Alkenone stable carbon isotopes, carbonate stable carbon and oxygen isotopes, planktic foraminifera boron isotopes and atmospheric CO2 calculations and box model results from Ras il-Pellegrin section, Malta

The development of a permanent, stable ice sheet in East Antarctica happened during the middle Miocene, about 14 million years (Myr) ago. The middle Miocene therefore represents one of the distinct phases of rapid change in the transition from the "greenhouse" of the early Eocene to the "icehouse" of the present day. Carbonate carbon isotope records of the period immediately following the main stage of ice sheet development reveal a major perturbation in the carbon system, represented by the positive d13C excursion known as carbon maximum 6 ("M6"), which has traditionally been interpreted as reflecting increased burial of organic matter and atmospheric pCO2 drawdown. More recently, it has been suggested that the d13C excursion records a negative feedback resulting from the reduction of silicate weathering and an increase in atmospheric pCO2. Here we present high-resolution multi-proxy (alkenone carbon and foraminiferal boron isotope) records of atmospheric carbon dioxide and sea surface temperature across CM6. Similar to previously published records spanning this interval, our records document a world of generally low (~300 ppm) atmospheric pCO2 at a time generally accepted to be much warmer than today. Crucially, they also reveal a pCO2 decrease with associated cooling, which demonstrates that the carbon burial hypothesis for CM6 is feasible and could have acted as a positive feedback on global cooling.

Stable carbon and oxygen isotope ratios of foraminifera from Cretaceous and Paleocene sediments

Detailed analysis of over 200 samples of uppermost Cretaceous and Paleocene sediments from Atlantic Ocean DSDP Sites 384, 86, 95, 152, 144, 20C, 21, 356, 357, and 329 provides new information on the temperature stratification of Paleocene planktonic foraminifera, the temperature and carbon isotopic changes across the Cretaceous/Tertiary boundary, and the fluctuating temperature and carbon isotopic records through the Paleocene ~64.5-54 m.y.). There was a significant temperature rise across the Cretaceous/Tertiary boundary both at the surface and in deep waters of the Atlantic Ocean. This temperature rise occurred before the basal Tertiary 'Globigerina' eugubina Zone, so that in the oldest Paleocene sample yet analyzed from the deep sea (Site 356) temperatures are already three degrees higher at the bottom and at the surface than in the Cretaceous. The temperature rise across the boundaryis more pronounced on the bottom and in samples from higher latitudes. Accompanying the temperature rise across the boundary there is a significant shift in the carbon isotope profile. In the basal Paleocene the foraminifera of the surface zone demonstrate very negative carbon isotope values (unlike in the Cretaceous of today's ocean), while deeper dwelling species have more positive values which then decrease to the bottom. The unusual carbon isotope gradients persist through the first three million years of the Paleocene until towards the top of planktonic foraminiferal Zone P.1 (G. trinidadensis Zone) the foraminifera record a profile more positive at the surface and decreasing towards the bottom (as in today's ocean). During the Paleocene there are two noteworthy rises in surface water temperature; the first around 62-61 m.y. (G. trinidadensis Zone), and the second near the base of the Globorotalia angulata Zone, 60-59 m.y. At this time surface temperatures at low to mid latitudes reached values near 25°C, while at mid-latitude Site 384 temperature highs near 22°C were registered. At a sample spacing of around one per million years, we have only produced some of the detail of these temperature fluctuations. The later Paleocene is generally cooler and there do not seem to be any large variations either through time or latitude. Middle-latitude sites average temperatures near 15°C at the surface, while high lower latitude site temperatures range near 18°C. The most salient feature of the bottom temperature record (based on multispecific samples) through the Paleocene is its lack of fluctuations. There is an overall temperature range of 5°C at these intermediate depth sites (paleodepth estimates between 1500 and 3000 m). Higher values near 13°C accompany the surface temperature peaks around 62 and 60 m.y., while low values near 8°C occur in Zone P.2 (61-60 m.y.). We detected no change in bottom temperature across the paleocene/Eocene boundary in the few samples studied so far. While there are several fluctuations in the carbon isotope values through the early Paleocene, the general trend is one of increasingly positive values at the surface and at depth. This trend culminates in the late Paleocene (upper Zone P.4, about 56-57 m.y.) with a major excursion in the carbon isotope values. At low latitudes the range between the surface and the deepest planktonic foraminifera is a delta13C of 4 per mil as compared with a range of 2 per mil today. The carbon values drop off slightly, but remain strongly positive through the remainder of the Paleocene at most sites. Accompanying the carbon isotope excursion at Site 384 is a productivity increase and a proposed rise in the CCD.

