999 resultados para Anesthetics, local


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Três experimentos foram realizados para verificar se o local de aplicação de fomesafen, folhas ou solo, afeta a eficácia desse herbicida em biótipos de E. heterophylla resistente e suscetível a ele; e determinar quais estruturas da planta são mais importantes no processo de absorção desse herbicida. Nos dois primeiros experimentos, testaram-se curvas de dose-resposta de fomesafen em biótipos com e sem resistência a inibidores da PROTOX, em pré-emergência (primeiro experimento) e em pós-emergência (segundo experimento). No terceiro experimento, diferentes locais de deposição de fomesafen foram avaliados, por meio do método de vaso duplo, para verificar quais as estruturas das plantas de E. heterophylla mais importantes na absorção do herbicida. Os resultados, em geral, indicam menor eficiência de controle quando o fomesafen é aplicado na parte aérea das plantas de E. heterophylla resistentes a esse herbicida, em comparação às suscetíveis, e que as diferenças entre os biótipos foram menores na aplicação em pré-emergência. Detectou-se maior eficiência do herbicida fomesafen aplicado ao solo quando este foi colocado junto à parte aérea emergente das plantas suscetíveis e resistentes do que junto ao sistema de raízes destas. Esses resultados apóiam a hipótese de que diferenças foliares entre plantas resistentes e suscetíveis podem dificultar a absorção de fomesafen nos biótipos resistentes aos inibidores da PROTOX.

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The usage of digital content, such as video clips and images, has increased dramatically during the last decade. Local image features have been applied increasingly in various image and video retrieval applications. This thesis evaluates local features and applies them to image and video processing tasks. The results of the study show that 1) the performance of different local feature detector and descriptor methods vary significantly in object class matching, 2) local features can be applied in image alignment with superior results against the state-of-the-art, 3) the local feature based shot boundary detection method produces promising results, and 4) the local feature based hierarchical video summarization method shows promising new new research direction. In conclusion, this thesis presents the local features as a powerful tool in many applications and the imminent future work should concentrate on improving the quality of the local features.

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Presentation at Open Repositories 2014, Helsinki, Finland, June 9-13, 2014

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Presentation at Open Repositories 2014, Helsinki, Finland, June 9-13, 2014

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The immune and central nervous systems are functionally connected and interacting. The concept that the immune signaling to the brain which induces fever during infection and inflammation is mediated by circulating cytokines has been traditionally accepted. Administration of bacterial lipopolysaccharide (LPS) induces the appearance of a so-termed "cytokine cascade" in the circulation more or less concomitantly to the developing febrile response. Also, LPS-like fever can be induced by systemic administration of key cytokines (IL-1ß, TNF-alpha, and others). However, anti-cytokine strategies against IL-1ß or TNF-alpha along with systemic injections of LPS frequently lead to attenuation of the later stages of the febrile response but not of the initial phase of fever, indicating that cytokines are rather involved in the maintenance than in the early induction of fever. Within the last years experimental evidence has accumulated indicating the existence of neural transport pathways of immune signals to the brain. Because subdiaphragmatic vagotomy prevents or attenuates fever in response to intraperitoneal or intravenous injections of LPS, a role for vagal afferent nerve fibers in fever induction has been proposed. Also other sensory nerves may participate in the manifestation of febrile responses under certain experimental conditions. Thus, injection of a small dose of LPS into an artificial subcutaneous chamber results in fever and formation of cytokines within the inflamed tissue around the site of injection. This febrile response can be blocked in part by injection of a local anesthetic into the subcutaneous chamber, indicating a participation of cutaneous afferent nerve signals in the manifestation of fever in this model. In conclusion, humoral signals and an inflammatory stimulation of afferent sensory nerves can participate in the generation and maintenance of a febrile response.

