Amorphous and crystalline ices studied by dielectric spectroscopy.

This work reports on frequency dependent ambient-pressure dielectric measurements of hyperquenched glassy water, ice IV, ice VI, as well as a CO2-filled clathrate hydrate, the latter featuring a chiral water network. The dipolar time scales and the spectral shapes of the loss spectra of these specimens are mapped out and compared with literature data on low-density and high-density amorphous ices as well as on amorphous solid water. There is a trend that the responses of the more highly dense amorphous ices are slightly more dynamically heterogeneous than those of the lower-density amorphous ices. Furthermore, practically all of the amorphous ices, for which broadband dielectric spectra are available, display a curved high-frequency wing. Conversely, the high-frequency flanks of the nominally pure ice crystals including ice V and ice XII can be characterized by an approximate power-law behavior. While the spectral shapes of the nominally pure ices thus yield some hints regarding their amorphicity or crystallinity, a comparison of their time scale appears less distinctive in this respect. In the accessible temperature range, the relaxation times of the crystalline ices are between those of low-density and high-density amorphous ice. Hence, with reference also to previous work, the application of suitable doping currently seems to be the best dielectric spectroscopy approach to distinguish amorphous from crystalline ices.

[Evaluation of the "Obeldicks Light Training" Programme for Overweight Children and Adolescents]. / Evaluation des Programms Obeldicks light für übergewichtige Kinder und Jugendliche.

In a randomised controlled study (n=34 intervention group, n = 32 control group) the effects of a 6-month outpatient training for overweight but not obese children and adolescents (BMI > 90(th) ≤ 97(th) percentile) were assessed up to 12 months after the end of intervention. BMI-SDS reduction was the main outcome. The results show that the lifestyle intervention "Obeldicks light" is effective to reduce overweight, as well as blood pressure and several other risk parameters in overweight children. Effects are stable over a 12 months period.

The time constant of the somatogravic illusion.

Without visual feedback, humans perceive tilt when experiencing a sustained linear acceleration. This tilt illusion is commonly referred to as the somatogravic illusion. Although the physiological basis of the illusion seems to be well understood, the dynamic behavior is still subject to discussion. In this study, the dynamic behavior of the illusion was measured experimentally for three motion profiles with different frequency content. Subjects were exposed to pure centripetal accelerations in the lateral direction and were asked to indicate their tilt percept by means of a joystick. Variable-radius centrifugation during constant angular rotation was used to generate these motion profiles. Two self-motion perception models were fitted to the experimental data and were used to obtain the time constant of the somatogravic illusion. Results showed that the time constant of the somatogravic illusion was on the order of two seconds, in contrast to the higher time constant found in fixed-radius centrifugation studies. Furthermore, the time constant was significantly affected by the frequency content of the motion profiles. Motion profiles with higher frequency content revealed shorter time constants which cannot be explained by self-motion perception models that assume a fixed time constant. Therefore, these models need to be improved with a mechanism that deals with this variable time constant. Apart from the fundamental importance, these results also have practical consequences for the simulation of sustained accelerations in motion simulators.

Integration of visual and inertial cues in the perception of angular self-motion.

The brain is able to determine angular self-motion from visual, vestibular, and kinesthetic information. There is compelling evidence that both humans and non-human primates integrate visual and inertial (i.e., vestibular and kinesthetic) information in a statistically optimal fashion when discriminating heading direction. In the present study, we investigated whether the brain also integrates information about angular self-motion in a similar manner. Eight participants performed a 2IFC task in which they discriminated yaw-rotations (2-s sinusoidal acceleration) on peak velocity. Just-noticeable differences (JNDs) were determined as a measure of precision in unimodal inertial-only and visual-only trials, as well as in bimodal visual-inertial trials. The visual stimulus was a moving stripe pattern, synchronized with the inertial motion. Peak velocity of comparison stimuli was varied relative to the standard stimulus. Individual analyses showed that data of three participants showed an increase in bimodal precision, consistent with the optimal integration model; while data from the other participants did not conform to maximum-likelihood integration schemes. We suggest that either the sensory cues were not perceived as congruent, that integration might be achieved with fixed weights, or that estimates of visual precision obtained from non-moving observers do not accurately reflect visual precision during self-motion.

