Longitudinal Study of Foraging Networks in the Grass-Cutting Ant Atta capiguara Gonçalves, 1944.

Colonies of leaf-cutting ants of the genus Atta need to collect large quantities of vegetal substrate in their environment to ensure their growth. They do so by building and extending over time a foraging network that consists of several underground tunnels extending above ground by physical trails. This paper presents a longitudinal study of the foraging network of two mature colonies of the grass-cutting ant Atta capiguara (Gonçalves) located in a pasture in central Brazil. Specifically, we investigated whether the extension of the foraging area of the colonies required to reach new resources occurs by building new and longer underground tunnels or by building new and longer physical trails. Each nest was surveyed at intervals of approximately 15 days during 1 year. At each survey we mapped the position of the tunnel entrances and foraging trails at which activity was observed. In addition, we assessed the excavation effort of the colonies since the last survey by the number and distance to the nest of new tunnel entrances, and the physical trail construction effort by the number and length of newly built physical trails. Our study reveals that in A. capiguara the collection of new resources around the nest required to ensure the continuous growth of the colonies is achieved mainly through the excavation of new underground tunnels, opening at greater distance from the nest, not through the building of longer aboveground physical trails.

Carcaça e componentes corporais de cordeiros lactentes em pastejo de azevém suplementados com leguminosa ou concentrado / Carcass and body components of suckling lambs grazing ryegrass and supplemented with legume or concentrate

O objetivo desta pesquisa foi avaliar o efeito da suplementação privativa, com concentrado ou leguminosa, sobre as características da carcaça e dos componentes corporais de cordeiros lactentes mantidos em pastejo de azevém. Foram utilizados 27 cordeiros lactentes, distribuídos nos tratamentos que corresponderam aos sistemas de alimentação: cordeiros lactentes mantidos em pasto de azevém, cordeiros lactentes mantidos em pasto de azevém e suplementados com concentrado em comedouro privativo (creep feeding) e cordeiros lactentes mantidos em pasto de azevém e suplementados com leguminosa no pasto privativo (creep grazing). O concentrado era composto por milho, farelo de soja e calcário calcítico, e a leguminosa utilizada foi o trevo-branco. O delineamento experimental foi o inteiramente ao acaso. Os resultados foram submetidos à análise de variância, e as médias comparadas pelo teste de Tukey a 5% de significância. O conteúdo do trato gastrintestinal juntamente com bile e urina e a proporção de esôfago foram maiores (P<0,05) nos cordeiros mantidos em pasto de azevém. As proporções de fígado e intestino grosso foram maiores (P<0,05) nos cordeiros suplementados com concentrado. Os sistemas alimentares testados produzem carcaças com características semelhantes. A suplementação, com leguminosa ou concentrado, altera os componentes corporais de cordeiros lactentes mantidos em azevém.(AU)

This research objective was to evaluate the effect of private supplementation with concentrated or legumes, on the carcass characteristics and body components from suckling lambs kept on ryegrass pasture. Twenty seven suckling lambs were used, with about 17 days of age and weighing 9,91±0,594kg, which were distributed in the treatments that corresponded to feeding systems: suckling lambs kept on ryegrass pasture, suckling lambs kept on ryegrass pasture and supplemented with concentrated in private feeder (creep feeding) and suckling lambs kept on ryegrass pasture and supplemented with legume in the private pasture (creep grazing). The concentrate supplement was composed by corn, soybean meal and limestone, and was supplied ad libitum. The supplementary pasture was white clover legume. The experimental design was completely randomized, where the results were submitted to analysis of variance and means compared by Tukey test at 5% of significance level. The gastrointestinal+bile+urine content and the proportion of esophagus were higher (P<0,05) in lambs kept on ryegrass. The liver and large intestine proportions were higher (P<0,05) in lambs supplemented with concentrate. The tested alimentary systems produce carcasses with similar characteristics. The supplementation with legume or concentrate cause changes in body components of suckling lambs grazing ryegrass.(AU)

Carcaça e componentes não carcaça de cordeiros terminados em confinamento com caroço de algodão na dieta / Carcass and non carcass components of lambs finished in feedlot with cottonseed on the diet

