Side forces on a tangent ogive forebody with a fineness ratio of 2.5 at high angles of attack and low speed

A wind tunnel study to determine the subsonic aerodynamic characteristics, at high angles of attack, of a tangent ogive forebody with a fineness ratio of 2.5, is reported. Static longitudinal and lateral-directional stability data were obtained at Reynolds numbers ranging from 0.4 x 1 million to 3.7 x 1 million (based on base diameter) at a Mach number of 0.25. Angle of attack was varied from 36 deg to 88 deg at zero sideslip. It was found that at low Reynolds numbers the forebody does not have a side force att high angles of attack; however, at Reynolds numbers above about 2 x 1 million, a side force occurs in the angle of attack range from 45 deg to 80 deg. The maximum side force is as large as the maximum normal force. The maximum normal force coefficient varies between 1.0 and 2.0 over the Reynolds number range tested and occurs at angles of attack near 65 deg

El razonamiento probabilístico informal de estudiantes de bachillerato

El objetivo del trabajo es explorar cómo los estudiantes articulan sus conocimientos sobre los enfoques de probabilidad (clásico y frecuencial) para dar respuesta a preguntas de probabilidad. Se describen y analizan los razonamientos informales de 10 estudiantes de bachillerato (12º grado) que habían estudiado un semestre de probabilidad y estadística. Los datos se recogieron mediante un cuestionario con tres situaciones de urnas en las que se pide estimar probabilidades y hacer predicciones. El análisis revela que dicha articulación y los diferentes niveles en la calidad de las respuestas dependen de ideas informales de aleatoriedad, independencia y variabilidad, y de la manera en que se combinan para hacer predicciones con incertidumbre. Se concluye con una propuesta de las proposiciones informales correspondientes a estas ideas cuyo manejo potenciaría el razonamiento probabilístico informal de los estudiantes

Single-Particle Density of States of a Superconductor with a Spatially Varying Gap and Phase Fluctuations

Recent experiments have shown that the superconducting energy gap in some cuprates is spatially inhomogeneous. Motivated by these experiments, and using exact diagonalization of a model d-wave Hamiltonian, combined with Monte Carlo simulations of a Ginzburg-Landau free energy functional, we have calculated the single-particle density of states LDOS$(\omega,r)$ of a model high-T$_c$ superconductor as a function of temperature. Our calculations include both quenched disorder in the pairing potential and thermal fluctuations in both phase and amplitude of the superconducting gap. Most of our calculations assume two types of superconducting regions: $\alpha$, with a small gap and large superfluid density, and $\beta$, with the opposite. If the $\beta$ regions are randomly embedded in an $\alpha$ host, the LDOS on the $\alpha$ sites still has a sharp coherence peak at $T = 0$, but the $\beta$ component does not, in agreement with experiment. An ordered arrangement of $\beta$ regions leads to oscillations in the LDOS as a function of energy. The model leads to a superconducting transition temperature $T_c$ well below the pseudogap temperature $T_{c0}$, and has a spatially varying gap at very low $T$, both consistent with experiments in underdoped Bi2212. Our calculated LDOS$(\omega,r)$ shows coherence peaks for $T T_c$, in agreement with previous work considering phase but not amplitude fluctuations in a homogeneous superconductor. Well above $T_c$, the gap in the LDOS disappears.Comment: 37 pages, 12 figures. Accepted by Phys. Rev. B. Scheduled Issue: 01 Nov 200

