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O uso de répteis como modelos experimentais é limitado, principalmente devido às particularidades fisiológicas da classe, como as oscilações diárias e sazonais em seu comportamento. O objetivo deste estudo foi avaliar a atividade locomotora e nociceptiva de teiús (Salvator merianae) e iguanas-verdes (Iguana iguana) submetidos a testes comportamentais, ao longo do dia e do ano. Foram utilizados seis exemplares de cada espécie, mantidos em sala com temperatura ambiental (24 a 30°C) e fotoperíodo (12h:12h) controlados. Esses foram avaliados ao longo do dia (0:00h, 6:00h, 12:00h, 18:00h) e ao longo do ano (análise mensal). A análise locomotora foi realizada através do teste de campo aberto (teiús e iguanas), no qual o animal foi colocado no centro de uma arena circular por 15 minutos, e recebeu um ponto por cada ultrapassagem pelas subdivisões da mesma; e pelo teste de natação forçada (iguanas), no qual o tempo de atividade foi mensurado em piscina sem saída por 2 minutos. A resposta nociceptiva foi avaliada por meio de mensuração do período de latência do membro em resposta a estímulo nocivo térmico (25 segundos; 245 ± 7 mW/cm2) na superfície plantar do membro do animal. Não foram detectadas oscilações ao longo do ano no teste de campo aberto em nenhuma das espécies. Ao longo do dia, oscilações foram detectadas de Fevereiro a Dezembro em teiús; e em Abril, Maio, Junho e Outubro em iguanas. O tempo de atividade das iguanas foi menor em Janeiro e às 0:00h. Maiores latências de retirada do membro foram observadas nos meses de Maio e Agosto e às 6:00h em ambas espécies. Conclue-se que teiús e iguanas-verdes em ambiente controlado apresentam oscilações significativas em comportamento observado em teste de campo aberto, teste de natação forçada (somente iguanas) e teste plantar, que aparentemente não seguem padrões anuais claros, sendo provavelmente influenciado por fatores múltiplos ainda não compreendidos para as espécies. / The use of reptiles as experimental models is limited due to their physiological particularities, such as daily and annual fluctuations in behavior. The aim of this study was to evaluate locomotor and nociceptive activities of tegus (Salvator merianae) and green iguanas (Iguana iguana) throughout the day and the year, when undergoing behavioral tests. Six animals from each species, kept under controlled room temperature (24 to 30°C) and photoperiod (12h:12h), were used. They were evaluated throughout the day (0:00h, 6:00h, 12:00h and 18:00) and the year (monthly). Locomotor activity was measured by the open field test, in which the animal was placed in the center of a round arena for 15 minutes and the number of crossings through the subdivisions of the arena was counted, and by the forced swim test (iguanas), in which the activity period was timed after animals were placed in a pool with no scape for 2 minutes. Nociceptive activity was measured as the latency to limb withdrawal reflex in response to a noxious thermal stimulus (25 seconds, 245 ± 7 mW/cm2) in the plantar surface of the animal\'s limb. No differences were detected in locomotor activity in the open field test throughout the year in both species. Throughout the day, fluctuations were detected from February to December in tegus, and in April, May, June and October in iguanas. Activity period in iguanas were shorter in January and at 0:00h. Longer latencies to withdrawal reflex were detected in May and August and at 6:00h in both species. In conclusion, tegus and green iguanas kept in controlled environment have fluctuations in behavior presented in the open field test, the forced swim (only iguanas) test and the plantar test, which apparently do not follow a clear seasonal pattern and are probably influenced by multiple factors that are still unknown for both species.

