Modeling of transpiration reduction in van Genuchten-Mualem type soils

We derive an analytic expression for the matric flux potential (M) for van Genuchten-Mualem (VGM) type soils which can also be written in terms of a converging infinite series. Considering the first four terms of this series, the accuracy of the approximation was verified by comparing it to values of M estimated by numerical finite difference integration. Using values of the parameters for three soils from different texture classes, the proposed four-term approximation showed an almost perfect match with the numerical solution, except for effective saturations higher than 0.9. Including more terms reduced the discrepancy but also increased the complexity of the equation. The four-term equation can be used for most applications. Cases with special interest in nearly saturated soils should include more terms from the infinite series. A transpiration reduction function for use with the VGM equations is derived by combining the derived expression for M with a root water extraction model. The shape of the resulting reduction function and its dependency on the derivative of the soil hydraulic diffusivity D with respect to the soil water content theta is discussed. Positive and negative values of dD/d theta yield concave and convex or S-shaped reduction functions, respectively. On the basis of three data sets, the hydraulic properties of virtually all soils yield concave reduction curves. Such curves based solely on soil hydraulic properties do not account for the complex interactions between shoot growth, root growth, and water availability.

Effect of follicular wave synchronization on in vitro embryo production in heifers

Aiming to achieve the ideal time of ovum pick-up (OPU) for in vitro embryo production (IVP) in crossbred heifers, two Latin square design studies investigated the effect of ovarian follicular wave synchronization with estradiol benzoate (EB) and progestins. For each experiment, crossbred heifers stage of estrous cycle was synchronized either with a norgestomet ear implant (Experiment 1) or a progesterone intravaginal device (Experiment 2) for 7d, followed by the administration of 150 mu g D-cloprostenol. On Day 7, all follicles >3 mm in diameter were aspirated and implants/devices were replaced by new ones. Afterwards, implant/device replacement was conducted every 14 d. Each experiment had three treatment groups. In Experiment I (n = 12), heifers in Group 2X had their follicles aspirated twice a week and those in Groups 1X and 1X-EB were submitted to OPU once a week for a period of 28 d. Heifers from Group 1X-EB also received 2 mg EB i.m. immediately after each OPU session. In Experiment 2 (n = 11), animals from Group 0EB did not receive EB while heifers in Groups 2EB and 5EB received 2 and 5 mg of EB respectively, immediately after OPU. The OPU sessions were performed once weekly for 28 d. Therefore, in both experiments, four OPU sessions were performed in heifers aspirated once a week and in Experiment 1, eight OPU sessions were done in heifers aspirated twice a week. Additionally, during the 7-d period following follicular aspiration, ovarian ultrasonography examinations were conducted to measure diameter of the largest follicle and blood samples were collected for FSH quantification by RIA. In Experiment 1, all viable oocytes recovered were in vitro matured and fertilized. Results indicated that while progestin and EB altered follicular wave patterns, this treatment did not prevent establishment of follicular dominance on the ovaries of heifers during OPU at 7-d intervals. Furthermore, the proposed stage of follicular wave synchronization strategies did not improve the number and quality of the recovered oocytes, or the number of in vitro produced embryos. (C) 2009 Elsevier B.V. All rights reserved.

Fatty acid profile and qualitative characteristics of meat from zebu steers fed with different oilseeds

