[pt] Os solos moles geram preocupações nos projetos de engenharia devido à sua alta compressibilidade e baixa resistência. Estes tipos de solos têm sido alvo de pesquisas, especialmente no litoral brasileiro, necessitando de contínuas investigações para sua melhor compreensão. Neste contexto, o presente trabalho apresenta a caracterização de um depósito de argila mole em Guaratiba, zona oeste do município do Rio de Janeiro. As amostras foram coletadas de uma área onde seria realizada a Missa da Jornada Mundial da Juventude – JMJ de 2013, denominada Campus Fidei. Para caracterização do depósito foram realizados ensaios de campo e laboratório, a saber, SPT, CPTu, Vane Test, adensamento edométrico convencional e ensaios triaxiais drenados e não drenados, além dos ensaios de caracterização físico-química, imprescindíveis para solos moles. Os resultados obtidos possibilitaram a obtenção de propriedades consideradas fundamentais para entendimento do comportamento desses solos, tais como, resistência ao cisalhamento não drenada, razão de sobreadensamento dos depósitos e coeficientes de adensamento. Os parâmetros geotécnicos obtidos mostraram-se concordantes com os valores encontrados na literatura no que tange aos solos moles da região. / [en] Soft ground generates concerns in engineering projects due to its high compressibility and low strength. These types of soils have been the subject of research in soil mechanics, especially on the Brazilian coast, requiring continuous investigations for better understand its behavior. In this context, this work presents the characterization of a soft clay deposit in Guaratiba, west of Rio de Janeiro city. Samples were collected from an area where it would celebrate the Mass of World Youth Day – WYD, called Campus Fidei. The characterization involved field and laboratory tests: SPT, CPTu, Vane test, conventional density and drained and undrained triaxial tests, in addition to the physical-chemical characterization. The results enabled the determination of some properties considered fundamentals to understanding the behavior of these soils, such as undrained shear strength, over consolidation ratio of deposits and consolidation coefficients. The found geotechnical parameters are consistent with the literature values with respect to the soft soils of the region.

Mole Crickets (Scapteriscus spp.) are the most destructive pests in southern turf and pasture grasses. In response to extensive losses from mole crickets, Florida formed a task force to identify natural enemies in the native range of these pests. Two parasitic insects, Larra bicolor and Ormia depleta, and Steinernema scapterisci, an entomopathogenic nematode, were imported and released. Of the two insects, only Larra bicolor has spread to other states infested with mole crickets in the southeast. The present study documents the seasonal biology of Larra bicolor in the northern Gulf region, ornamental plants that can be used as nectar sources, and the impact of these nectar sources on longevity of the wasp and parasitism of mole crickets. Results of field and laboratory experiments showed that the ornamental Pentas lanceolata attracted wasps in the field and provided comparable or better longevity than Spermacoce verticillata which was the only known nectar source.

No description available.

No description available.

Being the longest-lived rodent, naked mole-rats (NMR; Heterocephalus glaber) are an exceptional model for biogerontological research. However, unlike other rodents, not much is known about their wound healing process. To investigate that, full-thickness wounds were created in the back skin of naked mole rats. Our initial data confirmed that wound closure in NMR skin was achieved primarily by reepithelialization and granulation tissue formation, with only ~26% wound contraction, making them an excellent model to study human cutaneous wound healing. Similar to mice and human skin, changes in wound epithelial tongue included progressive enlargement of wound epithelium, increased proliferation and changes in the expression pattern of epidermal markers including K14, K17, integrin α6 and E-cadherin. Further analysis revealed characteristics of reduced scarring in NMR wounds including low collagen I to III ratio, increased HA expression (HMW) and increased fibronectin expression. Transcriptional profiling of TGFβ isoforms and different pro/anti-inflammatory cytokines revealed a balance in the expression and repression of different cytokines, potentially contributing into reduced scarring. Comparison of RNA-seq data from NMR and human fullthickness wounds revealed a delay in the activation of important biological processes and pathways in NMR skin in response to injury. Further analysis based on cultured human and NMR cells revealed differential regulation of TGFβ signalling pathway between both species. 3-D collagen gel contraction assay revealed that NMR fibroblast showed noticeable contraction but independently of TGFβ treatment, while human fibroblast showed marked increased in gel contraction in the presence of TGFβ. In conclusion, NMR can serve as a very useful model to study human cutaneous wound healing. The reduced scarring in NMR could be a result of multiple factors including HMW-HA, balanced cytokine expression and differential regulation of different TGFβ cytokines as observed in the in vitro studies. / The full text will be available at the end of the embargo: 3rd May 2024