Apresentamos dados e argumentos que indicam que: a) as crises epilépticas apresentadas por Trinomys yonenagae em campo e em cativeiro são espontâneas e idiopáticas; e b) elas podem ser decorrentes de processos evolutivos. A epilepsia nesta espécie foi caracterizada em cativeiro a partir de um cadastro iniciado há 16 anos, formado por progenitores e descendentes de seis colônias de T. yonenagae, coletados na Caatinga de Ibiraba (BA), e adultos (129,90 ± 5,92g) e filhotes nascidos em cativeiro num total de 295 indivíduos. A prevalência e a incidência em indivíduos epilépticos (EE) foram estimadas e as crises epilépticas foram analisadas por meio das manifestações comportamentais, baseando-se na escala de Racine. Aspectos da procriação (n=11), a locomoção, a ansiedade (testes de arena, n= 35) e índices fisiológicos (balanço hídrico-alimentar, n=6), importantes ao fitness, foram mensurados. Somente duas colônias apresentaram EE representando 9% e 28% dos nascimentos. Do total de indivíduos (165 e 130) 9,8% são EE (n=29; 14 e 15), sendo que as representam 52% e os 48%. A prevalência é de 20 a 30% e a incidência variou de 2 a 10 casos/ano, nos últimos cinco anos. As crises são observadas somente em adultos (n=24) a menor latência é de 13m e a frequência é variável (1 a 24 em seis anos). A maioria iniciou-se por congelamento e 50% atingiram o estágio 5 da escala de Racine. Em todos os casais, de 5 a 50% dos filhotes são EE e ocorreu estro pós-parto, como esperado para a espécie. Os filhotes são saudáveis e tanto a média de filhotes por ninhada (1,9±0,3), como a média do número de ninhadas por casal (6,5±5,0) é igual à de casais não epilépticos (NE). O teste de arena indica que descendentes de EE (DE) e as EE são menos ansiosas que as NE. Não há diferença entre os grupos dos índices fisiológicos estimados. A diferença no número de EE nas colônias, a alta prevalência e % de filhotes EE, e a diferença de comportamento das fêmeas DE indicam a base genética desta epilepsia. Neste contexto, consideramos que em Trinomys yonenagae, a epilepsia límbica não compromete o fitness, o que abre possibilidades de ser decorrente de processos evolutivos envolvendo o escalonamento de respostas de anti-predação / We present data and discuss the possibility that: a) the seizures presented by Trinomys yonenagae in the wild and in captivity are spontaneous and idiopathic, and b) they may be due to evolutionary processes. Epilepsy was characterized in this species in captivity from a survey started 16 years ago, made up of parents and descendants from six colonies of T. yonenagae collected in the Caatinga of Ibiraba (BA), and adults (129.90 ± 5.92 g) and pups born in captivity in a total of 295 individuals. The prevalence and incidence in individuals with epilepsy (EE) were estimated and seizures were analyzed by behavioral manifestations, based on Racine´s scale. Locomotion and anxiety indexes (open-field test, n = 35), as well as aspects of breeding (n = 11) and physiological indicators (balance food and water, n = 6), important to fitness were measured. Only two colonies showed EE, representing 9% and 28% of births. Approximately 10% of total individuals (165 and 130 ) are EE (n = 29, 14 and 15 ), and the represent 52 and 48%. In the last five years prevalence is 20-30%, and incidence ranged from 2 to 10 cases/ year. Seizures are only observed in adults (n = 24), the lowest latency is 13 months and the frequency is variable (1 to 24 in six years). The first stage is freezing and 50% reached stage 5 of Racine´s scale. In all couples, 5-50% of puppies are EE and occurred postpartum estrus, as expected for the species. The puppies are healthy and both the average offspring per litter (1.9 ± 0.3), as well as the average number of litters per couple (6.5 ± 5.0) is equal to values presented by non-epileptic couples (NE). The open-field test indicates that descendants of EE (DE) and EE are less anxious than NE. There is no difference between EE and NE regarding food and water intake. The difference in the number of EE in the colonies, the high percentage of EE pups, and the difference in the behavior of DE indicate the genetic basis of this epilepsy. In this context, we consider that in Trinomys yonenagae the limbic epilepsy seems to not compromise the fitness, which opens possibilities to be the result of evolutionary processes involving the escalation of antipredator responses

