Morphological and Crystallographic Transformation from Immature to Mature Coccoliths, <Emphasis Type="Italic">Pleurochrysis carterae</Emphasis>

Morphology and crystallographic orientations of coccoliths, Pleurochrysis carterae, at the various growth stages were investigated using electron back-scattered diffraction analyses and scanning electron microscope (SEM) stereo-photogrammetry to understand the developments of two different coccolith units, namely V and R units. SEM observation indicates that the immature coccolith units at the earliest stage were not perfectly fixed on the organic base plates and several units were often lacked. The all units showed platy morphology and often lay parallel to the organic base plate. Their crystal orientations were close to that of the mature R units. With further growth, the platy morphology changes to a trapezoid to anvil-shape for both units, resulting in the interlocking structure of VR units. Morphological analyses present that the edges of the platy crystals parallel to the organic base plate were estimated as $<48\;\overline 1>$<48\;\overline 1>, and their inner/upper surfaces were estimated as { 10  [`1]  4} \{ 10\;\overline 1 \,4\} . As they interlocked further, R units inclined more outward to develop the inner tube elements with { 10  [`1]  4} \{ 10\;\overline 1 \,4\} and then each unit develops differently distal and proximal shield elements, which are respectively estimated as { 10  [`1]  4} \{ 10\;\overline 1 \,4\} in the distal view and { 2 [`1]   [`1]  0} \{ 2\,\overline 1 \;\overline 1 \,0\} planes in the proximal view. Based on the above results, the formation of different coccolith units and their growth were discussed.     

Self-thinning lines of organs and aboveground parts based on allometric relationships in overcrowded Pinus densiflora stands

The allometric relationships of mean tree height [`(H)]( μ [`(w)]_x^q ) \bar{H}( \propto \bar{w}_{\rm {x}}^{\theta } ) and of organ mass density [`(d)]<sub>x</sub> ( μ [`(w)]_x^d ) \bar{d}_{\rm {x}} ( \propto \bar{w}_{\rm {x}}^{\delta } ) to mean organ mass [`(w)]_x \bar{w}_{\rm {x}} were studied in self-thinning Pinus densiflora Sieb. et Zucc. stands. Tree height increased significantly with increasing mean mass of organs and aboveground parts on log–log coordinates. The value of the allometric constant θ ranged from 0.2878 to 0.3349. On the other hand, the constant value δ was not significantly different from zero, except for leaves. The value of the allometric constant δ ranged from −0.2926 to 0.0120. According to Weller’s allometric model, the slope of the self-thinning line was calculated from the allometric constants θ and δ. The thinning slope was estimated to be −1.51 in stem, −1.39 in branches, −1.00 in leaf and −1.41 in aboveground parts, respectively. Mass density was high in stem, medium in branches and low in leaves. Mean leaf mass density decreased significantly with decreasing stand density on log–log coordinates, which could be interpreted as indicating the importance of the constant final leaf biomass in overcrowded P. densiflora stands. The self-thinning exponents of branch, stem and aboveground parts were not significantly different from 3/2, which indicated that the 3/2 power law of self-thinning holds for stem mass, branch mass and aboveground mass in overcrowded P. densiflora stands.     

Gene stacking strategies with doubled haploids derived from biparental crosses: theory and simulations assuming a finite number of loci

