Radar mapping, archaeology, and ancient land use in the Maya lowlands

Data from the use of synthetic aperture radar in aerial survey of the southern Maya lowlands suggest the presence of very large areas drained by ancient canals for the purpose of intensive cultivation. Preliminary ground checks in several very limited areas confirm the existence of canals and raised fields. Excavations and ground surveys by several scholars provide valuable comparative information. Taken together, the new data suggest that Late Classic period Maya civilization was firmly grounded in large-scale and intensive cultivation of swampy zones

Comprehensive HIV care and Anti-Retroviral Therapy in a conflict setting-outcomes, experiences, and lessons learned from Bukavu, Democratic Republic of Congo

2006 AIDS Conference in Toront

Randomized controlled trial of patient-controlled sedation for colonoscopy: Entonox vs modified patient-maintained target-controlled propofol

Aim Propofol sedation is often associated with deep sedation and decreased manoeuvrability. Patient-maintained sedation has been used in such patients with minimal side-effects. We aimed to compare novel modified patient-maintained target-controlled infusion (TCI) of propofol with patient-controlled Entonox inhalation for colonoscopy in terms of analgesic efficacy (primary outcome), depth of sedation, manoeuvrability and patient and endoscopist satisfaction (secondary outcomes). Method One hundred patients undergoing elective colonoscopy were randomized to receive either TCI propofol or Entonox. Patients in the propofol group were administered propofol initially to achieve a target concentration of 1.2 μ g/ml and then allowed to self-administer a bolus of propofol (200 μ g/kg/ml) using a patient-controlled analgesia pump with a handset. Entonox group patients inhaled the gas through a mouthpiece until caecum was reached and then as required. Sedation was initially given by an anaesthetist to achieve a score of 4 (Modified Observer's Assessment of Alertness and Sedation Scale), and colonoscopy was then started. Patients completed an anxiety score (Hospital Anxiety and Depression questionnaire), a baseline letter cancellation test and a pain score on a 100-mm visual analogue scale before and after the procedure. All patients completed a satisfaction survey at discharge and 24 h postprocedure. Results The median dose of propofol was 174 mg, and the median number of propofol boluses was four. There was no difference between the two groups in terms of pain recorded (95% confidence interval of the difference -0.809, 5.02) and patient/endoscopist satisfaction. There was no difference between the two groups in either depth of sedation or manoeuvrability. Conclusion Both Entonox and the modified TCI propofol provide equally effective sedation and pain relief, simultaneously allowing patients to be easily manoeuvred during the procedures. © 2010 The Authors. Colorectal Disease © 2010 The Association of Coloproctology of Great Britain and Ireland

Toward an automated signature recognition toolkit for mission operations

Signature recognition is the problem of identifying an event or events from its time series. The generic problem has numerous applications to science and engineering. At NASA's Johnson Space Center, for example, mission control personnel, using electronic displays and strip chart recorders, monitor telemetry data from three-phase electrical buses on the Space Shuttle and maintain records of device activation and deactivation. Since few electrical devices have sensors to indicate their actual status, changes of state are inferred from characteristic current and voltage fluctuations. Controllers recognize these events both by examining the waveform signatures and by listening to audio channels between ground and crew. Recently the authors have developed a prototype system that identifies major electrical events from the telemetry and displays them on a workstation. Eventually the system will be able to identify accurately the signatures of over fifty distinct events in real time, while contending with noise, intermittent loss of signal, overlapping events, and other complications. This system is just one of many possible signature recognition applications in Mission Control. While much of the technology underlying these applications is the same, each application has unique data characteristics, and every control position has its own interface and performance requirements. There is a need, therefore, for CASE tools that can reduce the time to implement a running signature recognition application from months to weeks or days. This paper describes our work to date and our future plans

Combined effects of heat waves and droughts on avian communities across the conterminous United States

Increasing surface temperatures and climatic variability associated with global climate change are expected to produce more frequent and intense heat waves and droughts in many parts of the world. Our goal was to elucidate the fundamental, but poorly understood, effects of these extreme weather events on avian communities across the conterminous United States. Specifically, we explored: (1) the effects of timing and duration of heat and drought events, (2) the effects of jointly occurring drought and heat waves relative to these events occurring in isolation, and (3) how effects vary among functional groups related to nest location and migratory habit, and among ecoregions with differing precipitation and temperature regimes. Using data from remote sensing, meteorological stations, and the North American Breeding Bird Survey, we used mixed effects models to quantify responses of overall and functional group abundance to heat waves and droughts (occurring alone or in concert) at two key periods in the annual cycle of birds: breeding and post-fledging. We also compared responses among species with different migratory and nesting characteristics, and among 17 ecoregions of the conterminous United States. We found large changes in avian abundances related to 100-year extreme weather events occurring in both breeding and post-fledging periods, but little support for an interaction among time periods. We also found that jointly-, rather than individually-occurring heat waves and droughts were both more common and more predictive of abundance changes. Declining abundance was the only significant response to post-fledging events, while responses to breeding period events were larger but could be positive or negative. Negative responses were especially frequent in the western U.S., and among ground-nesting birds and Neotropical migrants, with the largest single-season declines (36%) occurring among ground-nesting birds in the desert Southwest. These results indicate the importance of functional traits, timing, and geography in determining avian responses to weather extremes. Because dispersal to other regions appears to be an important avian response, it may be essential to maintain habitat refugia in a more climatically variable future

