Miracle-dz/UniFAR-FTUs huggingface dataset:
Cell biology of cheating: Mechanisms of chromosome segregation during female meiosis

Karyotype, chromosome number and composition, is a basic characteristic of species and its changes are frequently associated with speciation. Karyotype conversion, from mostly telocentric (centromere terminal) to mostly metacentric (centromere internal), typically reflects fixation of Robertsonian (Rb) fusions, a common chromosomal rearrangement that joins two telocentric chromosomes at their centromeres to create one metacentric. Fixation of Rb fusions can be explained by meiotic drive: biased chromosome segregation during female meiosis. However, there is no mechanistic explanation of why fusions preferentially segregate to the egg in some populations, leading to fixation and karyotype change, while other populations preferentially eliminate the fusions and maintain a telocentric karyotype. Using laboratory models and wild mice, we show that differences in centromere strength predict the direction of drive. Stronger centromeres, with higher kinetochore protein levels and altered interactions with spindle microtubules, are preferentially retained in the egg. Rb fusions preferentially segregate to the polar body in laboratory mouse strains when the fusion centromeres are weaker than those of telocentrics. Conversely, fusion centromeres are stronger relative to telocentrics in natural house mouse populations that have changed karyotype by accumulating metacentric fusions. Preferential chromosome segregation is predicted to depend on spindle asymmetry. We show that meiosis I (MI) spindles are asymmetric, with more stable microtubules (MTs) oriented towards the cortex. Based on our observations we propose a model in which a signal from the cortex induces MT asymmetry. We exploit Rb fusions to study mechanisms of meiotic chromosome segregation when erroneous kinetochore-MT attachments are recognized and destabilized. Improper attachments typically lack tension between kinetochores and are positioned off-center on the spindle. Low tension is a widely accepted mechanism for recognizing errors, but whether chromosome position regulates MT attachments is unknown. We show that proximity to spindle poles destabilizes kinetochore-MTs, and that stable attachments are restored by inhibiting Aurora A kinase at spindle poles. During the correction of attachment errors, kinetochore MTs detach near spindle poles to allow formation of correct attachments. We propose that chromosome position on the spindle provides spatial cues for the fidelity of meiotic cell division. Degree Type Dissertation Degree Name Doctor of Philosophy (PhD) Graduate Group Biology First Advisor Michael A. Lampson This dissertation is available at ScholarlyCommons: http://repository.upenn. edu/edissertations/1654
RESÍDUOS DE ANTIBIÓTICO EM AMOSTRAS DE LEITE PASTEURIZADO TIPO C COMERCIALIZADO NA REGIÃO CARIRIENSE

EnglishThe presence of antibiotics in milk is a risk factor for the consumer, may cause allergy, bacterial resistance and even anaphylactic shock in susceptible individuals. In order to investigate the antibiotic residues in milk, it was a study in 30 samples of pasteurized milk in the period from February to July 2010. The tests were conducted at the Laboratory of the Faculty of Technology Bromatology-Fatec - Cariri. The method was based on the specific culture medium with spores of Geobacillus stearothermophilus and an acid-base indicator. Although the waste has been found in only 13.33% of the samples, the results indicate that despite the low occurrence, the presence of these residues shows that the health standard procedures recommended by the Federal Inspection Service were not followed. portuguesA presenca de antibioticos no leite e um fator de risco para o consumidor, podendo causar alergia, resistencia bacteriana e ate mesmo choques anafilaticos em individuos suscetiveis. Com o objetivo de investigar os residuos de antibioticos no leite, fez-se um estudo em 30 amostras de leite pasteurizado, no periodo de fevereiro a julho 2010. Os ensaios foram realizados no Laboratorio de Bromatologia da Faculdade de Tecnologia-Fatec – Cariri. O metodo foi baseado na meio de cultivo especifico com esporos de Geobacillus stearothermophilus e um indicador acida-base. Embora os residuos tenham sido somente encontrados em 13,33% das amostras, os resultados indicam que, apesar da baixa ocorrencia, a presenca desses residuos comprova que os procedimentos sanitarios padronizados, recomendados pelo Servico de Inspecao Federal, nao foram seguidos.
Biogeochemistry of nitrogen and phosphorus in Australian catchments, rivers and estuaries: effects of land use and flow regulation and comparisons with global patterns