Experiment: The effect of temperature, salinity and growth rate on the stable hydrogen isotopic composition of long chain alkenones produced by Emiliania huxleyi and Gephyrocapsa oceanica

Two haptophyte algae, Emiliania huxleyi and Gephyrocapsa oceanica, were cultured at different temperatures and salinities to investigate the impact of these factors on the hydrogen isotopic composition of long chain alkenones synthesized by these algae. Results showed that alkenones synthesized by G. oceanica were on average depleted in D by 30 compared to those of E. huxleyi when grown under similar temperature and salinity conditions. The fractionation factor, alpha alkenones-H2O, ranged from 0.760 to 0.815 for E. huxleyi and from 0.741 to 0.788 for G. oceanica. There was no significant correlation of alpha alkenones-H2O with temperature but a positive linear correlation was observed between alpha alkenones-H2O and salinity with ~3 change in fractionation per salinity unit and a negative correlation between alpha alkenones-H2O and growth rate. This suggests that both salinity and growth rate can have a substantial impact on the stable hydrogen isotopic composition of long chain alkenones in natural environments.

(Table S1) Stable isotope record and growth rates of cultured Mytilus edulis

To study the effects of temperature, salinity, and life processes (growth rates, size, metabolic effects, and physiological/genetic effects) on newly precipitated bivalve carbonate, we quantified shell isotopic chemistry of adult and juvenile animals of the intertidal bivalve Mytilus edulis (Blue mussel) collected alive from western Greenland and the central Gulf of Maine and cultured them under controlled conditions. Data for juvenile and adult M. edulis bivalves cultured in this study, and previously by Wanamaker et al. (2006, doi:10.1029/2005GC001189), yielded statistically identical paleotemperature relationships. On the basis of these experiments we have developed a species-specific paleotemperature equation for the bivalve M. edulis [T °C = 16.28 (±0.10) - 4.57 (±0.15) {d18Oc VPBD - d18Ow VSMOW} + 0.06 (±0.06) {d18Oc VPBD - d18Ow VSMOW}**2; r**2 = 0.99; N = 323; p < 0.0001]. Compared to the Kim and O'Neil (1997) inorganic calcite equation, M. edulis deposits its shell in isotope equilibrium (d18Ocalcite) with ambient water. Carbon isotopes (d13Ccalcite) from sampled shells were substantially more negative than predicted values, indicating an uptake of metabolic carbon into shell carbonate, and d13Ccalcite disequilibrium increased with increasing salinity. Sampled shells of M. edulis showed no significant trends in d18Ocalcite based on size, cultured growth rates, or geographic collection location, suggesting that vital effects do not affect d18Ocalcite in M. edulis. The broad modern and paleogeographic distribution of this bivalve, its abundance during the Holocene, and the lack of an intraspecies physiologic isotope effect demonstrated here make it an ideal nearshore paleoceanographic proxy throughout much of the North Atlantic Ocean.

Sexual functioning in people with stable chronic diseases

Backgound - In developed countries people are living longer and the incidence of chronic disease (CD) is increasing. CD and its treatments can have a negative impact on sexual functioning and sexual satisfaction. Objective - To explore and to compare sexual function and sexual satisfaction in people with stable chronic diseases.