Recent progress in genotyping and doubled haploid (DH) techniques has created new opportunities for development of improved selection methods in numerous crops. Assuming a finite number of unlinked loci (ℓ) and a given total number (n) of individuals to be genotyped, we compared, by theory and simulations, three methods of marker-assisted selection (MAS) for gene stacking in DH lines derived from biparental crosses: (1) MAS for high values of the marker score (T, corresponding to the total number of target alleles) in the F₂ generation and subsequently among DH lines derived from the selected F₂ individual (Method 1), (2) MAS for augmented F₂ enrichment and subsequently for T among DH lines from the best carrier F₂ individual (Method 2), and (3) MAS for T among DH lines derived from the F₁ generation (Method 3). Our objectives were to (a) determine the optimum allocation of resources to the F₂ ( n₁^* \, n_{1}^{*} ) and DH generations (n - n₁^* ) (n - n_{1}^{*} ) for Methods 1 and 2 by simulations, (b) compare the efficiency of all three methods for gene stacking by simulations, and (c) develop theory to explain the general effect of selection on the segregation variance and interpret our simulation results. By theory, we proved that for smaller values of ℓ, the segregation variance of T among DH lines derived from F₂ individuals, selected for high values of T, can be much smaller than expected in the absence of selection. This explained our simulation results, showing that for Method 1, it is best to genotype more F₂ individuals than DH lines ($ n_{1}^{*} :n > 0.5 $ n_{1}^{*} :n > 0.5 ), whereas under Method 2, the optimal ratio n₁^* :n n_{1}^{*} :n was close to 0.5. However, for ratios deviating moderately from the optimum, the mean [`(X)] \overline{X} of T in the finally selected DH line ( T<sub>\textDH</sub><sup>*</sup> T_{\text{DH}}^{*} ) was hardly reduced. Method 3 had always the lowest mean [`(X)] \overline{X} of T_\textDH^* T_{\text{DH}}^{*} except for small numbers of loci (ℓ = 4) and is favorable only if a small number of loci are to be stacked in one genotype and/or saving one generation is of crucial importance in cultivar development. Method 2 is under most circumstances the superior method, because it generally showed the highest mean [`(X)] \overline{X} and lowest SD of T_\textDH^* T_{\text{DH}}^{*} for the finally selected DH.     

Different habitat use strategies by subadult and adult ringed seals (<Emphasis Type="Italic">Phoca hispida</Emphasis>) in the Bering and Chukchi seas

Habitat partitioning by adult and subadult ringed seals (Phoca hispida) is poorly understood. Conclusions about displacement of subadult seals to suboptimal offshore habitat are largely based on nearshore observations as few satellite tagging studies include data from winter months. In this study, movement patterns of 14 subadult and 11 adult ringed seals were monitored in the Bering and Chukchi seas using satellite-linked telemetry. Seals were captured in Kotzebue Sound, Alaska, during October 2007 and 2008 and tracked for 17–297 days. Subadult ringed seals traveled south from the Chukchi Sea into the Bering Sea ([`(x)] \bar{x}  = 36 km/day) as sea ice coverage increased during November and December, remained ~1,000 km south near the ice edge during winter and returned north in the spring with the receding ice edge. Adults remained in the Chukchi and northern Bering seas, where their movements were more localized ([`(x)] \bar{x}  = 22 km/day). Adults were on average 322 km farther from the ice edge and 48 km closer to land and shorefast ice than were subadults. During winter, adult ringed seals construct and maintain breathing holes through the ice, and in spring, females give birth in subnivean lairs, mostly in shorefast ice; adult males defend breeding territories around those lairs. Our results show that subadult ringed seals, unconstrained by the need to maintain territories that contain stable breeding/pupping habitat, moved south to the Bering Sea ice edge, where there are better feeding opportunities, lower energetic costs (no breathing hole maintenance), and less exposure to predation.     

Survival and cause-specific mortality of female Rocky Mountain elk exposed to human activity

Animal populations are becoming increasingly exposed to human activity as human populations expand and demand for energy resources (e.g., coal, oil and natural gas) increases. We initiated this study to document survival and cause-specific mortality patterns of female Rocky Mountain elk (Cervus elaphus) exposed to increasing levels of human activity. We fitted 184 females with VHF or GPS collars over 4 years and used the Kaplan–Meier survival estimator to calculate annual survival rates. We used multinomial logistic regression to assess differences in cause-specific mortality and generalized linear mixed models to determine how probability of survival was structured during hunting season; both analyses examined a suite of 5 covariates (i.e., age, year, extent of space use, cover, and human footprint) as potentially influencing cause-specific mortality and survival probability. Annual probability of survival averaged 0.8 (±0.02 SE) over 4 years but averaged 0.91 (±0.03 SE) when harvest mortality was excluded, which was the most significant source of mortality in most years ( [`(x)] = 0.13 ±0.02 \textSE \bar{x} = 0.13 \pm 0.02\,{\text{SE}} ). We found no difference between cause-specific mortality sources relative to elk that survived during the hunting season (χ ₁₀² = 5.79, P = 0.832). The probability of a female surviving during hunting season was negatively influenced by age, year, extent of space use, cover, and human footprint. We found evidence that human activity may have influenced annual rates of natural survival (i.e., exclusive of hunting mortality) and probability of survival during the hunting season. We note that this study occurred largely on privately owned and managed residential and ranch land and focused on female elk; we acknowledge that survival rate and cause-specific patterns of mortality may vary as a function of land ownership (private vs. public), demographic status, and management and harvest practices. While temporal and spatial scales of 1 week may be sufficient to describe patterns of direct mortality during hunting season, broad temporal or spatial scale analyses may be needed to address natural mortality during other seasons.     