Structural study of low concentration LiCl aqueous solutions in the liquid, supercooled, and hyperquenched glassy states.

Neutron diffraction experiments on a solution of LiCl in water (R = 40) at ambient conditions and in the supercooled and hyperquenched states are reported and analyzed within the empirical potential structure refinement framework. Evidence for the modifications of the microscopic structure of the solvent in the presence of such a small amount of salt is found at all investigated thermodynamic states. On the other hand, it is evident that the structure of the hyperquenched salty sample is similar to that of pure low density amorphous water, although all the peaks of the radial distribution functions are broader in the present case. Changes upon supercooling or hyperquenching of the ion's hydration shells and contacts are of limited size and evidence for segregation phenomena at these states does not clearly show up, although the presence of water separated contacts between ion of the same sign is intriguing.

[The Obeldicks concept. An example for a successful outpatient lifestyle intervention for overweight or obese children and adolescents]. / Das Obeldicks-Konzept. Beispiel eines erfolgreichen ambulanten Therapieprogramms für Kinder und Jugendliche mit Übergewicht oder Adipositas.

The outpatient lifestyle interventions Obeldicks (for 8- to 16-year-old obese children; 1-year intervention), Obeldicks Light (for 8- to 16-year-old overweight children; 6-month intervention), and Obeldicks Mini (for 4- to 7-year-old obese children; 1-year intervention) are based on nutrition education, physical activity, behavior therapy, and individual psychological care. Only 17% dropped out of the intervention, and 79% of the more than 1,000 participants reduced their degree of overweight. The mean SDS-BMI reduction was 0.4 (~1.5-2 kg/m(2) BMI reduction) and was associated with a significant improvement of hypertension, dyslipidemia, and disturbed glucose metabolism in the participants compared to an untreated control group. This efficiency was also proven by a multicenter randomized controlled trial. Furthermore, the quality of life of the participants improved significantly. Even 4 years after the end of intervention, the achieved weight loss was sustained. Training manuals and training seminars for professionals assist in the implementation of these lifestyle interventions at further locations.

SnakeMap: four years of experience with a national small animal snake envenomation registry.

SnakeMap is a national cloud-based, veterinary snakebite registry. It was designed to prospectively collect data of the clinical circumstances and temporospatial information on cases of snake envenomation in dogs and cats. We herein introduce the project and summarise the data from the first 4 years of SnakeMap. The registry is a veterinary community-based online database allowing case entry from veterinary hospitals across Australia. Registry data comprise hospital characteristics, patient characteristics, envenoming snake type, treatment and outcome variables, including time and geolocation of the snake bite. We present summative information on select key variables from the SnakeMap registry (1 July 2015 to 30 June 2019). Twenty-eight hospitals from 6 states/territories entered 624 cases into the registry, including 419 dogs (67%) and 205 cats (33%). Bite time was available in 216 animals of which 90 (42%) were reported to be bitten in the 3 hours between 03:00 pm and 05:59 pm; median bite to presentation interval was 60 (interquartile range [IQR] 30, 211) minutes in dogs and 95 (IQR 41, 238) minutes in cats. Bites occurred in the owner's yard in 356 dogs (85%) and 53 cats (26%). A snake venom detection kit was used in 172 cases (28%) and antivenom was administered in 523 cases (85%). Most animals (n = 534, 88%) survived to discharge (median hospitalisation of 25 [IQR 16, 62] hours). SnakeMap effectively collects relevant clinical data from dogs and cats with presumed snake bite and provides locally specific information on the epidemiology of snake envenomation in small animals.

Relaxation effects in low density amorphous ice: two distinct structural states observed by neutron diffraction.

Neutron diffraction with H/D isotopic substitution is used to investigate the structure of low density amorphous ice produced from (1) high density amorphous ice by isobaric warming and (2) very high density amorphous ice by isothermal decompression. Differences are found in the scattering patterns of the two low density amorphous ices that correlate with structural perturbations on intermediate length scales in the hydrogen bonded water network. Atomistic modeling suggests that the structural states of the two samples may relate to a competition between short range and intermediate range order and disorder. This structural difference in two low density amorphous (LDA) ices is also evident when comparing their compression behavior. In terms of the energy landscape formalism this finding implies that we have produced and characterized the structural difference of two different basins within the LDA-megabasin corresponding to identical macroscopic densities.