The objective of this study was to evaluate the effects of dietary addition of ground oilseed sources on the quality, fatty acid profile, and CLA content of meat from zebu steers. Thirty-one zebu steers with an initial average age of 23 mo and an initial BW of 365 kg were used in this study. The experimental period was 84 d, which was preceded by an adaption period of 28 d. The diet was provided ad libitum with a forage: concentrate ratio of 40:60. Corn silage was used as the forage source. Four different concentrates were formulated for each treatment: without additional lipids (control) or with ground soybeans (SB), ground cottonseed (CS), or ground linseed (LS). The SB, CS, and LS diets were formulated to have 6.5% ether extract on a total dietary DM basis. The experiment was set up as a completely randomized design. After slaughter, samples were taken from the longissimus thoracis muscle for the measurement of fatty acid concentration and the evaluation of meat quality. The luminosity index was greater in the control and LS diets (P < 0.01). The greatest percentages of myristic acid (C14:0), palmitic acid (C16:0), trans octadecenoic acid (C18:1 trans-10, trans-11, or trans-12), and SFA in the subcutaneous fat were observed in the CS treatment (P < 0.01). Moreover, the least percentages of oleic acid (C18:1 cis-9) and total unsaturated fatty acids in the subcutaneous fat were observed in the CS diet (P < 0.01). The meat linoleic acid and a-linolenic acid percentages were greatest in the SB and LS treatments, respectively (P < 0.001). The unsaturated fatty acid: SFA ratio was smallest for the CS diet (P < 0.01). A gradual increase in oxidation was observed as a function of storage time; however, the diets did not affect the rancidity of the meat (P > 0.05). The fatty acid profile of subcutaneous fat was impaired by the addition of CS. Supplying ground oilseeds did not increase the content of CLA in the meat.

Peptidase activities in the semen from the ductus deferens and uterus of the neotropical rattlesnake Crotalus durissus terrificus

To understand the role of peptidases in seminal physiology of Crotalus durissus terrificus, intra- and inter-seasonal activity levels of acid (APA), basic (APB), puromycin-sensitive (APN-PS) and puromycin-insensitive neutral (APN-PI), cystyl (CAP), dipeptidyl-IV (DPPIV), type-1 pyroglutamyl (PAP-I) and prolyl-imino (PIP) aminopeptidases as well as prolyl endopeptidase (POP) were evaluated in soluble (SF) and/or membrane-bound (MF) fractions of semen collected from the ductus deferens of the male reproductive tract and from the posterior portion of the uterus. Seminal APB, PIP and POP were detected in SF, while other peptidases were detected in SF and MF. Only the convoluted posterior uterus in winter and autumn had semen. Relative to other examined peptidases, in general, APN-PI, APN-PS and APB activities were predominant in the semen from the uterus and throughout the year in the semen from the ductus deferens, suggesting their great relevance in the seminal physiology of C. d. terrificus. The levels of peptidase activities in the ductus deferens semen varied seasonally and were different from those of semen in the uterus, suggesting that their modulatory actions on susceptible peptides are integrated to the male reproductive cycle events and spermatozoa viability of this snake.

Seasonal variation of peptidase activities in the reproductive tract of Crotalus durissus terrificus

Seasonal quantitative patterns of acid (APA), basic (APB), puromycin-sensitive (APN-PS) and puromycin-insensitive neutral (APN-PI), cystyl (CAP), dipeptidyl IV (DPPIV), type-1 pyroglutamyl (PAP-I) and prolylimino (PIP) aminopeptidases and prolyl oligopeptidase (POP) activities in soluble (SF) and solubilized membrane-bound (MF) fractions from ductus deferens, vagina and uterus were studied to evaluate their relationships with the reproductive cycle and the extensive long-term spermatozoa storage (LTSS) of the Neotropical rattlesnake Crotalus durissus terrificus. APB, PIP and POP were detected only in SF, while other peptidases were detected in SF and MF. APB, APN-PI and APN-PS were predominant in most tissues in all seasons. Peptidase activities had a common pattern of increment during the dry season (winter/autumn), which coincides with the mating period (autumn) and LTSS in the female (winter), as well as the reduction of spermatozoa motility and maintenance of fertilization capacity of spermatozoa. The high CAP activity in the soluble fraction of the vagina during winter, compared to summer (time of parturition) and spring, coincides with the relaxation of this tissue. In the soluble fraction, the low PAP-1 activity of the ductus deferens coincided with its high activity in the vagina during the winter; and the inverse occurred in summer, which is consistent with the physiological process of preserving spermatozoon viability. In conclusion, the studied peptidase activities had seasonal and tissue-specific characteristics, which suggest a relevant role in the reproductive physiology of C. d. terrificus. (C) 2008 Elsevier Inc. All rights reserved.