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The effects of various hypertonic solutions on the intraventricular conduction, ventricular repolarization and the arrhythmias caused by the intravenous (iv) injection of bupivacaine (6.5 mg/kg) were studied in sodium pentobarbital-anesthetized mongrel dogs. Hypertonic solutions, given iv 5 min before bupivacaine, were 7.5% (w/v) NaCl, 5.4% (w/v) LiCl, 50% (w/v) glucose (2,400 mOsm/l, 5 ml/kg), or 20% (w/v) mannitol (1,200 mOsm/l, 10 ml/kg). Bupivacaine induced severe arrhythmias and ventricular conduction and repolarization disturbances, as reflected by significant increases in QRS complex duration, HV interval, IV interval and monophasic action potential duration, as well as severe hemodynamic impairment. Significant prevention against ventricular electrophysiologic and hemodynamic disturbances and ventricular arrhythmias was observed with 7.5% NaCl (percent increase in QRS complex duration: 164.4 ± 21.8% in the non-pretreated group vs 74.7 ± 14.1% in the pretreated group, P<0.05; percent increase in HV interval: 131.4 ± 16.1% in the non-pretreated group vs 58.2 ± 7.5% in the pretreated group, P<0.05; percent increase in monophasic action potential duration: 22.7 ± 6.8% in the non-pretreated group vs 9.8 ± 6.3% in the pretreated group, P<0.05; percent decrease in cardiac index: -46 ± 6% in the non-pretreated group vs -28 ± 5% in the pretreated group, P<0.05). The other three hypertonic solutions were ineffective. These findings suggest an involvement of sodium ions in the mechanism of hypertonic protection.

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The rostral ventrolateral medulla (RVLM) contains neurons involved in tonic and reflex control of arterial pressure. We describe the effects of gamma-aminobutyric acid (GABA) and anesthetics injected into the RVLM of conscious and urethane (1.2 g/kg, iv) anesthetized Wistar rats (300-350 g). In conscious rats, bilateral microinjection of GABA (50 nmol/200 nl) induced a small but significant decrease in blood pressure (from 130 ± 3.6 to 110 ± 5.6 mmHg, N = 7). A similar response was observed with sodium pentobarbital microinjection (24 nmol/200 nl). However, in the same animals, the fall in blood pressure induced by GABA (from 121 ± 8.9 to 76 ± 8.8 mmHg, N = 7) or pentobarbital (from 118 ± 4.5 to 57 ± 11.3 mmHg, N = 6) was significantly increased after urethane anesthesia. In contrast, there was no difference between conscious (from 117 ± 4.1 to 92 ± 5.9 mmHg, N = 7) and anesthetized rats (from 123 ± 6.9 to 87 ± 8.7 mmHg, N = 7) when lidocaine (34 nmol/200 nl) was microinjected into the RVLM. The heart rate variations were not consistent and only eventually reached significance in conscious or anesthetized rats. The right position of pipettes was confirmed by histology and glutamate microinjection into the RVLM. These findings suggest that in conscious animals the RVLM, in association with the other sympathetic premotor neurons, is responsible for the maintenance of sympathetic vasomotor tone during bilateral RVLM inhibition. Activity of one or more of these premotor neurons outside the RVLM can compensate for the effects of RVLM inhibition. In addition, the effects of lidocaine suggest that fibers passing through the RVLM are involved in the maintenance of blood pressure in conscious animals during RVLM inhibition.

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Centrally stimulated sweat rate produced by graded exercise until exhaustion was compared to the local sweat rate induced by pilocarpine, often used as a sweating index for healthy individuals. Nine young male volunteers (22 ± 4 years) were studied in temperate environment in two situations: at rest and during progressive exercise with 25 W increases every 2 min until exhaustion, on a cycle ergometer. In both situations, sweating was induced on the right forearm with 5 ml 0.5% pilocarpine hydrochloride applied by iontophoresis (1.5 mA, 5 min), with left forearm used as control. Local sweat rate was measured for 15 min at rest. During exercise, whole-body sweat rate was calculated from the body weight variation. Local sweat rate was measured from the time when heart rate reached 150 bpm until exhaustion and was collected using absorbent filter paper. Pharmacologically induced local sweat rate at rest (0.4 ± 0.2 mg cm-2 min-1) and mean exercise-induced whole-body sweat rate (0.4 ± 0.1 mg cm-2 min-1) were the same (P > 0.05) but were about five times smaller than local exercise-induced sweat rate (control = 2.1 ± 1.4; pilocarpine = 2.7 ± 1.2 mg cm-2 min-1), indicating different sudorific mechanisms. Both exercise-induced whole-body sweat rate (P < 0.05) and local sweat rate (P < 0.05) on control forearm correlated positively with pilocarpine-induced local sweat rate at rest. Assuming that exercise-induced sweating was a result of integrated physiological mechanisms, we suggest that local and whole-body sweat rate measured during graded exercise could be a better sweating index than pilocarpine.

