the needs and disease perceptions of people in the Department of Yoro area of rural Honduras Methods: A needs assessment survey was administered in June 2008 in the Department of Yoro area of Honduras. The survey consisted of 29 multiple-choice questions that collected data on demographic information, environmental health pressures such as home environment, access to clean water and sanitation. The survey also assessed access to healthcare and the top 3 perceived critical issues affecting health. Surveys were randomly administered at multiple clinic sites. Surveys were voluntary, anonymous and in Spanish. A descriptive analysis of the responses was performed. The association between concern for infectious diseases and socio-environmental factors was explored. The Chi-square test was employed for statistical significance. Results: 70 surveys were collected. The mean age was 38. Twenty-one men and 49 women completed the survey. Only 8% of the respondents had completed 12 years of education. Thirty-eight (54%) were employed. The average number of adults living in a given home was 4.4. Forty-eight (69%) of respondents obtained their water from plumbing, with 14 (20%) reporting no purification treatment of water. Forty-seven percent of respondents used outhouses or latrines. Thirty-nine (56%) reported the presence of farm animals within their home. Sixteen percent of homes were constructed with adobe and 39% of all homes had dirt floors. The most common healthcare concerns were water sanitation (19, 32%), nutrition (19, 32%), infectious diseases (18, 31%) and access to doctors and medications (18, 31%). There was no statistically significant association between concern for infectious diseases and crowded household (>4 people/house) (p=0.90), dirt flooring (p=0.48) or the presence of farm animals in the home (p-0.48). Conclusion: Despite differences in socio-environmental factors in rural Honduras, the principal health concerns were water sanitation, nutrition, infectious diseases and access to doctors and medications. There were no associations between infectious diseases concerns and socio-environmental factors. Medical relief missions to rural Honduras should anticipate widespread infectious diseases related concerns and should prepare accordingly. Abstracts for SupplementInternational Journal of Infectious DiseasesVol. 14Preview Full-Text PDF Open Archive

The equatorial ionosphere is host to the most dramatic and enigmatic plasma instability mechanism in the geospace environment. Equatorial spread F (ESF) was discovered in early ionosonde measurements and interpreted theoretically using Rayleigh‐Taylor theory. Subsequent diagnostic and modeling advances have improved substantially our understanding of ESF onset and evolution and its associated effects on the ionosphere throughout the low‐latitude domain. The degree to which ESF mechanisms penetrate into the lower midlatitudes is a topic of current study, a reverse of the familiar concept of high‐to‐low latitude coupling for space weather phenomena. Optical diagnostic systems, first ground based and now space based, reveal the presence of ESF structures via images of airglow depletions that are aligned in the approximately north‐south direction spanning the geomagnetic equator. Ground‐based all‐sky camera systems used to capture the two‐dimensional horizontal patterns of airglow depletions are the main source of observations showing that ESF processes intrude to midlatitudes in the L ∼ 1.5 domain. In this paper we review the process of mapping airglow depletions along geomagnetic field lines to the equatorial plane, hence defining the maximum apex heights achieved. A case study comparison of simultaneous radar backscatter data from Kwajalein with optical data from Wake Island, sites that share common magnetic meridians in the Pacific section, confirms the utility of the approach and its applicability to sites at other longitudes. Modeling studies based on buoyancy arguments using flux tube–integrated mean density values versus L shell apex heights show that instability‐induced plasma depletions starting at F layer bottomside heights easily reach altitudes above 2000 km in the equatorial plane, implying that ESF intrusions to lower midlatitudes should be a relatively frequent occurrence.

Two widely used signatures of interplanetary coronal mass ejections are counterstreaming suprathermal electrons, implying magnetic structures connected to the Sun at both ends, and magnetic clouds, characterized by large‐scale field rotations, low temperature, and high field strength. In order to determine to what extent these signatures coincide, electron heat flux data were examined for 14 magnetic clouds detected by ISEE 3 and IMP 8 near solar maximum and 34 clouds detected by Wind near solar minimum. The percentage of time during each cloud passage that counterstreaming electrons were detected varied widely, from 6 clouds with essentially no counterstreaming to 8 clouds with nearly 100% counterstreaming. All of the former but less than half of the latter occurred near solar minimum, suggesting a possible solar cycle dependence on the degree of magnetic openness. The counterstreaming intervals were distributed randomly throughout the clouds, with a median length of 2.5 hours. A plot of counterstreaming percentages against cloud diameter for 33 clouds modeled as cylindrical flux ropes indicates a linear dependence of the percentage of closed flux on cloud size, with the largest clouds being the most closed. Overall the results are consistent with the view that although magnetic field lines within a magnetic cloud can form a large‐scale, coherent structure, reconnection in remote regions of the structure, presumably near the Sun, sporadically alters its topology from closed to open until the cloud assimilates into the ambient solar wind.

The largest density variations in the solar wind occur near the streamer belt, where frequently they are associated with interplanetary coronal mass ejections (ICMEs). They tend to be embedded in larger‐scale regions of high pressure: high densities in ICME sheaths and corotating interaction regions and low densities in structures with distinctive, high‐magnetic‐pressure profiles, sometimes within ICMEs. On average, however, ICME densities are similar to ambient‐wind densities. For a set of 34 ICMEs identified in Wind data as magnetic clouds, the average density was 11 cm−3 in both the clouds and all slow wind during the same period. A set of low‐density structures observed earlier by ISEE 3 recurred for three solar rotations, possibly owing to recurrence of the streamer belt itself, with its frequent transient outflows. Density averages less than 1 cm−3 show a possible solar cycle variation which peaks 1–2 years prior to the peak of ICME signatures.