Impact of adenosine nucleotide translocase (ANT) proline isomerization on Ca(2+)-induced cysteine relative mobility/mitochondrial permeability transition pore

Mitochondrial membrane carriers containing proline and cysteine, such as adenine nucleotide translocase (ANT), are potential targets of cyclophilin D (CyP-D) and potential Ca(2+)-induced permeability transition pore (PTP) components or regulators; CyP-D, a mitochondrial peptidyl-prolyl cis-trans isomerase, is the probable target of the PTP inhibitor cyclosporine A (CsA). In the present study, the impact of proline isomerization (from trans to cis) on the mitochondrial membrane carriers containing proline and cysteine was addressed using ANT as model. For this purpose, two different approaches were used: (i) Molecular dynamic (MD) analysis of ANT-Cys(56) relative mobility and (ii) light scattering techniques employing rat liver isolated mitochondria to assess both Ca(2+)-induced ANT conformational change and mitochondrial swelling. ANT-Pro(61) isomerization increased ANT-Cys(56) relative mobility and, moreover, desensitized ANT to the prevention of this effect by ADP. In addition, Ca(2+) induced ANT ""c"" conformation and opened PTP; while the first effect was fully inhibited, the second was only attenuated by CsA or ADP. Atractyloside (ATR), in turn, stabilized Ca(2+)-induced ANT ""c"" conformation, rendering the ANT conformational change and PTP opening less sensitive to the inhibition by CsA or ADP. These results suggest that Ca(2+) induces the ANT ""c"" conformation, apparently associated with PTP opening, but requires the CyP-D peptidyl-prolyl cis-trans isomerase activity for sustaining both effects.

Snake venomics and antivenomics of Crotalus durissus subspecies from Brazil: Assessment of geographic variation and its implication on snakebite management

We report the comparative proteomic and antivenomic characterization of the venoms of subspecies cascavella and collilineatus of the Brazilian tropical rattlesnake Crotalus durissus. The venom proteomes of C. d. collilineatus and C. d. cascavella comprise proteins in the range of 4-115 kDa belonging to 9 and 8 toxin families, respectively. Collilineatus and cascavella venoms contain 20-25 main toxins belonging to the following protein families: disintegrin, PLA(2), serine proteinase, cysteine-rich secretory protein (CRISP), vascular endothelial growth factor-like (VEGF), L-amino acid oxidase, C-type lectin-like, and snake venom metalloproteinase (SVMP). As judged by reverse-phase HPLC and mass spectrometry, cascavella and collilineatus share about 90% of their venom proteome. However, the relative occurrence of the toxin families departs among the two C. durissus subspecies venoms. The most notable difference is the presence of the myotoxin crotamine in some C. d. collilineatus specimens (averaging 20.8% of the total proteins of pooled venom), which is absent in the venom of C. d. cascavella. On the other hand, the neurotoxic PLA2 crotoxin represents the most abundant protein in both C. durissus venoms, comprising 67.4% of the toxin proteome in C. d. collilineatus and 72.5% in C. d. cascavella. Myotoxic PLA(2)s are also present in the two venoms albeit in different relative concentrations (18.1% in C. d. cascavella vs. 4.6% in C. d. collilineatus). The venom composition accounts for the clinical manifestations caused by C. durissus envenomations: systemic neurotoxicity and myalgic symptoms and coagulation disturbances, frequently accompanied by myoglobinuria and acute renal failure. The overall compositions of C. d. subspecies cascavella and collilineatus venoms closely resemble that of C. d. terrificus, supporting the view that these taxa can be considered geographical variations of the same species. Pooled venom from adult C.d. cascavella and neonate C.d. terrificus lack crotamine, whereas this skeletal muscle cell membrane depolarizing inducing myotoxin accounts for similar to 20% of the total toxins of venom pooled from C.d. collilineatus and C.d. terrificus from Southern Brazil. The possible relevance of the observed venom variability among the tropical rattlesnake subspecies was assessed by antivenomics using anti-crotalic antivenoms produced at Instituto Butantan and Instituto Vital Brazil. The results revealed that both antivenoms exhibit impaired immunoreactivity towards crotamine and display restricted (similar to 60%) recognition of PLA(2) molecules (crotoxin and D49-myotoxins) from C. d. cascavella and C. d. terrificus venoms. This poor reactivity of the antivenoms may be due to a combination of factors: on the one hand, an inappropriate choice of the mixture of venoms for immunization and, on the other hand, the documented low immunogenicity of PLA(2) molecules. C. durissus causes most of the lethal snakebite accidents in Brazil. The implication of the geographic variation of venom composition for the treatment of bites by different C. durissus subspecies populations is discussed. (C) 2010 Elsevier B.V. All rights reserved.

