Angular momentum generation in nuclear fission.

When a heavy atomic nucleus splits (fission), the resulting fragments are observed to emerge spinning1; this phenomenon has been a mystery in nuclear physics for over 40 years2,3. The internal generation of typically six or seven units of angular momentum in each fragment is particularly puzzling for systems that start with zero, or almost zero, spin. There are currently no experimental observations that enable decisive discrimination between the many competing theories for the mechanism that generates the angular momentum4-12. Nevertheless, the consensus is that excitation of collective vibrational modes generates the intrinsic spin before the nucleus splits (pre-scission). Here we show that there is no significant correlation between the spins of the fragment partners, which leads us to conclude that angular momentum in fission is actually generated after the nucleus splits (post-scission). We present comprehensive data showing that the average spin is strongly mass-dependent, varying in saw-tooth distributions. We observe no notable dependence of fragment spin on the mass or charge of the partner nucleus, confirming the uncorrelated post-scission nature of the spin mechanism. To explain these observations, we propose that the collective motion of nucleons in the ruptured neck of the fissioning system generates two independent torques, analogous to the snapping of an elastic band. A parameterization based on occupation of angular momentum states according to statistical theory describes the full range of experimental data well. This insight into the role of spin in nuclear fission is not only important for the fundamental understanding and theoretical description of fission, but also has consequences for the γ-ray heating problem in nuclear reactors13,14, for the study of the structure of neutron-rich isotopes15,16, and for the synthesis and stability of super-heavy elements17,18.

Anomalies in the Charge Yields of Fission Fragments from the

Fast-neutron-induced fission of ^{238}U at an energy just above the fission threshold is studied with a novel technique which involves the coupling of a high-efficiency γ-ray spectrometer (MINIBALL) to an inverse-kinematics neutron source (LICORNE) to extract charge yields of fission fragments via γ-γ coincidence spectroscopy. Experimental data and fission models are compared and found to be in reasonable agreement for many nuclei; however, significant discrepancies of up to 600% are observed, particularly for isotopes of Sn and Mo. This indicates that these models significantly overestimate the standard 1 fission mode and suggests that spherical shell effects in the nascent fission fragments are less important for low-energy fast-neutron-induced fission than for thermal neutron-induced fission. This has consequences for understanding and modeling the fission process, for experimental nuclear structure studies of the most neutron-rich nuclei, for future energy applications (e.g., Generation IV reactors which use fast-neutron spectra), and for the reactor antineutrino anomaly.

[Current Guidelines to Prevent Obesity in Childhood and Adolescence]. / Aktuelle Empfehlungen zur Prävention der Adipositas im Kindes- und Jugendalter.

BACKGROUND: Current guidelines for the prevention of obesity in childhood and adolescence are presented. METHODS: A literature search was performed in Medline via PubMed, and appropriate studies were analysed. RESULTS: Programs to prevent childhood obesity were to date mainly school-based. Effects were limited to date. Analyses tailored to different age groups show that prevention programs have the best effects in younger children (< 12 years). Evidence based recommendations for preschool- and early school age imply the need for interventions addressing parents and teachers alike. During adolescence, school-based interventions were most effective when adolescents were directly addressed. To date, obesity prevention programs have mainly focused on behavior oriented prevention. Recommendations for condition oriented prevention have been suggested by the German Alliance of Non-communicable Diseases and include one hour of physical activity at school, promotion of healthy food choices by taxing unhealthy foods, mandatory quality standards for meals at kindergarten and schools as well as a ban on unhealthy food advertisement addressing children. CONCLUSION: Behavior oriented prevention programs showed hardly any or only limited effects in the long term. Certain risk groups for the development of obesity are not reached effectively by available programs. Due to the heterogeneity of available studies, universally valid conclusions cannot be drawn. The combination with condition oriented prevention, which has to counteract on an obesogenic environment, is crucial for sustainable success of future obesity prevention programs.

Introducing excess body weight in childhood and adolescence and comparison with body mass index and waist-to-height ratio.

