Levi-flat Minimal Hypersurfaces in Two-dimensional Complex Space Forms

The purpose of this article is to classify the real hypersurfaces in complex space forms of dimension 2 that are both Levi-flat and minimal. The main results are as follows: When the curvature of the complex space form is nonzero, there is a 1-parameter family of such hypersurfaces. Specifically, for each one-parameter subgroup of the isometry group of the complex space form, there is an essentially unique example that is invariant under this one-parameter subgroup. On the other hand, when the curvature of the space form is zero, i.e., when the space form is complex 2-space with its standard flat metric, there is an additional `exceptional' example that has no continuous symmetries but is invariant under a lattice of translations. Up to isometry and homothety, this is the unique example with no continuous symmetries.

Developmental toxicity from exposure to various forms of mercury compounds in medaka fish (Oryzias latipes) embryos.

This study examined developmental toxicity of different mercury compounds, including some used in traditional medicines. Medaka (Oryzias latipes) embryos were exposed to 0.001-10 µM concentrations of MeHg, HgCl2, α-HgS (Zhu Sha), and β-HgS (Zuotai) from stage 10 (6-7 hpf) to 10 days post fertilization (dpf). Of the forms of mercury in this study, the organic form (MeHg) proved the most toxic followed by inorganic mercury (HgCl2), both producing embryo developmental toxicity. Altered phenotypes included pericardial edema with elongated or tube heart, reduction of eye pigmentation, and failure of swim bladder inflation. Both α-HgS and β-HgS were less toxic than MeHg and HgCl2. Total RNA was extracted from survivors three days after exposure to MeHg (0.1 µM), HgCl2 (1 µM), α-HgS (10 µM), or β-HgS (10 µM) to examine toxicity-related gene expression. MeHg and HgCl2 markedly induced metallothionein (MT) and heme oxygenase-1 (Ho-1), while α-HgS and β-HgS failed to induce either gene. Chemical forms of mercury compounds proved to be a major determinant in their developmental toxicity.

Type 1 ryanodine receptor interactions

Excitation-contraction coupling is an essential part of skeletal muscle contraction. It encompasses the sensing of depolarisation of the plasma membrane coupled with the release of Ca2+ from intracellular stores. The channel responsible for this release is called the Ryanodine receptor (RyR), and forms a hub of interacting proteins which work in concert to regulate the release of Ca2+ through this channel. The aim of this work was to characterise possible novel interactions with a proline-rich region of the RyR1, to characterise a monoclonal antibody (mAb VF1c) raised against a junctional sarcoplasmic reticulum protein postulated to interact with RyR1, and to characterise the protein recognised by this antibody in models of skeletal muscle disease such as Duchenne Muscular dystrophy (DMD) and sarcopenia. These experiments were performed using cell culture, protein purification via immunoprecipitation, affinity purification, low pressure chromatography and western blotting techniques. It was found that the RyR1 complex isolated from rat skeletal muscle co-purifies with the Growth factor receptor bound protein 2 (GRB2), very possibly via an interaction between the proline rich region of RyR1 and one of the SH3 domains located on the GRB2 protein. It was also found that Pleiotrophin and Phospholipase Cγ1, suggested interactors of the proline rich region of RyR1, did not co-purify with the RyR1 complex. Characterisation of mAb VF1c determined that this monoclonal antibody interacts with junctophilin 1, and binds to this protein between the region of 369-460, as determined by western blotting of JPH1 fragments expressed in yeast. It was also found that JPH1 and JPH2 are differentially regulated in different muscles of rabbit, where the highest amount of both proteins was found in the extensor digitorum longus (EDL) muscle. JPH1 and 2 levels were also examined in three rodent models of disease: the mdx mouse (a model of DMD), chronic intermittent hypoxia (CIH)-treated rat, and aged and adult mice, a model of sarcopenia. In the EDL and soleus muscle of CIH treated rats, no difference in either JPH1 or JPH2 abundance was detected in either muscle. An examination of JPH1 and 2 expression in mdx and wild type controls diaphragm, vastus lateralis, soleus and gastrocnemius muscle found no major differences in JPH1 abundance, while JPH2 was decreased in mdx gastrocnemius compared to wild type. In a mouse model of sarcopenia, JPH1 abundance was found to be increased in aged soleus but not in aged quadriceps, while in exercised quadriceps, JPH2 abundance was decreased compared to unexercised controls. Taken together, these results have implications for the regulation of RyR1 and JPH1 and 2 in skeletal muscle in both physiological and pathological states, and provide a newly characterised antibody to expand the field of JPH1 research.

