Saliva versus serum cortisol to identify subclinical hypercortisolism in adrenal incidentalomas: simplicity versus accuracy.

PURPOSE: Subclinical hypercortisolism (SCH) leads to metabolic derangements and increased cardiovascular risk. Cortisol autonomy is defined by the overnight 1 mg dexamethasone suppression test (DST). Saliva cortisol is an easier, stress-free, and cost-effective alternative to serum cortisol. We compared 23 h and post-1 mg DST saliva with serum cortisol to identify SCH in adrenal incidentalomas (AI). METHODS: We analyzed 359 DST obtained retrospectively from 226 AI subjects (173F/53 M; 19-83 years) for saliva and serum cortisol. We used three post-DST serum cortisol cutoffs to uncover SCH: 1.8, 2.5, and 5.0 µg/dL. We determined post-DST and 23 h saliva cortisol cutoffs by ROC curve analysis and calculated their sensitivities (S) and specificities (E). RESULTS: The sensitive 1.8 µg/dL cutoff defined 137 SCH and 180 non-functioning adenomas (NFA): post-DST and 23 h saliva cortisol S/E were: 75.2%/74.4% and 59.5%/65.9%, respectively. Using the specific 5.0 µg/dL cortisol cutoff (22 SCH/295 NFA), post-DST and 23 h saliva cortisol S/E were 86.4%/83.4% and 66.7%/80.4%, respectively. Using the intermediate 2.5 µg/dL cutoff (89 SCH/228 NFA), post-DST and 23 h saliva cortisol S/E were 80.9%/68.9% and 65.5%/62.8%, respectively. CONCLUSION: Saliva cortisol showed acceptable performance only with the 5.0 µg/dL cortisol cutoff, as in overt Cushing's syndrome. Lower cutoffs (1.8 and 2.5 µg/dL) that identify larger samples of patients with poor metabolic outcomes are less accurate for screening. These results may be attributed to pre-analytical factors and inherent patient conditions. Thus, saliva cortisol cannot replace serum cortisol to identify SCH among patients with AI for screening DST.

Hexapartite Entanglement in an above-Threshold Optical Parametric Oscillator.

We demonstrate, theoretically and experimentally, the generation of hexapartite modal entanglement by the optical parametric oscillator (OPO) operating above the oscillation threshold. We show that the OPO generates a rich structure of entanglement among sets of six optical sideband modes interacting through the nonlinear crystal. The class of quantum states thus produced can be controlled by a single parameter, the power of the external laser that pumps the system. Our platform allows for the generation of massive entanglement among many optical modes with well defined but vastly different frequencies, potentially bridging nodes of a multicolor quantum network.

Beyond spectral homodyne detection: complete quantum measurement of spectral modes of light.

Spectral homodyne detection, a widely used technique for measuring quantum properties of light beams, cannot retrieve all the information needed to reconstruct the quantum state of spectral field modes. We show that full quantum state reconstruction can be achieved with the alternative measurement technique of resonator detection. We experimentally demonstrate this difference by engineering a quantum state with features that go undetected by homodyne detection but are clearly revealed by resonator detection.

Zona fasciculata 21-hydroxysteroids and precursor-to-product ratios in 21-hydroxylase deficiency: further characterization of classic and non-classic patients and heterozygote carriers.