BACKGROUND: Weight status in children and adolescents is commonly defined using age- and gender-corrected standard deviation scores for body mass index (BMI-SDS, also called z-scores). Values are not reliable for the extremely obese however. Moreover, paediatricians and parents may have difficulties understanding z-scores, and while percentiles are easier to gauge, the very obese have values above the 99th percentile, making distinction difficult. The notion of excess body weight (EBW) is increasingly applied in adult patients, mainly in the context of bariatric surgery. However, a clear definition is not available to date for the paediatric population. METHODS: A simple definition of EBW for children and adolescents is introduced, with median weight as a function of height, age and gender (characterized by an asterisk): EBW (%) = 100x(weight-median weight*)/median weight*. EBW is compared with BMI-SDS and waist-to-height ratio (WHtR). Using two data sources (APV registry and German Health Interview and Examination Survey for Children and Adolescents (KiGGS)) including more than 14,000 children, the relationships between these anthropometric and various metabolic parameters are analysed for a group of overweight/obese children who have sought obesity therapy (APV), for the general paediatric population and for the subset of overweight/obese children from the general population (KiGGS). RESULTS: The three anthropometric parameters are strongly correlated, with the linear correlation coefficients exceeding 0.8 in the general population and 0.75 in those seeking obesity therapy. Moreover, their relationship to metabolic parameters is quite similar regarding correlations and area under the curve from receiver operating characteristic analyses. CONCLUSIONS: EBW has similar predictive value for metabolic or cardiovascular comorbidities compared with BMI and WHtR. As it is reliable at the extreme end of the obesity spectrum, easily communicable and simple to use in daily practice, it would make a very useful addition to existing tools for working with obese children and adolescents. Its usefulness in assessing weight change needs to be studied however.

Decay and Fission Hindrance of Two- and Four-Quasiparticle K Isomers in

Two isomers decaying by electromagnetic transitions with half-lives of 4.7(1.1) and 247(73) µs have been discovered in the heavy ^{254}Rf nucleus. The observation of the shorter-lived isomer was made possible by a novel application of a digital data acquisition system. The isomers were interpreted as the K^{π}=8^{-}, ν^{2}(7/2^{+}[624],9/2^{-}[734]) two-quasineutron and the K^{π}=16^{+}, 8^{-}ν^{2}(7/2^{+}[624],9/2^{-}[734])⊗8^{-}π^{2}(7/2^{-}[514],9/2^{+}[624]) four-quasiparticle configurations, respectively. Surprisingly, the lifetime of the two-quasiparticle isomer is more than 4 orders of magnitude shorter than what has been observed for analogous isomers in the lighter N=150 isotones. The four-quasiparticle isomer is longer lived than the ^{254}Rf ground state that decays exclusively by spontaneous fission with a half-life of 23.2(1.1) µs. The absence of sizable fission branches from either of the isomers implies unprecedented fission hindrance relative to the ground state.

Fission barrier of superheavy nuclei and persistence of shell effects at high spin: cases of 254No and 220Th.

We report on the first measurement of the fission barrier height in a heavy shell-stabilized nucleus. The fission barrier height of 254No is measured to be Bf=6.0±0.5 MeV at spin 15ℏ and, by extrapolation, Bf=6.6±0.9 MeV at spin 0ℏ. This information is deduced from the measured distribution of entry points in the excitation energy versus spin plane. The same measurement is performed for 220Th and only a lower limit of the fission barrier height can be determined: Bf(I)>8 MeV. Comparisons with theoretical fission barriers test theories that predict properties of superheavy elements.

Shell-structure and pairing interaction in superheavy nuclei: rotational properties of the z=104 nucleus (256)rf.

The rotational band structure of the Z=104 nucleus (256)Rf has been observed up to a tentative spin of 20ℏ using state-of-the-art γ-ray spectroscopic techniques. This represents the first such measurement in a superheavy nucleus whose stability is entirely derived from the shell-correction energy. The observed rotational properties are compared to those of neighboring nuclei and it is shown that the kinematic and dynamic moments of inertia are sensitive to the underlying single-particle shell structure and the specific location of high-j orbitals. The moments of inertia therefore provide a sensitive test of shell structure and pairing in superheavy nuclei which is essential to ensure the validity of contemporary nuclear models in this mass region. The data obtained show that there is no deformed shell gap at Z=104, which is predicted in a number of current self-consistent mean-field models.

[Certification of therapy institutions, obesity trainers, and obesity trainer academies by the German Working Group on Obesity in Children and Adolescents (AGA)]. / Was hat die Arbeitsgemeinschaft Adipositas im Kindes- und Jugendalter durch die Zertifizierung von Behandlungseinrichtungen, Adipositas-Trainern und Adipositas-Trainer-Akademien erreicht?

There is a vast choice of behavioral therapy for obesity in children and adolescents, with wide differences in quality. In order to provide orientation for families, physicians, and health insurance companies, the German Working Group on Obesity in Children and Adolescents (AGA), which is affiliated with the German Obesity Society (DAG) and the German Pediatric Society (DGKJ), offers to certify institutions providing patient education programs for obese children and adolescents, obesity trainers, and academies for obesity trainers. Currently, 60 institutions offer obesity care, while 81 obesity trainers and 8 trainer academies are certified. This article summarizes requirements for certification and preliminary experience.