This paper reviews the factors influencing the nitrogen (N) and phosphorus (P) exports from Australian catchments. Pristine, forested catchments export little N and P and the predominant form of N is dissolved organic nitrogen (DON). As catchments are cleared, exports increase and the predominant form of N changes from DON to dissolved inorganic N (DIN). Soluble reactive P (SRP) represents a roughly constant fraction of total P in these systems. As catchments are cleared, DIN:SRP export ratios increase sharply and DIN comes to represent a larger and larger fraction of the total N. The ratios of total N:P and DIN:SRP in rivers reflect land use and the residence times of the water. In Australian lakes and reservoirs, DON and total Kjeldahl N (TKN)are consumed and DIN is exported downstream. Australian freshwater systems with long residence times show stoichiometric evidence of N limitation, and the frequent occurrence of N-fixing cyanobacterial blooms. Despite TN:TP loading ratios equalling or exceeding Redfield stoichiometry, many Australian estuaries and coastal lagoons also show extensive evidence of rapid denitrification and N limitation. Coastal lagoons also have long water residence times (up to 1 year) and a high proportion of the N load is denitrified.
Tolerance and Immunity: Opposite Outcomes of Microbial Antigen Stimulation

The immune system is remarkable in many ways. It exerts immunity to defend us from foreign pathogens, while it is also responsible for maintaining tolerance to avoid autoimmune diseases and allergy. This thesis includes three separate papers concerning both tolerance and immunity. In paper I we report that repeated antigen stimulation results in an increased proportion of Foxp3+ cells in the CD4+ population of T cells in mice. This was caused by a decreased number of antigen-reactive conventional CD4+ T cells rather than by de novo development of Foxp3+ Tregs. Proliferation of naive transferred CD4+ T cells was inhibited in repeatedly immunized mice and cells transferred from such mice into naive recipients were shown to be anergic. Finally, we demonstrate that the in vitro anergy is partially dependent on Foxp3+ cells whereas the in vivo anergy is not. In paper II, bone marrow-derived dendritic cells from IFN-β-/- mice were used to study the role of IFN-β in TLR2-mediated induction of iNOS. We demonstrate that the TLR2 ligands LTA and Pam3Cys induce the expression of iNOS in an IFN-β dependent manner. Furthermore, iNOS activity induced by these ligands did not require receptor internalization or endosomal maturation, and was differentially dependent on the TRIF- and IRF3 molecules. In paper III we have investigated the impact of in vivo 5757-treatment on cells in lymph nodes and spleen of steady state mice. We show that the cell number of a specific DC-subset, CD4+CD8α-, is selectively reduced in the spleen of 5757-treated mice. The reduction was reversible and was not caused by decreased cell division or increased apoptosis. Finally, the overall structure of the marginal zone, where CD4+CD8α- DCs normally reside, remained intact in mice treated with 5757, ruling out the hypothesis that these DCs would emigrate from the spleen because of a disrupted marginal zone. (Less)
Distribution of viruses in the garlic germplasm collection of the czech republic

The Czech collection of garlic genetic resources (648 accessions) was surveyed by DAS-ELISA for the presence of four different viruses, namely Onion yellow dwarf virus, Leek yellow stripe virus, Garlic common latent virus, and Shallot latent virus. All viruses were widespread in the collection with an incidence ranging from 65 to 83% for genotypes and 39 to 61% for plants. Most of the genotypes tested were infected with two to four viruses.
Array-comparative genomic hybridization study in diffuse large B-cell lymphoma