INTRODUCTION: Although much is known about the increased levels of the 21-hydroxylase substrates 17-hydroxyprogesterone (17OHP) and 21-deoxycortisol (21DF) - the biochemical markers of all forms of 21-hydroxylase deficiency (21OHD), only limited information is available on the zona fasciculata (ZF) products distal to the enzymatic block: 11-deoxycortisol (S), 11-deoxycorticosterone (DOC), and corticosterone (B). OBJECTIVE: To investigate whether basal and post-ACTH levels of S, DOC, and B and the 21-hydroxylase precursor-to-product ratios determined by tandem mass spectrometry preceded by high-performance liquid chromatography separation (liquid chromatography-tandem mass spectrometry) could disclose distinct profiles in genotypically confirmed classic (no.=14) and non-classic (NC) (no.=18) patients, heterozygote carriers (no.=61) and wildtypes (WT) (no.=27) for 21OHD. RESULTS: Salt wasting (SW) and simple virilizing (SV) had higher basal levels of DOC with no further increase in response to ACTH. Stimulated DOC was similar in 21OHD patients and carriers but was reduced as compared to WT. ACTH-stimulated B increased gradually from SW and SV through WT. The post-ACTH 21DF/B ratio was able to detect 92% of the carriers among WT. All NC patients could be detected by post-ACTH 17OHP/DOC and 21DF/B, with no overlap with 21OHD carriers. CONCLUSION: Although 21-hydroxylase is a key enzymatic step in both 17-hydroxy and 17-deoxy pathways of ZF, the reaction is mostly affected in the latter pathway, leading to a significant impairment of B production, which may further characterize the 21OHD subtypes. Also, the precursor-to-product ratios, particularly 21DF/B, can demonstrate the distinctive outline of 21OHD subtypes, including carriers and normal subjects.

Characterization of a Chromobacterium haemolyticum population from a natural tropical lake.

AIM: To study genetic diversity of Chromobacterium haemolyticum isolates recovered from a natural tropical lake. METHODS AND RESULTS: A set of 31 isolates were recovered from a bacterial freshwater community by conventional plating methods and subjected to genetic and phenotypic characterization. The 16S ribosomal RNA (rRNA) gene phylogeny revealed that the isolates were related most closely with C. haemolyticum. In addition to the molecular data, our isolates exhibited strong ß-haemolytic activity, were nonviolacein producers and utilized i-inositol, D-mannitol and D-sorbitol in contrast with the other known chromobacteria. Evaluation of the genetic diversity in the 16S rRNA gene, tRNA intergenic spacers (tDNA) and 16S-23S internal transcribed spacers (ITS) unveiled different levels of genetic heterogeneity in the population, which were also observed with repetitive extragenic palindromic (rep)-PCR genomic fingerprinting using the BOX-AR1 primer. tDNA- and ITS-PCR analyses were partially congruent with the 16S rRNA gene phylogeny. The isolates exhibited high resistance to ß-lactamic antibiotics. CONCLUSION: The population genetic heterogeneity was revealed by 16S rRNA gene sequence, ITS and BOX-PCR analysis. SIGNIFICANCE AND IMPACT OF THE STUDY: This study provides for the first time an insight into the genetic diversity of phylogenetically close isolates to C. haemolyticum species.

Loss of biodiversity in a conservation unit of the Brazilian Atlantic Forest: the effect of introducing non-native fish species.

The introduction of species has become an important problem for biodiversity and natural ecosystem conservation. The lake system of the middle Rio Doce (MG, Brazil) comprises c. 200 lakes at various conservation states, of which 50 are located within the Rio Doce State Park (PERD). Previous studies had verified several of these lakes suffered non-native fishes introductions and the presence of these species needs for the implementation of actions aiming at not only their control but also the preservation of the native species. This study discusses the effects of non-native fish species in the largest conservation unit of Atlantic Forest in Minas Gerais, southeast of Brazil, using data from 1983 to 2010 distributed as follow: data prior to 2006 were obtained from previous studies, and data from September 2006 to July 2010 were obtained in Lake Carioca at four sampling stations using gillnets, seine nets and sieve. A total of 17 fish species was collected (2006-2010) of which five were introduced species. Among the small to medium size native species (30 to 2000 mm standard length) seven had disappeared, two are new records and one was recaptured. The non-native species Cichla kelberi (peacock bass) and Pygocentrus nattereri (red piranha) are within the most abundant captured species. Integrated with other actions, such as those preventing new introductions, a selective fishing schedule is proposed as an alternative approach to improve the conservation management actions and the local and regional biodiversity maintenance.