O objetivo deste estudo foi avaliar as características de carcaça e dos componentes não carcaça de cordeiros terminados em confinamento, com diferentes proporções de caroço de algodão na dieta. Foram utilizados 45 cordeiros, machos, não castrados, da raça Ile de France. Os tratamentos foram constituídos por níveis de inclusão de caroço de algodão na matéria seca (MS) da dieta total (0%; 10%; 20%; 30% ou 40%), sendo a dieta composta por silagem de milho (Zea mays L.), grão de milho triturado (Zea mays L.), farelo de soja (Glycine max L.), caroço de algodão (Gossypium hirsutum L.), calcário calcítico e sal mineral, em proporção de volumoso:concentrado de 40:60. Os animais foram abatidos com peso de abate preestabelecido. O peso de carcaça quente e o peso de carcaça fria, bem como o índice de quebra ao resfriamento, o índice de compacidade, a conformação e o estado de engorduramento da carcaça, não foram influenciados (P>0,05) pelo nível de inclusão de caroço de algodão na dieta. As características de rendimento de carcaça quente e rendimento de carcaça fria diminuíram linearmente (P≤0,05) à medida que se incluiu caroço de algodão na dieta. Com relação à medida de espessura de gordura de cobertura, pode-se observar que houve comportamento quadrático crescente e, em relação à variável área de olho de lombo, o comportamento observado foi o linear decrescente. Quanto às proporções dos cortes comerciais da carcaça, o peso de perna diminuiu linearmente (P≤0,05) enquanto a porcentagem de perna foi influenciada de forma quadrática (P≤0,05) pela inclusão de caroço de algodão nas dietas. O trato gastrointestinal cheio e o conteúdo do trato gastrointestinal aumentam linearmente (P≤0,05) com o incremento do nível de inclusão de caroço de algodão na dieta. Algumas das características de carcaça e dos componentes não carcaça tiveram influência negativa da elevação do teor de fibra e de lipídios da dieta à medida que se incluiu caroço de algodão na dieta total.(AU)

The objective of this study was to evaluate the carcass and non carcass components characteristics of lambs finished in feedlot with different proportions of cottonseed on the diet. Forty five lambs, non castrated males, from Ile de France race. The treatments were constituted by levels of inclusion of cottonseed on dry matter (DM) of the total diet (0%; 10%; 20%; 30% or 40%), being the diet composed by corn silage (Zea mays L.), ground corn grain (Zea mays L.), soybean meal (Glycine max L.), cottonseed (Gossypiumhirsutum L.), limestone and mineral salt in a roughage: concentrate proportion of 40:60. The animals were slaughtered with a pre- established slaughter weight. The hot and cold carcass weight, as well as the carcass chilling index, the compactness index, the conformation and the fattening state of the carcass were not influenced (P> 0.05) by the level of inclusion of cottonseed on the diet. The hot and cold carcass yield decreased linearly (P≤ 0.05) as the cottonseed was included on the diet. Regarding the subcutaneous fat thickness it is possible to observe that there was a crescent quadratic behavior and in relation to the rib eye area variable, the behavior observed was linear decrescent. Regarding the proportions of the commercial cuts of the carcass, the leg weight decreased linearly (P≤ 0.05) while the percentage of leg was quadratic influenced (P≤ 0.05) by the inclusion of cottonseed on the diets. The full gastrointestinal tract and the gastrointestinal tract content increased linearly (P≤ 0.05) with the increase on the level of inclusion of cottonseed on the diet. Some of the carcass and non carcass components characteristics had negative influence of level fiber content and dietary lipids as it included cottonseed in the total diet.(AU)

Consumo e desempenho de cordeiros e borregos alimentados com dietas de alto concentrado de milho ou sorgo / Intake and performance of lambs and hoggets fed high concentrate corn or sorghum diets

