Deep Impact collided with comet Tempel 1, excavating a crater controlled by gravity. The comet's outer layer is composed of 1- to 100-micrometer fine particles with negligible strength (<65 pascals). Local gravitational field and average nucleus density (600 kilograms per cubic meter) are estimated from ejecta fallback. Initial ejecta were hot (>1000 kelvins). A large increase in organic material occurred during and after the event, with smaller changes in carbon dioxide relative to water. On approach, the spacecraft observed frequent natural outbursts, a mean radius of 3.0 +/- 0.1 kilometers, smooth and rough terrain, scarps, and impact craters. A thermal map indicates a surface in equilibrium with sunlight.

Understanding how comets work--what drives their activity--is crucial to the use of comets in studying the early solar system. EPOXI (Extrasolar Planet Observation and Deep Impact Extended Investigation) flew past comet 103P/Hartley 2, one with an unusually small but very active nucleus, taking both images and spectra. Unlike large, relatively inactive nuclei, this nucleus is outgassing primarily because of CO(2), which drags chunks of ice out of the nucleus. It also shows substantial differences in the relative abundance of volatiles from various parts of the nucleus.

Background-Both psychological and physiological disturbances have been implicated in the aetiopathogenesis of irritable bowel syndrome (IBS). Aims-To investigate how the psychological factors act, and the involvement of infective and physiological factors. Methods-Consecutive patients hospitalised for gastroenteritis reported life events for the previous 12 months, and past illness experiences on standardised questionnaires. They also completed psychometric questionnaires for anxiety, neuroticism, somatisation, and hypochondriasis. In some patients, rectal biopsy specimens were obtained during the acute illness and at three months postinfection. Results-Ninety four patients completed all questionnaires: 22 patients were diagnosed with IBS after their gastroenteritis (IBS+), and 72 patients returned to normal bowel habits (IBS−). IBS+ patients reported more life events and had higher hypochondriasis scores than IBS− patients. The predictive value of the life event and hypochondriasis measures was highly significant and independent of anxiety, neuroticism, and somatisation scores, which were also elevated in IBS+ patients. Rectal biopsy specimens from 29 patients showed a chronic inflammatory response in both IBS+ and IBS− patients. Three months later, specimens from IBS+ patients continued to show increased chronic inflammatory cell counts but those from IBS− patients had returned to normal levels. IBS+ and IBS− patients exhibited rectal hypersensitivity and hyper-reactivity and rapid colonic transit compared with normal controls, but there were no significant diVerences between IBS+ and IBS− patients for these physiological measurements. Conclusion-Psychological factors most clearly predict the development of IBS symptoms after gastroenteritis but biological mechanisms also contribute towards the expression of symptoms. (Gut 1999;44:400-406)

There is rapidly evolving literature on water insecurity in the general adult population, but the role of water insecurity during the vulnerable periods of pregnancy and postpartum, or in the context of HIV, has been largely overlooked. Therefore, we conducted an exploratory study, using Go Along interviews, photo-elicitation interviews, and pile sorts with 40 pregnant and postpartum Kenyan women living in an area of high HIV prevalence. We sought to (1) describe their lived experiences of water acquisition, prioritisation, and use and (2) explore the consequences of water insecurity. The results suggest that water insecurity is particularly acute in this period, and impacts women in far-reaching and unexpected ways. We propose a broader conceptualisation of water insecurity to include consideration of the consequences of water insecurity for maternal and infant psychosocial and physical health, nutrition, and economic well-being.

To determine the effects of coronary angioplasty on coronary flow reserve (CFR), we studied 32 patients before and immediately after single-vessel coronary angioplasty and 31 patients evaluated late after angioplasty (7.5 + 1.2 months, mean + SEM). The geometry (percent area stenosis and minimal cross-sectional area) of each lesion was determined by quantitative coronary angiography (Brown/Dodge method) and the integrated optical density was measured by videodensitometry. CFR was measured with a No. 3F coronary Doppler catheter placed immediately proximal to the lesion and a maximally vasodilating dose of intracoronary papaverine. The translesional pressure gradient was obtained in all lesions before and immediately after angioplasty and in 18 of 31 vessels late after angioplasty. CFR immediately after angioplasty returned to normal levels (> 3.5 peak/resting velocity ratio) in 14 of 31 patients and was improved, although not normalized, in the remaining 17 patients. CFR immediately after dilation was not significantly correlated with any of the angiographic variables of arterial stenosis nor the resting pressure gradient. Moreover, the pressure gradient and absolute distal coronary pressure at peak hyperemia were not significantly different in vessels with normal and those with abnormal flow reserve immediately after dilation, suggesting that the residual stenosis did not significantly limit hyperemia. Late after angioplasty, however, a significant relationship emerged between CFR and all four indexes of residual arterial stenosis (percent area stenosis r = .70, p < .01; minimum arterial cross-sectional area r = .70, p < .01; integrated optical density r = .60, p < .01; and translesional pressure gradient r = .77, p < .01). Furthermore, in the absence of restenosis, CFR eventually normalized in all patients. These findings demonstrate that in one-half of patients there is a transient reduction in coronary flow reserve immediately after angioplasty. In the absence of restenosis, coronary flow reserve later normalizes. Consequently, measurements of coronary flow reserve immediately after angioplasty may not reflect the eventual success of the procedure in removing physiologic obstruction to coronary blood flow. Circulation 77, No. 4, 873-885, 1988. ALTHOUGH coronary angioplasty has been shown to increase coronary luminal cross-sectional area,1 reduce the translesional pressure gradient,2 ameliorate the symptoms of myocardial ischemia,3' 4and normalize previously positive noninvasive studies of provokable myocardial ischemia (e.g., exercise electrocardiographic,3' thallium-201 scintigraphic,4 and diastolic

