Emergence and initial growth of tall fescue free and infected with wild or safe endophytes

El objetivo de este trabajo fue evaluar, durante la etapa temprana de implantación de festuca alta, el porcentaje y la velocidad de emergencia, la producción de biomasa y la proporción de raíz en plantas provenientes de una población naturalizada del sudeste de la Provincia de Buenos Aires (S) y del cv. Taita (T), libres (S- y T-, respectivamente) e infectadas con el endófito silvestre Epichloë coenophiala (S+) y con el endófito seguro AR584 (T+) respectivamente. Se sembraron ocho bandejas plantineras de 50 celdas para cada tratamiento (i.e. S-, S+, T- y T+) y se ubicaron de forma tal que la superficie superior de la misma quedara al ras del suelo en una parcela preparada para la siembra de una pastura. El número de plántulas emergidas en cada bandeja se registró diariamente hasta los 28 días desde la siembra y se determinó el porcentaje y la velocidad de emergencia. A los 47 días desde la siembra se determinó la materia seca de la parte aérea y radical de las plantas emergidas. A los 28 días desde la siembra, no se registraron diferencias significativas en el número de plantúlas emergidas dentro de las festucas infectadas (p=0,9965) ni entre las libres (p=0,7525). No se encontraron diferencias significativas (p=0,4738) entre las festucas en la velocidad de emergencia. Las festucas infectadas presentaron una biomasa total por planta superior a la de las libres debido a una mayor biomasa de raíces, aunque las diferencias para ambas variables sólo fueron significativas (p<0,001) en el caso del cv. Taita. En nuestras condiciones la presencia del endófito aumentó el porcentaje de plántulas emergidas tanto en la población naturalizada como en Taita, y promovió el desarrollo radical en este último.The objective of this work was to assess, during the early stages of tall fescue implantation, the percentage of emergence, the emergence speed index, biomass production and root proportion of a naturalized population from Buenos Aires province (S) and cv. Taita (T), free (S- and T-, respectively) and infected with the wild endophyte Epichloë coenophiala (S+) and with the safe endophyte AR584 respectively (T+). Eight seedling trays with 50 cells were sown for each treatment (i.e. S-, S+, T- and T+) and placed on a bare soil in such a way that the upper surface of the trays was at soil level. The number of emerged seedlings was recorded daily up to 28 days after sowing and percentage and emergence speed index were calculated. At 47 days from sowing the biomass of shoot and roots of the plants was determined. At 28 days from sowing, no significant differences were registered in the number of emerged seedlings within endophyte-infected (p=0.9965) or endophyte-free (p=0.7525) treatments. No significant differences (p=0.4738) were found among treatments for the emergence speed index. The total biomass per plant for endophyte-infected tall fescues was higher than for endophyte-free ones due to a higher root biomass, although for both variables the differences were significant (p<0,001) only in cv. Taita. In our conditions, the presence of both endophytes allowed the respective tall fescues to increase the percentage of seedling emergence and to promote root development in cv. Taita.Facultad de Ciencias Agrarias y Forestale

Calidad del leño en <i>Eucalyptus globulus</i> spp. <i>globulus: II</i> : Variaciones en la densidad básica y la longitud de fibras en Lobería, provincia de Buenos Aires, Argentina