Lifestyle intervention "Obeldicks Mini" for obese children aged 4 to 7 years.

Interventions for obese preschool children are missing in Germany. However, an effective and long-lasting improvement of the health behaviour seems plausible especially in this age, since the health behaviour is impressed in this age span. Therefore, we developed the outpatient one-year lifestyle intervention "Obeldicks Mini" for obese children aged 4 to <8 years and their parents based on nutrition, education, physical activity, and behaviour therapy. This intervention addressed primarily the parents. The training program was evaluated in 84 patients. In the three months before intervention, the degree of overweight significantly increased in the participants (in mean+0.12 SDS-BMI; p=0.002). Based on an intention-to-treat approach, 69% of the participants reduced their overweight, while 24% dropped out of the intervention. The mean SDS-BMI reduction was 0.46 (p<0.001) and was associated with a significant improvement of cardiovascular risk factors such as hypertension, dyslipidemia and insulin resistance. Intima-media thickness as predictive factor for later atherosclerosis decreased significantly. Even 3 years after end of intervention, the achieved weight loss sustained.

The differences of platelet response to snake venoms: a comparative study of children and adults.

Platelets play a vital role in the coagulation, yet the potential for differences in platelet function, between adults and children, remains underexplored. This is despite the age-related variation in haemostatic proteins, that is encompassed by the term Developmental Haemostasis. Hemotoxins found in the venoms of Australian snakes mimic human blood coagulation factors. The effects of Australian snake venoms on platelets, as well as the possible differential response in adults and children were subject of this study.

Theory of mind, humour processing and executive functioning in alcoholism.

AIMS: Alcoholism is associated with cognitive deficits, which have been interpreted in terms of a specific vulnerability of the frontal lobes to the toxic effects of alcohol. While executive functions in alcoholism have been investigated extensively, only little work has been carried out on social cognition. The aim of the present study was to investigate the association between executive functions, theory of mind and humour processing in alcoholism. DESIGN, SETTING, PARTICIPANTS AND MEASUREMENTS: A comprehensive neuropsychological test battery was administered to 29 alcoholic patients (Alc) and 29 healthy controls (HC). The test battery included measurements of affect, general intellectual abilities, executive functions, humour processing and theory of mind. The two groups were comparable with respect to affective variables, IQ, gender and age. FINDINGS AND CONCLUSIONS: Group comparisons revealed cognitive as well as affective humour processing deficits of alcoholics in comparison with HC. The observed impairments were related to theory of mind and executive functions. The deficits may contribute to interpersonal problems and are thus of relevance to rehabilitation.

The molecular basis of cross-reactivity in the Australian Snake Venom Detection Kit (SVDK).

The Snake Venom Detection Kit (SVDK) is of major medical importance in Australia, yet it has never been rigorously characterised in terms of its sensitivity and specificity, especially when it comes to reports of false-negative and false-positive results. This study investigates reactions and cross-reactions of five venoms the SVDK is directed against and a number of purified toxins. Snakes showing the closest evolutionary relationships demonstrated the lowest level of cross-reactivity between groups. This was, instead, far more evident between snakes that are extraordinarily evolutionary separated. These snakes: Pseudechis australis, Acanthophis antarcticus and Notechis scutatus, in fact displayed more false-positive results. Examination of individual toxin groups showed that phospholipase A(2)s (PLA(2)s) tends to react strongly and display considerable cross-reactivity across groups while the three-finger toxins (3FTx) reacted poorly in all but the Acanthophis well. The hook effect was evident for all venoms, particularly Oxyuranus scutellatus. The results of this study show considerable variation in toxin detection, with implications in further development of venom detection, both in Australia and other countries.

Neural correlates of decision making on whole body yaw rotation: An fNIRS study.

