What Is the Prevalence of Social Anxiety Disorder Among Adolescents in Ireland? How Does It Impact Their Lives and How Do Schools Address It?

Social Anxiety Disorder (SAD) is the most common anxiety disorder encountered in adolescence; however, there is little research in this area in Ireland. The purpose of this study was to determine the prevalence of SAD among adolescents in Ireland, how it impacts on their lives and to examine what support is in place in schools to address it. The findings suggest that social anxiety is highly prevalent among the adolescents who participated in this study and it has a huge impact on both their academic and personal lives. It also found that most teachers who participated are not confident identifying or supporting students with social anxiety. The findings promote training for teachers and the use of school-based interventions to enable access to treatment and support for socially anxious adolescents

Anderson Receives 1991 Bowie Medal

Laboratory of the California Institute of Technology, was awarded the 1991 William Bowie Medal for outstanding contributions to fundamental geophysics and unselfish cooperation in research. The Bowie Medal, AGU's most distinguished honor, was presented to AGU Past-president Anderson on May 29 at the annual Spring Meeting Honors Night in Baltimore, Md

Comparison between the comet assay and pimonidazole binding for measuring tumour hypoxia

Pimonidazole is finding increasing use in histochemical analyses of hypoxia in tumours. Whether it can identify every hypoxic cell in a tumour, and whether the usual subjective criteria used to define ‘positive’ cells are optimal, are less certain. Therefore, our aim was to develop an objective flow cytometry procedure for quantifying pimonidazole binding in tumours, and to validate this method by using a more direct indicator of radiobiologic hypoxia, the comet assay. SCCVII tumours in C3H mice were analysed for pimonidazole binding using flow cytometry and an iterative curve-fitting procedure, and the results were compared to the comet assay for the same cell suspensions. On average, cells defined as anoxic by flow analysis (n = 43 tumours) bound 10.8 ± 0.95 times more antibody than aerobic cells. In samples containing known mixtures of aerobic and anoxic cells, hypoxic fractions as low as 0.5% could easily be detected. To assess the flow cytometry assay under a wider range of tumour oxygen contents, mice were injected with hydralazine to reduce tumour blood flow, or allowed to breathe various gas mixtures during the 90 min exposure to pimonidazole. Hypoxic fraction estimated by the pimonidazole binding method agreed well with the hypoxic fraction measured using the comet assay in SCCVII tumours (r2 = 0.87, slope = 0.98), with similar results in human U87 glioma cells and SiHa cervical carcinoma xenografts. We therefore conclude that this objective analysis of pimonidazole labelling by flow cytometry gives a convenient and accurate estimate of radiobiological hypoxia. Preliminary analyses of biopsies from 3 patients given 0.5 g m–2 pimonidazole also suggest the suitability of this approach for human tumours. © 2000 Cancer Research Campaign http://www.bjcancer.co

Barchan-Parabolic Dune Pattern Transition From Vegetation Stability Threshold

Many dune fields exhibit a downwind transition from forward-pointing barchan dunes to stabilized, backward-pointing parabolic dunes, accompanied by an increase in vegetation. A recent model predicts this pattern transition occurs when dune surface erosion/deposition rates decrease below a threshold of half the vegetation growth rate. We provide a direct test using a unique data set of repeat topographic surveys across White Sands Dune Field and find strong quantitative support for the model threshold. We also show the threshold hypothesis applied to a barchan dune results naturally in its curvature inversion, as the point of threshold crossing progresses from the horns to the crest. This simple, general threshold framework can be an extremely useful tool for predicting the response of dune landscapes to changes in wind speed, sediment supply, or vegetation growth rate. Near the threshold, a small environmental change could result in a drastic change in dune pattern and activity

Fish Eating Birds Can Spread Bacterial Diseases Between Catfish Ponds

Severe outbreaks of Motile Aeromonad Septicemia disease in commercial catfish aquaculture ponds have been associated with a virulent Aeromonas hydrophila strain (VAh) that is genetically distinct from less virulent strains. We demonstrated that Great Egrets (Arde alba), Double-crested Cormorants (Phalacrocorax auritus), American White Pelicans (Pelecanus erythrorhynchos), and Wood Storks (Mycteria americana) can carry and shed viable VAh after consuming fish infected with Vah. Edwardsiella ictaluri and E. tarda are considered the primary species of Edwardsiella to cause disease outbreaks in North American catfish aquaculture. Genetic analysis has determined that most isolates designated as E. tarda were actually a new species, E. piscicida. There has been an increase in E. piscicida diagnostic cases in recent years possibly due to an increase in hybrid (Channel x blue) catfish production. We conducted a study to determine if Great Egrets (Ardea alba) shed viable E. piscicida when fed catfish infected with the bacteria. Great Egrets fed infected fish shed viable E. piscicida bacteria for multiple days, (Table 1), after last consuming infected fish on day 2 of the study. Great Egrets in the control group did not shed the bacteria. Given that Great Egrets can shed viable E. piscicida after consuming diseased fish, we hypothesize that they could also serve as a reservoir for E. piscicida and could spread the pathogen while predating fish in catfish ponds. Additional research is needed to determine if this shedding could cause disease in these ponds

Modulation-Mode Assignment in SVD-Aided Downlink Multiuser MIMO-OFDM Systems

Multicarrier transmission such as OFDM (orthogonal frequency division multiplexing) is an established technique for radio transmission systems and it can be considered as a promising approach for next generation wireless systems. However, in order to comply with the demand on increasing available data rates in particular in wireless technologies, systems with multiple transmit and receive antennas, also called MIMO (multiple-input multiple-output) systems, have become indispensable for future generations of wireless systems. Due to the strongly increasing demand in high-data rate transmission systems, frequency non-selective MIMO links have reached a state of maturity and frequency selective MIMO links are in the focus of interest. In this field, the combination of MIMO transmission and OFDM can be considered as an essential part of fulfilling the requirements of future generations of wireless systems. However, single-user scenarios have reached a state of maturity. By contrast multiple users' scenarios require substantial further research, where in comparison to ZF (zero-forcing) multiuser transmission techniques, the individual user's channel characteristics are taken into consideration in this contribution. The performed joint optimization of the number of activated MIMO layers and the number of transmitted bits per subcarrier shows that not necessarily all user-specific MIMO layers per subcarrier have to be activated in order to minimize the overall BER under the constraint of a given fixed data throughput