Le secteur de communications sécurisés et portables connait une véritable révolution avec l’apparition des plateformes dites radios logiciels (Software Defined Radios, SDRs). Les performances exceptionnelles de ces systèmes sont les résultats d’une interaction assez complexe et souvent peu évidente entre le logiciel embarqué, le circuit de traitement numérique et les blocs mixtes analogiques/RF. Cette complexité limite la testabilité du produit fini. La méthodologie de test utilisée actuellement a atteint ses limites dues au cout élevé, le long temps de test et le bas degré de généralisation. De plus, les plateformes SDRs peuvent évoluer sur le terrain et elles vont supporter des standards et des scénarios qui n’ont pas été considérés pendant le la phase de conception. Donc, une stratégie de test sur le terrain (en ligne) n’est plus une caractéristique optionnelle mais une nécessité. Dans ce contexte, le but de notre recherche est d’inventer et développer une méthodologie de test capable de garantir le bon fonctionnement d’une plateforme SDR après la production et pendant sa vie. Notre objectif final est de réduire le coût du test en profitant de la reconfigurabilité de la plateforme. Pour les radios tactiques qui doivent être mises à jour sur le terrain sans équipement spécial, les stratégies Built-In Self-Test (BIST) sont, sans doute, la seule moyenne de garantir la conformité aux spécifications. Dans cette mémoire, nous introduisons une nouvelle architecture de test RF BIST qui utilise la technique de de sous-échantillonnage nonuniform à la sortie de l’émetteur (TX) d’une SDR afin d’évaluer la conformité de la masque spectrale. Notre solution s’appuie sur une implémentation autonome, est modulable et peut être appliquée pour le test sur le terrain avec des modifications minimes. Par rapport aux autres techniques de test analogiques/RF, cet approche ne dépends pas de la architecture du TX, ni d’un modèle ad-hoc, ce qui est idéale pour le test des SDRs. / The advent of increasingly powerful Integrated Circuits (IC) has led to the emergence of the Software Defined Radio (SDR) concept, which brought the sector of secured mobile communications into a new era. The outstanding performance of these systems results from optimal trade-offs among advanced analog/Radio Frequency (RF) circuitry, high-speed reconfigurable digital hardware and sophisticated real-time software. The inherent sophistication of such platforms poses a challenging problem for product testing. Currently deployed industrial test strategies face rising obstacles due to the costlier RF test equipment, longer test time and lack of flexibility. Moreover, an SDR platform is field-upgradeable, which means it will support standards and scenarii not considered during the design phase. Therefore, an in-field test strategy is not anymore 'a nice to have' feature but a mandatory requirement. In this context, our research aims to invent and develop a new test methodology able to guarantee the correct functioning of the SDR platform post-fabrication and over its operational lifetime. The overall aim of our efforts is to reduce post-manufacture test cost of SDR transceivers by leveraging the reconfigurability of the platform.For tactical radio units that must be field-upgradeable without specialized equipment, Built-in Self-Test (BIST) schemes are arguably the only way to ensure continued compliance to specifications. In this study we introduce a novel RF BIST architecture which uses Periodically Nonuniform Sampling (PNS2) of the transmitter (TX) output to evaluate compliance to spectral mask specifications. Our solution supports a stand-alone implementation, is scalable across a wide set of complex specifications and can be easily applied for in-field testing with small added hardware. Compared to existing analog/RF test techniques, this approach is not limited to a given TX architecture and does not rely on an ad-hoc TX model, which makes it ideal for SDR testing.