El objetivo del trabajo fue caracterizar una masa madura de Eucalyptus globulus ssp. globulus implantada en el Partido de Lobería, Provincia de Buenos Aires, en términos de densidad básica, longitud de fibras y sus variaciones dentro y entre individuos. Se estudiaron 10 árboles de 30 años, a 1,3 m del suelo, a niveles proporcionales a la altura comercial (30% y 60%), y en una secuencia de muestreo proporcional a la longitud de los radios norte y sur (10%, 50% y 90%). Los efectos de altura de muestreo y posición en el radio - y orientación cardinal para longitud de fibras- fueron evaluados según un modelo lineal mixto, considerando efectos aleatorios al árbol y sus interacciones. Se encontraron magnitudes y patrones de variación axial y radial acordes a los mencionados para la especie y para la región. La densidad básica manifestó diferentes magnitudes de aumento desde la médula a la corteza, según la altura de muestreo en el árbol (a 1,3 m: de 0,527 Kg.dm-3 a 0,666 Kg.dm-3; al 30%: de 0,609 Kg.dm-3 a 0,706 Kg.dm-3 y al 60%: de 0,668 Kg.dm-3 a 0,708 Kg.dm-3). La variación entre árboles, si bien significativa (p < 0.10), resultó de escasa relevancia. Para la longitud de fibras resultó de considerable importancia la variación radial, dentro de cada posición axial, (a 1,3 m: de 956,69 mm a 1169,25 mm; al 30%: de 912,61 mm a 1194,86 mm; al 60%: de 954,79 mm a 1212,49 mm). Fue poco destacada la influencia de la orientación cardinal de los radios, y no significativa la variación entre árboles.Axial and radial variations in wood density and fibre length of Eucalyptus globulus ssp globulus Labill. "eucalipto blanco", were studied in ten 30 year-old trees growing at Lobería, Province of Buenos Aires. Samples were taken at three axial levels (1,3 m, 30% and 60% of commercial height) and at three radial points (10%, 50% and 90% of radial length) in two cardinal positions (north and south) Effects of sampling height, radial and cardinal positions were assessed with a mixed linear model considering the tree and its interactions random effects. The outputs from the model agree in magnitude and patterns of axial and radial variation with those expected for this species. Wood density increased towards the bark in different magnitude according to sampling height (at 1,3 m: from 0,527 Kg.dm-3 to 0,666 Kg.dm-3; at 30%: from 0,609 Kg.dm-3 to 0,706 Kg.dm-3 and at 60%: from 0,668 Kg.dm-3 to 0,708 Kg.dm-3). Variation among trees was significant (p < 0.10) but of scarce relevance. For fibre length significant differences were found for radial variation at each axial position: at 1,3 m: from 956,69 mm to 1169,25 mm; at 30%: from 912,61 mm to 1194,86 mm; at 60%: from 954,79 mm to 1212,49 mm). There was not influence of cardinal position of radii and the variation among trees was not significantFacultad de Ciencias Agrarias y Forestale

Calidad del leño en <i>Eucalyptus globulus</i> spp. <i>globulus: II</i> : Variaciones en la densidad básica y la longitud de fibras en Lobería, provincia de Buenos Aires, Argentina

El objetivo del trabajo fue caracterizar una masa madura de Eucalyptus globulus ssp. globulus implantada en el Partido de Lobería, Provincia de Buenos Aires, en términos de densidad básica, longitud de fibras y sus variaciones dentro y entre individuos. Se estudiaron 10 árboles de 30 años, a 1,3 m del suelo, a niveles proporcionales a la altura comercial (30% y 60%), y en una secuencia de muestreo proporcional a la longitud de los radios norte y sur (10%, 50% y 90%). Los efectos de altura de muestreo y posición en el radio - y orientación cardinal para longitud de fibras- fueron evaluados según un modelo lineal mixto, considerando efectos aleatorios al árbol y sus interacciones. Se encontraron magnitudes y patrones de variación axial y radial acordes a los mencionados para la especie y para la región. La densidad básica manifestó diferentes magnitudes de aumento desde la médula a la corteza, según la altura de muestreo en el árbol (a 1,3 m: de 0,527 Kg.dm-3 a 0,666 Kg.dm-3; al 30%: de 0,609 Kg.dm-3 a 0,706 Kg.dm-3 y al 60%: de 0,668 Kg.dm-3 a 0,708 Kg.dm-3). La variación entre árboles, si bien significativa (p < 0.10), resultó de escasa relevancia. Para la longitud de fibras resultó de considerable importancia la variación radial, dentro de cada posición axial, (a 1,3 m: de 956,69 mm a 1169,25 mm; al 30%: de 912,61 mm a 1194,86 mm; al 60%: de 954,79 mm a 1212,49 mm). Fue poco destacada la influencia de la orientación cardinal de los radios, y no significativa la variación entre árboles.Axial and radial variations in wood density and fibre length of Eucalyptus globulus ssp globulus Labill. "eucalipto blanco", were studied in ten 30 year-old trees growing at Lobería, Province of Buenos Aires. Samples were taken at three axial levels (1,3 m, 30% and 60% of commercial height) and at three radial points (10%, 50% and 90% of radial length) in two cardinal positions (north and south) Effects of sampling height, radial and cardinal positions were assessed with a mixed linear model considering the tree and its interactions random effects. The outputs from the model agree in magnitude and patterns of axial and radial variation with those expected for this species. Wood density increased towards the bark in different magnitude according to sampling height (at 1,3 m: from 0,527 Kg.dm-3 to 0,666 Kg.dm-3; at 30%: from 0,609 Kg.dm-3 to 0,706 Kg.dm-3 and at 60%: from 0,668 Kg.dm-3 to 0,708 Kg.dm-3). Variation among trees was significant (p < 0.10) but of scarce relevance. For fibre length significant differences were found for radial variation at each axial position: at 1,3 m: from 956,69 mm to 1169,25 mm; at 30%: from 912,61 mm to 1194,86 mm; at 60%: from 954,79 mm to 1212,49 mm). There was not influence of cardinal position of radii and the variation among trees was not significantFacultad de Ciencias Agrarias y Forestale