Expression of Human Recombinant Antibody Fragments Capable of Partially Inhibiting the Phospholypase Activity of Crotalus durissus terrificus Venom

Crotoxin is the main toxic component of the South American rattlesnake Crotalus durissus terrificus venom. It is composed of two different subunits: CA, crotapotin, and CB (basic subunit of cortoxin isolated from C. d. terrificus), a weakly toxic phospholipase A(2) with high enzymatic activity. The phospholipases A(2) are abundant in snake venoms and are responsible for disruption of cell membrane integrity via hydrolysis of its phospholipids. However, in addition to their normal digestive action, a wide range of pharmacological activities, such as neurotoxic, myotoxic, oedema-inducing, hypotensive, platelet-aggregating, cardiotoxic, and anticoagulant effects have been attributed to venom phospholipases A(2). In this study, we used a non-immune human single-chain fragment variable library, Griffin.1 (Medical Research Council, Cambridge, UK) for selection of recombinant antibodies against antigens present in C. d. terrificus venom and identification of specific antibodies able to inhibit the phospholipase activity. Two clones were identified as capable of inhibiting partially this activity in vitro. These clones were able to reduce in vivo the myotoxic and oedema-inducing activity of CB and the lethality of C. d. terrificus venom and crotoxin, but had no effect on the in vitro anticoagulant activity of CB. These results demonstrate the potential of using recombinant single-chain fragment variable libraries in the production of antivenoms.

The actual incidence of congenital adrenal hyperplasia in Brazil may not be as high as inferred - An estimate based on a public neonatal screening program in the state of Goias

The incidence of 21-hydroxylase deficiency (CYP21 D) congenital adrenal hyperplasia (CAH) in Brazil is purportedly one of the highest in the world (1:7,533). However, this information is not based on official data. The aim of this study was to determine the incidence of CYP21 D CAH in the state of Goias, Brazil, based on the 2005 results of government-funded mandatory screening. Of the live births during this period, 92.95% were screened by heel-prick capillary 17 alpha-hydroxyprogesterone (17-OHP). Of these, 82,343 were normal, 28 were at high risk for CAH and 232 at low risk for CAH. Eight cases, all from the high risk group, were confirmed. Eight asymptomatic children at 6-18 months of age still have high 17-OHP levels and await diagnostic definition. Based on the number of confirmed CYP21 D CAH cases among the 82,603 screened, the estimated annual incidence of the disease was 1:10,325, lower than the previously reported rate in Brazil.