Le secteur de communications sécurisés et portables connait une véritable révolution avec l’apparition des plateformes dites radios logiciels (Software Defined Radios, SDRs). Les performances exceptionnelles de ces systèmes sont les résultats d’une interaction assez complexe et souvent peu évidente entre le logiciel embarqué, le circuit de traitement numérique et les blocs mixtes analogiques/RF. Cette complexité limite la testabilité du produit fini. La méthodologie de test utilisée actuellement a atteint ses limites dues au cout élevé, le long temps de test et le bas degré de généralisation. De plus, les plateformes SDRs peuvent évoluer sur le terrain et elles vont supporter des standards et des scénarios qui n’ont pas été considérés pendant le la phase de conception. Donc, une stratégie de test sur le terrain (en ligne) n’est plus une caractéristique optionnelle mais une nécessité. Dans ce contexte, le but de notre recherche est d’inventer et développer une méthodologie de test capable de garantir le bon fonctionnement d’une plateforme SDR après la production et pendant sa vie. Notre objectif final est de réduire le coût du test en profitant de la reconfigurabilité de la plateforme. Pour les radios tactiques qui doivent être mises à jour sur le terrain sans équipement spécial, les stratégies Built-In Self-Test (BIST) sont, sans doute, la seule moyenne de garantir la conformité aux spécifications. Dans cette mémoire, nous introduisons une nouvelle architecture de test RF BIST qui utilise la technique de de sous-échantillonnage nonuniform à la sortie de l’émetteur (TX) d’une SDR afin d’évaluer la conformité de la masque spectrale. Notre solution s’appuie sur une implémentation autonome, est modulable et peut être appliquée pour le test sur le terrain avec des modifications minimes. Par rapport aux autres techniques de test analogiques/RF, cet approche ne dépends pas de la architecture du TX, ni d’un modèle ad-hoc, ce qui est idéale pour le test des SDRs. / The advent of increasingly powerful Integrated Circuits (IC) has led to the emergence of the Software Defined Radio (SDR) concept, which brought the sector of secured mobile communications into a new era. The outstanding performance of these systems results from optimal trade-offs among advanced analog/Radio Frequency (RF) circuitry, high-speed reconfigurable digital hardware and sophisticated real-time software. The inherent sophistication of such platforms poses a challenging problem for product testing. Currently deployed industrial test strategies face rising obstacles due to the costlier RF test equipment, longer test time and lack of flexibility. Moreover, an SDR platform is field-upgradeable, which means it will support standards and scenarii not considered during the design phase. Therefore, an in-field test strategy is not anymore 'a nice to have' feature but a mandatory requirement. In this context, our research aims to invent and develop a new test methodology able to guarantee the correct functioning of the SDR platform post-fabrication and over its operational lifetime. The overall aim of our efforts is to reduce post-manufacture test cost of SDR transceivers by leveraging the reconfigurability of the platform.For tactical radio units that must be field-upgradeable without specialized equipment, Built-in Self-Test (BIST) schemes are arguably the only way to ensure continued compliance to specifications. In this study we introduce a novel RF BIST architecture which uses Periodically Nonuniform Sampling (PNS2) of the transmitter (TX) output to evaluate compliance to spectral mask specifications. Our solution supports a stand-alone implementation, is scalable across a wide set of complex specifications and can be easily applied for in-field testing with small added hardware. Compared to existing analog/RF test techniques, this approach is not limited to a given TX architecture and does not rely on an ad-hoc TX model, which makes it ideal for SDR testing.