Diffuse large B-cell lymphoma (DLBCL) is the most common type of non-Hodgkin's lymphoma. DLBCL is a heterogeneous disease and to better characterize the molecular mechanisms and to identify new candidate cancer genes, we performed the genome-wide DNA profiles of 166 DLBCL samples uniformly treated with R-CHOP. We evaluated the impact of recurrent aberrations on the clinical outcome of DLBCL patients and we then performed unsupervised clustering to identify biological subgroups according to the genetic features. Indeed, genomic profiling of samples, identified genetic aberrations and clusters, associated with a distinct outcome in DLBCL patients. We also identified a new gain, occurring at 11q24.3, containing two transcription factors, ETS1 and FLI1. We then provided experimental data indicating a role of the two genes in DLBCL pathogenesis.
Possible mechanisms of light-induced chlorophyll degradation in senescing leaves of Hydrilla verticillata

Light treatment markedly accelerated the chlorophyll loss in senescing leaves of Hydrilla verticillata [(L.f.) Royle] as compared to dark treatment, whereas such acceleration could not be observed in senescing spinach (Spinacia oleracea L.) leaves. The light-induced cholorophyll loss in Hydrilla was retarded slightly by chloramphenicol and markedly by cycloheximide. Catalase (EC 1.11.1.6) activity did not change appreciably in Hydrilla leaves either in light or in darkness, while in spinach it declined markedly in the dark, and light retarded such decline. Peroxidase activity in Hydrilla showed faster increase in light than in darkness, while in spinach it increased only in light during senescence. The activity of phenol(pyrogallol)-specific peroxidase increased markedly in light, and that of ascorbate-specific peroxidase decreased slightly both in light and darkness during senescence of Hydrilla leaves. This rise in phenolspecific peroxidase activity was prevented by cycloheximide treatment. Pretreatment of Hydrilla leaves with monophenol (2,4-dichlorophenol) and o-diphenol (hydroquinone) accelerated and retarded, respectively, the light-induced cholorophyll loss. Pretreatment of Hydrilla leaves with H2O2 augmented the chlorophyll loss more markedly in light than in darkness. The endogenous level of H2O2 increased more in light than in dark during senescence of Hydrilla leaves. Treatment of Hydrilla leaves with 3-(3.4-dichlorophenyl)-l,l-dimethylurea. a photosystem II inhibitor, prevented both light-induced rise in H2O: level and chlorophyll loss, but it was without effect in the dark. Retardation of light-induced chlorophyll loss occurred during senescence of Hydrilla leaves when light was given in different photoperiods in a 24-h daily cycle for 6 days instead of as continuous irradiance. There was a negative correlation between the length of the photoperiod and the extent of cholorophyll loss.
Historia del uso reciente de tierras de las sabanas de América del Sur.Estudios de casos en sabanas del Orinoco

Las sabanas de Sudamerica con una superficie de 269×106ha extendidas en Brasil, Colombia, Venezuela, Guyana y Bolivia representan una de las mayores extensiones de tierra con potencial para la produccion agricola, constituyendose en la principal alternativa para evitar la expansion agricola hacia areas de mayor fragilidad ecologica. Hasta hace unos 40 anos estas sabanas estuvieron muy poco afectadas por la actividad antropica, dedicandose principalmente a la ganaderia extensiva. En los ultimos 40 anos las pasturas nativas de bajos requerimientos nutricionales estan siendo reemplazadas por pastos africanos principalmente de los generos Brachiaria y Andropogon. Igualmente, ha ocurrido una reforestacion extensiva para produccion de madera y papel con especies introducidas de Pinos y Eucaliptos que se adaptan muy bien a las condiciones agroclimaticas del tropico bi-estacional. La introduccion de pastos y de cultivos anuales y perennes en sabanas ha sido posible solo, bajo un esquema de fertilizacion (N, P, K y encalado). Aunque las modificaciones al paisaje introducidas por los nuevos usos de la tierra son ahora en sitios alejados de los grandes centros urbanos y relativamente poco perceptibles, si se toma en consideracion las grandes extensiones de tierras de sabanas que estan siendo afectadas y las que lo seran por formar parte de proyectos agricolas, sera inevitable una modificacion profunda de esos biomas. En este trabajo se hace una revision preliminar comparativa del proceso de colonizacion agricola en los llanos y cerrados. En la necesidad de generar indicadores ligados a los procesos biogeoquimicos afectados, se presentan tres estudios de casos para sabanas venezolanas.
Effect of diets containing raw and extrusion‐cooked rice bran on growth and efficiency of food utilization of broilers