Objetivou-se avaliar os consumos de matéria seca, nutrientes e desempenho na terminação de cordeiros e borregos submetidos a dietas de alto concentrado de grão de milho ou sorgo. Foram utilizados 32 animais, sendo 16 cordeiros (dente de leite) e 16 borregos (dois dentes) da raça Corriedale. As dietas eram constituídas de feno de aveia- branca (Avena sativa), grão de milho (Zea mays) ou de sorgo (Sorghum bicolor (L.) Moench), farelo de soja (Glycine Max), calcário calcítico, bicarbonato de sódio e monensina. Os cordeiros apresentaram superioridade (P≤0,05) quanto ao CMS (% do PV e g/kg PV0,75), ao CPB (kg/dia, % do PV e g/kg PV0,75), ao CEE (% do PV), ao CFDN e ao CFDA (% do PV e g/kg PV0,75), ao CNDT (% do PV), ao ganho de peso médio diário, à conformação in vivo e à conversão alimentar. Por outro lado, o CEE, o CCHT e o CCNE (kg/dia), o peso vivo inicial, o peso vivo final e o peso vivo ao abate foram superiores (P≤0,05) na categoria dos borregos. Em relação aos grãos avaliados, verificou-se maior (P≤0,05) CEE (kg/dia, % do PV e g/kg PV0,75) e menor (P≤0,05) CFDN (% do PV) e CFDA (kg/dia, % do PV e g/kg PV0,75) para os animais alimentados com dieta de alto concentrado à base de grão de milho em relação àqueles alimentados com grão de sorgo. Os cordeiros apresentam consumos relativos superiores aos borregos, porém sua resposta zootécnica é maior. O uso de dietas de alto concentrado de sorgo ou de milho proporcionou resultados semelhantes.(AU)

This study aimed to evaluate the dry matter, nutrient intake, and performance on feedlot of lambs and hoggets submitted to corn or sorghum high concentrate diets. Thirty-two Corriedale animals, being 16 lambs (milk teeth) and 16 hoggets (two teeth) were used. The diets were composed of white oat hay (Avena sativa), corn (Zea mays) or sorghum grain (Sorghum bicolor (L.) Moench), soybean meal (Glycine Max), limestone, sodium bicarbonate, and monensin. The lambs presented a superiority (P≤0.05) regarding the DMI (% of LW and g/kg LW0.75), CPI (kg/day, % of LW and g/kg LW0.75), EEI (% of LW), NDFI and ADFI (% of LW and g/kg LW0.75), TDNI (% of LW), daily average weight gain, conformation in vivo and feed conversion. On the other hand, the EEI, TCI, and NSCI (kg/day), the initial live weight, final live weight and the live weight at slaughter were superior (P≤0.05) in the hoggets category. In relation to the evaluated grains, a higher (P≤0.05) EEI (kg/day, % of LW and g/kg LW0.75) and a lower (P≤0.05) NDFI (% of LW) and ADFI (kg/day, % of LW and g/kg LW0.75) were verified for the animals fed with high concentrate diets based on corn grain in relation to those fed with sorghum grain. The lambs presented an intake relatively superior to the hoggets, however their zootechnical response is higher. The use of high concentrate diets of sorghum or corn provides similar results.

Use of Seeds as Fungus Garden Substrate Changes the Organization of Labor Among Leaf-Cutting Ant Workers.

Seeds of different plant species constitute an alternative but also significant substrate that leaf-cutting ants use to cultivate their fungus garden. However, how they are processed inside the nest and if their use implies differential allocation of worker size classes are still poorly known. Using laboratory colonies of Acromyrmex subterraneus (Forel) as a model, the behaviors related to the processing of three different seeds (sesame, guava, and grape) as fungus substrate were listed. At the same time, we measured how each worker size class contributed to the execution of these behaviors by registering their respective frequency. It was found that medium-sized (1.2 > head width < 1.6 mm) and minimum-sized (head width <1.1 mm) workers assumed the role of incorporation for sesame and grape seeds, respectively. Major-sized workers (head width >1.7 mm) were concentrated on licking and holding guava seeds. Tegument removal was the only task observed that differs between treatment of seeds and treatment of leaves before their incorporation, as described in the literature. It was verified that different species of seeds imply a differential allocation of worker size classes and the inclusion or exclusion of some tasks from the behavioral repertoire. Regardless of the substrate type, leaf-cutting ant workers follow a coordinated and specialized procedure to cultivate the fungus garden but always maintain a high degree of cooperation.

