Extinction procedure induces pruning of dendritic spines in CA1 hippocampal field depending on strength of training in rats

Numerous reports indicate that learning and memory of conditioned responses are accompanied by genesis of dendritic spines in the hippocampus, although there is a conspicuous lack of information regarding spine modifications after behavioral extinction. There is ample evidence that treatments that typically produce amnesia become innocuous when animals are submitted to a procedure of enhanced training. We now report that extinction of inhibitory avoidance (IA), trained with relatively low foot-shock intensities, induces pruning of dendritic spines along the length of the apical dendrites of hippocampal CA1 neurons. When animals are trained with a relatively high foot-shock there is a high resistance to extinction, and pruning in the proximal and medial segments of the apical dendrite are seen, while spine count in the distal dendrite remains normal. These results indicate that pruning is involved in behavioral extinction, while maintenance of spines is a probable mechanism that mediates the protecting effect against amnesic treatments produced by enhanced training

The importance of the ligation of the inferior thyroid artery in parathyroid function after subtotal thyroidectomy

We prospectively studied the effects of the ligation of the inferior thyroid artery (ITA) on postoperative hypoparathyroidism in 48 patients who underwent functional subtotal thyroidectomy. Patients were randomized into two groups: A, with bilateral ligation of the ITA and B, without ligation of the ITA. Parathyroid function was checked preoperatively and after surgery by clinical examination and measurement of total calcium, intact PTH, urinary calcium, and AMPc. RESULTS: A significant incidence of postoperative hypocalcemia occurred: 17% in group A and 13% in B on the 4th postoperative day. Six months later, the incidence was 5% in Group A and 0% in Group B. These differences were not statistically significant between the two groups, and neither were any of the other clinical and laboratory observations. CONCLUSION: The ligation of the ITA was not an important causal factor for the occurrence of postoperative hypocalcemia after subtotal thyroidectomy.Com o objetivo de observar os efeitos da ligadura da artéria tireoidiana inferior (ITA) no hipoparatireoidismo, 48 pacientes submetidos à tireoidectomia subtotal funcional foram estudados de forma prospectiva. Dois grupos foram randomizados, A: com a ligadura troncular bilateral da ITA e B: sem a ligadura troncular da ITA. A função paratireoidiana foi verificada no período pré-operatório e após a cirurgia através de exame clínico e dosagens de cálcio total, PTH, cálcio urinário e cAMP. Os resultados demostraram incidência importante e significativa de hipocalcemia pós-operatória, de 17% no grupo A e 13% no grupo B no 4º PO. Seis meses após, a incidência foi de 5% no grupo A e 0% no grupo B. Estas diferenças não foram estatisticamente significativas entre os dois grupos, nem nenhum dos outros dados clínicos ou laboratoriais estudados. Concluímos que a ligadura da ITA não é um fator causal importante de hipocalcemia pós-operatória após tireoidectomia subtotal

The “ageing” experiment in the Spanish Soyuz mission to the international space station

Manuscript version.-- Final version of the publisher available on http://www.springerlink.com/content/5703g0375l066734/?p=1823d8063e69447cbbb58584de4e2425&pi=2Human exploration of outer space will eventually take place. In preparation for this endeavour, it is important to establish the nature of the biological response to a prolonged exposure to the space environment. In one of the recent Soyuz Missions to serve the International Space Station (ISS), the Spanish Soyuz mission in October 2003, we exposed four groups of Drosophila male imagoes to microgravity during the almost eleven days of the Cervantes mission to study their motility behaviour. The groups were three of young flies and one of mature flies, In previous space experiments, we have shown that when imagoes are exposed to microgravity they markedly change their behaviour by increasing their motility, especially if subjected to these conditions immediately after hatching. The constraints of the current Soyuz flights made it impossible to study the early post-hatching period. A low temperature cold transport was incorporated as a possible way out of this constraint. It turned out that on top of the space flight effects, the cold treatment by itself, modifies the motility behaviour of the flies. Although the four groups increased their motility, the young flies did it in a much lower extent than the mature flies that had not been exposed to the low temperature during transportation. Nevertheless, the flies flown in the ISS are still more active than the parallel ground controls. As a consequence of the lower motility stimulation in this experiment, a likely consequence of the cold transport step, no effects on the life spans of the flown flies were detected. Together with previous results, this study confirms that high levels of motility behaviour are necessary to produce significant decreases in fly longevity.Peer reviewe