Annotated record of the detailed examination of Mn deposits from DSDP Site 160, Leg 16 (Cores 16-160-1, 16-160-2 and 16-160-3)

DSDP 160 forms part of a series of sites in the eastern equatorial Pacific on the west flank of the East Pacific Rise. Earlier legs of the Deep Sea Drilling Project, in particular Legs 5 and 9, have reported sediments rich in oxides of iron and perhaps other transition metals just above basement in the eastern Pacific. These occurrences roughly define a broad zone on the west flank of the rise. Site DSDP 160 lies on this trend and were selected by the Pacific Site Selection Panel to test the extent of such deposits.

Occurence of monothalamous foraminifera in Admiralty Bay, King George Island, West Antarctica (Table 1, 2)

During the late 2007 austral summer, 20 sediment samples were collected in Admiralty Bay (King George Island, South Shetlands, West Antarctica) from 8 down to 254 m water-depth (mwd). The samples yielded abundant assemblage of monothalamous benthic foraminifera, belonging to at least 40 morphospecies. They constituted the first such collection from Antarctic Peninsula fjords and provided a new insight into this group's diversity and distribution. Among organic-walled taxa, Psammophaga sp., Allogromia cf. crystallifera, and three morphotypes of Gloiogullmia were especially abundant. Agglutinated forms were dominated by Hippocrepinella hirudinea, Psammosphaera spp., Lagenammina spp., and various mudballs. Although, the majority of the morphotypes were known from other high?latitude locations, somewere reported for the first time. Our quantitative data (>125 µm) showed the greatest differences between monothalamous foraminifera assemblages at shallowest water depths above 50 mwd. The deepest assemblages from between 179 and 254 mwd, were most similar, suggesting uniform near-bottom conditions at ~200 mwd throughout the Admiralty Bay.

Stable isotope ratios of benthic and planktonic foraminifera from Miocene to Pliocene sediments of DSDP Hole 7-62A on the Eauripik Rise, Pacific Ocean (Table 1)

Oxygen and carbon isotope analyses show that the biserial forarniniferal genus Streptochilus, which was originally described from pelagic sediments on the Eauripik Rise and Ontong Java Plateau, lived deep in the upper water column within the oxygen minimum layer. The species of Streptochilus average from 4 to 19% of the foraminiferal assemblages in which benthic forms compose less than 1 or 2%. Specimens of Streptochilus are selectively dissolved when in contact with the bottom water mass. Their rapid evolutionary turnover of less than a few million years and their wide areal distribution in the equatorial Indo-Pacific are indicative of planktonic foraminifera. Aside from usefulness of the species of Streptochilus as stratigraphic indices, these Neogene biserial planktonic foraminifera are potential indices of paleoceanographic stratification.

(Table 1) Peak intensities and stable carbon and oxygen isotope ratios of various diagenetic carbonates of ODP Site 128-799

