A Sexual Dimorphism in the Spatial Vision of North American Band-Winged Grasshoppers.

Visual acuity (VA)-a measurement of the fineness or coarseness of vision-may vary within a species including between the biological sexes. Although numerous studies have found males with finer VA than females, relatively few have shown the opposite with females having finer vision. This is surprising because our understanding of between species differences in VA suggests that females may have finer vision than males if they 1) are larger than males, or 2) need finer vision to detect and/or discriminate between males. Here, we estimate the interommatidial angle (ΔΦ, an anatomical measurement of VA) in three species of band-winged grasshoppers in which females are both the larger sex and likely interpret visual signals (Arphia pseudonietana, Dissosteira carolina, and Spharagemon equale; total n = 98). Using a radius of curvature estimation method, we find that females have ∼19% finer estimated ΔΦ than males in the most acute region and axis of the eye, but that this dimorphism varies between species. Further visual explorations of the species showing the greatest body size dimorphism (D. carolina) suggest that this ΔΦ dimorphism is driven by females having larger eyes with more ommatidia. In contrast to many diurnal flying insects where males have finer vision to acquire mates, our study is one of the first to demonstrate a female-biased sexual dimorphism in acuity. Given 1) the number of species in which females are larger than males, and 2) the variability of mating behaviors across taxa, our results suggest that differences in VA between the sexes may be more common than currently appreciated. Resumen La agudeza visual (AV)-una medida de la finura o la dificultad visual-puede variar dentro de una especie, incluso entre los sexos biológicos. Aunque numerosos estudios han encontrado machos con una AV más fina que las hembras, relativamente pocos han demostrado lo contrario, hembras con visión más fina. Esto es sorprendente porque nuestra comprensión de diferencias entre especies en AV sugiere que las hembras pueden tener una visión más fina que los machos si 1) son más grandes que los machos, o 2) necesitan una visión más fina para detectar y/o discriminar entre los machos. Aquí, estimamos el ángulo interommatidial (ΔΦ, una medida anatómica de AV) en tres especies de saltamontes de ala de banda en las que las hembras son el sexo más grande y probablemente interpretan señales visuales (Arphia pseudonietana, Dissosteira carolina, y Spharagemon equale; total n = 98). Usando un método de estimación de radio de curvatura, encontramos que las hembras tienen un estimado ΔΦ âˆ¼19% más fino que los machos en la región y eje más agudos del ojo, pero que este dimorfismo varía entre especies. Exploraciones visuales adicionales de la especie que muestra el mayor dimorfismo del tamaño corporal (D. carolina) sugieren que este dimorfismo de ΔΦ debe a que las hembras tienen ojos más grandes con más omatidios. En contraste con muchos insectos voladores diurnos donde los machos tienen una visión más fina para adquirir parejas, nuestro estudio es uno de los primeros en demostrar un dimorfismo sesgado por las hembras en la agudeza. Dado 1) el número de especies en las que las hembras son más grandes que los machos, y 2) la variabilidad de los comportamientos de apareamiento entre taxones, nuestros resultados sugieren que las diferencies de AV entre los sexos pueden ser más comunes de lo que se aprecia actualmente.

Fabrication and characterization of thermally-insulating coconut ash-based geopolymer foam.

This study aims at synthesizing porous coconut ash (CA)-based geopolymer foam with high thermal insulation property. Sodium hydroxide (NaOH), alumina slag (AS) and water contents as the main parameters, which affect the performance hardened CA, have been studied. The porosity was developed by hydrogen gas resulted from the interaction of Al metal, in AS, with NaOH. The compressive strength, bulk density, porosity and thermal conductivity were evaluated. The results proved that the AS has a potential impact on the reduction of thermal conductivity of CA-based geopolymer foam by creation of high porous system. Open celled hardened CA-based geopolymer with high porosity (∼87%), low thermal conductivity (∼0.045 W/m·K), compressive strength (1.3 MPa) and bulk density (∼0.60 g/cm3) was obtained when 7% AS (by weight of CA powder) and water to CA powder ratio of 0.4 were used.

Use of Paclitaxel-Coated Balloon Catheter Dilation to Reduce In-Stent Restenosis in Transjugular Intrahepatic Portosystemic Shunt (TIPS).

