The combined effect of light intensity and temperature on the chlorophyll and carotenoid pigments of phytoplankton

Chlorophyll a and other photosynthetic pigments are used as indicators of phytoplankton biomass, composition and physiological state. Extraction and HPLC procedures were developed to analyse for chlorophyll and carotenoid pigments. The effect of the environment on pigment production must be quantified before the pigments can be used to accurately estimate biomass or quantitatively describe phytoplankton composition.

Modelling the combined effect of grain size and grain shape on plastic anisotropy of metals

Within each columnar grain of a metallic film, the resistance to dislocation glide varies in function of the orientation of the slip plane with regard to the grain long axis. Plastic slip is impeded across grain boundaries and this contributes to the anisotropy of the overall mechanical response. A simplified (Taylor-type) crystal plasticity model is proposed that accounts for such effect of grain shape on the slip system selection. Assuming that dislocation density gradients are normal to the grain boundaries, backstresses developed at the onset of plasticity are estimated based on two definitions of the effective grain boundary spacing ‘‘seen’’ by individual slip systems. The first one reduces to the mean area-to-perimeter ratio of cross-sections of the grain cut parallel to the slip plane. Closed-form expressions of the average backstresses developed inside grains with spheroidal shapes are introduced in the crystal hardening law. The model reproduces the very high plastic anisotropy of electro-deposited pure iron with a strong c-fiber and a refined columnar grain structure [Yoshinaga, N., Sugiura, N., Hiwatashi, S., Ushioda, K., Kada, O., 2008. Deep drawability of electro-deposited pure iron having an extremely sharp h111i//ND texture. ISIJ Int. 48, 667–670]. It also provides valid estimates of the texture development and the influence of grain size on the yield strength.

Combined effect of the finasteride and doxazosin on rat ventral prostate morphology and physiology

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Differential/combined effect of water contamination with cadmium and nickel on tissues of rats

The contamination of water by metal compounds is a worldwide environmental problem. Concentrations of metals are widely related to biochemical values which are used in disease diagnosis due to environmental toxicity. The acute combined effects of cadmium and nickel on biochemical parameters were determined and compared with those of Cd2+ or Ni2+ alone in rats. Male adult rats were given drinking solutions of CdCl2 [Cd(II) cation, 100 mg/liter] or NiSO4 [Ni(II) cation, 100 mg/liter]. For the combined treatment, the animals (Ni+Cd) received both Ni(II)) cation (100 mg/liter) and Cd(II) cation (100 mg/liter). Nickel treatment induced increased alanine transaminase (ALT) activity and hepatotoxicity, but not renal injury. In contrast, cadmium exposure produced hepatic, renal and myocardial damage, characterized by increased creatinine, total and direct bilirubin concentrations and increased ALT and lactate dehydrogenase (LDH) activities. The combined effect Ni-Cd is less toxic than cadmium alone, suggesting antagonism between these toxicants. The toxicity of nickel and cadmium, alone and in combination, decreased Cu-Zn superoxide dismutase (SOD) activity and increased lipoperoxide formation. (C) 1998 Elsevier B.V. Ltd. All rights reserved.

Combined effect of linezolid and N-acetylcysteine against Staphylococcus epidermidis biofilms