Epidermal growth factor receptor kinase domain mutations are rare in salivary gland carcinomas.

Activating mutations within the epidermal growth factor (EGFR) tyrosine kinase domain identify non-small cell lung cancer patients with improved clinical response to tyrosine kinase inhibitor therapy. Recently, we identified two EGFR mutations in a cohort of 25 salivary gland carcinomas (SGCs) by screening the tumour samples for the both most common hotspot mutations in exons 19 and 21 by allele-specific PCR. Here, we present a comprehensive sequencing analysis of the entire critical EGFR tyrosine kinase domain in 65 SGC of the main histopathological types. We found EGFR mutations in the tyrosine kinase domain to be a rare event in SGCs. No additional mutations other than the two known exon 19 deletions (c.2235_2249del15) in a mucoepidermoid carcinoma and an adenoid cystic carcinoma have been detected. Other putative predictive markers for EGFR-targeted therapy in SGCs might be relevant and should be investigated.

A longitudinal study of autism spectrum disorders in individuals diagnosed with a developmental language disorder as children.

BACKGROUND: A number of studies have shown that the diagnosis of developmental language disorder (DLD) can be unstable over time, such that young children with a diagnosis of DLD may show symptoms more characteristics of autism spectrum disorder (ASD) at a later date. METHOD: To estimate the types and prevalence of ASD 469 individuals with a DLD, consecutively assessed in the same clinic during a period of 10 years, and 2345 controls from the general population were screened for ASD through the nationwide Danish Psychiatric Central Register (DPCR). The mean length of observation was 34.7 years, and the mean age at follow-up 35.8 (range: 28.3-46.7) years. RESULTS: At follow-up, 10 (2.1%) in the DLD group and two (0.09%) in the comparison group were known in the DPCR with a diagnosis of any ASD (P < 0.0001; odds ratio = 25.5; 95% confidence interval 5.5-116.9). CONCLUSION: Our results provide additional support to the notion that DLD is a marker of increased vulnerability to the development of ASD.

The role of taste and appetite regulation in the understanding of overweight and obesity. Proceedings of the 16th Aschauer Soiree, 26th April 2008.

Overweight and obesity have developed into major illnesses in most Western societies and significantly contribute to the financial burden of modern public health systems. Almost daily, new therapeutic proposals are published in the lay press, and also the scientific literature has increased dramatically in recent years. E.g., when searching MEDLINE (1966 - May 2008 (1)), the key word "obesity" meanwhile appears in more than 108,000 articles. Primary focus however, is put upon aspects of treatment, neglecting the role of taste and appetite regulation. Combining keywords like "obesity + treatment" results in over 50.000 citations, "obesity + diet" in over 23.000, "obesity + energy + expenditure" in over 13.000 citations (even "obesity + gastric + bypass" still evoke 2.600 citations), whereas "obesity + appetite + regulation" result in some 3.000, "obesity + NPY" - neuropeptid Y being one of the major chemical stimulators of appetite - evoke some 500 and "obesity + Arc + nucleus" - the arcuate nucleus being the anatomical centre of appetite regulation - no more than 370 scientific publications. The apparent scarcity of literature about taste and appetite regulation and the amazing lack of interest in neuronal information processing in overweight and obesity, has prompted the authors to brainstorm new aspects of the world-wide derailment of weight control.

Trends in overweight and obesity and changes in the distribution of body mass index in schoolchildren of Jena, East Germany.

OBJECTIVE: Data of Jena children (Germany) show increases in the prevalence estimates of overweight and obesity between 1975 and 2001. Our objective was to determine if these increases contribute to changes in the distribution of body mass index (BMI) in the entire population of children. The decade 1985-1995, which includes the time of German reunification, is of particular interest because of the significant socio-economic changes in East Germany, in which Jena is located. DESIGN AND SUBJECTS: The analyses were based on data from four cross-sectional growth studies in 7- to 14-year-old children performed in Jena, Germany, in 1975 (n=2013), 1985 (n=1534), 1995 (n=1906) and 2001 (n=1918). Overweight and obesity were estimated by German reference data and the reference of Cole et al. Mean difference plots were used to investigate the changes in the BMI distributions within sexes between the studies. RESULTS: Between 1985 and 1995, the prevalence of overweight and obesity increased significantly in both sexes, whereas nonsignificant changes were found between 1975 and 1985. Although there is a tendency towards increased overweight between 1995 and 2001, the differences were nonsignificant. Comparing data from 1975 and 1985, the mean difference plots showed virtually no changes in the BMI distribution. In the plots comparing the BMI distribution for 1985 data and 1995 data, the whole distribution tended to shift upwards with a greater shift in the upper BMI range. The entire population of children in Jena gained weight during this period of time. This increase may be linked to a transition towards a more Western lifestyle, that is, usually by lower energy expenditure and nutritional transitions, caused by the process of reunification of Germany in 1989. CONCLUSIONS: Weight gain appears to be a characteristic feature of the entire population studied and does not seem to be a separate problem of the obese children. This suggests that reported changes in the prevalence may be underestimating the looming public health crisis.