A novel biotransformation process of 4′-demethylepipodophyllotoxin to 4′-demethylepipodophyllic acid by Bacillus fusiformis CICC 20463, Part II: process optimization

This work optimized the novel biotransformation process of 4′-demethylepipodophyllotoxin (DMEP) into 4′-demethylepipodophyllic acid (DMEPA) by Bacillus fusiformis CICC 20463. Firstly, the biotransformation process was significantly affected by medium composition. 5 g/L of yeast extract and 10 g/L of peptone were optimal for DMEPA production (i.e., 2.81 ± 0.21 mg/L), while not beneficial for the cell growth of B. fusiformis. This indicated that the biosynthesis of DMEPA was not corresponded well to the cell growth of B. fusiformis. 40 g/L of sucrose was optimal for DMEPA production (i.e., 2.94 ± 0.17 mg/L), and 3 g/L of NaCl was the best for DMEPA production (i.e., 4.10 ± 0.18 mg/L). Secondly, the production of DMEPA was significantly enhanced by the control of substrate concentration and culture pH. 100 mg/L of substrate was optimal for DMEPA production (i.e., 6.47 ± 0.35 mg/L), and DMEPA concentration was enhanced to 38.78 mg/L by controlling culture pH at 9.0 in the stirred-tank bioreactors. The fundamental information obtained in this study provides a simple and efficient way to produce DMEPA by biotransformation.     

Effect of prebiotics on bacteriocin production and cholesterol lowering activity of <Emphasis Type="Italic">Pediococcus acidilactici</Emphasis> LAB 5

The in vitro influence of three prebiotics viz. mannitol, maltodextrin and sorbitol was evaluated on probiotic aspects like bile salt tolerance, cholesterol lowering efficiency and bacteriocin production of the strain, Pediococcus acidilactici LAB 5 which was isolated from vacuum packed fermented meat product. Optimum temperature for bacteriocin production in MRS medium was 37°C. The strain deconjugated bile salt (sodium taurocholate) to 607.66 ± 10.894 μg/ml from initial bile salt concentration 3 mg/ml. In vitro cholesterol removal capability of the strain P. acidilactici LAB 5 was 62 ± 2.742 μg/ml. Prebiotic sorbitol had a positive influence on the probiotic parameters like better cell growth, bacteriocin production and cholesterol removal capability. Anaerobic condition had influenced largely on bile salt deconjugation, cholesterol removal and bacteriocin production. Synbiotic treatment of P. acidilactici LAB 5 with sorbitol for 1 month lowered the plasma cholesterol level to 176.34 ± 12.66 μg/ml in comparison to untreated one (208.76 ± 20.27 μg/ml) in Swiss albino mice. Intestinal adherence of P. acidilactici LAB 5 was also more in synbiotic condition than only in probiotic and control treatments.     

