Indirect study of (11)B(p,alpha(0))(8)Be and (10)B(p,alpha)(7)Be reactions at astrophysical energies by means of the Trojan Horse Method: recent results

Nuclear (p,alpha) reactions destroying the so-called ""light-elements"" lithium, beryllium and boron have been largely studied in the past mainly because their role in understanding some astrophysical phenomena, i.e. mixing-phenomena occurring in young F-G stars [1]. Such mechanisms transport the surface material down to the region close to the nuclear destruction zone, where typical temperatures of the order of similar to 10(6) K are reached. The corresponding Gamow energy E(0)=1.22 (Z(x)(2)Z(X)(2)T(6)(2))(1/3) [2] is about similar to 10 keV if one considers the ""boron-case"" and replaces in the previous formula Z(x) = 1, Z(X) = 5 and T(6) = 5. Direct measurements of the two (11)B(p,alpha(0))(8)Be and (10)B(p,alpha)(7)Be reactions in correspondence of this energy region are difficult to perform mainly because the combined effects of Coulomb barrier penetrability and electron screening [3]. The indirect method of the Trojan Horse (THM) [4-6] allows one to extract the two-body reaction cross section of interest for astrophysics without the extrapolation-procedures. Due to the THM formalism, the extracted indirect data have to be normalized to the available direct ones at higher energies thus implying that the method is a complementary tool in solving some still open questions for both nuclear and astrophysical issues [7-12].

Trojan Horse Method: a useful tool for electron screening effect investigation

Direct measurements in the last decades have highlighted a new problem related to the lowering of the Coulomb barrier between the interacting nuclei due to the presence of the ""electron screening"" in the laboratory measurements. It was systematically observed that the presence of the electronic cloud around the interacting ions in measurements of nuclear reactions cross sections at astrophysical energies gives rise to an enhancement of the astrophysical S(E)-factor as lower and lower energies are explored [1]. Moreover, at present Such an effect is not well understood as the value of the potential for screening extracted from these measurements is higher than the tipper limit of theoretical predictions (adiabatic limit). On the other hand, the electron screening potential in laboratory measurement is different from that occurring in stellar plasmas thus the quantity of interest in astrophysics is the so-called ""bare nucleus cross section"". This quantity can only be extrapolated in direct measurements. These are the reasons that led to a considerable growth on interest in indirect measurement techniques and in particular the Trojan Horse Method (THM) [2,3]. Results concerning the bare nucleus cross sections measurements will be shown in several cases of astrophysical interest. In those cases the screening potential evaluated by means of the THM will be compared with the adiabatic limit and results arising from extrapolation in direct measurements.

Indirect Study of the (2)H(d,p)(3)H and (2)H(d,n)(3)He Reactions at Astrophysical Energies via the Trojan Horse Method

The (2)H(d,p)(3)H and (2)H(d,n)(3)He reactions have been indirectly studied by means of the Trojan Horse Method applied to the quasi-free (2)H((3)He, p(3)H)(1)H (2)H((3)He, n(3)He)(1)H reaction at 18 MeV of beam energy. This is the first experiment where the spectator (here (1)H) has been detected in coincidence with the charged participant, avoiding the limitations of standard neutron detectors. The d - d relative energy has been measured from 1.5 MeV down to 2 keV, at center of mass angles from 40A degrees to 170A degrees. Indirect angular distributions are compared with the direct behaviour in the overlapping regions.

Low-energy d plus d fusion reactions via the Trojan Horse Method

The bare nucleus S(E) factors for the (2)H(d, p)(3)H and (2)H(d.n)(3)He reactions have been measured for the first time via the Trojan Horse Method off the proton in (3)He from 1.5 MeV down to 2 key. This range overlaps with the relevant region for Standard Big Bang Nucleosynthesis as well as with the thermal energies of future fusion reactors and deuterium burning in the Pre-Main-Sequence phase of stellar evolution. This is the first pioneering experiment in quasi free regime where the charged spectator is detected. Both the energy dependence and the absolute value of the S(E) factors deviate by more than 15% from available direct data with new S(0) values of 57.4 +/- 1.8 MeVb for (3)H + p and 60.1 +/- 1.9 MeV b for (3)He + n. None of the existing fitting curves is able to provide the correct slope of the new data in the full range, thus calling for a revision of the theoretical description. This has consequences in the calculation of the reaction rates with more than a 25% increase at the temperatures of future fusion reactors. (C) 2011 Elsevier By. All rights reserved.

