Surface changes on comet 67P/Churyumov-Gerasimenko suggest a more active past.

The Rosetta spacecraft spent ~2 years orbiting comet 67P/Churyumov-Gerasimenko, most of it at distances that allowed surface characterization and monitoring at submeter scales. From December 2014 to June 2016, numerous localized changes were observed, which we attribute to cometary-specific weathering, erosion, and transient events driven by exposure to sunlight and other processes. While the localized changes suggest compositional or physical heterogeneity, their scale has not resulted in substantial alterations to the comet's landscape. This suggests that most of the major landforms were created early in the comet's current orbital configuration. They may even date from earlier if the comet had a larger volatile inventory, particularly of CO or CO2 ices, or contained amorphous ice, which could have triggered activity at greater distances from the Sun.

Rosetta's comet 67P/Churyumov-Gerasimenko sheds its dusty mantle to reveal its icy nature.

The Rosetta spacecraft has investigated comet 67P/Churyumov-Gerasimenko from large heliocentric distances to its perihelion passage and beyond. We trace the seasonal and diurnal evolution of the colors of the 67P nucleus, finding changes driven by sublimation and recondensation of water ice. The whole nucleus became relatively bluer near perihelion, as increasing activity removed the surface dust, implying that water ice is widespread underneath the surface. We identified large (1500 square meters) ice-rich patches appearing and then vanishing in about 10 days, indicating small-scale heterogeneities on the nucleus. Thin frosts sublimating in a few minutes are observed close to receding shadows, and rapid variations in color are seen on extended areas close to the terminator. These cyclic processes are widespread and lead to continuously, slightly varying surface properties.

Images of asteroid 21 Lutetia: a remnant planetesimal from the early Solar System.

Images obtained by the Optical, Spectroscopic, and Infrared Remote Imaging System (OSIRIS) cameras onboard the Rosetta spacecraft reveal that asteroid 21 Lutetia has a complex geology and one of the highest asteroid densities measured so far, 3.4 ± 0.3 grams per cubic centimeter. The north pole region is covered by a thick layer of regolith, which is seen to flow in major landslides associated with albedo variation. Its geologically complex surface, ancient surface age, and high density suggest that Lutetia is most likely a primordial planetesimal. This contrasts with smaller asteroids visited by previous spacecraft, which are probably shattered bodies, fragments of larger parents, or reaccumulated rubble piles.

E-type asteroid (2867) Steins as imaged by OSIRIS on board Rosetta.

The European Space Agency's Rosetta mission encountered the main-belt asteroid (2867) Steins while on its way to rendezvous with comet 67P/Churyumov-Gerasimenko. Images taken with the OSIRIS (optical, spectroscopic, and infrared remote( )imaging system) cameras on board Rosetta show that Steins is an oblate body with an effective spherical diameter of 5.3 kilometers. Its surface does not show color variations. The morphology of Steins is dominated by linear faults and a large 2.1-kilometer-diameter crater near its south pole. Crater counts reveal a distinct lack of small craters. Steins is not solid rock but a rubble pile and has a conical appearance that is probably the result of reshaping due to Yarkovsky-O'Keefe-Radzievskii-Paddack (YORP) spin-up. The OSIRIS images constitute direct evidence for the YORP effect on a main-belt asteroid.

Trans-iliac-sacral-iliac-bar procedure to treat insufficiency fractures of the sacrum.

BACKGROUND: Osteoporosis is an increasing problem attributed to the greater longevity of the population and the incidence of fractures related to osteoporosis. The presence of osteoporotic bone, comorbidities, and functional status of the patient require adequate solutions to improve the clinical outcome of sacral insufficiency fractures. Conservative treatment by means of prolonged bed rest and analgesics are associated with increased risks and complications. A sacroplasty significantly improves the functional outcome. We describe the trans-iliac-sacral-iliac-bar (TISIB) procedure and our clinical experience to treat insufficiency fractures of the sacrum. MATERIALS AND METHODS: The records of 19 consecutive patients with a mean age of 71.7 years (range: 57-82 years) who had been managed with a TISIB procedure from 2005 till 2007 were reviewed retrospectively. There were 15 females and 4 males. Predisposing factors for sacral insufficiency fractures were osteoporosis (n = 12, 63%), radiotherapy (n = 6, 32%), and rheumatoid arthritis (n =1). Diagnosis with a mean delay of 3.7 months was mainly made by CT. All patients were preoperatively and at follow-up assessed by means of the visual analogue score (VAS), analgesic consumption, and the ability to perform activities of daily living (ADLs) using a 5-point pain scale: 1, without pain; 2, mild pain; 3, moderate pain; 4, severe pain and, 5 unable to perform ADLs because of pain. RESULTS: The average duration of postoperative follow-up was 9 months (range: 3-24.5 months). No neurological complications occurred during the surgery. A postoperative radiographic study showed a well-positioned bar in every case. The mean VAS improved 44.7 mm (preoperative: 67.8; at follow-up: 23.2). Fifteen patients (79%) consumed narcotic analgesics before surgery, and only one (5%) at follow-up; two patients (10%) consumed NSAIDS before surgery and three (15%) after. Two patients (10%) consumed minor analgesics before, and 11 (58%) after the procedure. Finally, four patients (21%) were not taking any analgesics at follow-up. Before surgery, 9 patients (47%) were able to perform ADLs with a pain score of 4; 6 (32%) with a score of 3, and 4 (21%) a score of 2. At follow-up 1 (5%) did have a score of 4; 1 (5%) a score of 3, 8 (42%) a score of 2 and 9 (47%) a pain score of 1. CONCLUSION: A TISIB PROCEDURE RELIES ON THE PRINCIPLES OF FRACTURE TREATMENT: fracture stabilisation and compression. The incapacitating problem of an insufficiency fracture of the sacrum can be elegantly solved by means of this minimally invasive procedure. A near-immediate improvement is noticed when looking at the VAS score, analgesics consumption, and the ability to perform ADLs.