Introduction: Staphylococcus epidermidis is an organism commonly associated with infections caused by biofilms. Biofilms are less sensible to antibiotics and therefore are more difficult to eradicate. Linezolid and N-acetylcysteine (NAC), have demonstrated to be active against gram-positive microorganisms. Therefore and since linezolid and NAC have different modes of action, the main objective of this work was to investigate the single and synergistic effect of linezolid and NAC against S. epidermidis biofilms. Methods: This work reports the in vitro effect of linezolid and NAC against S. epidermidis biofilms, treated with MIC (4 mg ml-1) and 10×MIC of NAC, and MIC (1 μg ml-1) and peak serum concentration (PS = 18 μg ml-1) of linezolid alone and in combination. After exposure of S. epidermidis biofilms to linezolid and/or NAC for 24 h, several biofilm parameters were evaluated, namely the number of cultivable cells [colony forming unit (CFU) enumeration], total biofilm biomass and cellular activity. Results: When tested alone, NAC at 10×MIC was the most effective agent against S. epidermidis biofilms. However, the combination linezolid (MIC) + NAC (10×MIC) showed a synergistic effect and was the most biocidal treatment tested, promoting a 5 log reduction in the number of biofilm viable cells. Conclusion: This combination seems to be a potential candidate to combat infections caused by S. epidermidis biofilms, namely as a catheter lock solution therapy. © 2012 Elsevier España, S.L. All rights reserved.

The combined effect of acupuncture and Tanacetum parthenium on quality of life in women with headache: randomised study

Background The aim of the present study was to investigate the efficacy and tolerability of acupuncture (AC), Tanacetum (TAN) or combined treatment on quality of life in women with chronic migraine (CM). Methods A total of 69 women volunteers were randomly divided into 3 groups: AC, acupuncture administered in 20 sessions over 10 weeks (n=22); TAN, at 150 mg/day (n=23); and AC+TAN (n=23). The primary outcome was Short-Form 36 (SF-36) quality of life assessment score. Secondary outcomes included the Migraine Disability Assessment (MIDAS) and visual analogue scale (VAS) score experienced after randomisation. Results AC+TAN was statistically significantly more effective than AC or TAN alone in overall health-related quality of life (SF-36; p<0.05), on MIDAS score (-35.1 (10.6) AC vs -24.8 (11.7) TAN vs -42.5 (9.8) AC+TAN; p<0.05) and in reducing the mean score of pain on VAS (-5.6 (2.4) AC vs -3.7 (2.1) TAN vs -6.4 (3.1) AC+TAN; p<0.05). Conclusions The present work shows an improvement of the quality of life and better analgesic effect of acupuncture combined with TAN treatment on migraine pain in women when compared with acupuncture or TAN alone.

Combined effect of anterior malocclusion and inadequate lip coverage on dental trauma in primary teeth

Objectives: The main objective of this study was to investigate whether the interaction of malocclusion (open bite or increased overjet) combined with inadequate lip coverage strengthens its association with traumatic dental injury (TDI) in the primary teeth of preschool children compared to the presence of malocclusion alone. Subjects and methods: A cross-sectional survey was conducted with 376 children aged 3659 months who attended the National Day of Childrens Vaccination. Presence of TDI, tooth discoloration, and sinus tract were evaluated in the children. Variables associated with occlusion were also evaluated. A Poisson regression analysis was performed to verify the association between the explanatory variables and TDI as well as possible interactions among the variables. Then, the prevalence ratio was calculated. Results: The prevalence of TDI was 27.7%. The maxillary central incisor was the most affected tooth, without differences between the right and left sides. Boys had more dental trauma than girls (P = 0.04). The most common TDI was crown fracture restricted to the enamel (58.4%). Children with a combination of anterior open bite or increased overjet and inadequate lip coverage presented a higher prevalence of TDI than when the malocclusions were presented alone (P < 0.05). The same trends were observed when we included, in the final adjusted model, increased overjet instead of open bite. Conclusions: Anterior malocclusions of primary teeth such as increased overjet and anterior open bite are statistically significantly associated with dental trauma only when inadequate lip coverage is also present.