Risk of recurrent stroke and death after first stroke in long-distance ski race participants

Background: Physical activity is of benefit for primary prevention of cardiovascular diseases, but it appears to increase the risk for atrial fibrillation. We aimed to study a cohort of patients following a first stroke in individuals with previous high physical activity, compare them to the general population with respect to recurrent stroke and death, and relate these to atrial fibrillation. Methods and results: From the participants of the Vasaloppet, the world's largest ski-race, and matched individuals from the general population (n=708 604), we identified 5964 patients hospitalized with a first-time stroke between 1994 and 2010. Individuals with severe diseases were excluded. One half percent of skiers and 1% of nonskiers were hospitalized due to stroke. The incidence rate was 8.3 per 100 person-years among skiers and 11.1 among nonskiers. The hazard ratio (HR) for recurrent stroke or death between the 2 groups was 0.76 (95% CI 0.67 to 0.86). The result was consistent in subgroups. The HR for death was 0.66 (95% CI 0.56 to 0.78) and for recurrent stroke 0.82 (95% CI 0.70 to 0.96). After adjustment for smoking and socioeconomic factors, the HR for death was consistent at 0.70 (95% CI 0.56 to 0.87) while the HR for recurrent stroke was not statistically significant. Outcomes for skiers with atrial fibrillation tended to show a lower risk than for nonskiers. Conclusions: This large cohort study supports the hypothesis that patients with a stroke and with prior regular physical activity have a lower risk of death, while their risk for recurrent stroke is similar to that of nonskiers. The skiers had a higher incidence of atrial fibrillation, but still no increased risk of recurring stroke.

The influence of sex, age, and race experience on pacing profiles during the 90 km Vasaloppet ski race

The purpose of this study was to investigate pacing-profile differences during the 90 km Vasaloppet ski race related to the categories of sex, age, and race experience. Skiing times from eight sections (S1 to S8) were analyzed. For each of the three categories, 400 pairs of skiers were matched to have a finish time within 60 seconds, the same start group, and an assignment to the same group for the other two categories. Paired-samples Student’s t-tests were used to investigate sectional pacing-profile differences between the subgroups. Results showed that males skied faster in S2 (P=0.0042), S3 (P=0.0049), S4 (P=0.010), and S1–S4 (P<0.001), whereas females skied faster in S6 (P<0.001), S7 (P<0.001), S8 (P=0.0088), and S5–S8 (P<0.001). For the age category, old subjects (40 to 59 years) skied faster than young subjects (19 to 39 years) in S3 (P=0.0029), and for the other sections, there were no differences. Experienced subjects (≥4 Vasaloppet ski race completions) skied faster in S1 (P<0.001) and S1–S4 (P=0.0054); inexperienced skiers (<4 Vasaloppet ski race completions) had a shorter mean skiing time in S5–S8 (P=0.0063). In conclusion, females had a more even pacing profile than that of males with the same finish time, start group, age, and race experience. No clear age-related pacing-profile difference was identified for the matched subgroups. Moreover, experienced skiers skied faster in the first half whereas inexperienced skiers had higher skiing speeds during the second half of the race.

Exploration of the idea of the horse in graphics and sculpture

The exploration of the idea of the horse is a very complex and open quest. Primarily it entails some conception of what the idea of the horse is. In choosing to title the project as such, I was attempting to indicate that what was of major interest to me was the representation of those qualities of the horse which are abstract and intangible as well as the physical qualities of the horse. Because of this interest, much of my work is concerned with movement, gesture, and the effects of structure, or lack thereof, on movement and gesture.

Kicking a Gift Horse in the Mouth

Yes, of course I know the expression is “Don’t look,” not kicking, but our collective professional behavior makes “kicking” the more operative and appropriate verbal. More about this in due course. As an expression, “don’t look a gift horse in the mouth” comes to us from the Lain, Noli equi dentes inspicere donate. Some argue Jerome said it first in 400 A.D., in which his words, very nearly our Latin literally translated, ran, “Never inspect the teeth of a gift horse.”

Purchasing power parity: the choice of price index

Looking closely at the PPP argument, it states that the currencies purchasing power should not change when comparing the same basket goods across countries, and these goods should all be tradable. Hence, if PPP is valid at all, it should be captured by the relative price indices that best Öts these two features. We ran a horse race among six di§erent price indices available from the IMF database to see which one would yield higher PPP evidence, and, therefore, better Öt the two features. We used RER proxies measured as the ratio of export unit values, wholesale prices, value added deáators, unit labor costs, normalized unit labor costs and consumer prices, for a sample of 16 industrial countries, with quarterly data from 1975 to 2002. PPP was tested using both the ADF and the DFGLS unit root test of the RER series. The RER measured as WPI ratios was the one for which PPP evidence was found for the larger number of countries: six out of sixteen when we use DF-GLS test with demeaned series. The worst measure of all was the RER based on the ratio of foreign CPIs and domestic WPI. No evidence of PPP at all was found for this measure.