Abstract 1. Meat strain chicks were fed on diets containing 600 g rice bran/kg for the 7 to 8 week period required to reach broiler weight. 2. Extrusion cooking of rice bran resulted, in improved chick weight gain and food efficiency for the first two weeks of feeding, but this advantage was lost by the end of the feeding period. 3. Addition of 10 g calcium/kg to the stabilised rice bran diet prevented the decline in performance after two weeks of age, and birds fed on this diet continued to gain at an increasing rate until the end of the experiment. 4. Calcium supplementation of stabilised rice bran diets produced significantly greater gains and superior food utilisation compared to stabilised rice bran diets without added calcium. 5. Calcium supplementation did not affect weight gain of chicks fed on diets containing raw rice bran. 6. Taste panel evaluation of meat from birds fed on diets containing raw rice bran, stabilised rice bran, or no rice bran indicated a significant preference in only one combi.
Description of a Species of Bemisia (Homoptera: Aleyrodidae)

Bemisia argentifolii Bellows & Perring, n. sp. , is described from material collected in California and Florida. This species has been referred to elsewhere as B. tabaci strain B or B. tabaci poinsettia strain. The species has been demonstrated to be distinct from B. tabaci (Gennadius) by crossing experiments, studies on intraspecific and interspecific mating behavior, analysis of allozymic frequencies, PCR analysis of genomic DNA, and morphological evaluation. The description of the new species is based on morphological and allozymic characters. The species is distinguished from B. tabaci in the fourth nymphal instar by the absence of a dorsal seta, the width of the thoracic tracheal folds, the width of the wax extrusions from the tracheal folds, and, in the adult, by migration distances of allozymes for three enzyme systems.
The Regulation of Hippocampal Synaptic Plasticity by Upstream and Downstream Effectors of Histone Acetylation

Long-lasting forms of hippocampal plasticity and hippocampus-dependent memory share a requirement for gene expression. Activity-induced neuronal gene expression is regulated by epigenetic mechanisms such as the post-translational modification of histone proteins. Histone acetylation plays a major role in neuronal function, but our understanding of the upstream mechanisms that regulate recruitment of the HDAC enzymes, and of the genes and proteins downstream of histone acetylation that support plasticity, are poorly understood. In my thesis research I investigated the role of the SIN3A/HDAC complex, a repressive histonemodifying complex, and of the Nr4a nuclear receptors, which are acetylation-regulated and memory-related transcription factors, in hippocampal synaptic plasticity. In Chapter 1, I discussed the mechanisms that support memory formation and the stabilization of synaptic potentiation, described the mechanisms of posttranslational histone modification, and reviewed the role of epigenetic histone modification in memory and plasticity as well as in neuronal dysfunction. In Chapter 2, we demonstrated that reducing levels of the corepressor SIN3A enhanced long-term potentiation and long-term memory, increased expression of Cdk5 and Homer1, and altered signaling through the Group I metabotropic glutamate receptors. In the Appendix, I show additional data that demonstrates increased mGluR5-mediated signaling in hippocampal neurons with loss of SIN3A. In Chapter 3, I found that disrupting the function of the Nr4a family of nuclear receptor transcription factors impaired long-lasting forms of synaptic potentiation and blocked the enhancement of plasticity by pharmacological HDAC inhibition. In Chapter 4 I found that C-DIM compounds, activators of NR4A, enhanced hippocampal potentiation in a manner sensitive to Nr4a disruption; we also found that CREB/CBP interaction regulates activity-induced Nr4a2 promoter acetylation and gene expression. These findings improve our understanding of the role of epigenetic histone modification in synaptic plasticity and memory, and indicate that the NR4A nuclear receptors are exceptional downstream targets for the enhancement of cognitive function and the amelioration of neuronal dysfunction. Degree Type Dissertation Degree Name Doctor of Philosophy (PhD) Graduate Group Neuroscience First Advisor Edwin G. Abel
Antioxidant Defences under Hyperoxygenic and Hyperosmotic Conditions in Leaves of Two Lines of Maize with Differential Sensitivity to Drought

