Copolymers of PBT and nylon 4T

Polybutylene terephthalate-nylon 4T copolymers (PBT-PA 4T) are synthesized from the diamide of diaminobutane and dimethyl terephthalate (DMT) with butane diol and more DMT in a concentration range of up to 50% PA 4T. The polymerization conditions were similar to those for PBT: first, a melt polymerization, followed by solid-state post-condensation. The materials were studied by differential scanning analysis (DSC) (melting and crystallization behavior) and dynamic mechanical thermal analysis (DMTA) (glass transitions and torsion moduli). The water absorptions were determined at 100% RH. By increasing the PA 4T content in the copolymers, melting temperatures increased strongly, heats of fusion decreased slightly, and glass transition temperatures increased linearly. The torsion moduli above the glass transition temperature were higher

Theoretical Constructs for Design Lenses for Developing Cyberbullying Countering Games for Adolescences

The majority of serious games that counter cyberbullying do not provide evidence-based support of their effectiveness. Additionally, developed theoretical constructs to understand the cyberbullying process from social sciences seems not to be used in the creation of these games. This study proposes a set of theoretical constructs, built upon social interaction theory, as a theoretical perspective for understanding the social aspects of cyberbullying, to ground and introduce design lenses, that can be used as design principles, for informing the creation of counter cyberbullying games

Methane and nitrous oxide in tidal estuaries

Estuaries contribute significantly (5-10 %) to the marine emission budget of methane and nitrous oxide. During the BIOGEST project we have measured the distribution of these two gases in the water column of nine tidal estuaries. In well-mixed estuaries, methane concentrations were high in the river end-member and initially decreased with increasing salinity, then increased at intermediate or high salinities before decreasing again going offshore. Tidal flats and creeks were identified as a methane sources to estuarine waters. Methane concentrations in river-dominated stratified estuaries were rather erratic. Nitrous oxide concentrations were always above atmospheric saturation levels and showed consistent and systematic relationships with distribution patterns of oxygen, ammonium, nitrite and nitrification activities. Nitrous oxide concentrations were very high in ammonium-rich and oxygen-depleted systems such as the Scheldt and Thames estuaries. Nitrous oxide concentrations were also high in the suboxic zone of fluidised mud systems of the Gironde estuary. If time permits, we will show laboratory results for nitrous oxide production in Scheldt water and we will speculate on the role of sediment versus water-column processes

Molecular data reveal the hybrid nature of an introduced population of banded newts (Ommatotriton) in Spain

The three species of banded newt (genus Ommatotriton) are endemic to the Near East. Recently an introduced banded newt population was discovered in Catalonia, Spain. To determine the species involved and the geographical source, we genotyped 11 individuals for one mitochondrial and two nuclear genetic markers, and compared the observed haplotypes to a range-wide phylogeography of Ommatotriton. All haplotypes identified in Spain are identical to haplotypes known from the native range. The mitochondrial haplotypes derive from O. ophryticus and were originally recorded in northeast Turkey. The nuclear haplotypes reveal that all individuals are genetically admixed between O. ophryticus and O. nesterovi. While the geographical resolution for the nuclear markers is low, the source of the O. nesterovi ancestry must be Turkey, as this species is a Turkish endemic. Species distribution models suggest a large potential distribution for the two Ommatotriton species, extending over northern Iberia and southern France. The ecology of hybrids can differ substantially from that of the parent species, making the impact of the Spanish hybrid banded newt population difficult to predict

Utilization of food sources by invertebrates in a man-made intertidal ecosystem

The trophic interactions between primary consumers and the organic matter sources in a man-made intertidal ecosystem were investigated. The most representative invertebrates that occupied the di¡erent habitat types tend to use similar food sources, namely benthic diatoms and suspended particulate or sedimentary organic matter, although they do so in di¡erent proportions. Fucus vesiculosus was abundant on the rocky substrate but this macroalga nor its epiphytes contributed importantly to the diet of the primary consumers inhabiting these assemblages. In contrast, benthic diatoms from the nearby mud£at were directly used as a food source because of their re-suspension in the water and transport by the tide to the arti¢cial rocky shore. The results suggested that the trophic pathways in this intertidal environment were relatively simple

Diffusion-limited reaction for the one-dimensional trap system

We have previously discussed the one-dimensional multitrap system of finite range and found the somewhat unexpected result that the larger is the number of imperfect traps the higher is the transmission through them. We discuss in this work the effect of a small number of such traps arrayed along either a constant or a variable finite spatial section. It is shown that under specific conditions, to be described in the following, the remarked high transmission may be obtained for this case also. Thus, compared to the theoretical large number of traps case these results may be experimentally applied to real phenomenaComment: 18 pages, 8 PS Figures; 3 former figures were removed, a new section added and the representation is improve

Malignancies in Prader-Willi syndrome: results from a large international cohort and literature review

CONTEXT: Prader-Willi syndrome (PWS) is a complex disorder combining hypothalamic dysfunction, neurodevelopmental delay, hypotonia, and hyperphagia with risk of obesity and its complications. PWS is caused by the loss of expression of the PWS critical region, a cluster of paternally expressed genes on chromosome 15q11.2-q13. As life expectancy of patients with PWS increases, age-related diseases like malignancies might pose a new threat to health. OBJECTIVE: To investigate the prevalence and risk factors of malignancies in patients with PWS and to provide clinical recommendations for cancer screening. METHODS: We included 706 patients with PWS (160 children, 546 adults). We retrospectively collected data from medical records on past or current malignancies, the type of malignancy and risk factors for malignancy. Additionally, we searched the literature for information about the relationship between genes on chromosome 15q11.2-q13 and malignancies. RESULTS: Seven adults (age range 18-55 years old) had been diagnosed with a malignancy (acute lymphoblastic leukemia, intracranial hemangiopericytoma, melanoma, stomach adenocarcinoma, biliary cancer, parotid adenocarcinoma and colon cancer). All patients with a malignancy had a paternal 15q11-13 deletion. The literature review showed that several genes on chromosome 15q11.2-q13 are related to malignancies. CONCLUSION: Malignancies are rare in patients with PWS. Therefore, screening for malignancies is only indicated when clinically relevant symptoms are present such as unexplained weight loss, loss of appetite, symptoms suggestive of paraneoplastic syndrome, or localizing symptoms. Given the increased cancer risk associated with obesity, which is common in PWS, participation in national screening programs should be encouraged