Causes of death of thoroughbred racehorses at Octavio Dupont Veterinary Hospital, Brazilian Jockey Club, Rio de Janeiro

Existem poucas pesquisas que abordam estudos epidemiológicos de mortes em cavalos de corrida de uma forma ampla. A maioria restringe-se a uma afecção ou procedimento específico. O Brasil não possui um programa de monitoramento de mortes instituído. Através de um estudo descritivo em associação a metodologia multivariada de análise, realizou-se um estudo epidemiológico de causa mortis relacionadas com afecções musculosqueléticas (MS), gastrointestinais (GI), sistema respiratório (RES), neurológico (NEU) e mortes súbitas (SD) durante os anos de 2002 a 2008 no Hospital Octavio Dupont, Rio de Janeiro. Os machos representaram o sexo mais afetado e a causa mortis relacionada com a taxa geral de mortalidade por grandes grupos de causas determinadas apresentou a seguinte ordem decrescentemente: MS>GI>SD>NEU>RES. A maioria dos óbitos registrados foi de cavalos na faixa etária de quatro a cinco anos (ID4-ID5). Seguidamente, observaram-se as seguintes relações de correspondência: (Triênio = SM-ID>5-SD; ID>5-GI; ID4-5-MS; SF-ID<4-RES/NEU); (Quatriênio = SM - ID>5 - GI; SF - ID<4 - NEU; ID4-5 - MS; GI - ID>5). O presente estudo aponta a importância e necessidade de estudos epidemiológicos sobre lesões em cavalos atletas, objetivando o diagnostico, reconhecimento de fatores predisponentes e prevenção.

Effects of diclofenac and dexamethasone on horse experimental endotoxemia

Quinze eqüinos machos, da raça Mangalarga, com idades entre dois e três anos, foram utilizados para se avaliar os possíveis efeitos clínicos benéficos da administração de dexametasona ou diclofenaco sódico durante a endotoxemia experimental em eqüinos. Os animais foram divididos em três grupos de cinco animais cada: controle (C), diclofenaco sódico (SD) e dexametasona (DM). Todos os grupos receberam 0,1µg/kg de lipopolissarídeo de Escherichia coli 055:B5, durante 15 minutos, por via intravenosa mais: grupo SD - 2,2mg/kg de SD, por via oral, 60 minutos antes da infusão da endotoxina; grupo DM - 1,1mg/kg, por via intravenosa, 30 minutos antes da endotoxina; grupo C - 20ml de NaCl 0,9%, por via intravenosa, 30 minutos antes da endotoxina. O SD não preveniu a leucopenia, neutropenia e linfopenia ocorridas três horas após a indução da endotoxemia, porém a DM atenuou essas alterações. As taxas de proteínas plasmática e peritoneal, a concentração de glicose e de fósforo inorgânico e a contagem de células nucleadas totais peritoneais mantiveram-se inalteradas. O diclofenaco foi eficaz na prevenção da febre e alterações nos borborigmos intestinais enquanto que a dexametasona bloqueou as alterações no número de células inflamatórias em relação ao grupo controle.

Evaluation of the Integrity of Horse Hoof Dermal and Epidermal Tissues Collected by Dorsal Transmural Access

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Effects of caffeine on locomotor activity of horses: Determination of the no-effect threshold

Caffeine is the legal stimulant consumed most extensively by the human world population and may be found eventually in the urine and/or blood of race horses, the fact that caffeine is in foods led us to determine the highest no-effect dose (HNED) of caffeine on the spontaneous locomotor activity of horses and then to quantify this substance in urine until it disappeared. We built two behavioural stalls equipped with juxtaposed photoelectric sensors that emit infrared beams that divide the stall into nine sectors in a 'tic-tac-toe' fashion. Each time a beam was interrupted by a leg of the horse, a pulse was generated; the pulses were counted at 5-min intervals and stored by a microcomputer. Environmental effects were minimized by installing exhaust fans producing white noise that obscured outside sounds. One-way observation windows prevented the animals from seeing outside. The sensors were turned on 45 min before drug administration (saline control or caffeine), the animals were observed for up to 8 h after i.v. administration of 2.0, 2.5, 3.0 or 5.0 mg caffeine kg(-1). The HNED of caffeine for stimulation of the spontaneous locomotor activity of horses was 2.0 mg kg(-1). The quantification of caffeine in urine and plasma samples was done by gradient HPLC with UV detection. The no-effect threshold should not be greater than 2.0 mug caffeine ml(-1) plasma or 5.0 mug caffeine ml(-1) urine. Copyright (C) 2001 John Wiley & Sons, Ltd.

Gastric Torsion from an Intestinal Hernia Through a Rent in the Gastrosplenic Ligament in a Horse

The present report describes an 8-year-old gelding presenting with signs of severe abdominal pain. After performing a thorough physical examination, including rectal palpation and additional diagnostic tests, an exploratory laparotomy was recommended. The jejunum was found herniated through the gastrosplenic ligament, and the stomach was severely distended with gas. Given a poor prognosis, the horse was euthanized on the table. At necropsy, the stomach appeared dilated, with an 180 horizontal gastric torsion, from left (lateral) to right (medial), dividing the organ into dorsal and ventral compartments. We believe that the chronic traction exerted by an incarcerated and distended loop of jejunum, in the dorsal aspect of the gastrosplenic ligament, associated with trauma during episodes of intense rolling, enlarged the rent until it ruptured. Because of this rupture, the lateral dorsal aspect of the stomach became unattached, predisposing it to the torsion. (C) 2012 Elsevier B.V. All rights reserved.