The structural behaviour of pavements in cold regions can considerably be affected by seasonal variation in environmental factors such as temperature and moisture content. Along with the destructive effect of heavy traffic loads, climatic and environmental factors can considerably contribute to pavement deterioration. These factors can influence the structural and functional capacity of the pavement structures which, as a result, can trigger and accelerate pavement deterioration mechanisms. Studies on the influence of variation of the environmental factors on the response and behaviour of pavement materials have shown that proper consideration to these factors must be given in realistic pavement design and analysis. In flexible pavement structures, particularly with a thin hot mix asphalt (HMA) layer, unbound materials and subgrade soil largely contribute to the overall structural behaviour of the pavement system. In unbound materials, moisture content and its variation can significantly affect pavement layer stiffness and permanent deformation characteristics. Therefore, the moisture condition of pavements and its influence on the mechanical behaviour of pavement materials has been of interest among the pavement research community. A proper understanding of moisture transformation in pavement systems and its effects on pavement performance are important for mechanistic pavement design. The present summary of this doctoral thesis is based on four main parts. The first part of the thesis covers field measurements and findings from a test section along county road 126 in southern Sweden and consists of two journal papers (paper I and II) tackling different aspects of the research topic. This test section is located in a relatively wet ground condition and consists of a thin flexible pavement structure with a deep drainage system. It is instrumented with subsurface temperature, volumetric moisture content and groundwater probes. The mechanical response of the pavement structure was investigated using Falling Weight Deflectometer (FWD) measurements. The second part of the thesis (paper III and IV) are based on laboratory experiments and investigates different recent approaches that have been proposed to apply principles of unsaturated soil mechanics for incorporating seasonal variation of moisture content into the resilient modulus models using matric suction. The third part of the thesis (paper V) builds a bridge that spans between the laboratory and field investigations with an attempt to evaluate one of the predictive models presented in Paper III. The fourth part of the thesis (paper VI) mainly focuses on the laboratory-based investigation of the permanent deformation characteristic of subgrade soils. In this part, the permanent deformation characteristics of two different silty sand subgrade soils were investigated and modelled using the data obtained from repeated load traxial tests. Paper I mainly focuses on the spring-thaw weakening of the pavement structure. The environmental data collected using different sensors and the FWD tests were used to investigate variations in moisture content with thaw penetration and its influence on the stiffness of unbound layers and the pavement’s overall bearing capacity. Using the backcalculated layer stiffness and corresponding in situ moisture measurements in the unbound layers, a degree of saturation-based moisture-stiffness model was developed for the granular material and the subgrade. In Paper II, the drainage system of the structure was manually clogged during a three month period in summer to raise the groundwater level and increase the moisture content of the layers. Along with the subsurface groundwater level and moisture content monitoring, the structural response of the pavement was studied. In this research work, the FWD tests were conducted at three different load levels. The stress dependent behaviour of the unbound granular layer and the subgrade soil were further studied using the multilevel loads FWD test data. Additionally, parameters of a nonlinear stress-dependent stiffness model were backcalculated and their sensitivity to in situ moisture content was studied. In Paper III and IV, series of suction-controlled repeated load triaxial (RLT) tests were conducted on two silty sand (SM) subgrade materials. Several resilient modulus prediction models that account for seasonal moisture content variation through matric suction were summarized and after optimizing the model parameters, the capability of the prediction models in capturing the material response were