Síntese e estudo de polioxotungstatos do tipo Keggin com interesse catalítico

O objectivo principal deste trabalho foi estudar as propriedades e comportamento de polioxotungstatos (POM) do tipo Keggin com interesse em catálise oxidativa. Os estudos efectuados centraram-se no comportamento electroquímico dos aniões em meio não aquoso, na estabilidade das suas estruturas em diferentes meios, na sua capacidade de catalisar a oxidação de diferentes substratos orgânicos e na sua eficácia em oxidar, de forma selectiva, um modelo não fenólico da lenhina. Efectuou-se, igualmente, o estudo estrutural de diversos aniões pela técnica de EXAFS. Neste trabalho, prepararam-se e caracterizaram-se alguns dos sais de tetra-n-butilamónio (TBA) dos polioxotungstatos estudados: compostos de Keggin, TBAx[XW12O40], lacunares, TBAxHy[XW11O39], mono-substituídos, TBAxHy[XW11M(H2O)O39]·nH2O, com X= P e Si e M = CoII, NiII, ZnII, CuIl, RuIII, MnIII e FeIII e os compostos com mistura de átomos adenda TBAx[XW11VO40]·nH2O (X = P e Si). Seleccionou-se este conjunto de polioxotungstatos de forma a efectuar-se um estudo comparativo da influência da natureza do heteroátomo central (P e Si) e dos metais de transição M nas propriedades estudadas. O conjunto de sais de TBA dos silicotungstatos estudados mostraram ser isoestruturais, apresentando a mesma estrutura dos fosfotungstatos análogos. O comportamento electroquímico dos polioxotungstatos foi estudado em soluções de acetonitrilo por voltametria cíclica e electrólise a potencial controlado. Verificou-se a ocorrência de vários processos mono-electrónicos de oxi-redução, reversíveis ou quasi-reversíveis, associados aos átomos de WVI/V e a alguns dos metais de transição. Os metais em estado de oxidação +3 reduziram-se mais facilmente do que os átomos de WVI. O metal CuII apresentou um comportamento diferente dos outros metais de transição. Este metal, na estrutura do POM, reduziu-se a CuI, proporcionando a observação do anião [PW11CuIO39]6- pela primeira vez. A redução posterior do CuI conduziu à formação de Cu0, que se depositou na superfície do eléctrodo. A re-oxidação do cobre a CuII conduziu à reconstituição da estrutura do POM, nas condições estudadas. Constatou-se que a ocorrência de protões na fórmula molecular dos POMs influenciou o seu comportamento electroquímico. Para os compostos que apresentam protões, a redução dos átomos de tungsténio ocorreu a potenciais menos negativos do que para aqueles que não apresentam protões na sua fórmula. Para os primeiros observou-se a transferência global de um maior número de electrões no mesmo intervalo de potencial, originando soluções fortemente azuladas. Quando os catiões tetra-n-butilamónio foram substituídos por catiões de menor dimensão, como Li+ e Na+, ocorreu a formação de pares iónicos com os polianiões [PW12O40]3- e [SiW11VO40]5-, originando um aumento do potencial de redução. Não houve evidência da formação de pares iónicos com os catiões TBA+. Este foi o primeiro estudo sistemático do comportamento electroquímico dos aniões lacunares e mono-substituídos em meio não aquoso. Estudou-se a estrutura dos polioxotungstatos em sais de TBA e em soluções de acetonitrilo. A aplicação da técnica de EXAFS ao estudo deste tipo de compostos em solução foi realizada pela primeira vez. Pela análise estrutural nos sólidos verificou-se que, a natureza do metal de transição M e do átomo central X, na estrutura do POM, influenciam o tamanho dos vários octaedros que o constituem. Não se observaram diferenças significativas nas estruturas dos polianiões