Effect of a thrombin receptor (protease-activated receptor 1, PAR-1) gene polymorphism in chronic hepatitis C liver fibrosis

Background and Aim: Tissue injury leads to activation of coagulation and generation of thrombin. Inhibition of thrombin receptor protease-activated receptor 1 (PAR-1) has been shown to reduce liver fibrosis in animals. This study aimed to evaluate the effect of PAR-1 gene polymorphism on rate of liver fibrosis (RF) in chronic hepatitis C. Methods: Polymorphisms studied: C > T transition 1426 bp upstream of translation start site (-1426C/T), 13 bp repeat of preceding -506 5`-CGGCCGCGGGAAG-3` sequence (-506I/D), and A > T transversion in intervening sequence (IVS) 14 bp upstream of exon-2 start site (IVS-14A/T). A total of 287 European and 90 Brazilian patients were studied. Results: 1426C/T polymorphism: There was a trend to higher RF in patients with the TT genotype (P = 0.06) and an association between genotype CC and slow fibrosis (P = 0.03) in Europeans. In males, RF was significantly higher in those with the TT genotype compared to CT (P = 0.003) and CC (P = 0.007). There was a significant association between TT and fast fibrosis (P = 0.04). This was confirmed in an independent cohort of Brazilians where RF was higher in TT than in CC (P = 0.03). Analysis of -506I/D showed no difference in RF and distribution of slow/fast fibrosis among different genotypes in both populations. Analysis of IVS-14A/T showed no difference between genotypes. Conclusion: In conclusion, these findings suggest that PAR-1 receptor polymorphisms influence the progression of liver fibrosis.

Rickettsia in Synanthropic and Domestic Animals and Their Hosts from Two Areas of Low Endemicity for Brazilian Spotted Fever in the Eastern Region of Minas Gerais, Brazil

The aim of this study was to understand the current epidemiology of rickettsial diseases in two rickettsial-endemic regions in Brazil. In the municipalities of Pingo D`Agua and Santa Cruz do Escalvado, among serum samples obtained from horses and dogs, reactivity by immunofluorescent assay against spotted fever group rickettsiae was verified. In some serum samples from opossums (Didelphis aurita) captured in Santa Cruz do Escalvado, serologic response against rickettsiae was also verified. Polymerase chain reaction identified rickettsiae only in ticks and fleas obtained in Santa Cruz do Escalvado. Rickettsiae in samples had 100% sequence homology with Rickettsia fells. These results highlight the importance of marsupials in maintenance of the sylvatic cycle of rickettsial disease and potential integration with the domestic cycle. Our data also support the importance of horses and dogs as sentinels in monitoring circulation of rickettsiae in an urban area.

Prevention of Salmonella Typhimurium colonization and organ invasion by combination treatment in broiler chicks

The effects in broiler chicks of treatment with a competitive exclusion (CE) product, an experimental dietary probiotic, and the abiotic beta-glucan on cecal colonization, organ invasion, and serum and intestinal IgG and IgA levels to Salmonella challenge was evaluated. Four groups of 1-d-old chicks were treated by oral gavage on d 1 with an appropriate dose of a commercial CE product. Three groups received daily doses of probiotic, beta-glucan, or both, for 6 d. Three other groups were fed daily from d 1 onwards with probiotic, beta-glucan, or both. Subgroups of 30 chicks from each group were challenged on d 1, 9, 16, or 23 with 10(7) cfu/mL of Salmonella Typhimurium (1769NR) and killed 7 d later. Control groups were maintained untreated and remained unchallenged (negative control), or were challenged with Salmonella Typhimurium (1769NR; positive control), as described above. Cecum, liver, and spleen samples were examined for the presence of Salmonella, whereas serum and intestinal fluid samples were assayed for total antibody (IgG and IgA) concentrations. Data were analyzed by 1-way ANOVA, and means were compared using Duncan`s multiple range test. In comparison with other treatments, those involving CE product and beta-glucan, with or without probiotic during the first week, resulted in a superior inhibition of cecal colonization and organ invasion by Salmonella and also offered a higher level of protection (P < 0.05). During the second week, treatments containing experimental dietary probiotic and beta-glucan, with or without CE product, resulted in an inhibition of liver invasion (P < 0.05). The IgA levels were significantly higher (P < 0.05) in intestinal fluid compared with serum, whereas IgG had low levels. The results in the first and third week indicate that combination treatments involving CE product, probiotic, and beta-glucan are a more effective control of Salmonella colonization than the corresponding individual preparations.