Trp203 mutation in GroEL promotes a self-association reaction: a hydrodynamic study

A combination of sedimentation equilibrium and sedimentation velocity in the analytical ultracentrifuge is used to investigate the hydrodynamic integrity and increased self-association interactions of the mutant GroEL Y203W when compared to the wild-type GroEL molecule, which may be derived from increased hydrophobic exposure caused by the mutation. Sedimentation velocity has revealed that three distinct species were present throughout the concentration ranges used, corresponding to 14-mer (GroEL “super monomer”) and 28-mer (“super dimer”) subunit compositions with a small amount of 42-mer (“super trimer”), which, from the relative concentration of each species, would give an estimated weight average molecular weight of (1.0 ± 0.1) × 10⁶ Da. Sedimentation equilibrium gave an apparent weight average molecular weight (M _w,app) of (910,000 ± 5000) Da, which is in agreement with these findings. These results are in contrast to wild-type GroEL which, in excellent agreement with the previous findings of Behlke and co-workers, revealed a single species with an M _w,_app of (805,000 ± 5200) Da and a sedimentation coefficient s ⁰ _20,w of (21.6 ± 0.3) S. We therefore conclude that the tryptophan mutation at the Y203 location causes a significant degree of self-association of the GroEL 14-mer assembly (with dimer and trimer present). These findings would appear to correlate well with the findings of Gibbons et al., who showed an increase in hydrophobic exposure due to this mutation. Received: 4 January 2000 / Revised version: 5 April 2000 / Accepted: 5 April 2000     

Cross-talk between one-carbon metabolism and xenobiotic metabolism: implications on oxidative DNA damage and susceptibility to breast cancer

The aim of this case–control study is to explore the role of aberrations in xenobiotic metabolism in inducing oxidative DNA damage and altering the susceptibility to breast cancer. Cytochrome P4501A1 (CYP1A1) m1 (OR: 1.41, 95% CI 1.08–1.84), CYP1A1 m4 (OR: 5.13, 95% CI 2.68–9.81), Catecholamine-O-methyl transferase (COMT) H108L (OR: 1.49, 95% CI 1.16–1.92), and glutathione S-transferase (GST) T1 null (OR: 1.68, 95% CI 1.09–2.59) variants showed association with breast cancer risk. Reduced folate carrier 1 (RFC1) 80A/CYP1A1 m1/CYP1A1 m4 and RFC1 80A/thymidylate synthase (TYMS) 5′-UTR 2R/methionine synthase (MTR) 2756G/COMT 108L genetic combinations were found to inflate breast cancer risk under the conditions of low dietary folate (345 ± 110 vs. 379 ± 139 μg/day) and low plasma folate (6.81 ± 1.25 vs. 7.09 ± 1.26 ng/ml) by increasing plasma 8-oxo-2′-deoxyguanosine (8-oxodG). This increase in 8-oxodG is attributed to low methionine (49.38 ± 23.74 vs. 53.90 ± 23.85 μmol/l); low glutathione (378 ± 242 vs. 501 ± 126 μmol/l) and GSTT1 null variant; and hypermethylation of CpG island of extracellular-superoxide dismutase (EC-SOD) (92.78 ± 11.49 vs. 80.45 ± 9.86%), which impair O-methylation of catechol estrogens to methoxy estrogens, conjugation of glutathione to semiquinones/quinones and free radical scavenging respectively. Our results suggest cross-talk between one-carbon metabolism and xenobiotic metabolism influencing oxidative DNA damage and susceptibility to breast cancer.     

Characteristics of Se-Enriched Mycelia by Stropharia rugoso-annulata and its Antioxidant Activities in vivo

Selenium (Se) is an essential trace element for humans and animals. Stropharia rugoso-annulata is a nutritional and functional mushroom containing many kinds of bioactive ingredients. The aims of this study were to investigate the Se-enrichment characteristics of S. rugoso-annulata in submerged culture and evaluate the antioxidant activities of Se-enriched mycelia in vivo in terms of the values of glutathione peroxidase (GSH-Px), superoxide dismutase (SOD), and malondialdehyde (MDA). The optimum parameters of Se-enrichment under the optimal Se concentration (150 μg/mL) in media were as follows: biomass 8.11 ± 0.25 g/L, Se content in mycelia 4,727.68 ± 13 μg/g, Se-accumulated rate 24.68 ± 1.67%, and percentage of organic Se 96.27 ± 3.26%. The mainly subsistent forms of selenium in Se-enriched mycelia were selenoprotein and selenium-polysaccharide. The contents of total amino acids (TAA) and essential amino acids (EAA) in Se-enriched mycelia were increased by 13.5 ± 1.09% and 12.8 ± 0.89%, respectively. It was efficient for Se-enriched mycelia to elevate GSH-Px and SOD activities and decrease MDA content. These results indicated that Se-enriched mycelia of S. rugoso-annulata represent a novel dietary source of bioavailable supplemental selenium.     