Características da carcaça e dos componentes não carcaça de cordeiros oriundos de parto simples ou duplo / Carcass and non-carcass traits of single and twin lambs

Um experimento foi conduzido com o objetivo de avaliar as características da carcaça e dos componentes não carcaça de cordeiros nascidos de parto simples ou duplo. Dezesseis cordeiros mestiços Texel × Ile de France, machos não castrados, foram desmamados aos 56 dias de idade e abatidos com aproximadamente 28kg de peso corporal. Imediatamente após o abate, cada componente corporal foi pesado separadamente, sendo as carcaças avaliadas após 24 horas de refrigeração a 2°C. Os cordeiros oriundos de parto simples apresentaram superioridade no peso e nos rendimentos da carcaça, além de maior área de olho de lombo. Por outro lado, proporcionalmente ao peso de corpo vazio, o rúmen é maior em cordeiros nascidos de parto duplo, o que resulta incremento da proporção de conteúdo gastrintestinal ao abate. Os resultados deste estudo indicam que, quando abatidos a um mesmo peso, cordeiros oriundos de parto simples possuem carcaças de melhor qualidade, em comparação a cordeiros nascidos de parto gemelar...

An experiment was conducted to evaluate the carcass and non-carcass traits of single and twin lambs. Sixteen Texel × Ile de France crossbred, non-castrated male lambs were weaned at 56 days of age and slaughtered at 28kg of body weight. Immediately after the slaughter each body component was individually weighed, while carcasses were evaluated after a 24h period of refrigeration at 2°C. Single lambs presented higher values of carcass weight and carcass dressing percentage. Moreover, the Longissimus muscle area was also greater for single lambs. On the other hand, as a proportion of empty body weight, rumen was greater for twin lambs, increasing their gastrointestinal content at slaughter. The results of this study indicated that at a same slaughter weight single lambs have better quality carcasses in comparison with those from twin lambs...

Características produtivas de cordeiros terminados em confinamento com dietas contendo diferentes teores de borra de soja / Productive characteristics of lambs finished in feedlot fed different levels of soybean soapstock

Avaliou-se o efeito de dietas contendo diferentes teores de borra de soja sobre o consumo de nutrientes, o ganho de peso, as características de carcaça e os componentes do peso vivo de cordeiros terminados em confinamento. Foram utilizados 25 cordeiros, machos, castrados, da raça Texel, distribuídos aleatoriamente em cinco tratamentos compostos por proporções de 0%, 2,89%, 5,77%, 8,65% ou 11,55% de borra de soja na matéria seca das dietas. Houve redução linear do consumo de nutrientes, com exceção do consumo de extrato etéreo, que aumentou linearmente. O peso vivo ao abate, o ganho de peso diário, os pesos e rendimentos de carcaça quente e fria, e os pesos de perna e de costilhar diminuíram linearmente, ao passo que as proporções de rúmen e do trato gastrintestinal, com conteúdo, bem como o conteúdo gastrointestinal, aumentaram linearmente com o aumento dos níveis de borra de soja nas dietas. A proporção de perna foi influenciada de forma quadrática. O aumento da participação de borra de soja na dieta de cordeiros em sistema de confinamento leva à diminuição do desempenho produtivo dos animais. Contudo, o lucro diário obtido por animal não é influenciado, podendo-se inferir que a inclusão de borra de soja até o nível de 11,55% da matéria seca total da dieta é uma alternativa viável para a terminação de cordeiros em confinamento.

We evaluated the nutrient intake, weight gain, carcass characteristics and the non carcass components of lambs in feedlot finishing diets containing increasing levels of soybean soapstock . We used 25 male lambs , castrated Texel , randomly distributed into five treatments consisting of proporti ons of 0 %, 2 . 89 %, 5. 77 %, 8 . 6 5 % or 11 .55 % of soybean soapstock i n the dry matter this diets. Linear reduction of nutrient intake was observed , with the exception of the consumption of ether extract , which increased linearly. The live weight at slaughter , th e daily weight gain , the weights and yields from hot and cold carcass and the weights of hindquarter and rib decreased linearly , while the p roportions of rumen and gastrointestinal tract, full and gastrointestinal tract content increased in a linear way as it increased the proportion of level this soybean soapstock in the diet. The proportion of hindquarter varied in a quadratic way. The increase in soybean soapstock in the diet of lambs in confinement system leads to decrease in productive performance of a nimals. However, the daily profit obtained per animal is not affected, and we may infer that the inclusion of soybean soapstock to the level of 11.55% of the total dry matter of the diet is a viable alternative to termination of feedlot lambs.