Use of sexed sorted semen for fixed-time artificial insemination or fixed-time embryo transfer of in vitro-produced embryos in cattle.

Artificial insemination and in vitro embryo production are powerful tools for disseminating superior genetic qualities and improving the reproductive performance of dairy and beef cattle. In conjunction with these biotechnologies, sexed-sorted semen has been used to obtain offspring of a predetermined sex. This study compared the pregnancy rates obtained using in vitro fertilization/timed embryo transfer (IVF/TET) and timed artificial insemination (TAI), both performed using sexed-sorted (Y-chromosome-bearing) semen obtained from the same bull. For the in vitro embryo production, the ovaries of 250 Nelore cows with known histories were collected in the slaughterhouse and used for IVF. After evaluation of the recipients (IVF/TET group; n = 974), the resultant embryos were transferred to the females with corpus luteum (n = 822). The pregnancy-related data for this group were compared with those for the TAI group (n = 974). Ultrasonography was performed at 60 days to determine the pregnancy status and confirm the sex of the fetus. A total of 2008 oocytes produced 1050 embryos, with 52% of them reaching the blastocyst stage. The pregnancy rate and the accuracy in determining the fetal sex were 35.4% (345/974) and 95.07% (328/345), respectively, for the IVF/TET group and 30% (293/974; P < 0.05) and 94.88% (278/293), respectively, for the TAI group. In the present study, we concluded that male calves could be better obtained using IVF/TET rather than TAI; therefore, this strategy can be considered to increase the pregnancy rate of beef cattle.

Biodiversity assessment of benthic macroinvertebrates along a reservoir cascade in the lower São Francisco river (northeastern Brazil).

In order to verify the cascade-system effect in benthic macroinvertebrate communities, and the implications for policy making and proposals for conservation and sustainable use of the lower portion of São Francisco river basin (Bahia State, Brazil), a three-reservoir cascade system including two stretches downstream were studied during dry (June, 1997) and rainy (March, 1998) periods. The dominant groups found were Mollusca (Melanoides tuberculata), Oligochaeta, and Chironomidae larvae. Low Shannon-Wiener and Pielou index values were found, but with no significant difference between the sampling periods. However, density and taxonomic richness were significantly different (t(0.05: 31)) = -2.1945; p < 0.05; e t(0.05; 31) = -3.0600; p < 0.01) between the sampling periods, with a reduction in the number of taxa and macroinvertebrate abundance during the rainy period. An increasing gradient in benthic macroinvertebrate community structures was noted along the reservoir cascade from the first reservoir (Apolônio Sales), followed by a decrease downstream from the third reservoir of the system (Xing6). Despite the negative consequences of rapid proliferation of dams, which have caused widespread loss of freshwater habitats, the reservoir cascade system promoted an increase in benthic macroinvertebrate diversity, due to water-quality improvement along the system.

Eutrophication potential of lakes: an integrated analysis of trophic state, morphometry, land occupation, and land use.

Despite being inside a protected area, Lake Sumidouro has been impacted by the anthropogenic occupation of the surrounding area since the 1970's, compromising the ecological integrity of the lake and the sustainable use of natural resources. This study examined the current trophic classification of the lake and developed methods for improving it through an integrated analysis of morphometric and limnological parameters, land use and land occupation in the watershed, and eutrophication potential. Data for the limnological parameters, land use and land occupation, and morphometric characteristics of Lake Sumidouro were collected in the rainy and dry seasons of 2009 and 2010. Depending on the trophic classification system used, Lake Sumidouro is classified as oligotrophic to hypereutrophic. In our study, the highest concentration of nutrients occurred in the rainy season, indicating that high nutrient inputs played an important role during this period. Areas of anthropogenic occupation comprised approximately 62.9% of the total area of the watershed, with pasture and urban settlement as the main types of land use. The influent total phosphorus load was estimated to be 15,824.3 kg/year. To maintain mesotrophic conditions, this load must be reduced by 29.4%. By comparing the isolated use of trophic state indices, this study demonstrated that comparing the trophic state classification with morphometric analyses, land use and land occupation types in the watershed, and potential phosphorus load provided better information to guide management actions for restoration and conservation. Furthermore, this approach also allowed for evaluating the vulnerability of the environment to the eutrophication process.

