English cultural reflections of Chatham 1667

The shock of the Dutch descent on the Thames and Medway was reflected by diarists such as Samuel Pepys and John Evelyn who recorded confusion, fear and humiliation for the English and their King Charles II. What was to follow over the next hundred and forty years was neither the inevitable nor inexorable rise of the Royal Navy. However starting with Anglo Dutch operations the English gained a commercial and military confidence which was to be reflected in public displays and celebrations of victories gained. The building of the Naval Hospital Greenwich gave this solid form especially the Painted Hall and its allegories of British successes. Through the long 18th century the Royal Navy and its officers would be celebrated in in song, ballads & plays and their fashion aped by the nobility. This change in fortune was personified with the Nelson pediment at Greenwich at the start of the 19th century

Why Do Businesses Use (or Not Use) Arbitration Clauses?

Published in cooperation with the American Bar Association Section of Dispute Resolutio

Hidden terminal jamming problems in IEEE 802.11 mobile ad hoc networks

Abstract — This paper addresses recent experimental measurements from an IEEE 802.11 ad hoc network testbed, which indicate a strong signal strength dependence in the ability of a hidden terminal to gain access to the radio channel. We present analytical results investigating the ‘hidden terminal jamming ’ ability of the IEEE 802.11 DSSS physical layer. Results indicate that in a hidden terminal topology, the presence of an interfering transmission with a signal strength marginally greater than the transmission currently being received will result in an intolerable increase in BER, effectively jamming the ongoing transmission. These results confirm previous experimental measurements which show that after a number of MAC layer timeout/retransmission periods, the original (weaker) connection is effectively prevented from gaining access to the channel. I

Subsonic aerodynamic characteristics of the HL-20 lifting-body configuration

The HL-20 is proposed as a possible future manned spacecraft. The configuration consists of a low-aspect-ratio body with a flat undersurface. Three fins (a small centerline fin and two outboard (tip) fins set at a dihedral angle of 50 deg) are mounted on the aft body. The control system consists of elevon surfaces on the outboard fins, a set of four body flaps on the upper and lower aft body, and an all-movable center fin. Both the elevons and body flaps were capable of trimming the model to angles of attack from -2 deg to above 20 deg. The maximum trimmed lift-drag ratio was 3.6. Replacing the flat-plate tip fins with airfoil tip fins increased the maximum trimmed lift-drag ratio to 4.2. The elevons were effective as a roll control, but they produced about as much yawing moment as rolling moment because of the tip-fin dihedral angle. The body flaps produced less rolling moment than the elevons and only small values of yawing moment. A limited investigation of the effect of varying tip-fin dihedral angle indicated that a dihedral angle of 50 deg was a reasonable compromise for longitudinal and lateral stability, longitudinal trim, and performance at subsonic speeds

Prevention of microbial species introductions to the arctic: The efficacy of footwear disinfection measures on cruise ships

Source at https://doi.org/10.3897/neobiota.37.22088.Biosecurity measures are commonly used to prevent the introduction of non-native species to natural environments globally, yet the efficacy of practices is rarely tested under operational conditions. A voluntary biosecurity measure was trialled in the Norwegian high Arctic following concern that non-native species might be transferred to the region on the footwear of travellers. Passengers aboard an expedition cruise ship disinfected their footwear with the broad spectrum disinfectant Virkon S prior to and in-between landing at sites around the remote Svalbard archipelago. The authors evaluated the efficacy of simply stepping through a disinfectant foot bath, which is the most common practice of footwear disinfection aboard expedition cruise ships in the Arctic. This was compared to a more time consuming and little-used method involving drying disinfected footwear, as proposed by other studies. The two practices were evaluated by measuring microbial growth on paired footwear samples before and after disinfection under both conditions. Step-through disinfection did not substantially reduce microbial growth on the footwear. Allowing disinfected footwear to dry, however, reduced the microbial burden significantly to lower levels. Thus, the currently adopted procedures used aboard ships are ineffective at removing microbial burden and are only effective when footwear is given more time to dry than currently granted under operational conditions. These findings underscore results from empirical research performed elsewhere and suggest the need to better relay this information to practitioners. It is suggested that footwear should minimally be wiped dry after step-through disinfection as a reasonable compromise between biosecurity and practicability