em solução. A estabilidade da estrutura dos polioxometalatos na presença de um excesso de H2O2, em soluções de acetonitrilo/H2O foi analisada por espectroscopia de absorção de EXAFS, RMN de 31P, IV e espectrofotometria de absorção no UV-Vis. De uma forma geral, os POMs em que o átomo central da estrutura é o Si apresentaram maior estabilidade do que os POMs correspondentes com átomo de P no centro. Em solução de acetonitrilo, na ausência de H2O2, todos os aniões mostraram ser estáveis durante vários dias. Em solução, na presença de H2O2 em excesso (H2O2/POM = 1300), o anião lacunar [PW11O39]7- não é estável, transformando-se no anião de Venturello, {PO4[W(O)(O2)2]4}3-, após a formação de [PW12O40]3-, como produto intermediário. Em relação aos aniões substituídos [PW11M(H2O)O39]p-, M = MnIII, RuIII, FeIII, CoII e ZnII, verificou-se o seguinte na presença de H2O2: os aniões com MnIII e CoII transformaram-se no anião de Keggin, [PW12O40]3-. Os aniões de RuIII e FeIII mantiveram as suas estruturas e o anião de ZnII decompôs-se em {HPO4[W(O)(O2)2]2}2- e fosfato. Para estes casos de não estabilidade estrutural, o processo de decomposição foi mais rápido na presença de maiores conteúdos de água. Pela análise de EXAFS, na presença de um menor excesso de H2O2 (H2O2/POM = 70) e apenas 8% de parte aquosa, verificou-se que os aniões substituídos por MnIII mantiveram a sua estrutura, embora o ligando H2O, coordenado ao Mn, tivesse sido substituído por um grupo oxo no polianião [SiW11Mn(H2O)O39]5-, e por um grupo peroxo no polianião [PW11Mn(H2O)O39]4-. O anião com RuIII, nestas condições, também mostrou substituir o seu ligando H2O por um grupo peroxo ou hidrogenoperoxo. Os polioxotungstatos mono-substituídos e lacunares mostraram ser catalisadores eficientes para a oxidação de cis-cicloocteno, geraniol e ciclooctano com H2O2. A maior novidade deste trabalho residiu na actividade catalítica apresentada pelos silicotungstatos estudados, contrariando o que é referido na literatura. Outro aspecto inovador foi o elevado valor de conversão obtido para a oxidação de ciclooctano. Este substrato foi oxidado com 74% de conversão, após 2h de reacção e com 80% de selectividade para o hidroperóxido de ciclooctilo, na presença do anião [PW11Fe(H2O)O39]4-. Os restantes produtos de reacção foram o ciclooctanol e a ciclooctanona. Os silicotungstatos apresentaram maior selectividade para o hidroperóxido de ciclooctilo do que os fosfotungstatos. O geraniol foi completamente oxidado após 3h de reacção, com 82% de selectividade para o 2,3-epoxigeraniol, na presença do anião [PW11Mn(H2O)O39]4-. O cis-cicloocteno foi oxidado ao seu epóxido, com 92% de conversão ao fim de 5h de reacção, na presença do anião lacunar [PW11O39]7-. O estudo da capacidade oxidativa do anião [SiW11VO40]5- foi analisada utilizando-se um modelo não fenólico da lenhina, a anisoína. Estudaram-se as condições favoráveis à obtenção de uma reacção selectiva para o anisilo, de forma a poder estudar-se a cinética da reacção. A estequiometria da reacção mostrou ser de 1:2 anisoína/POM. As ordens de reacção foram determinadas pelo método das velocidades iniciais e, a partir destes resultados, conheceu-se que o POM não estava envolvido no passo que limita a velocidade da reacção, sendo esta limitada pela transformação da anisoína. O estudo realizado sobre o efeito isotópico sugeriu que o passo que limitou a velocidade de reacção correspondeu à enolação da anisoína. Desta forma, observou-se pela primeira vez, que o POM oxida um modelo não fenólico da lenhina por via de enolação.