Combined effect of AMPK/PPAR agonists and exercise training in mdx mice functional performance

The present investigation was undertaken to test whether exercise training (ET) associated with AMPK/PPAR agonists (EM) would improve skeletal muscle function in mdx mice. These drugs have the potential to improve oxidative metabolism. This is of particular interest because oxidative muscle fibers are less affected in the course of the disease than glycolitic counterparts. Therefore, a cohort of 34 male congenic C57Bl/10J mdx mice included in this study was randomly assigned into four groups: vehicle solution (V), EM [AICAR (AMPK agonist, 50 mg/Kg-1.day-1, ip) and GW 1516 (PPAR delta agonist, 2.5 mg/Kg-1.day-1, gavage)], ET (voluntary running on activity wheel) and EM+ET. Functional performance (grip meter and rotarod), aerobic capacity (running test), muscle histopathology, serum creatine kinase (CK), levels of ubiquitined proteins, oxidative metabolism protein expression (AMPK, PPAR, myoglobin and SCD) and intracellular calcium handling (DHPR, SERCA and NCX) protein expression were analyzed. Treatments started when the animals were two months old and were maintained for one month. A significant functional improvement (p<0.05) was observed in animals submitted to the combination of ET and EM. CK levels were decreased and the expression of proteins related to oxidative metabolism was increased in this group. There were no differences among the groups in the intracellular calcium handling protein expression. To our knowledge, this is the first study that tested the association of ET with EM in an experimental model of muscular dystrophy. Our results suggest that the association of ET and EM should be further tested as a potential therapeutic approach in muscular dystrophies.

Combined effect of 25-OH vitamin D plasma levels and genetic vitamin D receptor (NR 1I1) variants on fibrosis progression rate in HCV patients

Decreased vitamin D levels have been described in various forms of chronic liver disease and associated with advanced fibrosis. Whether this association is a cause or consequence of advanced fibrosis remains unclear to date.

Prothrombotic changes with acute psychological stress: combined effect of hemoconcentration and genuine coagulation activation

INTRODUCTION: Acute psychosocial stress accelerates blood coagulation and elicits hemoconcentration which mechanisms are implicated in acute coronary thrombotic events. We investigated the extent to which the change in prothrombotic measures with acute stress reflects hemoconcentration and genuine activation of coagulation. MATERIAL AND METHODS: Twenty-one middle-aged healthy men underwent three sessions of a combined speech and mental arithmetic task with one-week intervals. Coagulation and plasma volume were assessed at baseline, immediately post-stress, and 45 min post-stress at sessions one and three. Measures of both visits were aggregated to enhance robustness of individual biological stress responses. Changes in eight coagulation measures with and without adjustment for simultaneous plasma volume shift were compared. RESULTS: From baseline to immediately post-stress, unadjusted levels of fibrinogen (p=0.028), clotting factor VII activity (FVII:C) (p=0.001), FVIII:C (p<0.001), FXII:C (p<0.001), and von Willebrand factor (VWF) (p=0.008) all increased. Taking into account hemoconcentration, fibrinogen (p=0.020) and FVII:C levels (p=0.001) decreased, activated partial prothrombin time (APPT) shortened (p<0.001) and prothrombin time (PT) was prolonged (p<0.001). Between baseline and 45 min post-stress, unadjusted (p=0.050) and adjusted (p=0.001) FVIII:C levels increased, adjusted APTT was prolonged (p=0.017), and adjusted PT was shortened (p=0.033). D-dimer levels did not significantly change over time. CONCLUSIONS: Adjustment for stress-hemoconcentration altered the course of unadjusted levels of several prothrombotic factors. After adjustment for hemoconcentration, APPT was shortened immediately post-stress, whereas 45 min post-stress, FVIII:C was increased and PT was shortened. Procoagulant changes to acute stress may reflect both hemoconcentration and genuine activation of coagulation molecules and pathways.

Combined effect of heterogeneity, anisotropy and saturation on steady state flow and transport: Structure recognition and numerical simulation

1 Natural soil profiles may be interpreted as an arrangement of parts which are characterized by properties like hydraulic conductivity and water retention function. These parts form a complicated structure. Characterizing the soil structure is fundamental in subsurface hydrology because it has a crucial influence on flow and transport and defines the patterns of many ecological processes. We applied an image analysis method for recognition and classification of visual soil attributes in order to model flow and transport through a man-made soil profile. Modeled and measured saturation-dependent effective parameters were compared. We found that characterizing and describing conductivity patterns in soils with sharp conductivity contrasts is feasible. Differently, solving flow and transport on the basis of these conductivity maps is difficult and, in general, requires special care for representation of small-scale processes.