Biodiversity assessment of benthic macroinvertebrates in altitudinal lotic ecosystems of Serra do Cipó (MG, Brazil).

Five lotic systems of Serra do Cipó, south-east Brazil, were investigated in order to assess the existing diversity of benthic macroinvertebrates, habitats-microhabitats, and the available trophic resources. For each river it was analysed the communities of benthic macroinvertebrates and the composition of some taxonomic groups (Plecoptera, Ephemeroptera, Trichoptera and Diptera Chironomidae): the community with Bivalvia Sphaeriidae, Oligochaeta and Ephemeroptera Baetidae (being supposed a closed relation Bivalvia-Oligochaeta based on the process of bioturbation and enrichment of sediment in organic matter) in Tanque River; the macrofauna associated to aquatic macrophytes from rivers Peixe and Preto do Itambé reflecting the reaction of the ecosystems versus the quantities of nutrients which originate from the farmlands; the lithoreophilic communities of Cipó River; the community depending on deposits of leaves and filamentous algae in Congonhas Stream; the very rich community of the moss clumps in the Indaiá Stream. A proposal for biological zonation of Cipó River and some comments about the importance of the analysed benthic macroinvertebrates in the biological production of the aquatic communities were done.

Habitat diversity and benthic functional trophic groups at Serra do Cipó, Southeast Brazil.

The assessment of the diversity of habitats and the characterisation of the functional trophic groups of benthic macroinvertebrate communities of some rivers of Serra do Cipó (MG) were the main objectives of this study. The available trophic resources and the types of substrata were characterised along with the structure and composition of their using functional trophic groups. Serra do Cipó is a watershed divisor of the São Francisco and Doce River basins, including a series of streams and rivers, of good water quality and well preserved ecological characteristics. Samples were collected in Cipó, Peixe and Preto do Itambé rivers, besides the Indaiá and Capão da Mata streams at 26 sampling stations, during the rainy (February) and dry (October) seasons of 1998, using "Kicking nets" of 0.125 mm mesh size. The group of collectors (Baetidae, Leptophlebiidae and Leptohyphidae) was the most abundant, followed by collector-predators (Hydrophilidae, Ceratopogonidae, Chironomidae-Tanypodinae), and detritivorous-herbivores (Oligochaeta). The riparian vegetation, together with the aquatic macrophytes, are the substrata containing the highest richness of functional trophic groups and the higher habitat diversity. The results suggest that the use of functional trophic groups, together with habitat evaluation, are efficient tools in the evaluation of the diversity of benthic macroinvertebrates, particularly in altitudinal lotic ecosystems.

The influence of Eucalyptus plantations on the macrofauna associated with Salvinia auriculata in southeast Brazil.

The influence of Eucalyptus plantations on the structure and composition of macroinvertebrate communities associated with the aquatic fern Salvinia auriculata Aublet were investigated in a high altitude lake bordered by either secondary Atlantic forest or Eucalyptus plantations. Comparisons of the diversity of Chironomidae (Diptera, Insecta) larvae in the littoral zone between these two vegetation types showed higher diversity of larvae in waters bordered by Eucalyptus. The results demonstrated that the predominance of carnivorous taxa among the macroinvertebrate fauna appears to be the major controlling factor for limiting diversity in lake areas bordered by Eucalyptus.

On the natural diet of Daphnia laevis in the eutrophic Pampulha reservoir (Belo Horizonte, Minas Gerais).

