REXOR 2 rotorcraft simulation model. Volume 1: Engineering documentation

A rotorcraft nonlinear simulation called REXOR II, divided into three volumes, is described. The first volume is a development of rotorcraft mechanics and aerodynamics. The second is a development and explanation of the computer code required to implement the equations of motion. The third volume is a user's manual, and contains a description of code input/output as well as operating instructions

REXOR 2 rotorcraft simulation model. Volume 2: Computer implementation

For abstract, see N78-30042

Beyond Mortar and Bricks

This article was published in the Summer 2008 issue of the Journal of Undergraduate Researc

Functional characteristics of the calcium modulated proteins seen from an evolutionary perspective

We have constructed dendrograms relating 173 EF-hand proteins of known amino acid sequence. We aligned all of these proteins by their EF-hand domains, omitting interdomain regions. Initial dendrograms were computed by minimum mutation distance methods. Using these as starting points, we determined the best dendrogram by the method of maximum parsimony, scored by minimum mutation distance. We identified 14 distinct subfamilies as well as 6 unique proteins that are perhaps the sole representatives of other subfamilies. This information is given in tabular form. Within subfamilies one can easily align interdomain regions. The resulting dendrograms are very similar to those computed using domains only. Dendrograms constructed using pairs of domains show general congruence. However, there are enough exceptions to caution against an overly simple scheme in which one pair of gene duplications leads from one domain precurser to a four domain prototype from which all other forms evolved. The ability to bind calcium was lost and acquired several times during evolution. The distribution of introns does not conform to the dendrogram based on amino acid sequences. The rates of evolution appear to be much slower within subfamilies, especially within calmodulin, than those prior to the definition of subfamily

Watershed, Weddings and Workforces: Migration, Sedentarization, and Social Change among the BaAka of Southwestern Central African Republic

This brief demographic history of the BaAka pygmies of the Dzanga-Sangha Dense Forest Reserve analyses the BaAka's engagement with capital and the extent to which it influences immigration. The BaAka villages within the reserve have been influenced differently by coffee and timber boom/bust cycles. We superimpose local economic history with demographic data, then using five parameters; residence, place of origin, estimated year of birth, sex and parental place of origin, we seek to establish whether different immigration patterns are due to different local economies. Also discussed are the effects of local economies on traditional marriage migration patterns. We conclude that immigration patterns do change over time probably due to demands for labor in conjunction with preexisting marriage alliances

The crystal structure of annexin VI indicates relative rotation of the two lobes upon membrane binding

AbstractThe crystal structure of bovine liver annexin VI has been determined to low resolution by molecular replacement. The first lobe (domains 1–4) is rotated about 90° relative to the second lobe (domains 5–8). Since the same crystal form (P43, 68 × 68 × 205 Å) grew from (NH4)2SO4, polyethylene glycol, and sodium acetate with and without added calcium, this probably reflects the structure in solution. When bound to a lipid monolayer both lobes of annexin VI are coplanar. This implies a significant change in conformation upon binding to membranes

Attitudes of US Obstetricians Toward a Combined Tetanus-Diphtheria-Acellular Pertussis Vaccine for Adults

Objective. To describe obstetricians' perspectives related to tetanus-diphtheria-acellular pertussis (Tdap) vaccination of mothers and other adults in close contact with infants. Methods. Mail survey of national random sample of 400 obstetricians . Results. Response rate was 54%. Most respondents would likely recommend Tdap for women during the postpartum hospital stay (78%) or during pregnancy (69%) if a national recommendation was issued. Expected barriers were knowing the date of patients' most recent Td booster (74%) and patient resistance (46%). Most felt that obstetricians have a role in promoting and administering Tdap vaccine to adults other than mothers likely to come in close contact with infants. Conclusion. Obstetricians are likely to agree with the recent provisional US recommendation to administer Tdap to postpartum mothers and other adults expected to come in close contact with infants. Obstetricians would also be likely to support a potential recommendation to administer Tdap during pregnancy. Barriers to adoption of new Tdap vaccine recommendations should be monitored