evaluated. In Paper V, an attempt was made to evaluate the proficiency of one of the suction-resilient modulus models using the field moisture content and FWD measurements from the Torpsbruk test site. The backcalculated subgrade stiffness dataset at different moisture contents were compared with resilient modulus models obtained from the suction-resilient modulus predictive model. Paper VI presents an evaluation of several permanent deformation models for unbound pavement materials that incorporate the time-hardening concept using a series of multistage repeated load triaxial (RLT) tests conducted on silty sand subgrade materials. The permanent deformation tests were conducted at four different moisture contents with pore suctions measurement throughout the test. The effect of moisture content (matric suction) on the permanent deformation characteristics of the materials and the predictive model parameters were further investigated. / <p>QC 20150324</p>

Apresentamos dados e argumentos que indicam que: a) as crises epilépticas apresentadas por Trinomys yonenagae em campo e em cativeiro são espontâneas e idiopáticas; e b) elas podem ser decorrentes de processos evolutivos. A epilepsia nesta espécie foi caracterizada em cativeiro a partir de um cadastro iniciado há 16 anos, formado por progenitores e descendentes de seis colônias de T. yonenagae, coletados na Caatinga de Ibiraba (BA), e adultos (129,90 ± 5,92g) e filhotes nascidos em cativeiro num total de 295 indivíduos. A prevalência e a incidência em indivíduos epilépticos (EE) foram estimadas e as crises epilépticas foram analisadas por meio das manifestações comportamentais, baseando-se na escala de Racine. Aspectos da procriação (n=11), a locomoção, a ansiedade (testes de arena, n= 35) e índices fisiológicos (balanço hídrico-alimentar, n=6), importantes ao fitness, foram mensurados. Somente duas colônias apresentaram EE representando 9% e 28% dos nascimentos. Do total de indivíduos (165 e 130) 9,8% são EE (n=29; 14 e 15), sendo que as representam 52% e os 48%. A prevalência é de 20 a 30% e a incidência variou de 2 a 10 casos/ano, nos últimos cinco anos. As crises são observadas somente em adultos (n=24) a menor latência é de 13m e a frequência é variável (1 a 24 em seis anos). A maioria iniciou-se por congelamento e 50% atingiram o estágio 5 da escala de Racine. Em todos os casais, de 5 a 50% dos filhotes são EE e ocorreu estro pós-parto, como esperado para a espécie. Os filhotes são saudáveis e tanto a média de filhotes por ninhada (1,9±0,3), como a média do número de ninhadas por casal (6,5±5,0) é igual à de casais não epilépticos (NE). O teste de arena indica que descendentes de EE (DE) e as EE são menos ansiosas que as NE. Não há diferença entre os grupos dos índices fisiológicos estimados. A diferença no número de EE nas colônias, a alta prevalência e % de filhotes EE, e a diferença de comportamento das fêmeas DE indicam a base genética desta epilepsia. Neste contexto, consideramos que em Trinomys yonenagae, a epilepsia límbica não compromete o fitness, o que abre possibilidades de ser decorrente de processos evolutivos envolvendo o escalonamento de respostas de anti-predação / We present data and discuss the possibility that: a) the seizures presented by Trinomys yonenagae in the wild and in captivity are spontaneous and idiopathic, and b) they may be due to evolutionary processes. Epilepsy was characterized in this species in captivity from a survey started 16 years ago, made up of parents and descendants from six colonies of T. yonenagae collected in the Caatinga of Ibiraba (BA), and adults (129.90 ± 5.92 g) and pups born in captivity in a total of 295 individuals. The prevalence and incidence in individuals with epilepsy (EE) were estimated and seizures were analyzed by behavioral manifestations, based on Racine´s scale. Locomotion and anxiety indexes (open-field test, n = 35), as well as aspects of breeding (n = 11) and physiological indicators (balance food and water, n = 6), important to fitness were measured. Only two colonies showed EE, representing 9% and 28% of births. Approximately 10% of total individuals (165 and 130 ) are EE (n = 29, 14 and 15 ), and the represent 52 and 48%. In the last five years prevalence is 20-30%, and incidence ranged from 2 to 10 cases/ year. Seizures are only observed in adults (n = 24), the lowest latency is 13 months and the frequency is variable (1 to 24 in six years). The first stage is freezing and 50% reached stage 5 of Racine´s scale. In all couples, 5-50% of puppies are EE and occurred postpartum estrus, as expected