On The Symplectic Two-Form of Gravity in Terms of Dirac Eigenvalues

The Dirac eigenvalues form a subset of observables of the Euclidean gravity. The symplectic two-form in the covariant phase space could be expressed, in principle, in terms of the Dirac eigenvalues. We discuss the existence of the formal solution of the equations defining the components of the symplectic form in this framework.Comment: misprints corrected, final interpretation of results give

Electromagnetic absorption of a pinned Wigner crystal at finite temperatures

We investigate the microwave absorption of a pinned, two-dimensional Wigner crystal in a strong magnetic field at finite temperatures. Using a model of a uniform commensurate pinning potential, we analyze thermal broadening of the electromagnetic absorption resonance. Surprisingly, we find that the pinning resonance peak should remain sharp even when the temperature is comparable or greater than the peak frequency. This result agrees qualitatively with recent experimental observations of the ac conductivity in two-dimensional hole systems in a magnetically induced insulating state. It is shown, in analogy with Kohn's theorem, that the electron-electron interaction does not affect the response of a harmonically pinned Wigner crystal to a spatially uniform external field at any temperature. We thus focus on anharmonicity in the pinning potential as a source of broadening. Using a 1/N expansion technique, we show that the broadening is introduced through the self-energy corrections to the magnetophonon Green's functions.Comment: 21 pages, 9 eps figure

First Order Semiclassical Thermal String in the AdS Spacetime

We formulate the finite temperature theory for the free thermal excitations of the bosonic string in the anti-de Sitter (AdS) spacetime in the Thermo Field Dynamics (TFD) approach. The spacetime metric is treated exactly while the string and the thermal reservoir are semiclassically quantized at the first order perturbation theory with respect to the dimensionless parameter \epsilon = \a ' H^{-2}. In the conformal $D=2+1$ black-hole AdS background the quantization is exact. The method can be extended to the arbitrary AdS spacetime only in the first order perturbation. This approximation is taken in the center of mass reference frame and it is justified by the fact that at the first order the string dynamics is determined only by the interaction between the {\em free} string oscillation modes and the {\em exact} background. The first order thermal string is obtained by thermalization of the $T = 0$ system carried on by the TFD Bogoliubov operator. We determine the free thermal string states and compute the local entropy and free energy in the center of mass reference frame.Comment: Minor typos corrected. Two references added. LATeX file, 19 page

RELAÇÃO ENTRE A DURAÇÃO DO ATO DA INSEMINAÇÃO ARTIFICIAL EM BOVINOS E A FERTILIDADE

The aim of the present experiment was to establish a relationship between the time consumed to perform artificial insemination (AI) and fertility in beef cows. Furthermore, an analysis has been carried out in regard to the inseminators dexterity and the interference of different variables on the number of pregnancies: month, period, time, number of parturitions, body condition, bull, race, temperature. Two groups of Nelore cows from Navirai farms (MS) were used in this experiment. Cows from group I were inseminated during a time no longer than two minutes and cows from group II above two minutes. All cows were healthy and were artificially inseminated only once, the semen being fertile. The detection of the oestrus was performed twice a day, in the morning and the afternoon, with ruffians and in the presence of the inseminators. The length of the insemination has been considered as the time between the drying of the semen pellet, immediately after being melted and its deposition in the uterine body followed by the withdrawal of the universal semen applicator with the sheath from the female genital tract. The diagnosis of gestation has been carried out 60 days after the AI. It has been concluded that the dexterity of the inseminator in carrying on the process itself of AI significantly affects the rate of conception. In regard to the length of time taken to perform AI in bovines it has been found that it interferes in the rate of conception when considered alone (pO presente experimento objetivou estudar a velocidade, em termos de tempo dispendido, à execução da inseminação artificial (IA) propriamente dita, em bovinos de corte, correlacionandose com a fertilidade obtida nos animais pesquisados, bem como verificar a interferência da perícia dos inseminadores quando do ato da IA, além da interferência do conjunto de múltiplas variáveis (mês, período, tempo, número de partos, escore da condição corporal, touro,raça, temperatura) sobre a taxa de prenhez. Utilizou-se dois grupos de vacas da raça Nelore de Fazendas de Naviraí (MS), sendo o grupo I (=animais inseminados em período de tempo de até dois minutos) e o grupo II (= animais inseminados em período de tempo acima de dois minutos). As vacas foram inseminadas artificialmente uma única vez, com sêmen fértil e estavam clinicamente sadias. A detecção do estro era feita duas vezes /dia (manhã e tarde) mediante rufiões e acompanhada pelos inseminadores. A duração do ato inseminatório considerado foi o decorrido entre a secagem da palheta de sêmen, imediatamente após a descongelação, até a retirada do aplicador universal de sêmen com a bainha do trato genital da fêmea, após a deposição do sêmen no corpo uterino. O diagnostico de gestação foi executado 60 dias após a IA. Ao final concluiu-se que a perícia do inseminador ao executar o ato da IA propriamente dito, afeta significativamente a taxa de concepção e que o tempo dispendido à execução do ato da IA nos bovinos, interfere na taxa de concepção, ao ser analisado isoladamente (