Prominent accounts of decision making state that decisions are made on the basis of an accumulation of sensory evidence, orchestrated by networks of prefrontal and parietal neural populations. Here we assess whether these findings generalize to decisions on self-motion. Participants were presented with whole body yaw rotations of different durations in a 2-Interval-Forced-Choice paradigm, and tasked to discriminate motions on the basis of their amplitude. The cortical hemodynamic response was recorded using functional near-infrared spectroscopy (fNIRS) while participants were performing the task. The imaging data was used to predict the specific response on individual experimental trials, and to predict whether the comparison stimulus would be judged larger than the reference. Classifier performance on the former variable was negligible. However, considerable performance was achieved for the latter variable, specifically using parietal imaging data. The findings provide support for the notion that activity in the parietal cortex reflects modality independent decision variables that represent the strength of the neural evidence in favor of a decision. The results are encouraging for the use of fNIRS as a method to perform neuroimaging in moving individuals.

The influence of radiation therapy on T-lymphocyte subpopulations defined by monoclonal antibodies.

We studied the influence of radiation therapy on lymphocyte subpopulations in 17 patients undergoing adjuvant radiation therapy for primary breast cancer, and eight patients receiving brachytherapy and external beam irradiation for primary cancer of the uterus. Radiation therapy reduced B- and T-lymphocytes in proportion to the total lymphocyte population so that their percentages remained unchanged. Determination of helper and suppressor T-lymphocytes before, during and 6 months after completion of radiotherapy revealed that in both groups of patients suppressor T-lymphocytes were more resistant to and recovered faster after radiotherapy. This resulted in a decline of the "immunoregulatory balance" (helper/suppressor ratio). Although this ratio had been higher in both groups of patients than in healthy age- and sex-matched controls before therapy, it became normal and subnormal during and after radiotherapy. The clinical significance of the differential influence of radiotherapy on T-lymphocyte subpopulations remains to be determined.

Stereotactic percutaneous single dose irradiation of brain metastases with a linear accelerator.

The effectivity of stereotactic percutaneous single dose irradiations in the treatment of solitary brain metastases has been assessed in a series of 12 consecutive patients. Only radioresistant deeply localized metastases have been treated. Photon-irradiation was carried out with the convergent beam technique using stereotactic localization methods, in a linear accelerator facility. In 11 of the 12 patients no side effects occurred. The first 7 patients, who could be observed 3 months or longer, have been studied in detail. In each of these cases single dose irradiation with 20-30 Gy yielded arrest of tumor growth. In one case a marked decrease in contrast enhancement and in four cases shrinkage of the metastasis as well as a marked decrease of the edema occurred. In every patient a marked, sometimes dramatic improvement of the clinical condition was achieved, beginning a few days after irradiation. Stereotactic radiosurgery is a valuable tool in the treatment of inoperable, radioresistant brain metastases, the major advantage being high efficacy and smoothness of the procedure, as well as extremely short hospitalization times (2-3 days).

Scintigraphy of a neuroblastoma with I-131 meta-iodobenzylguanidine.

Radioiodinated m-iodobenzylguanidine has been applied mainly for the diagnosis of pheochromocytoma and blastoma. In this paper we show that an ontogenetically related tumor, the neuroblastoma, is also scintigraphically visualized by its high uptake of I-131 MIBG. Because of the kinetic findings and the high uptake of more than 30% of the injected activity, it is likely that the neuroblastoma, by analogy with pheochromocytoma, is susceptible to specific radionuclide therapy.

CD4 and CD8 expression by human and mouse thymic dendritic cells.

Dendritic cells (DC) from human and mouse thymus were compared. DC from both sources were isolated by digestion with collagenase, disruption of cellular complexes with a chelating agent, selection of light density cells, immunomagnetic bead depletion of other cell types (without depletion with anti-CD4 or anti-CD8) and finally sorting for cells expressing high levels of class II MHC. Yields of DC from human and mouse thymus were comparable (around 1 DC/10(3) thymocytes), they displayed similar DC morphology, and both showed strong expression of CD11c. DC from the human thymus all expressed very high levels of CD4 but low levels of CD8. In contrast, DC from the mouse thymus expressed high levels of CD8 but only low levels of CD4. Human thymic DC were also substantially larger than mouse thymic DC. The biological significance of CD4 and CD8 expression by DC is discussed in view of this major species difference and the possibility that human thymic DC may be targets for HIV infection.