Endogenous profiles of indoleamines: serotonin and melatonin in different tissues of Coffea canephora P ex Fr. as analyzed by HPLC and LC-MS-ESI

Endogenous indoleamine profiles in various ex vitro and in vitro tissues of commercially important Coffea canephora were analyzed by using a high performance liquid chromatography and further confirmed with electrospray ionization mass spectrometry. High content of serotonin (SER) (98.54 ± 5 μg/g) and melatonin (MEL) (115.25 ± 6 μg/g) were found in freshly harvested seeds of C. canephora followed by zygotic embryo (65.25 ± 4 and 96.54 ± 5 μg/g fresh weight) and endosperm (34.08 ± 2 and 51.08 ± 4 μg/g fresh weight) of ripened fruits. Similarly endogenous pools of SER and MEL were moderate in in vitro tissues of C. canephora, i.e. callus (25.85 ± 2 and 75.74 ± 4), somatic embryos (31.88 ± 2 and 19.30 ± 2 μg/g fresh weight) and in vitro regenerated plant stalk (15.78 ± 1 and 38.25 ± 3 μg/g fresh weight), respectively. In view of significant levels of both SER and MEL in various tissues and beans of Coffea, further investigations on their physiological role needs to be investigated.     

Contribution of central versus sweat gland mechanisms to the seasonal change of sweating function in young sedentary males and females

In summer and winter, young, sedentary male (N = 5) and female (N = 7) subjects were exposed to heat in a climate chamber in which ambient temperature (Ta) was raised continuously from 30 to 42°C at a rate of 0.1°C min⁻¹ at a relative humidity of 40%. Sweat rates (SR) were measured continuously on forearm, chest and forehead together with tympanic temperature (Tty), mean skin temperature ( [`T] s ) \left( {\overline {\hbox{T}} {\hbox{s}}} \right) and mean body temperature ( [`T] b ) \left( {\overline {\hbox{T}} {\hbox{b}}} \right) . The rate of sweat expulsions (Fsw) was obtained as an indicator of central sudomotor activity. Tty and ( [`T] b ) \left( {\overline {\hbox{T}} {\hbox{b}}} \right) were significantly lower during summer compared with winter in males; SR was not significantly different between summer and winter in males, but was significantly higher during summer in females; SR during winter was higher in males compared with females. The regression line relating Fsw to ( [`T] b ) \left( {\overline {\hbox{T}} {\hbox{b}}} \right) shifted significantly from winter to summer in males and females, but the magnitude of the shift was not significantly different between the two subject groups. The regression line relating SR to Fsw was steepened significantly from winter to summer in males and females, and the change in the slope was significantly greater in females than in males. Females showed a lower slope in winter and a similar slope in summer compared to males. It was concluded that sweating function was improved during summer mediated by central sudomotor and sweat gland mechanisms in males and females, and, although the change of sweat gland function from winter to summer was greater in females as compared with males, the level of increased sweat gland function during summer was similar between the two subject groups.     

Changes in Trace Elements during Follicular Atresia in Goat (<Emphasis Type="Italic">Capra hircus</Emphasis>) Ovary

Quantitative analysis of follicular fluid and granulosa cells from small, medium and large antral atretic follicles of goat (Capra hircus) ovaries was conducted to study the alterations in trace elements viz zinc (Zn), copper (Cu), manganese (Mn), and iron (Fe). The zinc content was lower in the follicular fluid (0.993 ± 0.001, 0.935 ± 0.002, 1.321 ± 0.001 μg/ml) and granulosa cells (0.867 ± 0.002, 0.801 ± 0.001, 1.073 ± 0.002 μg/mg) of small, medium, and large antral atretic follicles respectively than their respective controls. Copper quantity was higher in the follicular fluid (0.113 ± 0.001, 0.163±0.001 0.{163}\pm 0.00{1} , 0.224 ± 0.001 μg/ml) and granulosa cells (0.094 ± 0.001, 0.114 ± 0.001, 0.182 ± 0.001 μg/mg) from small, medium, and large antral atretic follicles respectively than their respective controls. Similarly, iron and manganese was also found higher in the follicular fluid and granulosa cells of small, medium, and large antral atretic follicles than their respective controls. The present study provides the basic data on trace elements that can be safely used as atretic marker and will find use in in vitro studies for fertility improvement plan. Thus, help in elevating the number of ovulations and screening of follicles to enhance the success rate in vivo and in vitro fertilization and embryo transfer technology.     

