Short-term studies underestimate 30-generation changes in a butterfly metapopulation

Most studies of rare and endangered species are based on work carried out within one generation, or over one to a few generations of the study organism. We report the results of a study that spans 30 generations (years) of the entire natural range of a butterfly race that is endemic to 35 km2 of north Wales, UK. Short-term studies (surveys in single years and dynamics over 4 years) of this system led to the prediction that the regional distribution would be quite stable, and that colonization and extinction dynamics would be relatively unimportant. However, a longer-term study revealed unexpectedly high levels of population turnover (local extinction and colonization), affecting 18 out of the 20 patches that were occupied at any time during the period. Modelling the system (using the 'incidence function model' (IFM) for metapopulations) also showed higher levels of colonization and extinction with increasing duration of the study. The longer-term dynamics observed in this system can be compared, at a metapopulation level, with the increased levels of variation observed with increasing time that have been observed in single populations. Long-term changes may arise from local changes in the environment that make individual patches more or less suitable for the butterfly, or from unusual colonization or extinction events that take metapopulations into alternative states. One implication is that metapopulation and population viability analyses based on studies that cover only a few animal or plant generations may underestimate extinction threats

Severe impact of the 1918-19 pandemic influenza in a national military force

The impact of pandemic influenza on the New Zealand Expeditionary Force (NZEF) in 1918-19 has never been studied using modern epidemiological methods. Therefore we analysed mortality and descriptive data from various sources for these military personnel. An estimated 930 NZEF personnel deaths from pandemic influenza occurred in 1918-19, making it the main cause of disease deaths, and representing 5.1% of all NZEF deaths from World War One (WW1). The epidemic curve was much more drawn out in the Northern Hemisphere compared with the Southern Hemisphere. Mortality rates varied markedly by setting (e.g. in military camps, by country and by hemisphere). Significantly higher mortality rates were found amongst NZEF personnel: aged 30-34 years, those of Māori ethnicity, those with a rural background, and those who left New Zealand for Europe in 1918. In conclusion, this work documents the heavy mortality burden from pandemic influenza amongst this national military force and highlights the large variations in mortality rates through host and environmental factors

BATSE flare observations in Solar Cycle 22

The Hard X-Ray Burst Spectrometer (HXRBS) group at GSFC has developed and is maintaining a quick-look analysis system for solar flare hard x-ray data from the Burst and Transient Source Experiment (BATSE) on the recently launched Compton Gamma-Ray Observatory (GRO). The instrument consists, in part, of 8 large planar detectors, each 2025 sq cm, placed on the corners of the GRO spacecraft with the orientation of the faces being those of a regular octahedron. Although optimized for the detection of gamma-ray bursts, these detectors are far more sensitive than any previous spacecraft-borne hard x-ray flare instrumentation both for the detection of small microflares and the resolution of fine temporal structures. The data in this BATSE solar data base are from the discriminator large area (DISCLA) rates. From each of eight detectors there are hard x-ray data in four energy channels, 25-50, 50-100, 100-300, and greater than 300 keV with a time resolution of 1.024 seconds. These data are suitable for temporal correlation with data at other wavelengths, and they provide a first look into the BATSE and other GRO instrument flare data sets. The BATSE and other GRO principle investigator groups should be contacted for the availability of data sets at higher time or spectral resolution or at higher energies

Learning Aquatic Locomotion with Animats

One of the challenges of researching spiking neural networks (SNN) is translation from temporal spiking behavior to classic controller output. While many encoding schemes exist to facilitate this translation, there are few benchmarks for neural networks that inherently utilize a temporal controller. In this work, we consider the common reinforcement problem of animat locomotion in an environment suited for evaluating SNNs. Using this problem, we explore novel methods of reward distribution as they impacts learning. Hebbian learning, in the form of spike time dependent plasticity (STDP), is modulated by a dopamine signal and affected by reward-induced neural activity. Different reward strategies are parameterized and the Covariance Matrix Adaptation Evolution Strategy (CMA-ES) is used to find the best strategies for fixed animat morphologies. The contribution of this work is two-fold: to cast the problem of animat locomotion in a form directly applicable to simple temporal controllers, and to demonstrate novel methods for reward modulated Hebbian learning

Implementation of an Integrated Approach to the National HIV/AIDS Strategy for Improving Human Immunodeficiency Virus Care for Youths

Importance Youths aged 13 to 24 years old living with human immunodeficiency virus (HIV) are less likely than adults to receive the health and prevention benefits of HIV treatments, with only a small proportion having achieved sustained viral suppression. These age-related disparities in HIV continuum of care are owing in part to the unique developmental issues of adolescents and young adults as well as the complexity and fragmentation of HIV care and related services. This article summarizes a national, multiagency, and multilevel approach to HIV care for newly diagnosed youths designed to bridge some of these fragmentations by addressing National HIV/AIDS Strategy goals for people living with HIV. Design, Setting, and Participants Three federal agencies developed memoranda of understanding to sequentially implement 3 protocols addressing key National HIV/AIDS Strategy goals. The goals were addressed in the Adolescent Trials Network, with protocols implemented in 12 to 15 sites across the United States. Outcome data were collected from recently diagnosed youth referred to the program. Main Outcomes and Measures Cross-agency collaboration, youth-friendly linkage to care services, community mobilization to address structural barriers to care, cooperation among services, proportion of all men who have sex with men who tested, and rates of linkage to prevention services. Results The program addressed National HIV/AIDS Strategy goals 2 through 4 including steps within each goal. A total of 3986 HIV-positive youths were referred for care, with more than 75% linked to care within 6 weeks of referral, with almost 90% of those youths engaged in subsequent HIV care. Community mobilization efforts implemented and completed structural change objectives to address local barriers to care. Age and racial/ethnic group disparities were addressed through targeted training for culturally competent, youth-friendly care, and intensive motivational interviewing training. Conclusions and Relevance A national program to address the National HIV/AIDS Strategy specifically for youths can improve coordination of federal resources as well as implement best-practice models that are adapted to decrease service fragmentation and systemic barriers at local jurisdictions