for the species. The puppies are healthy and both the average offspring per litter (1.9 ± 0.3), as well as the average number of litters per couple (6.5 ± 5.0) is equal to values presented by non-epileptic couples (NE). The open-field test indicates that descendants of EE (DE) and EE are less anxious than NE. There is no difference between EE and NE regarding food and water intake. The difference in the number of EE in the colonies, the high percentage of EE pups, and the difference in the behavior of DE indicate the genetic basis of this epilepsy. In this context, we consider that in Trinomys yonenagae the limbic epilepsy seems to not compromise the fitness, which opens possibilities to be the result of evolutionary processes involving the escalation of antipredator responses

O uso de répteis como modelos experimentais é limitado, principalmente devido às particularidades fisiológicas da classe, como as oscilações diárias e sazonais em seu comportamento. O objetivo deste estudo foi avaliar a atividade locomotora e nociceptiva de teiús (Salvator merianae) e iguanas-verdes (Iguana iguana) submetidos a testes comportamentais, ao longo do dia e do ano. Foram utilizados seis exemplares de cada espécie, mantidos em sala com temperatura ambiental (24 a 30°C) e fotoperíodo (12h:12h) controlados. Esses foram avaliados ao longo do dia (0:00h, 6:00h, 12:00h, 18:00h) e ao longo do ano (análise mensal). A análise locomotora foi realizada através do teste de campo aberto (teiús e iguanas), no qual o animal foi colocado no centro de uma arena circular por 15 minutos, e recebeu um ponto por cada ultrapassagem pelas subdivisões da mesma; e pelo teste de natação forçada (iguanas), no qual o tempo de atividade foi mensurado em piscina sem saída por 2 minutos. A resposta nociceptiva foi avaliada por meio de mensuração do período de latência do membro em resposta a estímulo nocivo térmico (25 segundos; 245 ± 7 mW/cm2) na superfície plantar do membro do animal. Não foram detectadas oscilações ao longo do ano no teste de campo aberto em nenhuma das espécies. Ao longo do dia, oscilações foram detectadas de Fevereiro a Dezembro em teiús; e em Abril, Maio, Junho e Outubro em iguanas. O tempo de atividade das iguanas foi menor em Janeiro e às 0:00h. Maiores latências de retirada do membro foram observadas nos meses de Maio e Agosto e às 6:00h em ambas espécies. Conclue-se que teiús e iguanas-verdes em ambiente controlado apresentam oscilações significativas em comportamento observado em teste de campo aberto, teste de natação forçada (somente iguanas) e teste plantar, que aparentemente não seguem padrões anuais claros, sendo provavelmente influenciado por fatores múltiplos ainda não compreendidos para as espécies. / The use of reptiles as experimental models is limited due to their physiological particularities, such as daily and annual fluctuations in behavior. The aim of this study was to evaluate locomotor and nociceptive activities of tegus (Salvator merianae) and green iguanas (Iguana iguana) throughout the day and the year, when undergoing behavioral tests. Six animals from each species, kept under controlled room temperature (24 to 30°C) and photoperiod (12h:12h), were used. They were evaluated throughout the day (0:00h, 6:00h, 12:00h and 18:00) and the year (monthly). Locomotor activity was measured by the open field test, in which the animal was placed in the center of a round arena for 15 minutes and the number of crossings through the subdivisions of the arena was counted, and by the forced swim test (iguanas), in which the activity period was timed after animals were placed in a pool with no scape for 2 minutes. Nociceptive activity was measured as the latency to limb withdrawal reflex in response to a noxious thermal stimulus (25 seconds, 245 ± 7 mW/cm2) in the plantar surface of the animal\'s limb. No differences were detected in locomotor activity in the open field test throughout the year in both species. Throughout the day, fluctuations were detected from February to December in tegus, and in April, May, June and October in iguanas. Activity period in iguanas were shorter in January and at 0:00h. Longer latencies to withdrawal reflex were detected in May and August and at 6:00h in both species. In conclusion, tegus and green iguanas kept in controlled environment have fluctuations in behavior presented in the open field test, the forced swim (only iguanas) test and the plantar test, which apparently do not follow a clear seasonal pattern and are probably influenced by multiple factors that are still unknown for both species.