Abundant and various diagenetic carbonates were recovered from a 1084-m-thick, Quaternary to lower Miocene section at ODP Site 799 in the Japan Sea. Petrographic, XRD, SEM, EDS-chemical, and isotopic analyses revealed wide variations in occurrence and textural relations and complex mineralogy and chemistry. Diagenetic carbonates include calcite, calcium-rich rhodochrosite, iron- and manganese-rich magnesite, iron- and manganese-rich dolomite and ankerite, and iron- and manganeserich lansfordite (hydrous Mg-carbonate). Rhodochrosite commonly occurs as small, solid nodules and semi-indurated, thin layers in bioturbated, mottled sediments of Units I and II (late Miocene to Quaternary). Lansfordite occurs as unindurated nodules and layers in Unit II (late Miocene and Pliocene), whereas magnesite forms indurated beds a few centimeters thick in slightly bioturbated-to-faintly laminated sediments of Unit III (middle and late Miocene). Some rhodochrosite nodules have dark-colored, pyritic cores, and some pyrite-rhodochrosite nodules are overgrown by and included within magnesite beds. Dolomite and ankerite tend to form thick beds (>10 cm) in bedded to laminated sediments of Units III, IV, and V (early to late Miocene). Calcite occurs sporadically throughout the Site 799 sediments. The d18O values of carbonates and the interstitial waters, and the measured geothermal gradient indicate that almost all of the Site 799 carbonates are not in isotopic equilibrium with the ambient waters, but were precipitated in the past when the sediments were at shallower depths. Depths of precipitation obtained from the d18O of carbonates span from 310 to 510 mbsf for magnesite and from 60 to 580 mbsf for dolomite-ankerite. Rhodochrosite and calcite are estimated to have formed within sediments at depths shallower than 80 mbsf. Diagenetic history in the Site 799 sediments have been determined primarily by the environment of deposition; in particular, by the oxidation-reduction state of the bottom waters and the alkalinity level of the interstitial waters. Under the well-oxygenated bottom-water conditions in the late Miocene and Pliocene, manganese initially accumulated on the seafloor as hydrogenous oxides and subsequently was mobilized and reprecipitated as rhodochrosite within the shallow sulfate-reduction, sub-oxic zone. Precipitation of lansfordite occurred in the near-surface sediments with abundant organic carbon and an extremely high alkalinity during the latest Miocene and Pliocene. The lansfordite was transformed to magnesite upon burial in the depth interval 310 to 510 mbsf. Dolomite first precipitated at shallow depths in Mn-poor, anoxic, moderately biocalcareous sediments of early to late Miocene. With increasing temperature and depth, the dolomite recrystallized and reequilibrated with ambient waters at depths below about 400 mbsf.

Mineralogy, isotopic composition of oxygen, hydrogen and carbon, and oxygen isotopic temperature of deep-sea silica and coexisting carbonates (Table 1)

Water extracted from opal-CT ("porcellanite", "cristobalite"), granular microcrystalline quartz (chert), and pure fibrous quartz (chalcedony) in cherts from the JOIDES Deep Sea Drilling Project is 56? to 87? depleted in deuterium relative to the water in which the silica formed. This large fractionation is similar in magnitude and sign to that observed for hydroxyl in clay minerals and suggests that water extracted from these forms of silica has been derived from hydroxyl groups within the silica. Delta18O-values for opal-CT at sites 61, 64, 70B and 149 vary from 34.3? to 37.2? and show no direct correlation with depth of burial. Granular microcrystaUine quartz in these cores is 0.5 ? depleted in 18O relative to coexisting opal-CT at sediment depths of 100 m and the depletion increases to 2? for sediments buried below 384 m. These relationships suggest that opal-CT forms before significant burial while granular microcrystalline quartz forms during deeper burial at warmer temperatures. The temperature at which opal-CT forms is thus probably approximately equal to the temperature of the overlying bottom water. Isotopic temperatures deduced for opal-CT formation are preliminary and very approximate, but yield Eocene deep-water temperatures of 5-13°C, and 6°C for the upper Cretaceous sample. Pure euhedral quartz crystals lining a cavity in opal-CT at 388 m in core 8-70B-4-CC have a ~delta18O value of +29.8? and probably formed near maximum burial. The isotopic temperature is approximately 32 ° C.

Sample locations, stratigraphic information and listing of carbon and oxygen isotope data of the measured planktonic foraminifera of surface sediments in the western South Atlantic Ocean (Table 1)

We explored the potential to use the stable isotopic compositions of planktonic foraminifera as a proxy for the position of the Brazil-Malvinas Confluence (BMC) in the Argentine Basin. For this purpose, we measured the oxygen and carbon isotopic compositions of Globigerinoides ruber (pink and white varieties measured separately), Globigerinoides trilobus, Globigerina bulloides, Globorotalia inflata and Globorotalia truncatulinoides (left- and right-coiling forms measured separately) from a latitudinal transect of 56 surface sediment samples from the continental slope off Brazil, Uruguay and Argentina between 20 and 48°S. Lowest oxygen isotopes values were found in G. ruber (pink), followed by G. ruber (white) and G. trilobus reflecting the highly stratified near surface water conditions north of the BMC. Globigerina bulloides was present mainly south of the BMC and records subsurface conditions supporting earlier plankton tow studies. Globorotalia inflata and G. truncatulinoides (left and right) were both available over the whole transect and calcify in the depth level with the steepest temperature change across the BMC. Accordingly, the delta18O of these species depict a sharp gradient of 2? at the confluence with remarkably stable values north and south of the BMC. Our data show that the oxygen isotopic composition of G. inflata and G. truncatulinoides (left and right) are the most reliable indicators for the present position of the BMC and can therefore be used to define the past migration of the front if appropriate cores are available.