Combined effect of soil bund with biological soil and water conservation measures in the northwestern Ethiopian highlands

Excessive runoff and soil erosion in the upper Blue Nile Basin poses a threat that has attracted the attention of the Ethiopian government because of the serious on-site effects in addition to downstream effects, such as the siltation of water harvesting structures and reservoirs. The objective of the study was to evaluate and recommend effective biophysical soil and water conservation measure(s) in the Debre Mewi watershed, about 30 km south of the Lake Tana. Six conservation measures were evaluated for their effects on runoff, soil loss, and forage yield using runoff plots. There was a significant difference between treatments for both runoff and soil loss. The four-year average annual soil loss in the different plots ranged from 26 to 71 t ha−1, and total runoff ranged from 180 to 302 mm, while annual rainfall varied between 854 mm in 2008 and 1247 mm in 2011. Soil bund combined with elephant grass had the lowest runoff and soil loss as compared to the other treatments, whereas the untreated control plot had the highest for both parameters. As an additional benefit, 2.8 and 0.7 t ha−1 year−1 of dried forage was obtained from elephant and local grasses, respectively. Furthermore, it was found that soil bund combined with Tephrosia increased soil organic matter by 13% compared to the control plot. Soil bund efficiency was significantly enhanced by combining them with biological measures and improved farmers’ perception of soil and water conservation measures.

Combined effect of a fluoride-, stannous- and chitosan-containing toothpaste and stannous-containing rinse on the prevention of initial enamel erosion-abrasion.

OBJECTIVES The aim of this study was to assess the preventive effect of a fluoride-, stannous- and chitosan-containing (F/Sn/chitosan-) toothpaste (TP) on initial enamel erosion and abrasion. METHODS In total, 150 human premolar enamel specimens were ground, polished and divided into 5 toothpaste/rinse groups (n=30): (G1) placebo-TP/tap water, (G2) sodium fluoride (NaF-) TP/tap water, (G3) F/Sn/chitosan-TP/tap water, (G4) F/Sn/chitosan-TP/Sn-rinse, (G5) NaF-TP/NaF-rinse. The 8-day erosion-abrasion cyclic treatment (one cycle/day) consisted of incubating the samples in artificial saliva (30min), then submitting the samples to toothbrush abrasion (2min incubation in toothpaste slurry; brushing with 20 toothbrush strokes) and rinsing (2min; 10ml) with the respective solution: tap water (G1-G3), Sn-rinse (G4) or NaF-rinse (G5). Afterwards, the samples were submitted to erosion (2min; 30ml 1% citric acid, pH=3.6). Surface microhardness (SMH) was measured initially and after every abrasion and erosion treatment. Enamel substance loss was calculated after each abrasion. Non-parametric ANOVA followed by Wilcoxon rank tests were used for analysis. RESULTS G1 presented the greatest SMH decrease, while G4 presented the least SMH decrease (p<0.001). G3 had a similar SMH decrease to G2 and G5. Substance loss was significantly lower in G4 than all other groups (p<0.05), closely followed by G3. Both G2 and G5 showed similar calculated enamel substance loss to G1. CONCLUSION The treatment with F/Sn/chitosan-TP and tap water provided a similar SMH decrease to both NaF-TP groups, but significantly lower substance loss. F/Sn/Chitosan-TP and Sn-rinse showed a better preventive effect, which promoted less SMH decrease and reduced substance loss. CLINICAL SIGNIFICANCE The toothpaste containing fluoride, stannous and chitosan shows promising results in reducing substance loss from erosion and abrasion. The combination of this toothpaste with the stannous-containing rinse showed even better prevention against erosion-abrasion.