The aim of this study was to assess the major food items ingested by adult specimens of Daphnia laevis within the eutrophic Pampulha reservoir in Belo Horizonte, Minas Gerais, Brazil. The gut content was analyzed after addition of sodium hypochlorite and also through the examination of dissected guts under scanning electron microscopy. The results showed that Chlorophyceae was the main food item ingested, representing c. 80.5% of the total ingested food. Moreover, Eutetramorus fottii, Coelastrum pseudomicroporum and Oocystis lacustris, the dominant phytoplankton species within the reservoir, were the most frequent cells found in the gut contents. Euglenophyta also represented an important food item accounting for 15% of the ingested material, including mainly Trachelomonas volvocina and Euglena oxyuris, although less abundant in the reservoir (< 10% of total phytoplankton). Blue-green algae occurred at much lower percentages in the guts than in the phytoplankton. A small amount of undigested Microcystis aeruginosa colonies were also found in the gut content of D. laevis. Scanning electron microscopy results showed that, besides phytoplankton cells, a great amount of abiogenic material was also ingested. The amount of this inorganic material increased considerably in the tract (from 15% to 75% of the gut content), when a peak of D. laevis was observed in the reservoir. Our assumption is that the ingestion of this inorganic material can be a strategy used by D. laevis to obtain additional food supply.

Diurnal sampling reveals significant variation in CO2 emission from a tropical productive lake.

It is well accepted in the literature that lakes are generally net heterotrophic and supersaturated with CO2 because they receive allochthonous carbon inputs. However, autotrophy and CO2 undersaturation may happen for at least part of the time, especially in productive lakes. Since diurnal scale is particularly important to tropical lakes dynamics, we evaluated diurnal changes in pCO2 and CO2 flux across the air-water interface in a tropical productive lake in southeastern Brazil (Lake Carioca) over two consecutive days. Both pCO2 and CO2 flux were significantly different between day (9:00 to 17:00) and night (21:00 to 5:00) confirming the importance of this scale for CO2 dynamics in tropical lakes. Net heterotrophy and CO2 outgassing from the lake were registered only at night, while significant CO2 emission did not happen during the day. Dissolved oxygen concentration and temperature trends over the diurnal cycle indicated the dependence of CO2 dynamics on lake metabolism (respiration and photosynthesis). This study indicates the importance of considering the diurnal scale when examining CO2 emissions from tropical lakes.

Morphological variation in Staurastrum rotula (Zygnemaphyceae, Desmidiales) in the deepest natural Brazilian lake: essence or accident?

For many decades, polymorphism and its consequences have only been studied from the taxonomic point of view. Presently, interest has switched to the environmental causes of morphological variation and its consequences in the form and essence of the species. This study aimed at evaluating desmids morphological modifications of Staurastrum rotula Nordstedt during inter-annual succession patterns in two warm monomitic tropical lakes: Dom Helvécio (19°45'- 19°48'45″S, 42°33'45″W) and Carioca (19°45'20″S, 42°37'12″W). The effect of thermal stability and light and nutrients availability was based on samples collected monthly from January 2002 to December 2006 compared the morphological modifications. Results indicated that morphological variation, asexual reproduction, theratological forms, mucilaginous envelope and fungal infection were highest in Lake Dom Helvécio and coincided with the biomass increase of species with complex morphology between September and March (stratification period). The Zmix oscillation, wind and rainfall occurring at the end of the mixing period and beginning of the stratification were suggested as autochthonous and allochthonous disturbance agents, respectively, identified as inducers of asexual reproduction and consequently of the morphological variation. It was suggested that incidence of parasitism may act as a potential controlling agent for the Staurastrum rotula population size. It was concluded that morphological variation represents accidents in the original form, i.e. in the desmid species essence, promoting the existence of ecoforms, not of new infraspecific taxa.

Toxic concentrations of metronidazole to Microcystis protocystis.