No / Recurrent fires have a considerable potential to influence the structure and composition of savanna vegetation. In Mole National Park in Ghana, the policy is to burn the vegetation annually early in the dry season. This study aimed to assess the effects of these perennial fires on the trees and shrubs of the Park. To achieve this, scars on tree bole bases as well as mortality and top-kill to trees ¿ 2 m tall resulting from perennial fires were assessed in twenty 50 m x 50 m plots in the savanna vegetation near Grupe camp at the south-western section of the Park. Fire scars on tree bole bases were widespread, but were significantly more frequent on large trees (> 5 m tall) than small ones (< 2 m tall). Also, certain tree species, notably Burkea africana and Detarium microcarpum were more prone to scarring. The greater proportion of the scars had reached an advanced stage and the affected individuals were either moribund or were likely to be killed by subsequent fires or toppled by the wind. Contrary to the popular opinion that fire generally affects tree recruitment and not adult survival, fire-induced mortality and top-kill to large trees (> 5 m tall) was widespread among all the tree species, particularly Acacia dudgeoni, Burkea africana, Detarium microcarpum and Vitellaria paradoxa. These fire impacts will likely lead to changes in the relative abundance of the constituent tree species as well as a decline in the density of woody elements in the plant community as a whole unless burning frequency is reduced. The areas for which these predicted vegetation changes are valid can be generalized to include the vegetation in the northern half of the Park where similar conditions of high fuel load and intense fires are likely to prevail.

Thesis (PhD (Botany and Zoology))--University of Stellenbosch, 2008. / The Bathyergidae are subterranean rodents endemic to Africa south of the Sahara. They are characterised by divergent diploid numbers that range from 2n=40 in Fukomys mechowi to 2n=78 in F. damarensis. In spite of this variation there is limited understanding of the events that shaped the extant karyotypes and in an attempt to address this, and to shed light on the mode and tempo of chromosomal evolution in the African mole-rats, a detailed analysis of both the autosomal and sex chromosome components of the genome was undertaken. In addition to G- and Cbanding, Heterocephalus glaber (2n=60) flow-sorted painting probes were used to conduct cross-species chromosome painting among bathyergids. This allowed the detection of a balanced sex chromosome-autosome translocation in F. mechowi that involved a complex series of rearrangements requiring fractionation of four H. glaber autosomes and the subsequent translocation of segments to sex chromosomes and to the autosomal partners. The fixation of this rare rearrangement has probably been favoured by the presence of an intercalary heterochromatic block (IHB) that was detected at the boundary with the translocated autosomal segment. Male meiosis in Cryptomys, the Fukomys sister clade, was investigated by immunostaining of the SCP1 and SCP3 proteins involved in the formation of the synaptonemal complex. This allowed confirmation of a Y-autosome translocation that is shared by C. hottentotus subspecies. We discuss reduced recombination between Y and X2 that seems to be heterochromatin dependent in the C hottentotus lineage, and the implications this holds for the evolution of a meiotic sex chromosome chain such as has been observed in platypus. By extending cross-species chromosome painting to Bathyergus janetta, F. damarensis, F. darlingi and Heliophobius argenteocinereus, homologous chromosomal regions across a total of 11 species/subspecies and an outgroup were examined using cladistic and bioinformatics approaches. The results show that Bathyergus, Georychus and Cryptomys are karyotypically highly conserved in comparison to Heterocephalus, Heliophobius and Fukomys. Fukomys in particular is characterised by a large number of rearrangements that contrast sharply with the conservative Cryptomys. The occurrence and fixation of rearrangements in these species has probably been facilitated by vicariance in combination with life history traits that are particular to these mammals.

Naked mole-rats are eusocial rodents that live in subterranean colonies with a strict reproductive and social hierarchy. Breeders are socially dominant and other colony members are non-reproductive subordinates. The effects of manipulating the serotonergic system on aggression are well studied in many species, but not in eusocial rodents like the naked mole-rat. For the current study, the effects of fluoxetine hydrochloride (FLX) on status-specific behaviours of subordinates (Experiment 1) and queens (Experiment 2) were evaluated both in-colony and in a social-pairing paradigm to investigate how the serotonergic system influences aggression in this species. In accordance with our main hypothesis, chronic treatment of FLX attenuated the frequency and duration of aggression in queens, but not subordinates, when paired with an unfamiliar conspecific. Further exploration of pharmacological manipulation on status-specific behaviours of this eusocial species may elucidate the neurobiological mechanisms underlying their unique and rigid social hierarchy.