Glicerina bruta no suplemento e seus efeitos nas características da carcaça e nos componentes do peso vivo de cordeiros lactentes / Crude glycerin in supplement and its effects on carcass characteristics and live weight components in suckling lambs

Objetivou-se avaliar o efeito da porcentagem de glicerina bruta em suplementos sobre as características da carcaça e os componentes do peso vivo de cordeiros lactentes mantidos em pasto de azevém. Foram utilizados 32 cordeiros lactentes, distribuídos nos tratamentos: 0, 10, 20 e 30% de glicerina bruta na matéria seca, em substituição ao milho, no suplemento isoproteico (18% de PB na matéria seca) fornecido diariamente em quantidade equivalente a 2% do peso corporal. As porcentagens de glicerina bruta tiveram efeito linear decrescente sobre peso de carcaça quente, peso de carcaça fria, rendimento de carcaça quente e rendimento de carcaça fria, enquanto as perdas pelo jejum aumentaram. O peso da paleta e o peso do costilhar diminuíram, enquanto a proporção de perna aumentou com o incremento de glicerina bruta no suplemento. Na composição tecidual da paleta, observou-se que a gordura subcutânea, a gordura intermuscular e a gordura total da paleta decresceram linearmente segundo as porcentagens de glicerina bruta. Sobre os componentes do peso vivo, observaram-se diferenças nas proporções de pele, rúmen, omaso, intestino grosso, que aumentaram, enquanto a de gordura renal diminuiu linearmente. Conclui-se que o uso de glicerina bruta em até 30% em suplemento fornecido em comedouro privativo para cordeiros lactentes mantidos em pasto de azevém interfere nas características da carcaça e nos componentes corporais.

The objective was to evaluate the effect of crude glycerin levels in supplement on carcass characteristics and live weight components of suckling lambs maintained on ryegrass pasture. Thirty two suckling lambs were used and were distributed among the treatments: 0, 10, 20 and 30% crude glycerin, in replacement of corn, in the isoproteic supplement (18% CP) provided daily in amounts equivalent to 2% of body weight. The levels of crude glycerin had negative linear effects on hot and cold carcass weight, hot and cold carcass yield but an increasing effect was observed on gastrointestinal content and fasting losses. The shoulder and rib weights decreased, while the leg proportion increased with the elevation of crude glycerin use. In the tissue composition of the shoulder, it was observed that the subcutaneous fat, intermuscular fat and total fat decreased linearly according to the levels of crude glycerin. Regarding body weight components, differences were observed in the proportions of skin, rumen, omasum, large intestine, which increased, while the kidney fat decreases linearly. The use of crude glycerin in up to 30% in the supplement provided in creep feeding for suckling lambs kept in ryegrass pasture influences carcass characteristics and corporal components.

Potencial mirmecológico na vetoração mecânica de helmintos em gatos / Myrmecological potential in mechanic vectoring of helminthes in cats rescue center

Vector potential of ants in mechanic dissemination of helminthes in a cat rescue center was analyzed in this study. Ants walking over cat's food and feces were collected and conditioned in distilled water. Cat feces were collected too. Ants were identified and the water where they were conditioned was observed on optic microscope. It was made the simple sedimentation technique to analyze feces. The results show that ants species Pheidole and Paratrechina can be potential vectors of nematode eggs, mainly Ascaridida, Toxocaridae.

The effect of personality on measures of quality of life related to vision in glaucoma patients.