Antimicrobials are among the most commonly used drugs and have become a class of contaminants with great environmental importance. Metronidazole is an antimicrobial used for the therapeutic management of several human diseases. The toxicity of antimicrobials on aquatic species may affect sensitive microorganisms and reduce metabolic processes. Cyanobacteria is a group of organisms that are of great ecological importance in aquatic environments. Studies indicate that cyanobacteria are very sensitive to some antimicrobials. Therefore, it is necessary to evaluate the effects of metronidazole contamination on phytoplankton. The aim of this study was to investigate the effects of metronidazole on the growth of the cyanobacterium Microcystis protocystis and to evaluate the stability of this antimicrobial agent in the culture medium over a period of 96 hours. M. protocystis was resistant to growth inhibition by metronidazole. The EC50 of this antimicrobial for M. protocystis was 117.3 mg L(-1). Under the growth inhibition test conditions, neither a significant change in the MNZ concentration nor the presence of drug metabolites or degradation products was observed. These results indicate low cellular uptake of the antimicrobial agent and its persistence in the culture medium.

Virginiamycin and sodium monensin supplementation for beef cattle on pasture / Suplementação com virginiamicina e monensina sódica para bovinos de corte a pasto

The aim of this paper was to evaluate the effects of including virginiamycin (VM), sodium monensin (MON) or the association (VM+MON) in the energetic mineral supplement, on the intake and performance of beef cattle on pasture. Forty Nellore heifers with 24 months of age and initial body weight (BW) of 251.5±16.6kg, were distributed in four treatments in a randomized block design. Treatments consisted of adding VM, MON or VM+MON to the supplement (CONT). Additive concentrations were defined to reach a dose of 40 to 45mg/100kg BW. The herbage allowance was not a limiting factor for the animals' intake. Supplement intake was lower than expected, with 33.0, 18.8 and 26.3mg per 100kg BW for VM, MON and VM+MON, respectively. Dry matter intake (DMI, mean=2.65% BW) and animal performance were not affected by the inclusion of additives. The average daily gain (ADG) was 0.561kg/animal day-1. The inclusion of additives in energetic mineral supplement does not affect the DMI and the ADG of grazing animals. The variability in supplement intake and daily dose intake of additives may have influenced the performance of the animals. Monensin inclusion presented the less expensive supplementation cost, due to reduction in supplement intake without changing weight gain.(AU)

Objetivou-se avaliar o efeito da inclusão dos aditivos virginiamicina (VM), monensina sódica (MON) e associação (VM+MON) no suplemento energético-mineral sobre o consumo e desempenho de bovinos manejados em pastagem de Urochloa Brizantha cv. Marandu. Foram utilizadas 40 novilhas Nelore com 24 meses de idade e peso corporal (PC) inicial médio de 251,5+16,6kg distribuídas em delineamento em blocos ao acaso com quatro tratamentos. Os tratamentos consistiam de suplemento energético-mineral (CONT) acrescido de VM, MON ou VM+MON. A oferta de forragem não limitou o consumo dos animais. O consumo dos aditivos foi de 0; 33,0; 18,8 e 26,3mg por 100kg de PC para CONT, VM, MON e VM+MON, respectivamente. O consumo de matéria seca e o desempenho dos animais não foram afetados pela inclusão dos aditivos. O ganho médio diário dos animais foi de 0,561kg dia -1 , sem diferença entre os tratamentos. A inclusão de aditivos no suplemento energético-mineral não alterou o CMS e o desempenho dos animais em pastejo. A variabilidade no consumo de suplemento e na dose ingerida dos aditivos pode ter influenciado o desempenho dos animais.(AU)

Taxa de fertilidade de novilhas de diferentes grupos genéticos com primeiro serviço aos 14 meses de idade / Fertility rate of heifers of different genetic groups with 1st service at 14 months of age