Nitrogen use efficiency and optimization of nitrogen fertilizer application for stable yields and high quality of cereals grown in conservation agriculture

In most agroecosystems, nitrogen (N) is the most important nutrient limiting plant growth. One management strategy that affects N cycling and N use efficiency (NUE) is conservation agriculture (CA), an agricultural system based on a combination of minimum tillage, crop residue retention and crop rotation. Available results on the optimization of NUE in CA are inconsistent and studies that cover all three components of CA are scarce. Presently, CA is promoted in the Yaqui Valley in Northern Mexico, the country´s major wheat-producing area in which from 1968 to 1995, fertilizer application rates for the cultivation of irrigated durum wheat (Triticum durum L.) at 6 t ha-1 increased from 80 to 250 kg ha-1, demonstrating the high intensification potential in this region. Given major knowledge gaps on N availability in CA this thesis summarizes the current knowledge of N management in CA and provides insights in the effects of tillage practice, residue management and crop rotation on wheat grain quality and N cycling. Major aims of the study were to identify N fertilizer application strategies that improve N use efficiency and reduce N immobilization in CA with the ultimate goal to stabilize cereal yields, maintain grain quality, minimize N losses into the environment and reduce farmers’ input costs. Soil physical and chemical properties in CA were measured and compared with those in conventional systems and permanent beds with residue burning focusing on their relationship to plant N uptake and N cycling in the soil and how they are affected by tillage and N fertilizer timing, method and doses. For N fertilizer management, we analyzed how placement, time and amount of N fertilizer influenced yield and quality parameters of durum and bread wheat in CA systems. Overall, grain quality parameters, in particular grain protein concentration decreased with zero-tillage and increasing amount of residues left on the field compared with conventional systems. The second part of the dissertation provides an overview of applied methodologies to measure NUE and its components. We evaluated the methodology of ion exchange resin cartridges under irrigated, intensive agricultural cropping systems on Vertisols to measure nitrate leaching losses which through drainage channels ultimately end up in the Sea of Cortez where they lead to algae blooming. A throughout analysis of N inputs and outputs was conducted to calculate N balances in three different tillage-straw systems. As fertilizer inputs are high, N balances were positive in all treatments indicating the risk of N leaching or volatilization during or in subsequent cropping seasons and during heavy rain fall in summer. Contrary to common belief, we did not find negative effects of residue burning on soil nutrient status, yield or N uptake. A labeled fertilizer experiment with urea 15N was implemented in micro-plots to measure N fertilizer recovery and the effects of residual fertilizer N in the soil from summer maize on the following winter crop wheat. Obtained N fertilizer recovery rates for maize grain were with an average of 11% very low for all treatments.

A Highly Improved Method For Sensitive Determination Of Amitriptyline In Pharmaceutical Formulations Using An Unmodified Carbon Nanotube Electrode In The Presence Of Sulfuric Acid.

The present paper describes a novel, simple and reliable differential pulse voltammetric method for determining amitriptyline (AMT) in pharmaceutical formulations. It has been described for many authors that this antidepressant is electrochemically inactive at carbon electrodes. However, the procedure proposed herein consisted in electrochemically oxidizing AMT at an unmodified carbon nanotube paste electrode in the presence of 0.1 mol L(-1) sulfuric acid used as electrolyte. At such concentration, the acid facilitated the AMT electroxidation through one-electron transfer at 1.33 V vs. Ag/AgCl, as observed by the augmentation of peak current. Concerning optimized conditions (modulation time 5 ms, scan rate 90 mV s(-1), and pulse amplitude 120 mV) a linear calibration curve was constructed in the range of 0.0-30.0 μmol L(-1), with a correlation coefficient of 0.9991 and a limit of detection of 1.61 μmol L(-1). The procedure was successfully validated for intra- and inter-day precision and accuracy. Moreover, its feasibility was assessed through analysis of commercial pharmaceutical formulations and it has been compared to the UV-vis spectrophotometric method used as standard analytical technique recommended by the Brazilian Pharmacopoeia.

Primary Relapse Site Pattern In Women With Triple-negative Breast Cancer.

Despite the remarkable improvements in breast cancer (BC) characterization, accurate prediction of BC clinical behavior is often still difficult to achieve. Some studies have investigated the association between the molecular subtype, namely the basal-like BC and the pattern of relapse, however only few investigated the association between relapse pattern and immunohistochemical defined triple-negative breast cancers (TNBCs). The aim of this study was to evaluate the pattern of relapse in patients with TNBC, namely the primary distant relapse site. One-hundred twenty nine (129) invasive breast carcinomas with follow-up information were classified according to the molecular subtype using immunohistochemistry for ER, PgR and Her2. The association between TNBC and distant relapse primary site was analyzed by logistic regression. Using multivariate logistic regression analysis patients with TNBC displayed only 0.09 (95% CI: 0.00-0.74; p=0.02) the odds of the non-TNBC patients of developing bone primary relapse. Regarding visceral and lymph-node relapse, no differences between in this cohort were found. Though classically regarded as aggressive tumors, TNBCs rarely development primary relapse in bone when compared to non-TNBC, a clinical relevant fact when investigating a metastasis of an occult or non-sampled primary BC.