Body condition score, weight variation and reproductive performance of beef cows in rangelands from the Pantanal region

Objetivou-se avaliar a influência do escore de condição corporal (ECC) sobre a eficiência reprodutiva de vacas de cria nos períodos pré e pós-parto e a probabilidade de parição, usando o escore de condição corporal e a variação ponderal no período crítico do ciclo reprodutivo. Utilizaram-se 248 vacas multíparas mantidas em pastagens nativas distribuídas em quatro estratégias de suplementação: mistura mineral (controle); suplemento farelado; suplemento líquido; suplemento líquido para vacas e bezerros. As avaliações de peso e ECC, na escala de 1 a 9, foram realizadas no período crítico: em agosto (período pré-parto, 60-90 dias antes da parição) e em janeiro (período pós-parto e reprodutivo) durante quatro anos consecutivos. Para a análise dos anos consecutivos de reprodução, criou-se um escore de reprodução, ou seja, somou-se o número de parições de cada vaca durante os quatro anos pecuários avaliados. O escore de condição corporal nos períodos pré e pós-parto e a idade da vaca influenciaram o escore de reprodução. Portanto, para avaliação da probabilidade de parição, foram utilizadas todas as vacas, classificadas em paridas e vazias. Utilizando equações de estimação generalizadas (EEG), foi modelada a probabilidade de as matrizes serem classificadas como paridas considerando variáveis exploratórias ao longo do tempo. Para se obter probabilidade de parição superior a 80%, as vacas devem possuir escore de aproximadamente 5,5 no período pré-parto. Aproximadamente 60% das vacas paridas mantiveram ou ganharam peso no período crítico do ano, o que levou a maior probabilidade de reconcepção, similar ao observado para as vacas vazias, porém com probabilidade menor de parição. O período pré-parto é o melhor para estimar a probabilidade de parição das vacas por meio da avaliação do escore corporal. A seleção de vacas adaptadas às condições bioclimáticas do Pantanal aumenta a probabilidade de produção de um bezerro por vaca por ano. _________________________________________________________________________________ ABSTRACTThe aim of this study was to evaluate the influence of body condition score (BCS) on reproductive performance of beef cows before and after calving and to evaluate the calving probability using body condition score and weight variation during critical periods of the cow reproductive cycle. From 2001 to 2005, the body condition score was recorded in 248 multiparous cows raised in native pastures, submitted to different supplementation treatments (mineral mixture only - control; dry supplement; liquid supplement and liquid supplement for cow and calves). Weighing and body condition evaluation were made on a 1-9 point scale in August (prepartum period, 60-90 days before parturition) and January (postpartum and reproductive period). A reproduction score was created in function of the body scores in four consecutive years. Except for the treatment, the other factors (body condition score in the prepartum and postpartum periods and cow age) influenced the reproduction score. Thus, the calving probabilities were estimated for all cows. Generalized estimating equations (GEE) were used to evaluate the calving probability in function of the exploratory variables over time. Calving probability higher than 80% was obtained when cows scored 5,5 before calving. In relation to weight, the results showed that about 60% of calving cows maintained or gained weight in the postpartum period, leading to increase in the rebreeding probability. Similar situation occurred with single cows; however, the calving probability was lower. These results indicate that the calving probability using BCS is better estimated before calving. Furthermore, it indicates the presence of cows more adapted to the Pantanal climatic and feeding conditions than others