Although stream interfaces are steady-state, corotating boundaries between slow and fast solar wind, their signatures are sometimes associated with transient features. Here we illustrate two modes of association: interfaces trailing interplanetary coronal mass ejections (ICMEs) at 1 AU and interfaces within ICMEs in the range 4-5 AU. The former are readily understood as boundaries between transient slow wind and steady-state fast wind, where the ICMEs add variability to the interface signatures. The latter are puzzling and may be related to evolution of interfaces.

With ISEE 3 and WIND data, we have studied cases where the solar wind density exceeded 30 cm(-3) at two different phases of the solar cycle, and a distinct pattern emerges. Superposed on the broad regions of elevated density in the slow flow are minutes-to-hours-long density peaks of pressure balance structures. Most of the high-density events result from intensification of these pressure balance structures owing to compression over a day-long time scale, usually in the sheaths of ejecta at solar maximum and in corotating interaction regions at solar minimum. The data indicate that the pressure balance structures have a transient source.

From 2000 UT on March 17 to 0400 UT on March 18, 1993, when Geotail was in the distant tail, it underwent a series of mantle crossings. These mantle crossings are manifested in the magnetic field and plasma data as smooth excursions between magnetosheath values and lobe values. We test the one‐dimensional self‐similar MHD slow mode expansion fan model of the mantle by comparing the modeled predictions with the data, including, for the first time, magnetic field data. We use the measured speed, density, magnetic field strength, ion and two different electron temperatures to initialize the mantle flow. Using this range of upstream parameters, we show that the model reasonably well brackets the observed variations of both magnetic field and plasma parameters through the mantle. The total pressure through the modeled fan remains constant as the thermal pressure at the outer edge converts into magnetic field pressure at the inner edge. Using the modeled fit, we estimate the mantle to be 10–12 RE thick.

On March 18–19, 1993, when Geotail was beyond 150 RE down the tail, for about 30 hours it frequently transited between magnetosheath‐like plasma and lobe‐like plasma. The transitions take the form of smooth variation by about a factor of 10 in both density and speed. Some of the transitions are distinctly asymmetric with a fast rise to sheath‐like values and a slow decline to lobe‐like values. We have suggested that these transitional regions are the plasma mantle, but this raises the question of why the mantle crossed Geotail many times in 30 hours. Three possible causes are flapping of the tail in response to solar wind flow changes (the windsock mechanism), intrinsic expansions and contractions of the tail boundary, perhaps in response to substorm phases (the breathing mechanism), and an IMF‐squeezed elliptical tail cross section changing its orientation to follow the IMF (the wrenching mechanism). We test these possibilities here by examining simultaneous solar wind velocity and magnetic field data from IMP 8. For the cases studied, both the windsock and the breathing mechanisms appear to contribute to the motions that cause the transitions, whereas the wrenching mechanism seems less effective. Breathing dominates on a timescale of tens of minutes, and windsock dominates on a scale of hours. Since the windsock mechanism is unavoidable, the important finding here is that the breathing mechanism appears also to operate. We use the windsock variation to estimate the thickness of the mantle at Geotail's position and find that the density drops by a factor of 10 in 9 RE. We model the mantle as a one‐dimensional slow‐mode expansion fan and use the model to predict the change in plasma parameters that occurs from the outer edge of the mantle to its inner edge. A comparison of the predicted profile with the observed profile shows that the model simulates the observed changes reasonably well.

The inclinations of the neutral line at the ecliptic plane derived from source surface model maps of coronal fields are measured for the interval from June 1976 to March 1992. The mean and median values of 53 degrees and 57 degrees are close to the average inclinations determined earlier from minimum variance analyses of solar wind measurements at sector boundaries, but the mode falls in the 80 degrees-90 degrees bin. This result, which is based on the model assumptions implicit in deriving the source surface maps, predicts that the heliospheric current sheet typically intersects the ecliptic plane nearly at right angles, even without steepening by stream interaction regions. High inclinations dominate the solar cycle for about 7 years around solar maximum. Dips to lower inclinations occur near solar minimum, but high variance admits a wide range of inclinations throughout the cycle. Compared to the smooth solar cycle variation of the maximum latitudinal excursion of the neutral line, often treated as the tilt angle of a flat heliospheric current sheet, the noisy variation of the inclinations reflects the degree to which the neutral line deviates from a sine wave, implying warps and corrugations in the current sheet. About a third of the time the neutral line so deviates that it doubles back in longitude.

The occurrence of multiple directional discontinuities in the coronal streamer belt at sector boundary crossings in the heliosphere, often ascribed to waves or kinks in the heliospheric current sheet, may alternatively be attributed to a network of extended current sheets from multiple helmet streamers with a hierarchy of sizes at the base of the corona. Frequent transient outflows from these helmets can account for a variety of signatures observed at sector boundaries, including ordered field rotations, planar magnetic structure, and sandwichlike plasma structure.

CCD uvby photometry for the intermediate age, southern open cluster, NGC 3680, is analyzed. For a reddening of E(b-y) = 0.034, a true cluster modulus of 9.74 + or - 0.20 and a cluster metallicity of Fe/H abundance = 0.10 + or - 0.09, based on 18 probable nonbinary members of the cluster brighter than V = 14. The color-magnitude diagram for the cluster suggests that, although the main sequence may be subject to the same bimodal distibution as NGC 752, the likely source in both clusters is a combination of binaries and a sharply curved turnoff. The color-magnitude diagram is compared to the theoretical isochrones of Bertelli et al. (1988), showing an age of (1.9 + or - 0.3) X 10 to the 9th yr.