[Long-term inpatient treatment of extreme juvenile obesity: an 18-month catamnestic study]. / Studie zur stationären Langzeittherapie der extremen juvenilen Adipositas. Jeder Zweite nimmt langfristig ab.

Eighteen months after completion of long-term treatment of 98 extremely overweight juveniles in the rehabilitation center Insula, this study revealed an improvement in the age-specific body mass index (BMI-SDS) in 55.1% of the cases, when all the non-responders (approx. 22%) were evaluated as failures. An improvement of at least 0.2 or 0.5 BMI SDS points was achieved in 41.8% and 21.4%, respectively.

Dental enamel defects in German medieval and early-modern-age populations.

SUMMARY: Aim of this study was to investigate the frequency and type of developmental defects of enamel (DDE) in a medieval and an early-modern-age population from Thuringia, Germany. Sixty-six skeletons subdivided into 31 single burials (12th/13th c.) and 35 individuals buried in groups (15th/16th c.) were examined. DDE were classified on 1,246 teeth according to the DDE index. Molar-incisor-hypomineralisation (MIH), a special type of DDE, was recorded according to the European Academy of Paediatric Dentistry (EAPD) criteria. DDE was found in 89.4% of the individuals (single burials 90.3% and group burials 88.6%). Hypoplastic pits were the most frequent defect in primary teeth and linear enamel hypoplasia (LEH) in permanent teeth. 13 individuals (24.1%) showed at least one hypomineralised permanent tooth, 12.2% had MIH on at least one first permanent molar and 10.0% in permanent incisors. Second primary molars were affected in 8.0% of the children and juveniles. No individual suffered from affected molars and incisors in combination. Endogenous factors like nutritional deficiencies and health problems in early childhood could have been aetiological reasons of DDE and MIH. The frequency of DDE and MIH might have been masked by extended carious lesions, dental wear and ante-mortem tooth loss.

Excretion of thiosulphate, the main detoxification product of sulphide, by the lugworm arenicola marina L

Thiosulphate, the main sulphide detoxification product, is accumulated in the body fluids of the lugworm Arenicola marina. The aim of this study was to elucidate the fate of thiosulphate. Electrophysiological measurements revealed that the transepithelial resistance of body wall sections was 76+/-34 capomega cm2 (mean +/- s.d., N=14), indicating that the body wall of the lugworm is a leaky tissue in which mainly paracellular transport along cell junctions takes place. The body wall was equally permeable from both sides to thiosulphate, the permeability coefficient of which was 1. 31x10(-)3+/-0.37x10(-)3 cm h-1 (mean +/- s.d., N=30). No evidence was found for a significant contribution of the gills or the nephridia to thiosulphate permeation. Thiosulphate flux followed the concentration gradient, showing a linear correlation (r=0.997) between permeated and supplied (10-100 mmol l-1) thiosulphate. The permeability of thiosulphate was not sensitive to the presence of various metabolic inhibitors, implicating a permeation process independent of membrane proteins and showing that the lugworm does not need to use energy to dispose of the sulphide detoxification product. The present data suggest a passive permeation of thiosulphate across the body wall of A. marina. In live lugworms, thiosulphate levels in the coelomic fluid and body wall tissue decreased slowly and at similar rates during recovery from sulphide exposure. The decline in thiosulphate levels followed a decreasing double-exponential function. Thiosulphate was not further oxidized to sulphite or sulphate but was excreted into the sea water.

[Freiburg intervention program for ambulatory therapy of obesity in childhood (FITOC)]. / Freiburger Interventionsprogramm zur ambulanten Therapie der Adipositas im Kindesalter (FITOC).