LASP SmallSat Science Data Services

We are developing of a set of turn-key science data services for smallsat data management, processing, and hosting. Using cloud computing resources and existing infrastructure, we can rapidly deploy a modular data system for a mission or project. A basic system includes reliable, secure data storage, an API for fast data access worldwide, and a lightweight website with information about the mission and data API documentation. Optional add-ons include the ability to deploy science processing software using Docker containers, interactive web-based data displays, and archive deliveries to NASA or other archive facilities. The use of AWS CloudFormation templates to build new systems makes deployment and support straightforward and cost-efficient, and provides a consistent interface for both mission teams and science data users

Evolution of the northern KwaZulu-Natal coastal dune cordon : evidence from the fine-grained sediment fraction.

Thesis (M.Sc.)--University of KwaZulu-Natal, Durban, 2001.Abstract available in PDF file

Novel use Of Hydroxyurea in an African Region with Malaria (NOHARM): a trial for children with sickle cell anemia

Hydroxyurea treatment is recommended for children with sickle cell anemia (SCA) living in high-resource malaria-free regions, but its safety and efficacy in malaria-endemic sub-Saharan Africa, where the greatest sickle-cell burden exists, remain unknown. In vitro studies suggest hydroxyurea could increase malaria severity, and hydroxyurea-associated neutropenia could worsen infections. NOHARM (Novel use Of Hydroxyurea in an African Region with Malaria) was a randomized, double-blinded, placebo-controlled trial conducted in malaria-endemic Uganda, comparing hydroxyurea to placebo at 20 ± 2.5 mg/kg per day for 12 months. The primary outcome was incidence of clinical malaria. Secondary outcomes included SCA-related adverse events (AEs), clinical and laboratory effects, and hematological toxicities. Children received either hydroxyurea (N = 104) or placebo (N = 103). Malaria incidence did not differ between children on hydroxyurea (0.05 episodes per child per year; 95% confidence interval [0.02, 0.13]) vs placebo (0.07 episodes per child per year [0.03, 0.16]); the hydroxyurea/placebo malaria incidence rate ratio was 0.7 ([0.2, 2.7]; P = .61). Time to infection also did not differ significantly between treatment arms. A composite SCA-related clinical outcome (vaso-occlusive painful crisis, dactylitis, acute chest syndrome, splenic sequestration, or blood transfusion) was less frequent with hydroxyurea (45%) than placebo (69%; P = .001). Children receiving hydroxyurea had significantly increased hemoglobin concentration and fetal hemoglobin, with decreased leukocytes and reticulocytes. Serious AEs, sepsis episodes, and dose-limiting toxicities were similar between treatment arms. Three deaths occurred (2 hydroxyurea, 1 placebo, and none from malaria). Hydroxyurea treatment appears safe for children with SCA living in malaria-endemic sub-Saharan Africa, without increased severe malaria, infections, or AEs. Hydroxyurea provides SCA-related laboratory and clinical efficacy, but optimal dosing and monitoring regimens for Africa remain undefined. This trial was registered at www.clinicaltrials.gov as #NCT01976416

A Phantom Road Experiment Reveals Traffic Noise is an Invisible Source of Habitat Degradation

Decades of research demonstrate that roads impact wildlife and suggest traffic noise as a primary cause of population declines near roads. We created a “phantom road” using an array of speakers to apply traffic noise to a roadless landscape, directly testing the effect of noise alone on an entire songbird community during autumn migration. Thirty-one percent of the bird community avoided the phantom road. For individuals that stayed despite the noise, overall body condition decreased by a full SD and some species showed a change in ability to gain body condition when exposed to traffic noise during migratory stopover. We conducted complementary laboratory experiments that implicate foraging-vigilance behavior as one mechanism driving this pattern. Our results suggest that noise degrades habitat that is otherwise suitable, and that the presence of a species does not indicate the absence of an impact

Internet Safety: Positioning VCU as a National Leader in Internet Safety

While a multitude of information from a host of sources exists on how to keep children safe on the Internet, there is not a unified effort to combine it all and get it to the right people. This is not a plan to teach college students about Internet safety. This is a proposal to begin much earlier, targeting middle-school aged children and their parents, many of whom have no idea of the dangers – and opportunities – that exist in cyberspace