Dental cell type atlas reveals stem and differentiated cell types in mouse and human teeth

Understanding cell types and mechanisms of dental growth is essential for reconstruction and engineering of teeth. Therefore, we investigated cellular composition of growing and non-growing mouse and human teeth. As a result, we report an unappreciated cellular complexity of the continuously-growing mouse incisor, which suggests a coherent model of cell dynamics enabling unarrested growth. This model relies on spatially-restricted stem, progenitor and differentiated populations in the epithelial and mesenchymal compartments underlying the coordinated expansion of two major branches of pulpal cells and diverse epithelial subtypes. Further comparisons of human and mouse teeth yield both parallelisms and differences in tissue heterogeneity and highlight the specifics behind growing and non-growing modes. Despite being similar at a coarse level, mouse and human teeth reveal molecular differences and species-specific cell subtypes suggesting possible evolutionary divergence. Overall, here we provide an atlas of human and mouse teeth with a focus on growth and differentiation. Unlike human teeth, mouse incisors grow throughout life, based on stem and progenitor cell activity. Here the authors generate single cell RNA-seq comparative maps of continuously-growing mouse incisor, non-growing mouse molar and human teeth, combined with lineage tracing to reveal dental cell complexity.Peer reviewe

Effect of four different finishing and polishing systems on resin composites: Roughness surface and gloss retention evaluations

BACKGROUND: Finishing and polishing procedures play a crucial role to achieve the best aesthetic result of direct restorations. Many manufacturers to the clinicians offer different finishing and polishing systems. This study aims to examine the behavior of four different finishing and polishing systems on the roughness, gloss and morphology surface of one resin composite. METHODS: Twelve Filtek XTE Supreme (3M ESPE) discs were prepared and divided into 4 groups (N.=3), depending on the different finishing and polishing systems: Group 1 (GP1) Sof-Lex Extra-Thin XT discs; Group 2 (GP2) Sof-Lex Coarse black disc, multi-fluted bur, Sof-Lex Diamond Polishing System Spirals; Group 3 (GP3) Sof-Lex Coarse black disc, multi-fluted bur, Sof-Lex Diamond Polishing System Spirals, Diamond Twist SCL; Group 4 (GP4) with Sof-Lex Coarse black disc, multi-fluted bur and Occlubrush. The roughness and gloss were evaluated and then samples examined by Scanning Electron Microscopy (SEM) to analyse the morphology after finishing and polishing. RESULTS: Regarding the surface roughness, GP1 and GP2 showed similar values for Ra, Ry, Rz and Rq parameters; while GP3 displayed the lowest values in all parameters; GP4 had the highest Ra value. Regarding the gloss, the values decreased as follows: GP3&gt;GP2=GP4&gt;GP1 (P&lt;0.05). Scanning electron micrographs showed the abrasion of the samples with an increase in the surface roughness in GP1 and GP4. One-way ANOVA followed by Tukey's Test was used for statistical evaluations (P&lt;0.05). CONCLUSIONS: The roughness and gloss surface of resin composites depend on the finishing and polishing systems used. This study demonstrates that satisfactory gloss outcomes are obtained using asystem based on diamond paste