Intravascular ultrasound imaging of coronary arteries provides important information about coronary lumen, wall, and plaque characteristics. Quantitative studies of coronary atherosclerosis using intravascular ultrasound and manual identification of wall and plaque borders are limited by the need for observers with substantial experience and the tedious nature of manual border detection. We have developed a method for segmentation of intravascular ultrasound images that identifies the internal and external elastic laminae and the plaque-lumen interface. The border detection algorithm was evaluated in a set of 38 intravascular ultrasound images acquired from fresh cadaveric hearts using a 30 MHz imaging catheter. To assess the performance of our border detection method we compared five quantitative measures of arterial anatomy derived from computer-detected borders with measures derived from borders manually defined by expert observers. Computer-detected and observer-defined lumen areas correlated very well (r=0.96, y=1.02x+0.52), as did plaque areas (r=0.95, y=1.07x-0.48), and percent area stenosis (r=0.93, y=0.99x-1.34.) Computer-derived segmental plaque thickness measurements were highly accurate. Our knowledge-based intravascular ultrasound segmentation method shows substantial promise for the quantitative analysis of in vivo intravascular ultrasound image data.

IntroductionA wide range of water-related problems contribute to the global burden of disease. Despite the many plausible consequences for health and well-being, there is no validated tool to measure individual- or household-level water insecurity equivalently across varying cultural and ecological settings. Accordingly, we are developing the Household Water Insecurity Experiences (HWISE) Scale to measure household-level water insecurity in multiple contexts.Methods and analysisAfter domain specification and item development, items were assessed for both content and face validity. Retained items are being asked in surveys in 28 sites globally in which water-related problems have been reported (eg, shortages, excess water and issues with quality), with a target of at least 250 participants from each site. Scale development will draw on analytic methods from both classical test and item response theories and include item reduction and factor structure identification. Scale evaluation will entail assessments of reliability, and predictive, convergent, and discriminant validity, as well as the assessment of differentiation between known groups.Ethics and disseminationStudy activities received necessary ethical approvals from institutional review bodies relevant to each site. We anticipate that the final HWISE Scale will be completed by late 2018 and made available through open-access publication. Associated findings will be disseminated to public health professionals, scientists, practitioners and policymakers through peer-reviewed journals, scientific presentations and meetings with various stakeholders. Measures to quantify household food insecurity have transformed policy, research and humanitarian aid efforts globally, and we expect that an analogous measure for household water insecurity will be similarly impactful.

We derive the spin state of the nucleus of Comet 103P/Hartley 2, its orientation in space, and its shortterm temporal evolution from a mixture of observations taken from the DIXI (Deep Impact Extended Investigation) spacecraft and radar observations. The nucleus is found to spin in an excited long-axis mode (LAM) with its rotational angular momentum per unit mass, M, and rotational energy per unit mass, E, slowly decreasing while the degree of excitation in the spin increases through perihelion passage. M is directed toward (RA, Dec; J2000) = 8 ± 4°, 54 ± 1°(obliquity = 48 ± 1°). This direction is likely changing, but the change is probably <6°on the sky over the $81.6 days of the DIXI encounter. The magnitudes of M and E at closest approach (JD 2455505.0831866 2011-11-04 13:59:47.310) are 30.0 ± 0.2 m 2 /s and (1.56 ± 0.02) Â 10 À3 m 2 /s 2 respectively. The period of rotation about the instantaneous spin vector, which points in the direction (RA, Dec; J2000) = 300 ± 3.2°, 67 ± 1.3°at the time of closest approach, was 14.1 ± 0.3 h. The instantaneous spin vector circulates around M, inclined at an average angle of 33.2 ± 1.3°, with an average period of 18.40 ± 0.13 h at the time of closest approach. The period of roll around the principal axis of minimum inertia (''long'' axis) at that time is 26.72 ± 0.06 h. The long axis is inclined to M by $81.2 ± 0.6°on average, slowly decreasing through encounter. We infer that there is a periodic nodding motion of the long axis with half the roll period, i.e., 13.36 ± 0.03 h, with amplitude of $1°again decreasing through encounter. The periodic variability in the circulation and roll rates during a cycle was at the 2% and 10-14% level respectively. During the encounter there was a secular lengthening of the circulation period of the long axis by 1.3 ± 0.2 min/d, in agreement with ground-based estimates, while the period of roll around the long axis changed by $À4.4 min/d at perihelion. M decreased at a rate of À0.038 (m 2 /s) per day in a roughly linear fashion. Assuming a bulk density between 230-300 kg/m 3 and a total volume for the nucleus of 8.09 Â 10 8 m 3 , the net torque acting on the nucleus was in the range 0.8-1.1 Â 10 5 kg m 2 /s 2. In order to bring the spacecraft photometric and imaging data into alignment on the direction of M, the directions of the intermediate and short principal axes of inertia had to be adjusted by 33°(on the sky) from the values indicated by the shape model with an assumed homogeneous interior. The adjusted direction of the intermediate axis is RA, Dec = 302°, À16.5°. The morning and evening terminators in the images are identified, and the variation of the insolation at three regions on the nucleus associated with active areas calculated. The plume of water vapor observed in the inner coma is found to be directed close to the direction of local gravity over the sub-solar region for a range of reasonable bulk densities. The plume does not follow the projected normal to the surface at the sub-solar point.