Malaria en niños: discusión de algunos aspectos clínicos, diagnósticos y terapéuticos

Malaria infections in children often present dificulties in diagnosis and chemotherapy. Here we describe three cases of malaria with several considerations about the diagnosis, course of infection and post-treatment evolution. The first case was a 2 month old girl with a severe malnutrition and a post-transfusional Plasmodium vivax infection. Three different regimens of chloroquine were required to clear the infection. The second case was a 25 day-old boy who developed a Plasmodium vivax infection and methahemoglobinemia after treatment with primaquine. The last patient was a 8 year-old boy in fected with a chloroquine-resistent Plasmodium folciparum. After radical treatment with sulfadoxine-pyrimethamine and due to the presence of circualting gametocytes the patient received at the hospital 4 different therapeutic schemes including 10 days of I.V. quinine, sulfadoxine-pyrimethamine and trimethorpim-sulfamethoxazol.Se describen 3 casos de malaria en niños incluyendo el diagnóstico y tratamiento, la evolución y las complicaciones. El primer caso corresponde a una lactante menor con un avanzado estado de desnutrición y una infección post-transfusional por Plasmodium vivax. La respuesta a la cloroquina no fue adecuada requiriendo 2 ciclos adicionales para eliminar los parásitos circulantes. El segundo caso describe un neonato de 25 días de edad con una infección por Plasmodium vivax cuyo mecanismo de transmisión pudo ser transplacentario aunque no se descartó la transmisión natural. La madre fue positiva pera Plasmodium vivax durante el embarazo y puerperio. El paciente presentó además un metahemaglobinemia como complicación del tratamiento con primaquina. Finalmente se presenta el caso de un escolar con una malaria por Plasmodium falciparum resistente a la cloroquina tratada en forma inadecuada con 4 esquemas terapéuticos diferentes, que incluyen quinina intravenosa, trimetoprim-sulfametoxazol y sulfadoxina-pirimetamina

Stopping power of Au for silver ions at low velocities

Energy loss measurements for the slowing down of Ag ions in Au, in the velocity range 1:6v0 < v < 4:4v0, where v0 is the Bohr velocity, are presented. The measurements were performed using the Doppler shift technique and also with a new method, where a secondary beam of low velocity heavy ions is produced by elastic scattering of the accelerated beam. The results are compared to the SRIM2000 calculations (www.srim.org) and to recent measurements in this velocity region

Effect of magnetically simulated zero-gravity and enhanced gravity on the walk of the common fruitfly†

Understanding the effects of gravity on biological organisms is vital to the success of future space missions. Previous studies in Earth orbit have shown that the common fruitfly (Drosophila melanogaster) walks more quickly and more frequently in microgravity, compared with its motion on Earth. However, flight preparation procedures and forces endured on launch made it difficult to implement on the Earth's surface a control that exposed flies to the same sequence of major physical and environmental changes. To address the uncertainties concerning these behavioural anomalies, we have studied the walking paths of D. melanogaster in a pseudo-weightless environment (0g*) in our Earth-based laboratory. We used a strong magnetic field, produced by a superconducting solenoid, to induce a diamagnetic force on the flies that balanced the force of gravity. Simultaneously, two other groups of flies were exposed to a pseudo-hypergravity environment (2g*) and a normal gravity environment (1g*) within the spatially varying field. The flies had a larger mean speed in 0g* than in 1g*, and smaller in 2g*. The mean square distance travelled by the flies grew more rapidly with time in 0g* than in 1g*, and slower in 2g*. We observed no other clear effects of the magnetic field, up to 16.5 T, on the walks of the flies. We compare the effect of diamagnetically simulated weightlessness with that of weightlessness in an orbiting spacecraft, and identify the cause of the anomalous behaviour as the altered effective gravity