<div>Pavement drainage systems are one of the key drivers of pavement function and longevity, and effective drain maintenance can significantly extend a pavement's service life. Maintenance of these drains, however, is often hampered by the challenge of locating the drains. Ground Penetrating Radar (GPR) typically offers a rapid and effective method to detect these underground targets. However, typical detection schema that rely upon the observation of the hyperbolic return from a GPR scan of a buried conduit still tend to miss many of the older drains beneath pavements as they may be partially or fully filled with sediment and/or may be fabricated from clay or other earthen materials, yielding a return signal that is convolved with significant background noise. </div><div><br></div><div>To manage this challenge, this work puts forward an improved background noise and clutter reduction method to enhance the target signals in what amounts to a constructed environment that tends to have more consistent subsurface properties than one might encounter in a general setting. Within this technique, two major algorithms are employed. Algorithm 1 is the core of this method, and plays the role of reducing background noise and clutter. Algorithm 2 is supplementary, and helps eliminate anomalous discontinuous returns generated by the equipment itself, which could otherwise lead to false detection indications in the output of Algorithm 1. Instead of traditional 2-D GPR images, the result of the proposed algorithms is a 1-D plot along the survey line, highlighting a set of “points of interest” that could indicate buried drain locations identified at any given GPR operating frequency. Subsurface exploration using two different operating frequencies, 900 MHz and 400 MHz herein, is then employed to further enhance detection confidence. Points of interest are ultimately coded to define the confidence of the detection. Comparing the final result of proposed algorithms with the original GPR images, the improved algorithm is demonstrated to provide significantly improved detection results, and could potentially be applied to similar problems in other contexts.</div><div><br></div><div>Besides the background reduction methods, a group of simulations performed using GPRMAX2D software are examined to explore the influence of road cross-section designs on sub-pavement drainage conduit GPR signatures, and evaluate the effectiveness of alternate GPR antennae configurations in locating these buried conduits in different ground conditions. Two different models were explored to simulate conduit detection. In addition, different pipe and soil conditions were modeled, such as pipe size, pipe material, soil moisture level, and soil type. Four different quantitative measurements are used to analyze GPR performance based on different key factors. The four measurements are 1) signal to background ratio (SBR) in dB; 2) signal to receiver noise ratio (SNR) in dB; 3) signal energy in Volts; and 4) average signal band power in Watts.</div><div><br></div><div>The water and clay content of subsurface soil can significantly influence the detection results obtained from ground penetrating radar (GPR). Due to the variation of the material properties underground, the center frequency of transmitted GPR signals shifts to a lower range as wave attenuation increases. Examination of wave propagation in the subsurface employing an attenuation filter based on a linear system model shows that received GPR signals will be shifted to lower frequencies than those originally transmitted. The amount of the shift is controlled by a wave attenuation factor, which is determined by the dielectric constant, electric conductivity, and magnetic susceptibility of the transmitted medium. This work introduces a receiver-transmitter-receiver dual-frequency configuration for GPR that employs two operational frequencies for a given test - one higher and one slightly lower - to take advantage of this phenomenon to improve subpavement drain detection results. In this configuration, the original signal is transmitted from the higher frequency transmitter. After traveling through underground materials, the signal is received by two receivers with different frequencies. One of the receivers has the same higher center frequency as the transmitter, and the other receiver has a lower center frequency. This configuration can be expressed as Rx(low-frequency)-Tx(high-frequency)-Rx(high-frequency) and was applied in both laboratory experiments and field tests. Results are analyzed in the frequency domain to evaluate and compare the properties of the signal obtained by both receivers. The laboratory experiment used the configuration of Rx(400MHz)-Tx(900MHz)-Rx(900MHz). The field tests, in addition to the configuration used in the lab tests, employed another configuration of Rx(270MHz)-Tx(400MHz)-Rx(400MHz) to obtain more information about this phenomenon. Both lab and field test results illustrate the frequency-shift phenomenon described by theoretical calculations. Based on the power spectrum for each signal, the lower frequency antenna typically received more energy (higher density values) at its peak frequency than the higher frequency antenna.</div>

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