In this study we first try to answer the question, whether it is possible to make a successful treatment for obese children in an interdisciplinary program. Second it is asked whether a transfer of this program to further regions in Germany leads to comparable results. In FITOC children from the age of 8-11 years and over the 97. BMI-percentile are integrated in this program. The goals weight management, increased physical fitness and improvement of the cardiac risk profile are checked by weight, height, fasting blood serum, a standardized cycle ergometry and a medical measurement at the beginning, after treatment and at all check-ups. The recorded medical data show clearly that the intervention leads to a significant improvement in almost all checked parts. The successful treatment can be recorded after 8 months, likewise after 2.5 years as a long-term result. The further cornerstones of FITOC nutrition and psychology are not subject of this publication. In future the psychological part in FITOC will be evaluated by standardized inventories. The group from Düren has a success in therapy according to the definition of the program. Thereby it is shown that FITOC is extendable, if teams are trained intensively and the conditions are comparable. FITOC is able to treat obese children successfully over a long period of time. In consideration of the rising prevalence of obesity in childhood and the limited financial resources in health care this outpatient interdisciplinary program is an effective choice of treatment.

[Ever more children and adolescents are overweight. How can the obesity epidemic be stopped?]. / Immer mehr Kinder und Jugendliche zu dick. Wie lässt sich die Adipositas-Epidemie stoppen?

In Germany, the number of overweight children and adolescents is increasing. The increase in the prevalence of obesity shows considerable regional differences. Related to recent German reference data with an expected prevalence of 3%, we find today in some regions a prevalence of 7% in 5- to 6-year-olds and 8% in 13- to 15-year-olds. While the reasons for this development are not fully clear, it may be assumed that the increase in physical inactivity, together with the ready availability of an abundance of high-energy foods are significant contributing factors. A large percentage of children and adolescents suffering from obesity also have considerable co-morbidity. It is to be expected that this will in the future considerably increase the financial burden on public health care and society as a whole. Effective prevention and therapeutic countermeasures are necessary to deal with this problem.

"Obese equals lazy?" analysis of the association between weight status and physical activity in children.

INTRODUCTION: Literature provides evidence that overweight children are more sedentary. To verify this generalized statement behavior patterns of overweight and nonoverweight children needs to be understood. Therefore, we investigated the distribution of sedentary and activity levels in a quantitative and qualitative way. METHODS: Data was collected from 37 randomly selected nonoverweight and 55 overweight children. They were 8 to 11 years of age. Height and weight were measured and weight status was characterized by BMI (BMI-percentile, BMI-SDS). Daily PA (physical activity) was measured by direct accelerometry. Spare time and screen time entertainment were obtained by questionnaires. RESULTS: The amount of time spent "passive" was significantly higher in overweight children, while nonoverweight children were more "active." The multiple regression model shows a significant association between weight status (BMI-SDS) and activity parameters. Additionally, screen time entertainment was significantly related to BMI-SDS. CONCLUSION: The results support the statement that overweight children are less active than nonoverweight children. The high amount of PA seems to be an important factor to prevent overweight in children given that PA shows the highest correlation to weight status. Quantitative and qualitative measurements are needed for further analysis.

Adiposity rebound is misclassified by BMI rebound.

BACKGROUND/OBJECTIVES: Adiposity rebound (AR) is defined as the nadir or the inflexion point of body mass index (BMI) percentiles between the age of 3 and 7 years. An early rebound is seen as a risk of obesity and, thus, AR is considered as a suitable time period for prevention. As BMI does not reflect body composition, we aimed to examine the rebounds of fat mass index (FMI) and fat-free mass index (FFMI) together with BMI. SUBJECTS/METHODS: Cross-sectional data of 19 264 children aged 3-11 years were pooled from three German studies (Kiel Obesity Prevention Study, the project 'Better diet. More exercise. KINDERLEICHT-REGIONS' and regular examinations of Jena children). Height and weight were measured. Fat mass (FM) and fat-free mass (FFM) were obtained from bioelectrical impedance analysis and analysed using a population-specific algorithm. Percentiles of BMI, FMI and FFMI were constructed by the LMS method. RESULTS: Both BMI and FMI percentiles showed a rebound, whereas FFMI percentiles steadily increased with age. On P90, FMI rebound was about 1.6-1.8 years later compared with that of BMI, that is, at ages 4.2 years (BMI) and 5.8 years (FMI) in boys and at 4.2 years (BMI) and 6.0 years (FMI) in girls. At AR, the slope of the BMI-P90 was explained by increases in FFMI rather than FMI. By contrast, at FMI rebound, the slope of BMI was strongly related to FMI. CONCLUSIONS: BMI rebound does not equal the rebound of FM. At AR, the slope in BMI is determined by the increase in FFMI. AR should be defined as FMI rebound rather than BMI rebound.