Submitted by Ana Damasceno (ana.damasceno@unipampa.edu.br) on 2017-05-09T18:30:20Z No. of bitstreams: 2 license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) Ação de Senecio brasiliensis (spreng) Less sobre a taxa de eclosão e modulação de marcadores de toxicidade em larvas de Drosophila Melanogaster.pdf: 2537151 bytes, checksum: c5213c1eaff7c1ecdeaf706e6ced1e1a (MD5) / Made available in DSpace on 2017-05-09T18:30:20Z (GMT). No. of bitstreams: 2 license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) Ação de Senecio brasiliensis (spreng) Less sobre a taxa de eclosão e modulação de marcadores de toxicidade em larvas de Drosophila Melanogaster.pdf: 2537151 bytes, checksum: c5213c1eaff7c1ecdeaf706e6ced1e1a (MD5) Previous issue date: 2017-03-02 / O Brasil apresenta uma rica biodiversidade, sendo que muitas das espécies aqui encontradas tem servido como fonte de compostos com propriedades únicas tanto na medicina como na área biotecnológica. Muitos destes compostos são sintetizados a partir do metabolismo secundário vegetal e nas plantas atuam como atrativos ou mecanismos de defesa. Pesquisas relacionadas com os potenciais das plantas são necessárias para um melhor entendimento das propriedades biológicas que apresentam. Senecio brasiliensis (Spreng) Less., é uma espécie vegetal conhecida popularmente como “maria mole”, presente em pastagens da região Sul do país, sendo suas folhas consumidas pelos animais e capaz de causar hepatotoxicidade. Tal toxicidade se deve ao seu metabolismo secundário, responsável pela síntese de metabólitos tóxicos, principalmente os alcaloides pirrolizidínicos. A espécie é utilizada popularmente para fins medicinais, e possui demonstrada ação tóxica em insetos. Em vista de sua toxicidade e potencial biotecnológico, um estudo mais completo de sua ação se faz necessário. Neste trabalho avaliou-se o efeito biológico da exposição do extrato hidroalcoólico das folhas de Senecio brasiliensis (EHSB) no modelo experimental de Drosophila melanogaster. A análise do perfil fitoquímico do EHSB demonstrou a presença de ácidos fenólicos e flavonoides, e atividade antioxidante in vitro através dos ensaios de ABTS, DPPH, fenóis totais e FRAP. Em ensaios in vivo, EHSB não causou mortalidade de moscas na fase adulta, entretanto a taxa de eclosão foi significativamente diminuída quando as moscas desenvolveram-se em meio de cultura contendo 1 mg/mL de EHSB. Nas larvas do terceiro ínstar observaram-se diminuição da viabilidade celular, aumento da atividade das enzimas antioxidantes GST e SOD, EROs, e diminuição da CAT e aumento da razão GSH/GSSG. Houve aumento na expressão dos genes Nrf2, TrxR, CAT, Drice e Dilp6, e diminuição da fosforilação de proteínas quinases JNK1/2, ERK2 e p38MAPK e AKT, além de um aumento na clivagem de PARP, em paralelo com aumento da atividade de caspase 3/7. Também observou-se uma diminuição nos níveis de glicose, glicogênio e triglicerídeos. O aumento da expressão gênica de Nrf2, da atividade das enzimas GST e SOD e razão GSH/GSSG servem como um indicativo de um estado de estresse oxidativo ocasionado pelo EHSB e atuação da defesa antioxidante das larvas. A diminuição nos níveis de glicose, glicogênio e triglicerídeos pode indicar uma diminuição na reserva energética necessária para fases posteriores ao desenvolvimento larval, como para a eclosão em indivíduo alado, podendo isto ser ocasionado pela inibição da fosforilação de proteínas de transdução de sinal envolvidas neste processo pela diminuição do ATP. Dessa forma, nossos resultados demonstram a toxicidade do HESB e sua capacidade em induzir marcadores de estresse oxidativo e apoptose celular, prejudicando o desenvolvimento de larvas de D. melanogaster e processo de eclosão de moscas adultas. / Brazil has a high biodiversity, and many species found here are source of compounds with unique medicinal and biotechnological properties. These compounds are synthetized by plants secondary metabolism and can act as attractive or defensive to other species. Thus, studies with plant species are necessary to knowledge about their biologial properties. Senecio brasiliensis (Spreng) Less., is a native species popularly known as “maria mole” and is found in pastures of the south region of the country, its leaves serving as food to animals and are able to cause hepatotoxicity due to its secondary metabolism, responsible for the synthesis of toxic metabolites, such as pirrolizidinic alkaloids. In spite of its documented toxicity, this plant is used by Brazilian folk with medicinal purposes. In this study, we have evaluated the biological effects to hydroalcoholic extract of leaves of S. brasiliensis (HESB) exposure in Drosophila melanogaster experimental model. The fruit fly D. melanogaster is an advantageous alternative model useful for the screening of natural substances. Phytochemical constitution of HESB showed the presence of phenolic acids and flavonoids but when comparing with other species, it presented a lower in vitro antioxidant activity by ABTS, DPPH, FRAP assays. Survival and locomotor activity of adult flies was unaltered by extract. Nevertheless, we have observed a significant decreasing in eclosion rate of flies, since its embryonic period at 1 mg/mL concentration of HESB. Biochemical and molecular parameters revealed significant changes in third instar larvae of D. melanogaster exposed to 1 mg/mL of HESB such as decreased cell viability, stimulation of the activity of antioxidant enzymes SOD and GST, decreasing of CAT, and increasing in GSH/GSSG ratio. The mRNA expression of Nrf2, TrxR, CAT, Drice and Dilp6 were also significantly up-regulated. Decreasing in the phosphorylation of JNK1/2, ERK2, p38MAPK and AKT protein kinases were verified. Apoptotic cell death was inducted by extract. This fact was attested PARP cleavage, in parallel with increasing of caspases 3/7 activity. The increased expression of Nrf2, augmented activity of GST and SOD enzymes activities, and GSH/GSSG ratio in parallel with induction of ROS formation, is an indicative of a state of oxidative stress caused by the HESB and the action of the antioxidant defense of the larvae. It was also observed a decreasing in glucose, glycogen and triglycerides levels indicating a diminution in the energetic reserve required for later stages of larval development, such as for eclosion of winged individuals. Therefore, our results demonstrated of the HESB toxicity and its capacity to induce of cell stress markers and of apoptotic cell death impairing thus the development of D. melanogaster larvae and eclosion process of adult flies.