Rain, winds and haze during the Huygens probe's descent to Titan's surface.

The irreversible conversion of methane into higher hydrocarbons in Titan's stratosphere implies a surface or subsurface methane reservoir. Recent measurements from the cameras aboard the Cassini orbiter fail to see a global reservoir, but the methane and smog in Titan's atmosphere impedes the search for hydrocarbons on the surface. Here we report spectra and high-resolution images obtained by the Huygens Probe Descent Imager/Spectral Radiometer instrument in Titan's atmosphere. Although these images do not show liquid hydrocarbon pools on the surface, they do reveal the traces of once flowing liquid. Surprisingly like Earth, the brighter highland regions show complex systems draining into flat, dark lowlands. Images taken after landing are of a dry riverbed. The infrared reflectance spectrum measured for the surface is unlike any other in the Solar System; there is a red slope in the optical range that is consistent with an organic material such as tholins, and absorption from water ice is seen. However, a blue slope in the near-infrared suggests another, unknown constituent. The number density of haze particles increases by a factor of just a few from an altitude of 150 km to the surface, with no clear space below the tropopause. The methane relative humidity near the surface is 50 per cent.

New approaches to the visualization, quantification and explanation of acid-induced water loss from Ca-alginate hydrogel beads.

The water loss of Ca-alginate hydrogels at pHs below 4.0 was visualized with 1HNMR-imaging by covering a single alginate bead with cyclohexane-d12 in a specially equipped NMR-tube and adding propionic acid at defined concentrations. The exact amount of water expelled from the beads was calculated from their weight loss and correlated with the acid concentrations and pHs within the hydrogel matrix. The maximum water loss of 52% (w/w) occurred at pH 1.0, while only 5% (w/w) of the initial water content were lost at pH 3.6. The analysis of the water collected from several alginate beads for Ca2+ -ions and free polysaccharides led to the assumption that, due to the acid-induced protonation of the carboxyl functions, the ionotropic network is gradually converted to an alginic acid gel structured by H-bonds. This contradicts existing theories explaining the pH-induced water loss by a lower solubility of the alginate chains and decreased repulsion between protonated carboxyl functions, but explains previously reported pH-dependent alterations of mass transport and drug retention of Ca-alginate gels. Thus, the presented experiments enable a more precise and complete view of the acid-induced process within Ca-alginate hydrogels. The transfer to the characterization of other hydrogels is possible and should be advantageous, especially if a calibration of the NMR-measurement could be achieved.

Interdisciplinary clinical assessment of patients with illness attributed to environmental factors.

Patients with health problems attributed to environmental factors such as chemical pollutants and electromagnetic fields often do not present evidence of an environmental aetiology of their symptoms. It has been postulated, that their problems are due to disorders diagnosed by other medical disciplines, especially allergology and psychiatry. Our study was designed to subject these patients to a comprehensive diagnostic program involving several medical disciplines in order to achieve diagnoses appropriate to explain the patients' symptoms. Fifty patients consecutively referred to the department of environmental medicine in the university hospital of Aachen, Germany, were submitted to the following examinations: (i) environmental medicine (history, clinical examination, biological and/or ambient monitoring for environmental agents); (ii) allergological examination (history, clinical examination, skin tests); (iii) psychiatric examination (psychopathological examination, psychometric and neuropsychological testing). In addition, the patients were examined in other hospital departments according to the symptoms presented. The findings were discussed in case conferences attended by the physicians involved in order to achieve individual diagnoses. The numbers of patients to whom diagnoses were given by different medical disciplines are as follows: psychiatry (32 patients), dermatology (4), allergology (2), neurology (2), rheumatology (2), gynaecology (1), haematology (1). The most frequent mental disorders diagnosed by the psychiatrists were somatoform disorders (19), followed by schizophreniform and delusion disorders (7). In spite of extensive diagnostic efforts, patients with health problems attributed to the environment usually do not present sufficient evidence of an environmental aetiology of their symptoms. On the other hand the symptoms often meet the diagnostic criteria of other diseases, especially of mental disorders.