As bases farmacológicas dos cuidados farmacêuticos: o caso dos AINEs

Polypharmacy – a frequent situation found among the elderly, related to their physiological changes and multiple morbidities – increases the risk of adverse reactions, interactions, drugs misuse and drug-related problems. Knowing that non-steroidal anti-inflammatory drugs (NSAIDs) are widely used among the elderly, the aims of the present study were to assess the potential interactions that may occur between prescribed NSAIDs and other drugs and to create a list of recommendations for monitoring elderly patients taking NSAIDs, in order to prevent or minimize those negative outcomes. With this purpose, a retrospective study was performed at Centro de Saúde de Eiras (Coimbra, Portugal). The study involved the systematic analyses of the medication regimens of a sample of elderly patients selected from the elderly population of this primary health care unit. Eligible subjects were patients aging 65 or more years and at least with one NSAID included in their therapeutic schemes in the last three months. A total of 37 prescribed NSAIDs were found in the 29 patients of the sample. 125 potential NSAID-drug interactions were found: 2 minor and 123 moderate. Most interactions occurred between NSAIDs and anti- hypertensive drugs, such as diuretics (17.6%), angiotensin receptor blockers (14.4%), calcium channel block- ers (12.0%) and angiotensin converting enzyme inhibitors (8.8%). The prevalence of interactions between NSAIDs was 12.8%. These interactions can cause adverse effects with particular manifestations in the elderly, such as renal impairment and increased blood pressure. The pharmacist can develop a relevant role in services such as medication review, to identify these potential interactions, or pharmacotherapy follow-up, in the management of these situations when properly identified. Stresses the importance of positive interaction with General and Family Practice for the safe and efficiency of therapies. A polimedicação aumenta o risco de reações adversas, interações e uso incorreto dos medicamentos. Nos idosos é bastante prevalente, potenciando ainda mais os problemas relacionados com os medicamentos, uma vez que estes também resultam das alterações fisiológicas e multimorbilidades do envelhecimento. Sabendo que os anti-inflamatórios não esteroides (AINEs) são fármacos muito usados pelos idosos, foram objetivos deste trabalho caracterizar potenciais interações entre AINEs prescritos e a restante medicação em idosos e criar uma lista de recomendações relacionadas com a monitorização destes doentes, de modo a evitar ou detetar precocemente tais interações. Análise retrospetiva dos dados referentes à medicação prescrita de uma amostra de idosos de uma Unidade de Cuidados de Saúde Primários (Centro de Saúde de Eiras, Coimbra, Portugal) presentes numa consulta médica entre 2 e 16 de janeiro de 2012. Foram revistos os regimes farmacoterapêuticos de 29 doentes a tomar pelo menos 1 AINE, cerca de 3 meses antes da recolha de dados, num total de 37 AINEs prescritos. Foram encontradas 123 interações moderadas e 2 minor. As principais interações ocorreram entre AINEs e diuréticos (17,6%), antagonistas dos recetores da angiotensina (14,4%), bloqueadores da entrada do cálcio (12,0%) e inibidores da enzima de conversão da angiotensina (8,8%). A prevalência de interações entre AINEs foi de 12,8%. Elaborou-se uma lista de recomendações para monitorização dos doentes quando não se podem evitar as ditas interações. Estas interações devem ser tidas em conta no momento da prescrição e cedência de AINEs, pois podem desencadear efeitos negativos tais como alterações renais e aumento da pressão arterial. O farmacêutico pode desenvolver um papel relevante em serviços como a revisão da medicação, para identificar estas interações potenciais, ou no acompanhamento farmacoterapêutico, na gestão destas situações quando devidamente identificadas. Salienta-se a importância da interação positiva com a Medicina Geral e Familiar para a segurança e a eficiência das terapêuticas.

Quantum fluids in the Kaehler parametrization

In this paper we address the problem of the quantization of the perfect relativistic fluids formulated in terms of the K\"{a}hler parametrization. This fluid model describes a large set of interesting systems such as the power law energy density fluids, Chaplygin gas, etc. In order to maintain the generality of the model, we apply the BRST method in the reduced phase space in which the fluid degrees of freedom are just the fluid potentials and the fluid current is classically resolved in terms of them. We determine the physical states in this setting, the time evolution and the path integral formulation.Comment: 12 pages. Minor typos correcte

Diketopyrrolo[3,4-c]pyrrole derivative as a promising ligand for the stabilization of G-quadruplex DNA structures

Telomerase, oncogenes and tumor suppressors are closely associated with tumour occurrence, therefore these structures are being recognized as targets for the development of new anticancer drugs. The efficacy of several molecules in telomerase inhibition and regulation of genes expression, by adduct formation with G-quadruplexes (G4), has been studied by biophysical and biochemical methods with promising results. We report here the synthesis and structural characterization of a small positively charged diketopyrrolo[3,4–c]pyrrole derivative, identified as DPP(PyMe)2, that showed very promising results as G4 stabilizing ligand. The data obtained from UV–Vis and fluorescence experiments suggest that DPP(PyMe)2 presents high affinity to G4 structures. Docking studies and molecular dynamics simulations unraveled the binding modes of the ligand with four G4 structures. The obtained results also allowed us to conclude that the DPP(PyMe)2 ligand binds into the top G-tetrad or in a mixed binding mode depending on the GQ structure. A remarkable selectivity of DPP(PyMe)2 for c-MYC and KRAS 32R in the presence of ds26 was observed by circular dichroism (CD) and fluorescence resonance energy transfer (FRET) melting experiments. CD titrations revealed a stabilization higher than 30 °C in the case of c-MYC G4 structure and, for the same sequence, DPP(PyMe)2 showed the ability to block the activity of Taq polymerase in a dose-dependent manner. The subcellular localization obtained with confocal microscopy corroborates the results obtained by the other techniques and the obtained data suggest that DPP(PyMe)2 is an attractive ligand for the development of G4 labelling probes.Peer reviewe