Sessualità e contraccezione: un'indagine sugli effetti indotti da un contraccettivo orale sulla soddisfazione sessuale femminile

ricerca sugli effetti della contraccezione orale sulla soddisfazione sessuale femminil

How Can Different Polishing Timing Influence Methacrylate and Dimethacrylate Bulk Fill Composites? Evaluation of Chemical and Physical Properties

The polishing procedure is commonly performed after direct composite restorations, and little information exists regarding the right timing during which it should be performed on bulk fill composites. This study investigated the effect of polishing timing on the degree of conversion (DC), Vickers microhardness (VMH), and surface morphology of a methacrylate- (MET-) and dimethacrylate- (DMET-) based bulk fill composite, by using FT-NIR, microhardness tester, and SEM. Composite samples were divided as follows: in Group I (immediate), samples were polished immediately after curing (t0); in Group D (delayed), samples were polished after 24 h from curing (t24), whereas the unpolished samples were considered as controls (Group C). The DC and VMH values were evaluated before and after polishing, at t0 and t24. Statistical analysis was performed with a significance level set at p<0.05. At t0, DC increased after polishing in both tested composites (p<0.05), while at t24, Group I and Group D were not different. By considering VMH, in the case of MET, all groups were not different both at t0 and t24. On the other hand, at t0, VMH values of DMET increased after polishing. At t24, DMET Group I and DMET Group D were not different. Qualitative evaluations of scanning electron micrographs showed that the surface morphology of MET presented a more irregular aspect than the DMET one. In summary, since the immediate polishing of MET can improve the DC, without negatively affecting VMH, but showing an irregular surface, it is suggested to wait 24 hours before proceeding with polishing. Otherwise, for DMET, the immediate polishing could definitively be recommended, since it improves both DC and VMH, also producing a regular surface. Therefore, clinicians may always safely polish a restoration performed using DMET-based bulk fill composites in one-chair appointment, avoiding a second appointment

Comparison of three different bulk-filling techniques for restoring class II cavities: μCT, SEM-EDS combined analyses for margins and internal fit assessments

Objective: Evaluation of the behavior of three different bulk-filling techniques in terms of internal adaptation and external marginal sealing for restoring class II cavities. Methods: Fifteen extracted sound molar teeth were used. Two standardized class II mesio/disto-occlusal (MO/DO) slot cavities, 4 mm long, 4 mm wide and 3 mm deep were prepared in each tooth, obtaining n=30 cavity preparations. The cavities were randomly assigned into three groups (n=10 per group) according to three bulk filling techniques: Bulk Traditional (BT), Bulk&Go (BG) and Bulk&Flow (BF). The teeth were analyzed by scanning electron microscopy (SEM) to investigate the external marginal seal. Thereafter, the chemical composition of tooth-restoration interface was analyzed by energy-dispersive X-ray spectroscopy (EDS). Complementary information to the SEM and EDS were obtained by micro-computed tomography (μCT) to assess the internal fit. Results: SEM analysis showed a proper external marginal seal for all groups tested as confirmed by the EDS investigation, highlighting the presence of adhesive layer at the tooth-restoration interface. The internal marginal adaptation by means of μCT analysis revealed gaps formation at the tooth–restoration interface only for BT group, while an intimate contact free of gaps were found in the other two groups. Moreover, in BT and BF groups voids were present within the restoration. Significance: BG and BF techniques can be considered as reliable alternatives to BT technique, as they simplify the class II restoration without transforming it into class I, thus ensuring a successful result