Biological activity of enantiomeric complexes [PtCl2L2] (L2 is aromatic bisphosphanes and aromatic diamines)

Enantiomeric complexes of formula [PtCl₂L₂] [L₂ is (R)-(+)-BINAP and (S)-(−)-BINAP, where BINAP is 2,2′-bis(diphenylphosphane)-1,1′-binaphthyl, and (R)-(+)-DABN and (S)-(−)-DABN, where DABN is 1,1′-binaphthyl-2,2′-diamine], were tested for their cytotoxic activity against three cancer cell lines and for their ability to bind to the human telomeric sequence folded in the G-quadruplex structure. Similar experiments were carried out on prototypal complexes cisplatin and cis-[PtCl₂(PPh₃)₂] for comparison. Platinum complexes containing phosphanes proved less cytotoxic to cancer cell lines and less likely to interact with the nucleobases of the G-quadruplex than those containing amines; in both cases the S-(−) isomer was more active than the R-(+) counterpart. More specifically, whereas all the platinum complexes were able to platinate the G-quadruplex structure from the human telomeric repeat, the extent and sites of platination depended on the nature of the ligands. Complexes containing (bulky) phosphanes interacted only with the adenines of the loops, whereas those containing the less sterically demanding amines interacted with adenines and some guanines of the G-quartet.     

Oxidized LDL and its correlation with lipid profile and oxidative stress biomarkers in young healthy Spanish subjects

The biological effects of oxidized LDL (oxLDL) may contribute to initiation and progression of the atherosclerotic process, and the association between cardiovascular disease and oxidation of LDL has been largely demonstrated. The objectives of this study were to establish the reference values of oxidative stress biomarkers in a young healthy Spanish population to determine the concentration of oxLDL and its relationship with lipid profile and with these biomarkers. oxLDL, F₂-isoprostanes, protein carbonyls (PC), and 8-hydroxy-2′-deoxyguanosine (8-OHdG) were determinate by ELISA in 72 healthy subjects. Antioxidant enzymes, superoxide dismutase (SOD), glutathione peroxidase (GPx), and glutathione reductase (GR) were carried out on a Hitachi 912 analyzer; lipid profile were assayed using automated systems (Cobas 711, Roche Diagnostics). All statistics were analyzed by using SPSS for Windows 15.0. SPSS Inc, Chicago, IL, USA. (Normal mean reference values): oxLDL (63.23 ± 16.23 U/L), (Male/Female 68.06 ± 17.69/58.39 ± 13.6 U/L), F₂-isoprostanes (2.26 ± 0.9 μg/g creatinine), PC (0.34 ± 0.15 nmol/mg), 8-OHdG (23.27 ± 10.58 ng/ml), SOD (931.97 ± 271.09 U/g Hb), GR (46.56 ± 11.68 U/L), GPx (27.58 ± 6.89 U/gHb (Male/Female 25.91 ± 5.03/29.2 ± 8.07 U/L)). OxLDL (63.23 U/L) was significantly (p < 0.05) positively correlated with BMI (22.53 Kg/m²), total cholesterol (175.79 mg/dl), triglycerides (87.58 mg/dl), LDL cholesterol (96.25 mg/dl), and uric acid (4.78 mg/dl), while negatively correlated with HDL-cholesterol (62.25 mg/dl). We have found different correlation between oxLDL and isoprostanes by gender with the rest of parameters. Normal reference values have been found significantly different for oxLDL and GPx by gender. Oxidized LDL is correlated with lipid profile but not with the oxidative stress biomarkers. Urinary isoprostanes are positively correlated with triglycerides and negatively with GR and GPx.     