AIM: To determine the effect of personality on vision-specific health-related quality of life (HRQoL). METHODS: Based on power calculations, 148 individuals diagnosed as having glaucoma or ocular hypertension, without ocular comorbidity, were selected using criteria that included age over 30, no recent or upcoming surgery, the absence of a diagnosis of clinical depression or any other psychiatric illness. Qualifying participants completed the 25-Item National Eye Institute's Visual Function Questionnaire (VFQ), the Neuroticism, Extraversion and Openness Personality Inventory Revised (NEO PI-R) and the 15-Item Geriatric Depression Scale (GDS-15), and provided information regarding their demographic characteristics and past medical history. Each patient also underwent an ocular examination. Data analysis was conducted to determine the relationship between NEO PI-R personality profiles and VFQ scoring, while controlling for the effects of a range of demographic, psychiatric, past medical and clinical ophthalmic variables. RESULTS: Multivariate analysis indicated that after controlling for a range of covariates, three out of five NEO PI-R personality domains shared statistically significant associations with a variety of VFQ total and subscale score measurements. CONCLUSION: Normal variations in personality characteristics influence how patients report their vision-specific HRQoL.

Lack of relation between drug-seeking behavior in an addiction model and the expression of behavioral sensitization in response to ethanol challenge in mice.

Drug-induced sensitization has been associated with enhanced self-administration and may contribute to addiction. The possible association between sensitization and voluntary ethanol consumption using an addiction model was investigated. Mice (n = 60) were individually housed with ad libitum access to food and had free choice between ethanol (5% and 10%) and water in a four-phase paradigm: free choice (12 weeks), withdrawal (2 weeks), re-exposure (2 weeks), and quinine-adulteration (2 weeks). Control mice (n = 10) had access to water. Mice were characterized as addicted (n = 10, ethanol preference without reducing intake with adulterated ethanol), heavy (n = 22, ethanol preference but reduced intake with adulterated ethanol), and light (n = 21, water preference). Oral ethanol then was withdrawn, and 24 h later mice received a 2 g/kg ethanol (i.p.) challenge dose or saline, and ambulation was evaluated 10 min later. Half of the classified mice received daily 2 g/kg ethanol injections for 14 days, and ambulation was assessed 10 min after the last dose. Acute ethanol increased ambulation in all groups compared to the control group, and chronic ethanol induced sensitization, showing no difference among ethanol-treated mice. The data suggest that independent neural mechanisms are responsible for the development of addiction and sensitization.

Leaf and stem morphoanatomy of Petiveria alliacea.

Petiveria alliacea is a perennial herb native to the Amazonian region and used in traditional medicine for different purposes, such as diuretic, antispasmodic and anti-inflammatory. The morphoanatomical characterization of the leaf and stem was carried out, in order to contribute to the medicinal plant identification. The plant material was fixed, freehand sectioned and stained either with toluidine blue or astra blue and basic fuchsine. Microchemical tests were also applied. The leaf is simple, alternate and elliptic. The blade exhibits paracytic stomata on the abaxial side, non-glandular trichomes and dorsiventral mesophyll. The midrib is biconvex and the petiole is plain-convex, both traversed by collateral vascular bundles adjoined with sclerenchymatic caps. The stem, in incipient secondary growth, presents epidermis, angular collenchyma, starch sheath and collateral vascular organization. Several prisms of calcium oxalate are seen in the leaf and stem.

The water quality of the Ria de Aveiro lagoon, Portugal: from the observations to the implementation of a numerical model.

Ria de Aveiro is a very important area of the Portuguese coast, which has been under an increasing anthropogenic pressure for several decades and, contributes to the degradation of the lagoon's water quality. This work presents both a characterisation of the water quality of the Ria de Aveiro lagoon, using physical, chemical and biological experimental data, and an implementation of a numerical model for the water quality of the lagoon. The ultimate goal is to obtain an accurate numerical model able to simulate major water quality features of the lagoon under the influence of different forcing conditions. Data analysis reveals good correlations between the salinity and almost all the water quality variables as well as between the different variables. The maximum biochemical oxygen demand concentration (BOD) depends on the light intensity, the temperature and the river inputs. The main vulnerable areas of the lagoon, from the water quality point of view, seem to be the far end of the main channels, where low dissolved oxygen concentration (DO) and high BOD concentrations are observed. The numerical model of the Ria de Aveiro has reproduced both winter-spring and spring-summer events related to the lagoon water quality as well as its main pattern. Both data and modelling results show that the BOD5 concentrations (where the subscript '5' means that the BOD measurements were conducted for five days, without inhibitor of nitrification) are driven by the river influence, during the winter-spring period, and by the biological activity during the spring-summer period. The DO concentrations show high values in the spring-summer period and smaller concentrations in the winter-spring period at the far end of the lagoon. The application of the model to the study of scenarios has demonstrated the role of nutrients and light in the phytoplankton growth, the relationship between DO and phytoplankton concentrations, as well as the effect of the BOD degradation in the ammonia (NH4) regeneration.