Development and Validation of the Trauma-Related Cognitions Scale

Cognitive theories suggest the manner in which individuals process trauma-related information influences posttraumatic sequelae. Interpretations about trauma can be maladaptive and lead to cognitive distortions implicated in the development of posttraumatic stress disorder (PTSD) through the processes of overaccommodation and assimilation. Alternatively, adaptive interpretations about trauma through the process of accommodation can lead to post-trauma resilience and recovery. The Trauma-Related Cognitions Scale (TRCS) provides a measure of beliefs associated with these cognitive processes. The TRCS was developed over the course of four phases. During Phase 1, 94 items derived from previously validated trauma cognition/beliefs measures were aggregated with 40 items developed by the authors. Phase 2 investigated the TRCS factor structure by fitting exploratory factor analysis (EFA) models to data from a non-clinical sample, resulting in a reduced 69-item TRCS representing four factors: the three theoretical cognitive processes of overaccommodation, assimilation, and accommodation, and an additional optimism factor. Phases 3 and 4 fit confirmatory factor analysis (CFA) models of the 69-item TRCS in a new non-clinical and a clinical sample, respectively, and further validation analyses were conducted. Initial evidence suggests the TRCS is a valid and reliable measure of trauma beliefs. Continued validation can determine its utility in both research and clinical contexts

Living on the Edge: High-Latitude Porites Carbonate Production Under Temperate Eutrophic Conditions

Non-framework building high-latitude coral communities have recently received increased attention as a result of their potential to act as refugia during global change, as proxies for such change and for testing the environmental tolerance limits of various species of coral. In this study, we report on high-resolution in situ measured environmental factors influencing the development of monospecific (Porites panamensis) non-framework building coral communities and the resulting coral-derived carbonate sediment production in the northern Gulf of California, Mexico (Bahía de Los Angeles, 29°N, 113°E). Half-hourly measurements of temperature and chlorophyll a (a nutrient proxy) for a 1-year period indicate temperature extremes ranging from 14°C to 30°C, and average chlorophyll a values of 2.2 mg Chl a/m3(eutrophic). Even though P. panamensis only occur as small massive and encrusting colonies, they nonetheless show a significant carbonate sediment production potential (0.14 kg CaCO3/m2/year). A calculation of carbonate production rates vs amount of coral found in the sediment shows that this high-latitude community must have persisted for an extended period of time

Expression of Novel Opsins and Intrinsic Light Responses in the Mammalian Retinal Ganglion Cell Line RGC-5. Presence of OPN5 in the Rat Retina

The vertebrate retina is known to contain three classes of photoreceptor cells: cones and rods responsible for vision, and intrinsically photoresponsive retinal ganglion cells (RGCs) involved in diverse non-visual functions such as photic entrainment of daily rhythms and pupillary light responses. In this paper we investigated the potential intrinsic photoresponsiveness of the rat RGC line, RGC-5, by testing for the presence of visual and non-visual opsins and assessing expression of the immediate-early gene protein c-Fos and changes in intracellular Ca2+mobilization in response to brief light pulses. Cultured RGC-5 cells express a number of photopigment mRNAs such as retinal G protein coupled receptor (RGR), encephalopsin/panopsin (Opn3), neuropsin (Opn5) and cone opsin (Opn1mw) but not melanopsin (Opn4) or rhodopsin. Opn5 immunoreactivity was observed in RGC-5 cells and in the inner retina of rat, mainly localized in the ganglion cell layer (GCL). Furthermore, white light pulses of different intensities and durations elicited changes both in intracellular Ca2+ levels and in the induction of c-Fos protein in RGC-5 cell cultures. The results demonstrate that RGC-5 cells expressing diverse putative functional photopigments display intrinsic photosensitivity which accounts for the photic induction of c-Fos protein and changes in intracellular Ca2+ mobilization. The presence of Opn5 in the GCL of the rat retina suggests the existence of a novel type of photoreceptor cell

Use and Protection of GPS Sidelobe Signals for Enhanced Navigation Performance in High Earth Orbit