Somatization disorders in non psychiatric settings: A multidimensional diagnostic approach.

Given the diagnostic ambiguity of physically unexplained complaints we wanted to study whether the clinically and symptomatically characterized groups, all of them defined according to DSM-III-R criteria, could be reclassified using selected empirical and theoretical variables of operationally defined parameters. Patients with conversion (N = 75), somatization or undifferentiated somatoform disorders (N = 74) and major depression (N = 70) according to DSM-III-R underwent multidimensional work-up including psychopathological, personality-psychological, illness, behavioral and coping assessment. The clinically characterized groups should be statistically reclassified by discriminant analytic techniques. The existing diagnostic categories according to DSM-III-R could be widely confirmed by the statistical reconstitution of the clinical groups. Conversion, somatization and depressive disorder presented as distinct clinical categories. A classification relying widely on symptoms still seems to be too superficial and does not represent the complexity of these patients. Thus, the modern classification systems with their purely phenomenological criteria should be added with further dimensions.

[Course and prognosis of anorexia nervosa: catamnesis of 41 patients]. / Zu Verlauf und Prognose der Anorexia nervosa: Katamnese von 41 Patienten.

The purpose of the following study was a multidimensional assessment of the course of anorexia nervosa. In our follow-up-study we were able to examine 41 out of 51 patients meeting DMS-111 R criteria for anorexia nervosa in our department at a mean follow-up of 5.3 years. At the first evaluation the patients were characterized by an early age of onset (mean 14.2 years), no or very little previous psychiatric treatment, and restrictive eating habits (72.5%); the mean age was 15.2 years. At the time of follow-up, the physical outcome was unfavourable for 50% of the patients; one patient had died. The psychosocial outcome was less favourable for 60%. Against the background of a neurotic structure, social and sexual disturbances were found although the patient's weight was often normal. Depressive symptoms and a "slimness ideal" were found among a large number of patients, just as much as the fear of gaining weight--which prove to be a reliable indicator for the continuation of an eating disorder. A multidimensional evaluation facilitates an assessment of the determinants of prognosis. Previous psychiatric treatment and low body weight were associated with an unfavourable, mention of problems/disturbances in the family environment with a good somatic outcome. Outpatient treatment indicates a favourable psychosocial outcome.

Optical observations of comet Hale-Bopp (C/1995 O1) at large heliocentric distances before perihelion.

The activity of comet Hale-Bopp (C/1995 O1) was monitored monthly by optical imaging and long-slit spectroscopy of its dust and gas distribution over heliocentric distances of 4.6 to 2.9 astronomical units. The observed band intensities of the NH2 radical and the H2O+ ion cannot be explained by existing models of fluorescence excitation, warranting a reexamination of the corresponding production rates, at least at large heliocentric distances. Comparing the production rate of the CN radical to its proposed parent, HCN, shows no evidence for the need of a major additional source for CN in Hale-Bopp at large heliocentric distances. The dust and CN production rates are consistent with a significant amount of sublimation occurring from icy dust grains surrounding Hale-Bopp.

Intracranial vertebral artery disease in the New England Medical Center Posterior Circulation Registry.

We studied 75 patients with severe intracranial vertebral artery (ICVA) occlusive disease from the New England Medical Center Posterior Circulation Registry to learn the etiologies and locations of the vascular lesions, the location and patterns of related ischemia and infarctions, and the outcomes. All patients had neuroimaging and vascular studies. Thirty-nine percent of patients had bilateral ICVA lesions. Twenty-four percent also had basilar artery disease and 36% had associated extracranial disease. The most common site of lesions was the distal ICVA after the origin of the posterior inferior cerebellar artery (PICA). Twenty-five percent of patients had only proximal intracranial posterior circulation territory infarcts (medullary and PICA cerebellar); 32% had infarcts that involved other intracranial territories in addition to the proximal territory. We found more distal intracranial territory infarcts resulting mainly from embolism from ICVA lesions than reported previously; this occurred in 17% of all patients. The ICVA was a recipient site for emboli in 8% of patients. Thirteen percent of patients died during follow-up. The outcome was favorable in most surviving patients. Three-fourths of them had no deficit or only slight disability. The patients with distal territory infarcts due to emboli from the ICVA had the worst outcome.