PURPOSE: Paclitaxel-coated balloons (PCB) inhibit neointimal proliferation in arteries. The purpose of this retrospective analysis was to investigate the effect of PCB in in-stent restenosis after transjugular intrahepatic portosystemic shunt (TIPS) in patients with cirrhotic liver disease. MATERIALS AND METHODS: Six patients (mean age: 65 ±â€Š10 years) with recurrent in-stent restenoses in TIPS (5 bare stents, 1 covered stent) underwent a single percutaneous transluminal angioplasty (PTA) with PCB (3 µg paclitaxel/mm(2)). Post-interventional outcome and patency were compared with those of prior plain optimal balloon angioplasty (POBA) in the same patients. During a two-year follow-up period, all patients underwent angiographic examinations at 6-month intervals. In-stent minimal lumen diameter (MLD) and late lumen loss (LLL) were assessed. Paclitaxel residues on balloon and sheath surfaces as well as venous plasma concentrations (0 - 24 hours) were analyzed. RESULTS: PCB decreased the need for clinically driven repeat PTA (POBA: 53 % of angiographic examinations; paclitaxel PTA: 19 %; P = 0.014). LLL/diameter stenosis was higher after POBA (2.4 ±â€Š1.5 mm/28 ±â€Š18 %) than after PCB (0.5 ±â€Š0.8 mm/7 ±â€Š11 %, P = 0.029). Residual paclitaxel on balloons was 28 ±â€Š9 % of dose and 0.2 ±â€Š0.1 % on sheath surfaces. Paclitaxel plasma concentrations were below detectable levels throughout the first 24 hours after the interventions in all patients. The procedure was well tolerated and no clinical side effects attributable to paclitaxel were observed. CONCLUSION: In patients with recurrent in-stent stenoses, a single PTA with PCB resulted in a prolonged secondary patency due to pseudointimahyperplasia without a systemic effect of paclitaxel. KEY POINTS: •Intimahyperplasia is a common reason for long-time TIPS dysfunction. •First-in-man local paclitaxel application in TIPS patients with recurrent in-stent stenoses. •PTA with PCB resulted in a prolonged secondary patency compared to POBA. •No systemic effects of Paclitaxel were detected.

Effects of housing and feeding systems on performance of neonatal Holstein bull calves.

As the dairy industry continues to grow, more dairy calves are available for dairy, beef, and veal purposes. Rearing systems must be highly efficient to make this industry cost efficient, making the evaluation of rearing methods important to establish the most practical method. A study was designed and conducted to evaluate effects of housing and feeding systems on performance of neonatal Holstein bull calves. Treatments (2 × 2 factorial arrangement) consisted of: 1) individually housed, bottle-fed (n = 5 bull calves); 2) individually housed, bucket-fed (n = 5 bull calves); 3) group-housed, bottle-fed (n = 5 pens; 4 bull calves/pen); and 4) group-housed, bucket- (trough) fed (n = 5 pens; 3 or 4 bull calves/pen). Feeding treatments began on d 7 when calves had been acclimated to their new environment. Body weight measurements were collected every 7 d and blood samples were collected on d 0, 28, 55, and 66 for ß-hydroxybutyrate (BHBA) concentration as a gross indicator of ruminal development. No housing × feeding interactions or feeding treatment effects were observed (P > 0.10). Average DMI (dry feed plus milk replacer) was increased (P < 0.05) for group-housed vs. individual animals after d 41, and final BW was greater (P < 0.05) for group-housed calves compared with individually housed calves. Feed efficiency and ADG, however, remained similar (P > 0.10) for all treatments. Fecal scores (P > 0.26), CV for BW (P > 0.26), and BHBA concentrations (P > 0.14) showed no differences among treatments. Housing system had greater effect on calf performance compared with milk feeding regimen.

Organochlorine compound residues in the eggs of broad-snouted caimans (Caiman latirostris) and correlation with measures of reproductive performance.