The application of the Global Positioning System (GPS) for navigation of spacecraft in High and Geosynchronous Earth Orbit (HEO/GEO) has crossed a threshold and is now being employed in operational missions. Utilizing advanced GPS receivers optimized for these missions, space users have made extensive use of the sidelobe transmissions from the GPS satellites to realize navigation performance that far exceeds that predicted by pre-launch simulations. Unfortunately, the official specification for the GPS Space Service Volume (SSV), developed in 2006, assumes that only signals emanating from the main beam of the GPS transmit antenna are useful for navigation, which greatly under-estimates the number of signals available for navigation purposes. As a result, future high-altitude space users may be vulnerable to any GPS design changes that suppress the sidelobe transmissions, beginning with Block III space vehicles (SVs) 11-32. This paper presents proposed changes to the GPS system SSV requirements, as informed by data from recent experiments in the SSV and new mission applications that are enabled by GPS navigation in HEO/GEO regimes. The NASA/NOAA GOES-R series satellites are highlighted as an example of a mission that relies on this currently-unspecified GPS system performance to meet mission requirements

Knowledge and practices of tour guides in Cuzco on the prevention and treatment of traveler's diarrhea

Objectives: To describe the knowledge and practices among tour guides in Cuzco, Peru regarding prevention and treatment of traveler's diarrhea. Methods: The main tour guide association in Cuzco organized a mandatory re-certification course for tour guides in February 2004. We invited tour guides attending this course to participate in the study. Those aged 18 to 50 who had worked as a tour guide for at least one year were asked to complete a brief anonymous questionnaire. Results: A total of 173 questionnaires were returned; 137 met the inclusion criteria and were included in the analysis. The median age was 31 years (interquartile range (IQR): 28-34 years), and 56.7% were male. The median number of foreign languages spoken by subjects included was 1, being English (91.9%) the most common, followed by French (17.9%) and Italian (16.8%). The median time working as a tour guide was 4 years (IQR: 2-8 years). Tour guidance was a full-time job for 47.1% of the subjects, and for 82.4% Inca Trail was the most commonly covered route. Traveler's diarrhea was considered a food-borne disease by 85.4%, but only 60.6% considered it a water-borne disease. The majority of subjects identified raw salads (84.4%), cold sauces (81.5%) and tap water (81.1%) as risky products whereas hot soups (77 8%) and bread (75.0%) were mainly considered as safe. Most of the tour guides considered bloody stools (84.8%) and fever (60.6%) as indications to seek medical attention. The medications most frequently recommended by tour guides were oral re-hydration solutions ( 85.1%), trimethoprim-sulphamethoxazole (26.1%) and loperamide (20.1%). Conclusions: Tour guides have a basic knowledge about traveler's diarrhea. However, more training is necessary to improve management while trekking outside of Cuzco The recommendation to seek pharmacists should be particularly addressed

Fairtrade Coffee A study to assess the impact of Fairtrade for coffee smallholders and producer organisations in Indonesia, Mexico, Peru, and Tanzania

This report presents the findings of a major evaluation commissioned by Fairtrade International. This evaluation aims to assess the impact of Fairtrade for coffee smallholders and their organisations to contribute to the evidence base on Fairtrade’s impact to date and to inform Fairtrade on the potential to improve its impact in the future. Millions of smallholder farmer households around the world rely upon coffee for their livelihoods, and the challenges they face are numerous and growing. Fairtrade supports around 812,500 coffee-producing smallholder farmers in 445 producer organisations in 30 countries. In 2013-14 Fairtrade coffee producers reported selling 150,800 MT of coffee on Fairtrade terms. Producer organisations (POs) in four countries, Peru, Mexico, Tanzania, and Indonesia, were selected as cases by the research team to capture the range and depth of the Fairtrade experience. The evaluation covered two Fairtrade producer organisations in each country. Counterfactual comparisons are included in each case – either with a comparison producer organisation or with individual independent farmers cultivating coffee in the same area, but who are not part of Fairtrade certification. The evaluation used the recently developed and published ‘Fairtrade International Theory of Change’ to examine Fairtrade impact. Data was collected along the impact chain to understand how far Fairtrade’s interventions have led to intended outputs and impacts, and to identify other influencing factors. The team developed a research protocol to support comparisons between countries, and used mixed methods to carry out the research