Evaluation Of Fe Uptake And Translocation In Transgenic And Non-transgenic Soybean Plants Using Enriched Stable (57)fe As A Tracer.

A tracer experiment is carried out with transgenic T (variety M 7211 RR) and non-transgenic NT (variety MSOY 8200) soybean plants to evaluate if genetic modification can influence the uptake and translocation of Fe. A chelate of EDTA with enriched stable (57)Fe is applied to the plants cultivated in vermiculite plus substrate and the (57)Fe acts as a tracer. The exposure of plants to enriched (57)Fe causes the dilution of the natural previously existing Fe in the plant compartments and then the changed Fe isotopic ratio ((57)Fe/(56)Fe) is measured using a quadrupole-based inductively coupled plasma mass spectrometer equipped with a dynamic reaction cell (DRC). Mathematical calculations based on the isotope dilution methodology allow distinguishing the natural abundance Fe from the enriched Fe (incorporated during the experiment). The NT soybean plants acquire higher amounts of Fe from natural abundance (originally present in the soil) and from enriched Fe (coming from the (57)Fe-EDTA during the experiment) than T soybean ones, demonstrating that the NT soybean plants probably absorb higher amounts of Fe, independently of the source. The percentage of newly incorporated Fe (coming from the treatment) was approximately 2.0 and 1.1% for NT and T soybean plants, respectively. A higher fraction (90.1%) of enriched Fe is translocated to upper parts, and a slightly lower fraction (3.8%) is accumulated in the stems by NT plants than by T ones (85.1%; 5.1%). Moreover, in both plants, the Fe-EDTA facilitates the transport and translocation of Fe to the leaves. The genetic modification is probably responsible for differences observed between T and NT soybean plants.

Analysis Of The Contribution Of Immunologically-detectable Her2, Steroid Receptors And Of The Triple-negative" Tumor Status To Disease-free And Overall Survival Of Women With Epithelial Ovarian Cancer."

We assessed associations between steroid receptors including: estrogen-alpha, estrogen-beta, androgen receptor, progesterone receptor, the HER2 status and triple-negative epithelial ovarian cancer (ERα-/PR-/HER2-; TNEOC) status and survival in women with epithelial ovarian cancer. The study included 152 women with primary epithelial ovarian cancer. The status of steroid receptor and HER2 was determined by immunohistochemistry. Disease-free and overall survival were calculated and compared with steroid receptor and HER2 status as well as clinicopathological features using the Cox Proportional Hazards model. A mean follow-up period of 43.6 months (interquartile range=41.4 months) was achieved where 44% of patients had serous tumor, followed by mucinous (23%), endometrioid (9%), mixed (9%), undifferentiated (8.5%) and clear cell tumors (5.3%). ER-alpha staining was associated with grade II-III tumors. Progesterone receptor staining was positively associated with a Body Mass Index≥25. Androgen receptor positivity was higher in serous tumors. In stand-alone analysis of receptor contribution to survival, estrogen-alpha positivity was associated with greater disease-free survival. However, there was no significant association between steroid receptor expression, HER2 status, or TNEOC status, and overall survival. Although estrogen-alpha, androgen receptor, progesterone receptor and the HER2 status were associated with key clinical features of the women and pathological characteristics of the tumors, these associations were not implicated in survival. Interestingly, women with TNEOC seem to fare the same way as their counterparts with non-TNEOC.

Dyspareunia In Hiv-positive And Hiv-negative Middle-aged Women: A Cross-sectional Study.