Organochlorine compounds (OCCs), like pesticides (OCPs) and polychlorinated biphenyls (PCBs), are persistent lipophilic chemicals classified as endocrine-disruptors. Caiman latirostris inhabits wetlands throughout north-eastern Argentina and may accumulate OCCs. The aims of this study were to determine OCC residues in the eggs of C. latirostris and to correlate OCC burden with clutch size, hatching success and hatchling survival as measures of reproductive performance. Fourteen caiman clutches were harvested from sites with different degrees of anthropogenic intervention on wetlands surrounding Paraná River tributaries. Two to four eggs by clutch were used to quantify OCCs. OCP residues were found in all clutches. The principal contributors to the OCPs burden were the DDT family (range BDL-153.0 ng g(-1) lipid) and oxychlordane (range BDL-34.3 ng g(-1) lipid). PCBs were present in 92.9% of the clutches (range BDL-136.6 ng g(-1) lipid). Both higher concentrations and higher diversity of pesticides, including endosulfan sulfate, were found in the nests harvested close to croplands. A negative correlation was found between clutch size and ∑OCCs (p=0.02, Pearson r=-0.53, r(2)=0.28), mainly due to the ∑OCPs (p=0.04, Pearson r=-0.54, r(2)=0.30). Since egg OCCs concentrations predict maternal burden, present findings suggest that higher OCCs exposure could lead to smaller clutches. Although, other factors like mother age could influence clutch size. Additionally, as caimans are a long-lived and non-migratory species, the maternal OCCs burden reflects the environmental status throughout their home range; thus, caiman eggs could be useful as a biomonitor of local contamination.

Hybrid natural-synthetic chitosan resin: thermal and mechanical behavior.

Poly(methyl methacrylate) (PMMA) is one of the most commonly plastics used as dental-base material, due to its good biological compatibility and mechanical properties. Chitosan has wide application in chemical, biochemical and biomedical fields of research. In this work, chitosan (CTS) was functionalized with glycidyl methacrylate (GMA), to ease a further reaction with MMA. The resulting co-polymer was finally blended with PMMA and poly(butyl acrylate) PBA which works as a damper, the polymers were cured by UV to obtain the final resin. Characterization of UV-cured resins was carried out by thermal measurements, X-ray diffraction, atomic force microscopy (AFM), micro and nanoindentation, water absorption and elution in water. As a result a higher thermal stability of the final resin compared with the precursor co-polymer ((CTS-GMA)-g-PMMA) was obtained. The resin presented roughness in the nanometer scale and nanoparticles embedded in the acrylic matrix producing a tough material. However, XRD measurements show that all materials are in an amorphous state. Values of hardness and elastic modulus results were very near to those of the dentine. The results of elution in water of the tested resin samples show them as clinically acceptable as a dental base material.

Nitric oxide modulation of coronary artery myogenic tone in spontaneously hypertensive and Wistar-Kyoto rats.

1. The endothelium contributes substantially to the modulation of myogenic tone in coronary arteries from spontaneously hypertensive rats (SHR) and Wistar-Kyoto rats (WKY). This study has addressed the contributions of endothelium-derived nitric oxide and cyclo-oxygenase products to this modulation in small coronary arteries (approximately 200 microns internal diameter) from 20-week-old SHR and WKY under pressurized, no-flow conditions in an arteriograph. 2. Active pressure-diameter relationships were uninfluenced by the cyclo-oxygenase inhibitor indomethacin (10 mumol/l) in either rat strain. In the presence of indomethacin and the nitric oxide synthase inhibitor N omega-nitro-L-arginine (L-NNA, 0.1 mmol/l), coronary arteries from SHR and WKY generated significantly greater myogenic tone. This increase in tone was similar in both strains. 3. In endothelium-denuded arteries, indomethacin and L-NNA did not influence tone. 4. Therefore, these results demonstrate that endothelium-derived nitric oxide is basally released to attenuate SHR and WKY coronary artery myogenic tone, whereas endothelium-derived cyclo-oxygenase products have no net vasoactive influence. Additionally, these data suggest that basal nitric oxide-mediated relaxation is normal in SHR coronary arteries and is therefore unlikely to be a pathogenic mechanism in this animal model of hypertension.

Myogenic tone in coronary arteries from spontaneously hypertensive rats.

The aims of this study were to investigate myogenic tone in cannulated coronary arteries from SHR (spontaneously hypertensive rats) and WKY (Wistar-Kyoto rats) at 5 and 20 weeks of age under pressurised no-flow conditions. Pressure-diameter relationships (20-200 mm Hg) were determined in the presence (active) and absence (passive) of calcium and myogenic tone at each pressure was calculated. Active, but not passive diameter-pressure relationships were significantly different between strains at both ages. Active diameters were similar between strains at pressures up to 140 mm Hg at 5 and 20 weeks. At higher pressures SHR arteries generated more tone. Maximum myogenic tone was similar between strains in spite of increased wall thickness in the SHR at both ages. Endothelium denudation increased myogenic tone to a greater extent in the SHR at both ages. Active diameters of endothelium-denuded SHR arteries were smaller than those of WKY in the range 20-120 mm Hg at 5 week and 20-80 and 160-180 mm Hg at 20 weeks. These results demonstrate that during both the developmental and established phases of hypertension, myogenic tone is not enhanced in intact SHR coronary arteries, except at the highest pressures. Following endothelium removal SHR arteries generated greater myogenic tone also at lower pressures. These data demonstrate a greater endothelium-mediated antagonism of myogenic tone in SHR coronary arteries.