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Feature extraction is the part of pattern recognition, where the sensor data is transformed into a more suitable form for the machine to interpret. The purpose of this step is also to reduce the amount of information passed to the next stages of the system, and to preserve the essential information in the view of discriminating the data into different classes. For instance, in the case of image analysis the actual image intensities are vulnerable to various environmental effects, such as lighting changes and the feature extraction can be used as means for detecting features, which are invariant to certain types of illumination changes. Finally, classification tries to make decisions based on the previously transformed data. The main focus of this thesis is on developing new methods for the embedded feature extraction based on local non-parametric image descriptors. Also, feature analysis is carried out for the selected image features. Low-level Local Binary Pattern (LBP) based features are in a main role in the analysis. In the embedded domain, the pattern recognition system must usually meet strict performance constraints, such as high speed, compact size and low power consumption. The characteristics of the final system can be seen as a trade-off between these metrics, which is largely affected by the decisions made during the implementation phase. The implementation alternatives of the LBP based feature extraction are explored in the embedded domain in the context of focal-plane vision processors. In particular, the thesis demonstrates the LBP extraction with MIPA4k massively parallel focal-plane processor IC. Also higher level processing is incorporated to this framework, by means of a framework for implementing a single chip face recognition system. Furthermore, a new method for determining optical flow based on LBPs, designed in particular to the embedded domain is presented. Inspired by some of the principles observed through the feature analysis of the Local Binary Patterns, an extension to the well known non-parametric rank transform is proposed, and its performance is evaluated in face recognition experiments with a standard dataset. Finally, an a priori model where the LBPs are seen as combinations of n-tuples is also presented

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Reciprocal selection between interacting species is a major driver of biodiversity at both the genetic and the species level. This reciprocal selection, or coevolution, has led to the diversification of two highly diverse and abundant groups of organisms, flowering plants and their insect herbivores. In heterogeneous environments, the outcome of coevolved species interactions is influenced by the surrounding community and/or the abiotic environment. The process of adaptation allows species to adapt to their local conditions and to local populations of interacting species. However, adaptation can be disrupted or slowed down by an absence of genetic variation or by increased inbreeding, together with the following inbreeding depression, both of which are common in small and isolated populations that occur in fragmented environments. I studied the interaction between a long-lived plant Vincetoxicum hirundinaria and its specialist herbivore Abrostola asclepiadis in the southwestern archipelago of Finland. I focused on mutual local adaptation of plants and herbivores, which is a demonstration of reciprocal selection between species, a prerequisite for coevolution. I then proceeded to investigate the processes that could potentially hamper local adaptation, or species interaction in general, when the population size is small. I did this by examining how inbreeding of both plants and herbivores affects traits that are important for interaction, as well as among-population variation in the effects of inbreeding. In addition to bi-parental inbreeding, in plants inbreeding can arise from self-fertilization which has important implications for mating system evolution. I found that local adaptation of the plant to its herbivores varied among populations. Local adaptation of the herbivore varied among populations and years, being weaker in populations that were most connected. Inbreeding caused inbreeding depression in both plants and herbivores. In some populations inbreeding depression in herbivore biomass was stronger in herbivores feeding on inbred plants than in those feeding on outbred ones. For plants it was the other way around: inbreeding depression in anti-herbivore resistance decreased when the herbivores were inbred. Underlying some of the among-population variation in the effects of inbreeding is variation in plant phenolic compounds. However, variation in the modification of phenolic compounds in the digestive tract of the herbivore did not explain the inbreeding depression in herbivore biomass. Finally, adult herbivores had a preference for outbred host plants for egg deposition, and herbivore inbreeding had a positive effect on egg survival when the eggs were exposed to predators and parasitoids. These results suggest that plants and herbivores indeed exert reciprocal selection, as demonstrated by the significant local adaptation of V. hirundinaria and A. asclepiadis to one another. The most significant cause of disruption of the local adaptation of herbivore populations was population connectivity, and thus probably gene flow. In plants local adaptation tended to increase with increasing genetic variation. Whether or not inbreeding depression occurred varied according to the life-history stage of the herbivore and/or the plant trait in question. In addition, the effects of inbreeding strongly depended on the population. Taken together, inbreeding modified plant-herbivore interactions at several different levels, and can thus affect the strength of reciprocal selection between species. Thus inbreeding has the potential to affect the outcome of coevolution.