Foram avaliadas as taxas de reconcepção de 98 novilhas primíparas (34 Guzerá - G, 32, 1/2 Guzerá x 1/2 Nelore - GN e 32,1/2 Red Angus x 1/2 Nelore - AN) com 14 meses de idade e peso médio de aproximadamente 249,65kg, criadas em pastos de Brachiaria brizantha cv Marandu. Na segunda estação de monta (EM), foram utilizadas apenas as 36 primíparas gestantes na primeira EM (três G, nove GN e 24 AN), com média de idade de 26 meses e peso corporal de 313,67±25,01kg, 336,50±45,84kg e 399,86±44,45kg, respectivamente, para as fêmeas dos grupos G, GN e AN. O grupo AN apresentou ganho médio diário (GMD) de 0,30±0,06 (kg/dia) e maiores taxas (58,33) de reconcepção (P<0,05), comprovando que a heterose resultante do cruzamento entre raças distintas com maior distância genética (Bos taurus taurus x Bos taurus indicus) proporciona maior desempenho produtivo e reprodutivo.

A total of 98 heifers of three genetic groups: 34 Guzerá (G), 32, 1/2 Guzerá x 1/2 Nelore (GN) and 32 1/2 Red Angus x 1/2 Nelore (AN), 14 month old and average body weight of 249,65kg, raised in Brachiaria brizantha cv Marandu were used to evaluate reconception rates. In the second breeding season (BS), only those 36 pregnant in the first BS (three G, nine GN and 24 AN), age 26 months and body weight of 313.67±25.01kg, 336.50±45.84kg and 399.86±44.45kg, respectively, G , GN and AN were evaluated. The highest reconception rate (58.33%, P<0.05) was registered for the AN group and showed that average daily gain of 0.30±0.06kg, showing that crosses between Bos taurus taurus x Bos taurus indicus leads to higher reproductive and productive performances.

Loss of biodiversity in a conservation unit of the Brazilian Atlantic Forest: the effect of introducing non-native fish species / Perda de biodiversidade em uma unidade de conservação da Mata Atlântica brasileira: efeitos da introdução de espécies não nativas de peixes

Abstract The introduction of species has become an important problem for biodiversity and natural ecosystem conservation. The lake system of the middle Rio Doce (MG, Brazil) comprises c. 200 lakes at various conservation states, of which 50 are located within the Rio Doce State Park (PERD). Previous studies had verified several of these lakes suffered non-native fishes introductions and the presence of these species needs for the implementation of actions aiming at not only their control but also the preservation of the native species. This study discusses the effects of non-native fish species in the largest conservation unit of Atlantic Forest in Minas Gerais, southeast of Brazil, using data from 1983 to 2010 distributed as follow: data prior to 2006 were obtained from previous studies, and data from September 2006 to July 2010 were obtained in Lake Carioca at four sampling stations using gillnets, seine nets and sieve. A total of 17 fish species was collected (2006-2010) of which five were introduced species. Among the small to medium size native species (30 to 2000 mm standard length) seven had disappeared, two are new records and one was recaptured. The non-native species Cichla kelberi (peacock bass) and Pygocentrus nattereri (red piranha) are within the most abundant captured species. Integrated with other actions, such as those preventing new introductions, a selective fishing schedule is proposed as an alternative approach to improve the conservation management actions and the local and regional biodiversity maintenance.