The relationship between interimplant distances and vascularization of the interimplant bone

Background Long-term success of the implant restorations is based upon the biology and vasculature of the bone surrounding the implants, especially for the bone between two implants. Purpose The aim of this study was to evaluate how loaded implants placed 2 or 3 mm apart influence bone vessel organization. Material and methods Six mongrel dogs were used for the study. The four mandibular premolars were extracted and 3 months later, four 4.5 x 10 mm implants were placed on each side of the mandible. The implants were placed so that two adjacent implants were 2 mm (group 1) or 3 mm (group 2) distant from each other. After 12 weeks, the implants were loaded with provisional prostheses, then metallic crowns were placed 4 weeks later. Both temporary and metallic restorations were made so that the distance between the contact point and the bone crest was 5 mm. The animals were sacrificed after 8 weeks. The hemi-mandibles were removed and prepared for analysis. The interimplant bone vasculature of the two groups was studied using scanning electron microscopic images fractal analysis. The fractal dimension (D(f)) was calculated using the box-counting method. Results The values of the D(f) for the blood vessels were significantly higher (P <.05) in the specimens of the group 2 (1.969 +/- 0.169) than the group 1 (1.556 +/- 0.246). Conclusion The presence of more blood vessels in the group 2 is another indication that 3 mm is a preferable distance for contiguous implants than the 2 mm distance. To cite this article:Traini T, Novaes AB, Piattelli A, Papalexiou V, Muglia VA. The relationship between interimplant distances and vascularization of the interimplant bone.Clin. Oral Impl. Res. 21, 2010; 822-829.doi: 10.1111/j.1600-0501.2010.01926.x.

Reliability of orbital fits for resonant extrasolar planetary systems: the case of HD82943

We perform a statistical study of the process of orbital determination of the HD82943 extrasolar planetary system, using the current observational data set of N = 165 radial velocity (RV) measurements. Our aim is to analyse the dispersion of possible orbital fits leading to residuals compatible with the best solution, and to discuss the sensitivity of the results with respect to both the data set and the error distribution around the best fit. Although some orbital parameters (e.g. semimajor axis) appear well constrained, we show that the best fits for the HD82943 system are not robust, and at present it is not possible to estimate reliable solutions for these bodies. Finally, we discuss the possibility of a third planet, with a mass of 0.35M(Jup) and an orbital period of 900 d. Stability analysis and simulations of planetary migration indicate that such a hypothetical three-planet system could be locked in a double 2/1 mean-motion resonance, similar to the so-called Laplace resonance of the three inner Galilean satellites of Jupiter.

Copia Retrotransposon in the Zaprionus Genus: Another Case of Transposable Element Sharing with the Drosophila melanogaster Subgroup

Copia is a retrotransposon that appears to be distributed widely among the Drosophilidae subfamily. Evolutionary analyses of regulatory regions have indicated that the Copia retrotransposon evolved through both positive and purifying selection, and that horizontal transfer (HT) could also explain its patchy distribution of the among the subfamilies of the melanogaster subgroup. Additionally, Copia elements could also have transferred between melanogaster subgroup and other species of Drosophilidae-D. willistoni and Z. tuberculatus. In this study, we surveyed seven species of the Zaprionus genus by sequencing the LTR-ULR and reverse transcriptase regions, and by using RT-PCR in order to understand the distribution and evolutionary history of Copia in the Zaprionus genus. The Copia element was detected, and was transcriptionally active, in all species investigated. Structural and selection analysis revealed Zaprionus elements to be closely related to the most ancient subfamily of the melanogaster subgroup, and they seem to be evolving mainly under relaxed purifying selection. Taken together, these results allowed us to classify the Zaprionus sequences as a new subfamily-ZapCopia, a member of the Copia retrotransposon family of the melanogaster subgroup. These findings indicate that the Copia retrotransposon is an ancient component of the genomes of the Zaprionus species and broaden our understanding of the diversity of retrotransposons in the Zaprionus genus.