Effects of drought on avian community structure

Droughts are expected to become more frequent under global climate change. Avifauna depend on precipitation for hydration, cover, and food. While there are indications that avian communities respond negatively to drought, little is known about the response of birds with differing functional and behavioral traits, what time periods and indicators of drought are most relevant, or how response varies geographically at broad spatial scales. Our goals were thus to determine (1) how avian abundance and species richness are related to drought, (2) whether community variations are more related to vegetation vigor or precipitation deviations and at what time periods relationships were strongest, (3) how response varies among avian guilds, and (4) how response varies among ecoregions with different precipitation regimes. Using mixed effect models and 1989–2005 North American Breeding Bird Survey data over the central United States, we examined the response to 10 precipitation- and greenness based metrics by abundance and species richness of the avian community overall, and of four behavioral guilds. Drought was associated with the most negative impacts on avifauna in the semiarid Great Plains, while positive responses were observed in montane areas. Our models predict that in the plains, Neotropical migrants respond the most negatively to extreme drought, decreasing by 13.2% and 6.0% in abundance and richness, while permanent resident abundance and richness increase by 11.5% and 3.6%, respectively in montane areas. In most cases, response of abundance was greater than richness and models based on precipitation metrics spanning 32-week time periods were more supported than those covering shorter time periods and those based on greenness. While drought is but one of myriad environmental variations birds encounter, our results indicate that drought is capable of imposing sizable shifts in abundance, richness, and composition on avian communities, an important implication of a more climatically variable future

Using the quality circle approach to empower disadvantaged youth in addressing cyberbullying: an exploration across five European countries

Digital communication technologies play an important role in the social development of young people, but can create vulnerabilities to cyberbullying and other negative online experiences. The Blurred Lives project aimed to tackle cyberbullying innovatively using a co-participatory approach, collaborating with 14–16-year olds living in areas of socio-economic disadvantage in five European countries. In phase one, 2,658 teenagers were surveyed on their internet use and any unpleasant online experiences. This data informed the second phase where the participating countries worked together with 237 adolescents across 10 schools with adult facilitators to create original anti-cyberbullying resources for teachers, parents/carers, peers, and social media providers using the Quality Circle approach. This methodology adopts an ethos of working together to solve a problem in small, peer-led groups. Each group was tasked with creating a resource for one of the target audience groups. The final resources comprise a rich variety of different formats including videos, comic strips, a board game, leaflets, posters, and newsletters. The pupil feedback highlights, for most but not all participants, an increased knowledge of cyberbullying and e-safety skills, as well as enhanced problem-solving skills, levels of confidence, and group work skills. Several operational challenges are also discussed, including the importance of school-level support, planning, staffing, and finding an appropriate balance between facilitator support and pupil agency

Controlling the self-assembly and material properties of β-sheet peptide hydrogels by modulating intermolecular interactions

Self-assembling peptides are a promising biomaterial with potential applications in medical devices and drug delivery. In the right combination of conditions, self-assembling peptides can form self-supporting hydrogels. Here, we describe how balancing attractive and repulsive intermolecular forces is critical for successful hydrogel formation. Electrostatic repulsion is tuned by altering the peptide’s net charge, and intermolecular attractions are controlled through the degree of hydrogen bonding between specific amino acid residues. We find that an overall net peptide charge of +/−2 is optimal to facilitate the assembly of self-supporting hydrogels. If the net peptide charge is too low then dense aggregates form, while a high molecular charge inhibits the formation of larger structures. At a constant charge, altering the terminal amino acids from glutamine to serine decreases the degree of hydrogen bonding within the assembling network. This tunes the viscoelastic properties of the gel, reducing the elastic modulus by two to three orders of magnitude. Finally, hydrogels could be formed from glutamine-rich, highly charged peptides by mixing the peptides in combinations with a resultant net charge of +/−2. These results illustrate how understanding and controlling self-assembly mechanisms through modulating intermolecular interactions can be exploited to derive a range of structures with tuneable properties

HIV Treatment in a Conflict Setting: Outcomes and Experiences from Bukavu, Democratic Republic of the Congo

Providing HIV care in conflict settings involves additional obstacles to those generally encountered in other resource-limited settings, say Heather Culbert and colleagues

A qualitative study of diphenhydramine injection in Kyrgyz prisons and implications for harm reduction.

BACKGROUND: To reduce opioid dependence and HIV transmission, Kyrgyzstan has introduced methadone maintenance therapy and needle/syringe programs into prisons. Illicit injection of diphenhydramine, an antihistamine branded as Dimedrol®, has been anecdotally reported as a potential challenge to harm reduction efforts in prisons but has not been studied systematically. METHODS: We conducted qualitative interviews in Kyrgyz or Russian with prisoners (n = 49), former prisoners (n = 19), and stakeholders (n = 18), including prison administrators and prisoner advocates near Bishkek, Kyrgyzstan from October 2016 to September 2018. Interviews explored social-contextual factors influencing methadone utilization in prisons. Transcripts were coded by five researchers using content analysis. Dimedrol injection emerged as an important topic, prompting a dedicated analysis. RESULTS: After drinking methadone, some people in prison inject crushed Dimedrol tablets, a non-prescription antihistamine that is banned but obtainable in prison, to achieve a state of euphoria. From the perspectives of the study participants, Dimedrol injection was associated with devastating physical and mental health consequences, including psychosis and skin infections. Moreover, the visible wounds of Dimedrol injecting contributed to the perception of methadone as a harmful drug and supporting preference for heroin over methadone. CONCLUSION: Dimedrol injecting is a potentially serious threat to harm reduction and HIV prevention efforts in Kyrgyzstan and elsewhere in the Eastern European and Central Asian region and requires further investigation