Evidence that 4-aminobutyric acid and 5-aminolevulinic acid share a common transport system into Saccharomyces cerevisiae.

It has been previously reported that 5-aminolevulinic acid (ALA) and 4-aminobutyric acid (GABA) share a common permease in Saccharomyces cerevisiae (Bermúdez Moretti et al., 1993). The aim of the present work was to determine the relationship between the transport of these compounds in isolated cells. Assessment of amino acid incorporation was performed in S. cerevisiae using 14C-ALA or 3H-GABA. Initial rates of ALA incorporation in cells grown in the presence of 5 mM ALA and 5 mM GABA, were three to four times lower than in cells grown without supplements. Kinetic studies indicate that GABA competitively inhibits ALA transport. During the growth phase GABA uptake was also inhibited by 74% and 60% in the presence of ALA and GABA, respectively. These findings indicate that in S. cerevisiae the structurally related compounds, ALA and GABA, may be incorporated into the cells by a common carrier protein. Should this occur in other lukaryotic cells it may explain the neurotoxic effect attributed to ALA in the pathogenesis of acute porphyrias.

Studies on porphobilinogen-deaminase from Saccharomyces cerevisiae.

Porphobilinogen-deaminase from Saccharomyces cerevisiae has been isolated and partially purified 80- and 230-fold in the absence or presence of phenylmethylsulphonyl fluoride, respectively. Some properties of the isolated enzyme were studied. Porphyrin formation was linear with time and protein concentration. Optimum pH was about 7.5-7.8. Molecular mass of the protein was 30,000 +/- 3000 Dalton when the enzyme was purified in the presence of phenylmethylsulphonyl fluoride. A less active and unstable 20,000 Da molecular mass species was obtained when purification was performed in the absence of the protease inhibitor. Porphobilinogen-deaminase exhibited classical Michaelis-Menten kinetics. The apparent Km for uroporphyrinogen formation was 19 microM; Vmax was 3.6 nmol uroporphyrin/h and the Hill coefficient was n = 1. Also the action of several reagents on the activity was studied. Protective thiol agents had no effect. Heavy metals inhibited both porphyrin formation and porphobilinogen consumption, but known sulphydryl inactivating chemicals inhibit the former without modifying the latter. Ammonium ions had no effect on the activity while hydroxylamine completely inhibited both porphyrin formation and porphobilinogen consumption.

Different porphobilinogen-deaminase forms in wild and mutant strains of Saccharomyces cerevisiae. A possible correlation with its segregants behaviour.

1. Different porphobilinogen-deaminase (PBG-D) enzyme forms were found for D 27 and D 27/C6 (HEM R+) strains of Saccharomyces cerevisiae. 2. PBG-D was partially purified and chromatographed on Sephadex G-100 in either the presence or absence of a protease inhibitor. For D 27 only one active peak was observed while for D 27/C6 strain two active peaks were found. 3. A correlation between this differential behaviour and the presence of HEM R+ gene was looked for employing two segregants of one tetrad from D 27 and D 27/C6 mating.

Optically clear and vacuolated nuclei. Two useful signs for the transoperative diagnosis of papillary carcinoma of the thyroid.

Ground glass nuclei and Orphan Annie Eye nuclei are currently accepted as the most useful signs for the diagnosis of papillary carcinoma of the thyroid. The nuclear appearance, however, is not used in transoperative studies because the general opinion is that they are only found in permanent sections. To compare the nuclear aspect of the permanent with frozen sections and imprints, a prospective double-blind study of 48 transoperative thyroid specimens was performed. The results show that the nuclei are similar when examined by the three techniques.

Distrofia das 20 unhas em criancas. / Distrophy of 20 nails in children

Os autores apresentam quatro criancas sendo duas gemeas, com distrofia das 20 unhas Varios diagnosticos diferenciais sao discutidos. O acometimento das unhas em criancas e em duas gemeas leve a considerar uma condicao familial