Thrombolytic therapy of acute basilar artery occlusion. Variables affecting recanalization and outcome.

BACKGROUND AND PURPOSE: Thrombolysis may reduce mortality after acute basilar artery (BA) occlusion. We intended to find variables affecting recanalization and clinical outcome in patients with BA occlusion undergoing thrombolytic therapy. METHODS: We analyzed in retrospect the clinical and angiographic data of a consecutive series of 51 patients treated with intra-arterial urokinase (n = 44; 0.3 to 1.5 mIU) or intravenous or intra-arterial recombinant tissue plasminogen activator (n = 7; 22 to 100 mg). We identified effective variables by multiple logistic regression analyses and univariate tests. RESULTS: Sites of occlusion were the caudal (n = 23), middle (n = 18), and distal (n = 10) segments of the BA. The pathogenesis was embolism in 35 and local atherothrombosis in 16 patients. Collateral circulation was good in 32 patients and poor or absent in 19 patients. Recanalization was achieved in 26 of 51 (51%) patients and was associated with occlusions of embolic etiology (P = .0025). Mortality was 46% (12/26) in the recanalization group and 92% (23/25) in the nonrecanalization group (P = .0004). Other independent variables affecting mortality were length of BA obstruction (P = .0011), age (P = .0008), and collateral state (P = .0454). After follow-up (median, 32 months), 10 of the 16 survivors were only minimally impaired, with a Barthel Index score of 95 or greater; 5 patients were moderately and 1 severely disabled. CONCLUSIONS: Recanalization of acute BA occlusion reduces mortality significantly. Length of BA obstruction and state of the collaterals are additional independent variables affecting survival. Young patients with monosegmental embolic occlusion of the BA seem to have the best chance to considerably profit from thrombolysis.

Leaf gas exchange of beech (Fagus sylvatica L.) seedlings in lightflecks: A system for measuring rapid changes in CO2 partial pressures.

A system is described for the measurement of fast transient responses of leaf gas exchange to lightflecks. Any chamber adulterates a true signal unless in the steady-state; therefore, a procedure for estimating an 'effective chamber volume' is presented which is an essential parameter for correcting a measured transient signal. A common correction is critically commented on. With the system, responses of net photosynthesis to lightflecks as short as 1 s have been observed in leaves of seedlings of Fagus sylvatica L.

[The beginnings of child analysis]. / Aus den Anfängen der Kinderanalyse.

The notions hitherto existing of the beginnings of child analysis have to be rectified. The meaning of childhood neuroses within the scope of scientific theory, i.e. the sexual genesis of the neuroses can no longer be maintained. The approach of distinguishing between the latent period and the Oedipus complex as the two phases of sexual development can nowadays be considered to be refuted. The personality of the first children's analyst--Hermine Hug-Hellmuth--needs to be redescribed. She fell victim to her father-transference and deceased murdered by her nephew with the help of whom she had satisfied her own scientific ambitions.

Ecological significance of above-ground architectural patterns in woody plants: A question of cost-benefit relationships.

Different branching patterns and their repetitive expression during growth of woody plants can lead to different growth forms such as shrubs and trees, although they may also result in similar crown shapes. Recent work has shown that an integrated view of carbon gain, increment of biomass and its architectural arrangement in space is essential in assessing cost-benefit relationships of crown formation and structure, especially in situations where crowns compete for space and light.

[Homicides by adolescents and young adults from the viewpoint of the adolescent psychiatry expert]. / Tötungsdelikte Jugendlicher und Heranwachsender aus der Sicht des jugendpsychiatrischen Gutachters.

From 1966 to 1986, the Department of Child and Adolescent Psychiatry of the Psychiatric Hospital of the University of Heidelberg gave expert opinions at the request of criminal courts in 37 cases involving homicide and 8 attempted homicide. Eighteen of the offenders were between 14 and 17 years old ("Jugendliche" under German law), 17 between 18 and 20 ("Heranwachsende") and 2 over 20. The largest group (N = 18) consisted of maladjusted male adolescents who had grown up in disadvantageous surroundings, had limited education and, not infrequently following the example of other members of their families, tended to show aggressive behaviour, intolerance to frustration, emotional instability and uncontrolled drinking. The questions the expert was asked by the court were mainly concerned with: liability for crime (section 3 JGG), applicability of juvenile law to offenders aged 18 to 20 years (section 105 JGG) penal responsibility (section 20 and 21 StBG or section 51, Section 1 and 2 StGB a.F.), and measures under section 63 StGB. The court took the expert's position in 28 of the 33 decisions which we were able to obtain for examination; 2 other proceedings were quashed. The juridical classification of the homicides was attempted or completed first-degree murder in 17 and attempted or completed second-degree murder in 6 cases.