The influence of the scout upon the decision-making process of recruited workers in three Acromyrmex species (Formicidae: Attini).

We examined how the information communicated by a scout worker influences the plant species transported by recruited workers in Acromyrmex balzani, Acromyrmex rugosus, and Acromyrmex crassispinus, three species of leaf-cutting ant that have different substrate and habitat preferences. We verified that certain plant species were more likely to be transported than others and that recruitment occurs. We found that recruited workers were more likely to transport non-preferred plant species when they were recruited to these by scout workers. The results suggest that the scout worker can communicate information about plant identity to recruited workers, but that recruited workers integrate the information communicated with their own experience during the decision-making process.

Histological analysis of urethral healing after tubularized incised plate urethroplasty.

PURPOSE: Tubularized incised plate urethroplasty has rapidly gained popularity for treating hypospadias. It is presumed that healing occurs with the postoperative migration of epithelial cells into the incised urethral plate. We describe the time course and histology of the healing urethral wound in an animal model after dorsal incision and stenting. MATERIALS AND METHODS: A procedure was developed for use in an immature porcine model. The ventral aspect of the urethra was opened and a dorsal incision was made in the urethra to the level of the corpus spongiosum. The urethra was then catheterized and closed ventrally. Animals were sacrificed at intervals of 1, 2, 3, 5, 7, 14 and 21 days. Slides were made from multiple cross sections taken from each penis, and stained with hematoxylin and eosin, and Masson trichrome before analysis. RESULTS: Migration of epithelial cells into the dorsal epithelial defect was evident on postoperative day 2 with apparent complete re-epithelialization by postoperative day 5. Regions of increased fibroblastic activity were observed in the subepithelial stroma below the incised area on postoperative day 3 and early collagen deposition was noted in these areas when stained with Masson trichrome. These areas appeared to organize and by postoperative day 21 there was little evidence of increased fibroblastic activity or excess collagen deposition. CONCLUSIONS: Urethral healing after incision and tubularization over a catheter in our model occurred through normal re-epithelialization without excess collagen deposition or scarring.

Cystoscopy at the time of ureteral reimplantation for primary vesicoureteral reflux: is it necessary? Incidence of undetected anomalies and cost.

OBJECTIVES: To evaluate the impact on the planned procedure and associated cost of cystoscopy performed immediately before the surgical repair of vesicoureteral reflux. Cystoscopy is commonly performed at the time of ureteroneocystostomy to rule out a previously unsuspected anomaly such as ureterocele or ureteral duplication. METHODS: We retrospectively reviewed the results of preoperative voiding cystourethrograms and ultrasound studies performed on 128 patients who underwent ureteral reimplantation for primary vesicoureteral reflux between 1994 and 2000. Radiographic findings were compared with observations made at cystoscopy and reimplantation to determine the rate of unsuspected ureterocele or duplication in the presence of a radiologic evaluation considered adequate by the operating surgeon and/or radiologist. We then performed an itemized analysis to determine the cost cystoscopy contributed to the procedure. RESULTS: Of the 128 patients, 1 (0.7%) was found to have a small, undiagnosed ureterocele at cystoscopy. A review of this patient's preoperative evaluation revealed that her ultrasound examination was incomplete, lacking views of the bladder. At our institution, cystoscopy increased the total direct and indirect operating room costs of this procedure by 16.2%, adding $123.77 to the original cost of $762.97. CONCLUSIONS: Routine cystoscopic examination before ureteral reimplantation in the setting of an adequate preoperative radiologic evaluation yields little diagnostic information. In this series, it did not have an impact on the surgical procedure to be performed but did add significantly to the cost. Cystoscopy before ureteral reimplantation for primary reflux should only be considered in those children with suspicious or inadequate radiologic studies.