Heavy-light decay topologies as a new strategy to discover a heavy gluon

We study the collider phenomenology of the lightest Kaluza-Klein excitation of the gluon, G*, in theories with a warped extra dimension. We do so by means of a two-site effective lagrangian which includes only the lowest-lying spin-1 and spin-1/2 resonances. We point out the importance of the decays of G* to one SM plus one heavy fermion, that were overlooked in the previous literature. It turns out that, when kinematically allowed, such heavy-light decays are powerful channels for discovering the G*. In particular, we present a parton-level Montecarlo analysis of the final state Wtb that follows from the decay of G* to one SM top or bottom quark plus its heavy partner. We find that at \sqrt{s} = 7 TeV and with 10 fb^{-1} of integrated luminosity, the LHC can discover a KK gluon with mass in the range M_{G*} = (1.8 - 2.2) TeV if its coupling to a pair of light quarks is g_{G*qqbar} = (0.2-0.5) g_3. The same process is also competitive for the discovery of the top and bottom partners as well. We find, for example, that the LHC at \sqrt{s} = 7 TeV can discover a 1 TeV KK bottom quark with an integrated luminosity of (5.3 - 0.61) fb^{-1} for g_{G*qqbar} = (0.2-0.5) g_3.Comment: 36 pages, 13 figures. v2: a few typos corrected, comments added, version published in JHE

Neoliberalismo e conservadorismo: quem são os “cidadãos de bem” ressentidos? / Neoliberalism and conservatism: who are the resentful "good citizens"?

Nos últimos anos, candidatos de extrema direita, que flertam com o autoritarismo e põem em risco a democracia, ascenderam ao poder em diversos países do mundo. No Brasil, esse processo também aconteceu, e, nas eleições presidenciais de 2018, Jair Bolsonaro foi eleito com o discurso que prometia um governo “conservador nos costumes e liberal na economia”. Após dois anos e meio de mandato marcado por múltiplas crises e polêmicas, sua popularidade atingiu o grau mais baixo em maio de 2021. Contudo, de acordo com a pesquisa de opinião realizada pelo Instituto Datafolha neste mesmo mês, 24% dos entrevistados continuam avaliando seu governo como “ótimo/bom”. A partir disso, o presente estudo visa a investigar o que motiva esse apoio ao Presidente, lançando-se, para tanto, mão de estudos da Filosofia Política, da Psicanálise e da Antropologia. Conclui-se que é possível explicar pelo viés psicanalítico a motivação do grupo que permanece apoiando Jair Bolsonaro, valendo-se da categoria do ressentimento, paixão condizente com a subjetividade forjada no contexto neoliberal

A review of the ecological value of Cusuco National Park an urgent call forconservation action in a highly threatened Mesoamerican cloud forest

Cloud forests are amongst the most biologically unique, yet threatened, ecosystems in Mesoamerica. We summarize the ecological value and conservation status of a well-studied cloud forest site: Cusuco National Park (CNP), a 23,440 ha protected area in the Merendón mountains, northwest Honduras. We show CNP to have exceptional biodiversity; of 966 taxa identified to a species-level to date, 362 (37.5%) are Mesoamerican endemics, 67 are red-listed by the IUCN, and at least 49 are micro-endemics known only from the Merendón range. CNP also provides key ecosystem services including provision of drinking water and downstream flood mitigation, as well as carbon sequestration, with an estimated stock of 3.5 million megagrams of carbon in 2000. Despite its ecological importance, CNP faces multiple environmental threats and associated stresses, including deforestation (1,759 ha since 2000 equating to 7% of total forest area), poaching (7% loss of mammal relative abundance per year), amphibian declines due to chytridiomycosis (70% of species threatened or near-threatened), and climate change (a mean 2.6 °C increase in temperature and 112 mm decrease in rainfall by 2100). Despite conservation actions, including community ranger patrols, captive-breeding programmes, and ecotourism initiatives, environmental degradation of CNP continues. Further action is urgently required, including reinforcement and expansion of ranger programmes, greater stakeholder engagement, community education programmes, development of alternative livelihood projects, and legislative enforcement and prosecution. Without a thorough and rapid response to understand and mitigate illegal activities, the extirpation and extinction of species and the loss of vital ecosystem services are inevitable in the coming decades