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Anesthetics can affect the structure and biological function of tissues and systems differentially. The aim of the present study was to compare three injectable anesthetics generally used in experiments with animals in terms of the degree of hemolysis and glycogenolysis occurring after profound anesthesia. Twenty-four male Wistar rats (330-440 g) were divided into three groups (N = 8): chloral hydrate (CH), ketamine + xylazine (KX), Zoletil 50® (zolazepam and tiletamine) + xylazine (ZTX). After deep anesthesia, total blood was collected. The liver and white (WG) and red gastrocnemius (RG) muscles were also immediately removed. The degree of serum hemolysis was quantified on the basis of hemoglobin concentration (g/L). Hepatic and muscular glycogen concentrations (mmol/kg wet tissue) were quantified by the phenol-sulfuric method. The CH and KX groups exhibited serum hemolysis (4.0 ± 2.2 and 1.9 ± 0.9 g/L, respectively; P < 0.05) compared to the ZTX group, which presented none. Only KX induced elevated glycogenolysis (mmol/kg wet tissue) in the liver (86.9 ± 63.2) and in WG (18.7 ± 9.0) and RG (15.2 ± 7.2; P < 0.05). The CH and ZTX groups exhibited no glycogenolysis in the liver (164.4 ± 41.1 and 176.8 ± 54.4, respectively), WG (28.8 ± 4.4, 32.0 ± 6.5, respectively) or RG (29.0 ± 4.9; 25.3 ± 8.6, respectively). Our data indicate that ZTX seems to be an appropriate general anesthetic for studies that seek to simultaneously quantify the concentration of glycogen and serum biochemical markers without interferences. ZTX is reasonably priced, found easily at veterinary markets, quickly induces deep anesthesia, and presents a low mortality rate.

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Local anesthetic efficacy of tramadol has been reported following intradermal application. Our aim was to investigate the effect of perineural tramadol as the sole analgesic in two pain models. Male Wistar rats (280-380 g; N = 5/group) were used in these experiments. A neurostimulation-guided sciatic nerve block was performed and 2% lidocaine or tramadol (1.25 and 5 mg) was perineurally injected in two different animal pain models. In the flinching behavior test, the number of flinches was evaluated and in the plantar incision model, mechanical and heat thresholds were measured. Motor effects of lidocaine and tramadol were quantified and a motor block score elaborated. Tramadol, 1.25 mg, completely blocked the first and reduced the second phase of the flinching behavior test. In the plantar incision model, tramadol (1.25 mg) increased both paw withdrawal latency in response to radiant heat (8.3 ± 1.1, 12.7 ± 1.8, 8.4 ± 0.8, and 11.1 ± 3.3 s) and mechanical threshold in response to von Frey filaments (459 ± 82.8, 447.5 ± 91.7, 320.1 ± 120, 126.43 ± 92.8 mN) at 5, 15, 30, and 60 min, respectively. Sham block or contralateral sciatic nerve block did not differ from perineural saline injection throughout the study in either model. The effect of tramadol was not antagonized by intraperitoneal naloxone. High dose tramadol (5 mg) blocked motor function as well as 2% lidocaine. In conclusion, tramadol blocks nociception and motor function in vivo similar to local anesthetics.