Dealing with dark times : the changing forms and functions of humor in Mark Twain's later writings

Otto-von-Guericke-Universität Magdeburg, Fakultät für Verfahrens- und Systemtechnik, Dissertation, 2016

A new insight about pharmaceutical dosage forms for benzathine penicillin G

In this work, a micellar system of benzathine penicillin G (BPG) in sodium deoxycholate (NaDC) was developed and evaluated physicochemically. The solubility profile of the drug in water and buffer solutions at various pH was determined, as well as its n-octanol/water partition coefficient. The Critical Micellar Concentration of NaDC and its ability to incorporate BPG were also assessed. The study was carried out at low and high ionic strength which was adjusted by the addition of sodium chloride. The results demonstrated the ability of the micellar system to incorporate BPG, as well as to increase its apparent solubility in water. The enhancement of the solubility of BPG by the presence of NaDC micelles could be analyzed quantitatively within the framework of the pseudo-phase model. Concentration analysis showed that the micellar system could attain up to 90% incorporation of BPG. The incorporated drug is expected to exhibit improved stability, since the antibiotic enclosed in the hydrophobic core of micelles is rather shielded from the aqueous external environment

The metabolic and epigenetic effects of the isocitrate dehydrogenase-1 mutation in glioma

Cancer cells have been noted to have an altered metabolic phenotype for over ninety years. In the presence of oxygen, differentiated cells predominately utilise the tricarboxylic acid (TCA) cycle and oxidative phosphorylation to efficiently produce energy and the metabolites necessary for protein and lipid synthesis. However, in hypoxia, this process is altered and cells switch to a higher rate of glycolysis and lactate production to maintain their energy and metabolic needs. In cancer cells, glycolysis is maintained at a high rate, even in the presence of oxygen; a term described as “aerobic glycolysis”. Tumour cells are rapidly dividing and have a much greater need for anabolism compared to normal differentiated cells. Rapid glucose metabolism enables faster ATP production as well as a greater redistribution of carbons to nucleotide, protein, and fatty acid synthesis, thus maximising cell growth. Recently, other metabolic changes, driven by mutations in genes related to the TCA cycle, indicate an alternative role for metabolism in cancer, the “oncometabolite”. This is where a particular metabolite builds up within the cell and contributes to the tumorigenic process. One of these genes is isocitrate dehydrogenase (IDH) IDH is an enzyme that forms part of the tricarboxylic acid (TCA) cycle and converts isocitrate to α-ketoglutarate (α-KG). It exists in three isoforms; IDH1, IDH2 and IDH3 with the former present in the cytoplasm and the latter two in the mitochondria. Point mutations have been identified in the IDH1 and IDH2 genes in glioma which result in a gain of function by converting α-KG to 2-hydroxyglutarate (2HG), an oncometabolite. 2HG acts as a competitive inhibitor of the α-KG dependent dioxygenases, a superfamily of enzymes that are involved in numerous cellular processes such as DNA and histone demethylation. It was hypothesised that the IDH1 mutation would result in other metabolic changes in the cell other than 2HG production, and could potentially identify pathways which could be targeted for therapeutic treatment. In addition, 2HG can act as a potential competitive inhibitor of α-KG dependent dioxygenases, so it was hypothesised that there would be an effect on histone methylation. This may alter gene expression and provide a mechanism for tumourogenesis and potentially identify further therapeutic targets. Metabolic analysis of clinical tumour samples identified changes associated with the IDH1 mutation, which included a reduction in α-KG and an increase in GABA, in addition to the increase in 2HG. This was replicated in several cell models, where 13C labelled metabolomics was also used to identify a possible increase in metabolic flux from glutamate to GABA, as well as from α-KG to 2HG. This may provide a mechanism whereby the cell can bypass the IDH1 mutation as GABA can be metabolised to succinate in the mitochondria by GABA transaminase via the GABA shunt. JMJ histone demethylases are a subset of the α-KG dependent dioxygenases, and are involved in removing methyl groups from histone tails. Changes in histone methylation are associated with changes in gene expression depending on the site and extent of chemical modification. To identify whether the increase in 2HG and fall in α-KG was associated with inhibition of histone demethylases a histone methylation screen was used. The IDH1 mutation was associated with an increase in methylation of H3K4, which is associated with gene activation. ChiP and RNA sequencing identified an increase in H3K4me3 at the transcription start site of the GABRB3 subunit, resulting in an increase in gene expression. The GABRB3 subunit forms part of the GABA-A receptor, a chloride channel, which on activation can reduce cell proliferation. The IDH1 mutation was associated with an increase in GABA and GABRB3 subunit of the GABA-A receptor. This raises the possibility of GABA transaminase as a potential therapeutic target. Inhibition of this enzyme could reduce GABA metabolism, potentially reducing any beneficial effect of the GABA shunt in IDH1 mutant tumours, and increasing activation of the GABA-A receptor by increasing the concentration of GABA in the brain. This in turn may reduce cell proliferation, and could be achieved by using Vigabatrin, a GABA transaminase inhibitor licensed for use in epilepsy.