Cardiovascular, haematological and neurological effects of the venom of the Papua New Guinean small-eyed snake (Micropechis ikaheka) and their neutralisation with CSL polyvalent and black snake antivenoms.

Cardiovascular and haematological effects of venom of the small-eyed Snake (Micropechis ikaheka) were examined in ventilated anaesthetised piglets. Neurotoxic effects were examined in chick biventer cervicis nerve-muscle preparations. Immunoreactivity of venom was tested against the monovalent antivenom components in a CSL Ltd Venom Detection Kit. Neutralisation was tested in vivo and in vitro with CSL Ltd polyvalent snake and Black Snake (Pseudechis australis) antivenoms. Venom in 0.1% bovine serum albumin in saline was infused into piglets in doses 1-2000 microg/kg. Pulmonary hypertension (P= 0.0007) and depression of cardiac output (P= 0.002) were observed up to 3 h after 150-160 microg/kg. The concentration of plasma free-haemoglobin increased more than 50-fold, indicating haemolysis. Neither coagulopathy nor thrombocytopenia occurred. Creatine phosphokinase and serum potassium levels did not increase suggesting absence of acute rhabdomyolysis. The venom caused post-synaptic neurotoxicty. Immunoreactivity of venom with Black Snake antivenom was observed at very high venom concentrations. Cardiovascular effects were absent and haemolysis was less after venom was pre-incubated at 37 degrees C for 30 min with polyvalent antivenom. Neutralisation by Black Snake antivenom was less effective. The neurotoxicity was neutralised by polyvalent or Black Snake antivenoms. Human envenomation may be treated with CSL Ltd polyvalent snake antivenom.

Radiological evaluation of temporal bone disease: high-resolution computed tomography versus conventional X-ray diagnosis.

Sixty-two patients with different temporal bone lesions were prospectively examined by high-resolution computed tomography (CT) and conventional plain radiography, including pluridirectional tomography. High-resolution CT enabled a clear diagnosis in 80% of cases, conventional radiology in 63%; 1.6-times more bone information was recorded by high-resolution CT which is clearly superior for imaging cholesteatomas, metastases and inflammatory processes and for evaluating osseous destruction. With regard to pathological soft tissue or effusions filling the tympanic cavities, conventional radiology shows poor sensitivity (0.61). High-resolution CT is the most sensitive method for the imaging and classification of temporal bone fractures, including labyrinthine damage and ossicular chain injuries. Only in cases of atypical fractures with an unfavourable relationship to the CT planes, can carefully directed tomography be more effective. In most cases high-resolution CT replaces conventional radiology and should be the method of choice for comprehensive radiological examination of the temporal bone.

Neutrophil function in localized juvenile periodontitis. Phagocytosis, superoxide production and specific granule release.

Patients with localized juvenile periodontitis (LJP) exhibit defective neutrophil functions to a variety of environmental and host stimuli. It is not clear, however, how many of the measurable functions are defective and whether individual patients exhibit single or multiple dysfunctions. The purpose of this study was to evaluate chemotaxis, phagocytosis, specific granule release and superoxide production in a group of 23 previously unreported LJP patients. Our results indicate that all 23 of these LJP patients exhibited chemotaxis depression to N-formyl-L-methionyl-L-leucyl-L-phenylalanine (FMLP) and endotoxin-activated serum (EAS). Smaller groups from the 23 chemotactically defective LJP group were used to test other function due to inability to obtain sufficient quantities of blood. Fourteen of 14 LJP patients tested exhibited defective phagocytosis. Ten LJP patients were evaluated for specific granule release, and 14 LJP patients were evaluated for superoxide production. Both granule release and superoxide production were found to be normal in chemotactically defective LJP patients. Since both defective and normal responses noted in the same neutrophil populations are mediated by the same receptor, it is hypothesized that the cellular defect lies in a post receptor pathway.