Resumo A introdução de espécies tornou-se um importante problema para a conservação da biodiversidade e dos ecossistemas naturais. O sistema de lagos do médio Rio Doce (MG, Brasil) compreende cerca de 200 lagos em vários estados de conservação, dos quais 50 estão localizados dentro do Parque Estadual do Rio Doce (PERD). Estudos anteriores demonstraram que vários desses lagos sofreram introduções de peixes não nativos. Este estudo discute os efeitos das espécies de peixes não nativos na maior unidade de conservação da Mata Atlântica em Minas Gerais, sudeste do Brasil, utilizando dados de 1983 até 2010, distribuídos da seguinte forma: dados de 1983 a 2005 obtidos de estudos realizados anteriormente, e dados de setembro de 2006 a julho de 2010 obtidos no lago Carioca, utilizando redes de emalhar, redes de arrasto e peneira. Um total de 17 espécies de peixes foi coletado (2006-2010), sendo cinco introduzidas. Dentre estas, Cichla kelberi (tucunaré) e Pygocentrus nattereri (piranha vermelha) estiveram dentre as mais abundantes. Entre as espécies nativas de pequeno a médio porte (30-2000 mm de comprimento padrão), duas foram novos registros e uma foi recapturada. O desaparecimento de sete destas espécies, registradas em estudos anteriores, e a baixa representatividade nas amostragens da maioria das espécies remanescentes, evidencia o alto impacto da invasão de peixes na comunidade estudada. Considerando a importância de ações de manejo de espécies não nativas visando à conservação e manutenção da biodiversidade local e regional, propõem-se a realização de pescas seletivas intensivas, juntamente com ações que previnam novas introduções, incluindo ações educativas junto às comunidades locais.

Ganho compensatório no desempenho e eficiência econômica de novilhos Nelore submetidos a diferentes regimes alimentares / Compensatory gain in performance and economic efficiency of Nellore steers under different feeding regimes

Avaliaram-se o efeito do ganho compensatório no desempenho produtivo e a eficiência econômica de novilhos submetidos a diferentes estratégias de suplementação alimentar na fase de recria e engorda. Cinquenta e quatro bezerros, com peso médio inicial de 169,6±16,7kg, foram divididos em oito tratamentos, sendo cada tratamento uma estratégia de suplementação alimentar. No período da seca, os animais receberam suplemento proteico-energético-mineral (SP), com ingestão média diária de 0,1 ou 0,2% do peso vivo. No período das águas, os novilhos receberam SP com ingestão média diária de 0,5% do peso vivo ou suplementação mineral (SM). No período de terminação, os animais receberam SP com ingestão média diária de 1,4% do peso vivo ou foram confinados. Os animais que receberam SM não tiveram ganho compensatório. Animais que receberam SP nas águas (0,51±0,07kg/dia) tiveram ganho compensatório em relação ao período anterior e obtiveram ganho adicional diário de 123g quando comparados com SM (0,39±0,07kg/dia), entretanto não obtiveram ganho compensatório na fase de terminação. O efeito do ganho compensatório é muito pequeno ou até mesmo nulo no sistema de recria e engorda precoce com terminação em confinamento. A suplementação com menor ingestão de proteína, energia e mineral durante a primeira seca e águas, pós-desmame, da vida de novilhos pode ser compensada com o uso do confinamento na fase de terminação desses animais com resultados econômicos positivos.

The effect of compensatory growth on performance and economical efficiency of steers on different dietary supplementation strategies in the rearing and fattening stages was evaluated. Fifty-four calves with average initial weight of 169.6±16.7kg were divided into eight treatments, each of them being a strategy of food supplementation. During the dry season the animals received protein - energy - mineral supplement (SP) with an average daily intake of 0.1 or 0.2 % of body weight (BW). During the rainy season the animals received SP with an average daily intake of 0.5 % of body weight or mineral supplementation (SM). In the fattening period, the animals received SP with an average daily intake of 1.4 % of body weight or were placed in feedlot. Animals that received SM had no compensatory gain. Animals that received SP during the rainy season (0,51±0,07kg/day) had compensatory growth when compared to the previous period, and obtained additional daily gain of 123g when compared to SM group (0,39±0,07kg/day), however did not obtain compensatory gain during the fattening phase. The effect of compensatory gain becomes minimal or zero in feedlot finished. Supplementation strategies with protein, energy and mineral intake in the first dried and the first water in steer's life can be compensated with the use of these animals in the feedlot finishing phase with positive economic results.