The effects of hyperoxygenic and hyperosmotic stress on several aspects of antioxidant defences were studied in the leaves of a drought-sensitive (LG11) and a drought-to)erant (LIZA) line of maize (Zea mays L,). When leaf disks were the (100% 02 and O.5M mannitol), the activities of antioxidant enzymes, such as superoxide dismutase (SOD), catalase (Cat), ascorbate peroxidase (Asc-Px) and glutathione reductase (GSSG-Red), remained in disks of LIZA than in disks of LG11, The ratios of activities of SOD to Cat, SOD to Asc-Px and SOD to GSSG-Red were much than in those from LIZA. Damage, as indicated by, for example, the extend of lipid peroxidation, the destruction of chlorophyll and carotenoids, the decrease in levels of protein sulihydryl groups and the leakage of electrolytes from cells was apparent in leaf disks of both LIZA and LGI 1 as consequence of the applied stresses. However, the was
Fine structure of the male genital systems, spermatophores and unusual sperm cells of Saxidromidae (Acari, Actinotrichida)

The early derivative actinedid Saxidromidae, Saxidromus delamarei, Bovidromus roussouwi, and Rhinodromus lootsi perform indirect spermatophore transfer by means of a peculiar mating behaviour. The anatomy and fine structure of the male genital systems are described and are shown to exhibit the organisation considered to be fundamental in Actinotrichida: paired testes with germinal and glandular parts, paired vasa deferentia, unpaired ejaculatory duct, pro-genital chamber containing genital papillae. The genital system is located ventral of the digestive tract. The testes produce relatively few or even very few aflagellate sperm cells, which represent synspermia consisting of likely four undivided sperm cell equivalents in a common cytoplasm. Whereas S. delamarei produces a rather large stalked spermatophore containing many synspermia, both the other species produce very tiny stalked spermatophores with a spherical head representing only one synspermium. Thus, in these latter species only one synspermium is transferred to the female at a time, but the male can convey several (possibly five or more) spermatophores to the female during the mating session. A scenario is suggested which could describe the evolution of this remarkable mating system and behaviour.
Root herbivore effects on above-ground herbivore, parasitoid and hyperparasitoid performance via changes in plant quality

1. Plants and insects are part of a complex multitrophic environment, in which they closely interact. However, most of the studies have been focused mainly on bi-tritrophic above-ground subsystems, hindering our understanding of the processes that affect multitrophic interactions in a more realistic framework. 2. We studied whether root herbivory by the fly Delia radicum can influence the development of the leaf feeder Pieris brassicae, its parasitoid Cotesia glomerata and its hyperparasitoid Lysibia nana, through changes in primary and secondary plant compounds. 3. In the presence of root herbivory, the development time of the leaf herbivore and the parasitoid significantly increased, and the adult size of the parasitoid and the hyperparasitoid were significantly reduced. The effects were stronger at low root fly densities than at high densities. 4. Higher glucosinolate (sinigrin) levels were recorded in plants exposed to below-ground herbivory, suggesting that the reduced performance of the above-ground insects was via reduced plant quality. Sinigrin contents were highest in plants exposed to low root fly densities, intermediate in plants exposed to high root fly densities and lowest in plants that were not exposed to root herbivory. 5. Our results show, for the first time, that root herbivory via changes in plant quality can reduce the performance of an above-ground multitrophic level food chain. This underlines the importance of integrating a broader range of above- and below-ground organisms to facilitate a better understanding of complex multitrophic interactions and interrelationships. [KEYWORDS: above–below-ground interactions ; Cotesia glomerata ; Lysibia nana ; Pieris brassicae ; plant–insect interactions]