A new insight about pharmaceutical dosage forms for benzathine penicillin G

In this work, a micellar system of benzathine penicillin G (BPG) in sodium deoxycholate (NaDC) was developed and evaluated physicochemically. The solubility profile of the drug in water and buffer solutions at various pH was determined, as well as its n-octanol/water partition coefficient. The Critical Micellar Concentration of NaDC and its ability to incorporate BPG were also assessed. The study was carried out at low and high ionic strength which was adjusted by the addition of sodium chloride. The results demonstrated the ability of the micellar system to incorporate BPG, as well as to increase its apparent solubility in water. The enhancement of the solubility of BPG by the presence of NaDC micelles could be analyzed quantitatively within the framework of the pseudo-phase model. Concentration analysis showed that the micellar system could attain up to 90% incorporation of BPG. The incorporated drug is expected to exhibit improved stability, since the antibiotic enclosed in the hydrophobic core of micelles is rather shielded from the aqueous external environment

Prática de ensino supervisionada em Educação Pré-escolar e Ensino do 1.º Ciclo do Ensino Básico

Este documento espelha o relatório final de Prática de Ensino Supervisionada, realizado no âmbito do curso de Mestrado em Educação Pré-escolar e Ensino do 1.º Ciclo do Ensino Básico, e procura focalizar-se nas práticas realizadas em contexto de Educação Pré-escolar e de 1.º Ciclo do Ensino Básico, onde se destaca a arte como um meio pedagógico através do qual as crianças de dois níveis de ensino, Pré-Escolar e 1.º Ciclo do Ensino Básico, se apropriaram de novos conhecimentos. Assim, o tema escolhido para este estudo foi A educação pela arte: olhar, ouvir e sentir, e prendeu-se com a necessidade de familiarizar a criança com a arte, pela importância que esta assume no seu desenvolvimento pessoal, social e cultural na medida em que a construção do conhecimento se efetiva através de recursos expressivos que preconizam criação, participação e envolvimento, dando a ver e a sentir, oferecendo ainda possibilidades interpretativas. Destaca-se ainda a importância da cooperação com outros profissionais, a interação com as crianças, a reflexão sistemática antes, durante e após a ação e pesquisa contínua, com vista à melhoria das nossas práticas e do sucesso das crianças. Desta forma, pensamos na seguinte questão problema: Como explorar a arte com as crianças em situações de aprendizagem plurais, através de um objeto real e/ou imaginado, de uma forma concreta e lúdica, apelando a diversas formas de expressão artística? e estipulamos como intencionalidades: (i) compreender os olhares das crianças sobre a imaginação, (ii) conhecer as conceções que as crianças têm sobre a arte e os artistas; e, (iii) compreender a importância da Educação e Expressão Plástica para o desenvolvimento da criança. Em termos metodológicos posicionamo-nos numa abordagem qualitativa e para a recolha de dados atendemos à observação, às notas de campo, aos registos em áudio e fotográficos, e ao inquérito por entrevista. Pensamos que as experiências de aprendizagem que realizámos com as crianças contribuíram, de forma positiva, para o desenvolvimento de competências em vários domínios das diferentes áreas do conhecimento, envolvendo a arte, vivenciada em espaços plurais. As atividades realizadas despertaram nas crianças participantes a imaginação, a sensibilidade, o sentimento e a criatividade. Da análise e reflexão ao trabalho realizado conclui-se que a Arte deve ser assumida no ensino e seriamente desenvolvida, pois é de extrema importância o seu contributo na formação das crianças.