A execução de obras apoiadas em solos moles constitui um desafio para a engenharia geotécnica. Pela baixa capacidade de suporte do solo mole, tais obras estão sujeitas a sofrer colapso, geralmente por ruptura do solo de base; e recalques excessivos, que ocorrem ao longo do tempo por efeito do adensamento do solo mole. Em virtude destes problemas, quaisquer soluções que promovam o aumento da capacidade de carga do solo mole representam uma enorme contribuição ao tema. Este trabalho apresenta resultados de uma série de provas de carga realizadas em laboratório sobre uma camada de areia apoiada em solo mole. A camada de areia foi ensaiada em três condições: sem reforço, reforçada apenas por geocélulas e pela associação de geocélulas e geogrelha. Foram utilizadas geocélulas de geotêxtil com ligações costuradas e geocélulas de polietileno com ligações soldadas nas alturas de 5, 10 e 15 cm. Os resultados apontam uma melhora significativa quando do confinamento com geocélulas, tanto em termos de recalque quanto de capacidade de suporte. A utilização de geocélulas conjugadas a um reforço basal com geogrelha permitiu uma melhora do desempenho ainda mais significativa / Works resting on soft soils represent a large task to geotechnical engineers. Due to the soft soil low bearing capacity, such works might present a rotational failure or present large settlements that occurwith time due to consolidation. For these problems any technical contribution that would allow an increase fo the bearing capacity of the soft soils would represent an enormous help to geotechnical engineering. This work presents results of laboratory loading plate tests carried out on a sandy layer resting on the topo of a soft soil deposit. The sandy layer was tested in there different conditions: unreinforced, reiforced with geocells and with geocells and geogrids. Geocells made out of strips of non woven geotextile with sewed joints and made from welded joint poliethylene strips were used. The results of plate tests showed a significant improvement not only in terms of bearing capacity but also in terms of settlement reduction when geocells alonge were used. The use of geocells associated with geogrids allowed further improvements in the bearing capacity and settlement reductions