To evaluate whether dyspareunia is associated with HIV status in menopausal women and also to assess which factors are associated with dyspareunia in a group of HIV-positive menopausal women. A cross-sectional study was conducted with 178 HIV-negative and 128 HIV-positive women aged 40-60 years. The Short Personal Experiences Questionnaire (SPEQ) was used to collect data. Sociodemographic, clinical, behavioural and reproductive factors were evaluated, as well as factors related to the HIV infection. Dyspareunia was defined as pain during intercourse. A bivariate analysis and Poisson multiple regression analysis were performed. Overall, 41.4% of the HIV-positive women reported dyspareunia compared with 34.8% of the HIV-negative women (p=0.242). In the HIV-positive women, bivariate analysis revealed an association between dyspareunia and having a steady partner (p=0.047); the woman's partner having undergone HIV testing (p=0.020); vaginal dryness (p<0.001); muscle/joint pain (p=0.021); physical/emotional violence (p=0.049); urinary incontinence (p=0.004); and the use of lamivudine/zidovudine (p=0.048). The Poisson multiple regression analysis found an association between dyspareunia and vaginal dryness (prevalence ratio (PR)=1.96, 95% CI 1.10 to 3.50, p=0.023) and urinary incontinence (PR=1.86, 95% CI 1.06 to 3.27, p=0.031). Dyspareunia was common in this group of HIV-positive women and was associated principally with vaginal dryness and urinary incontinence. The importance of treating dyspareunia within the context of sexual health in this group of women should be emphasised and appropriate management of this issue may reduce the likelihood of lesions on the vaginal wall, which may act as a portal of entry for other infections.

Development Plates For Stable Internal Fixation: Study Of Mechanical Resistance In Simulated Fractures Of The Mandibular Condyle.

To develop Y-shaped plates with different thicknesses to be used in simulated fractures of the mandibular condyle. Ten plates were developed in Y shape, containing eight holes, and 30 synthetic polyurethane mandible replicas were developed for the study. The load test was performed on an Instron Model 4411 universal testing machine, applying load in the mediolateral and anterior-posterior positions on the head of the condyle. Two-way ANOVA with Tukey testing with a 5% significance level was used. It was observed that when the load was applied in the medial-lateral plate of greater thickness (1.5 mm), it gave the highest strength, while in the anteroposterior direction, the plate with the highest resistance was of the lesser thickness (0.6 mm). A plate with a thickness of 1.5 mm was the one with the highest average value for all displacements. In the anteroposterior direction, the highest values of resistance were seen in the displacement of 15 mm. After comparing the values of the biomechanical testing found in the scientific literature, it is suggested that the use of Y plates are suitable for use in subcondylar fractures within the limitations of the study.

Is size structure a good measure of future trends of plant populations? an empirical approach using five woody species from the Cerrado (Brazilian savanna)

Size distributions in woody plant populations have been used to assess their regeneration status, assuming that size structures with reverse-J shapes represent stable populations. We present an empirical approach of this issue using five woody species from the Cerrado. Considering count data for all plants of these five species over a 12-year period, we analyzed size distribution by: a) plotting frequency distributions and their adjustment to the negative exponential curve and b) calculating the Gini coefficient. To look for a relationship between size structure and future trends, we considered the size structures from the first census year. We analyzed changes in number over time and performed a simple population viability analysis, which gives the mean population growth rate, its variance and the probability of extinction in a given time period. Frequency distributions and the Gini coefficient were not able to predict future trends in population numbers. We recommend that managers should not use measures of size structure as a basis for management decisions without applying more appropriate demographic studies.

Antimicrobial susceptibility of coagulase-negative Staphylococci isolated from mastitic cattle in Brazil

Um total de 109 cepas de Staphylococci coagulase-negativa foi isolado de leite de vacas com mastite clínica e subclínica, em 35 fazendas, situadas em nove estados brasileiros, no período de fevereiro a maio de 2005. Os isolados foram investigados em relação a susceptibilidade in vitro a diversos agentes antimicrobianos. A resistência à penicilina foi a observação mais freqüente (93,5%), seguida por sulfonamida (88,9%), novobiocina (88,6%) e ampicilina (85,3%). Todas as cepas examinadas mostraram resistência a pelo menos uma das drogas antimicrobianas testadas. Cepas apresentando resistência múltipla foram extremamente comuns, com 10,0% dos microrganismos isolados apresentando resistência a todas as drogas antimicrobianas. Os resultados obtidos indicaram que as cepas de Staphylococci coagulase-negativas, isoladas no Brasil, apresentaram um alto grau de resistência a antimicrobianos. Estes resultados são, provavelmente, uma conseqüência da pressão devida ao uso intensivo de drogas antimicrobianas.