Guillain-Barré syndrome after tetanus toxoid, reduced diphtheria toxoid and acellular pertussis vaccine: a case report

<p>Abstract</p> <p>Introduction</p> <p>The association of Guillain-Barré syndrome with vaccination has been described in the literature; it is infrequent and controversial. An association with swine influenza, influenza, hepatitis and tetanus vaccination has been documented in few case reports.</p> <p>Case presentation</p> <p>A 40-year-old Caucasian man sustained a small right temporal epidural hematoma and nondisplaced right skull fractures after a fall from a roof. He was managed conservatively; a tetanus toxoid, reduced diphtheria toxoid and acellular pertussis vaccine was administered and a week later he was discharged home. A few days after his discharge, he experienced weakness and numbness in his legs, which progressed to involve his arms. Three weeks after his initial fall, he was readmitted with quadriparesis. A lumbar puncture revealed a cerebrospinal fluid protein of 790 mg/dL and one white blood cell. We diagnosed Guillain-Barré syndrome. Our patient was treated with intravenous immunoglobulin. Three months later his muscle strength had improved, but he continued to have tingling in his hands and feet and used a walker intermittently.</p> <p>Conclusion</p> <p>To the best of our knowledge, this is the first case of Guillain-Barré syndrome to be reported in the English literature after administration of tetanus toxoid, reduced diphtheria toxoid and acellular pertussis vaccine.</p

Calcium buffering in the heart in health and disease

Changes of intracellular Ca2+ concentration regulate many aspects of cardiac myocyte function. About 99% of the cytoplasmic calcium in cardiac myocytes is bound to buffers, and their properties will therefore have a major influence on Ca2+ signaling. This article considers the fundamental properties and identities of the buffers and how to measure them. It reviews the effects of buffering on the systolic Ca2+ transient and how this may change physiologically, and in heart failure and both atrial and ventricular arrhythmias, as well. It is concluded that the consequences of this strong buffering may be more significant than currently appreciated, and a fuller understanding is needed for proper understanding of cardiac calcium cycling and contractility

Combining serological and contact data to derive target immunity levels for achieving and maintaining measles elimination

AbstractBackgroundVaccination has reduced the global incidence of measles to the lowest rates in history. However, local interruption of measles virus transmission requires sustained high levels of population immunity that can be challenging to achieve and maintain. The herd immunity threshold for measles is typically stipulated at 90–95%. This figure does not easily translate into age-specific immunity levels required to interrupt transmission. Previous estimates of such levels were based on speculative contact patterns based on historical data from high-income countries. The aim of this study was to determine age-specific immunity levels that would ensure elimination of measles when taking into account empirically observed contact patterns.MethodsWe combined estimated immunity levels from serological data in 17 countries with studies of age-specific mixing patterns to derive contact-adjusted immunity levels. We then compared these to case data from the 10 years following the seroprevalence studies to establish a contact-adjusted immunity threshold for elimination. We lastly combined a range of hypothetical immunity profiles with contact data from a wide range of socioeconomic and demographic settings to determine whether they would be sufficient for elimination.ResultsWe found that contact-adjusted immunity levels were able to predict whether countries would experience outbreaks in the decade following the serological studies in about 70% of countries. The corresponding threshold level of contact-adjusted immunity was found to be 93%, corresponding to an average basic reproduction number of approximately 14. Testing different scenarios of immunity with this threshold level using contact studies from around the world, we found that 95% immunity would have to be achieved by the age of five and maintained across older age groups to guarantee elimination. This reflects a greater level of immunity required in 5–9 year olds than established previously.ConclusionsThe immunity levels we found necessary for measles elimination are higher than previous guidance. The importance of achieving high immunity levels in 5–9 year olds presents both a challenge and an opportunity. While such high levels can be difficult to achieve, school entry provides an opportunity to ensure sufficient vaccination coverage. Combined with observations of contact patterns, further national and sub-national serological studies could serve to highlight key gaps in immunity that need to be filled in order to achieve national and regional measles elimination.</jats:sec