Effects of zinc ex vivo and intracellular zinc chelator in vivo on taurine uptake in goldfish retina

Taurine and zinc exert neurotrophic effects. Zinc modulates Na⁺/Cl⁻-dependent transporters. This study examined the effect of zinc (ZnSO₄) ex vivo and zinc chelator N,N,N′,N′-tetrakis-(2-pyridylmethyl) ethylenediamine (TPEN) in vivo on [³H]taurine transport in goldfish retina. The effect of TPEN in vivo on taurine and zinc levels was determined. Isolated cells were incubated in Ringer with zinc (0.1–100 μM). Taurine transport was done with taurine (0.001–1 mM) and 50 nM [³H]taurine. Zinc (100 μM) noncompetitively inhibited taurine transport. TPEN was administered intraocularly and retinas extracted 3, 5 and 10 days later. Taurine was determined by HPLC (nmol/mg protein) and zinc by spectrophotometry ICP (mg/mg protein). Taurine and zinc levels decreased at 3 days and increased at 10 days after TPEN administration. At 10 days after intraocular TPEN, taurine transport affinity increased (K _s = 0.018 ± 0.006 vs. 0.028 ± 0.008 mM). Apparently, zinc deficiency affects the taurine–zinc complex and taurine availability. The increased taurine uptake affinity by TPEN was possibly associated with a response to maximize retinal taurine content at low zinc concentration.     

Monitoring of resistance or susceptibility of adults and larvae of <Emphasis Type="Italic">Amblyomma cajennense</Emphasis> (Acari: Ixodidae) to synthetic acaricides in Goiás,Brazil

Amblyomma cajennense or the Cayenne tick is a three-host ixodid tick species of low parasitic specificity that is the principal vector of Brazilian spotted fever. The primary objective of this study was to evaluate the possible development of resistance by adult specimens of A. cajennense to deltamethrin, a synthetic pyrethroid insecticide and the principal miticide/acaricide commercially available in the region. The second objective was to monitor the susceptibility and/or resistance of larvae of this species to 12 synthetic acaricide formulations selected from the principal pesticides available in Goiás for the control of ticks. Unfed male and female adult specimens of A. cajennense were collected from leaves of bushes along a nature trail in the municipality of Caldas Novas, Goiás, Brazil. They were submitted to immersion in the highest recommended dose of deltamethrin and subsequently, were placed in contact with filter paper impregnated with the substance. The toxicological effects caused by the insecticide were observed every 6 h over a 36 h period. To obtain larvae, engorged females of A. cajennense were collected from naturally infested horses that had been free of acaricidal residue for at least 45 days, in farms situated in five different municipalities in the state (Caldas Novas, Hidrolandia, Goiás, Terezópolis and Goiania). The larvae were exposed to different concentrations of 12 commercially available acaricidal formulations using the larval packet test (LPT) method. The control groups were treated with distilled water alone. The bioassays were performed in quadruplicate at a temperature of 27°C, relative air humidity >80% and 12 h light/dark cycles. The mean percentage of mortality (M[`(X)] M\bar{X} ) was 72.6% in the adult specimens after 24 h of expsure to the dose of deltamethrin recommended by the manufacturer, characterizing a status of resistance. M[`(X)] M\bar{X} of 82, 89, 89.6 and 90% of the larvae were obtained, respectively, for deltamethrin, cypermethrin + piperonyl butoxide (PBO), amitraz and permethrin, characterizing a status of probable resistance of the larvae to these acaricides. No significant mortality was found in the control groups.     

Comparison of metabolite levels in callus of <Emphasis Type="Italic">Tecoma stans</Emphasis> (L.) Juss. ex Kunth. cultured in photoperiod and darkness

Tecoma stans is a tropical plant from the Americas. Antioxidant activity and both phenolic compound and flavonoid total content were determined for callus tissue of T. stans cultured in either a set photoperiod or in darkness. Callus lines from three explant types (hypocotyls, stem, and leaf) were established on B5 culture medium supplemented with 0.5 μM 2,4-D and 5.0 μM kinetin. While leaf-derived callus grew slower under a 16-h photoperiod (specific growth rate, μ = 0.179 d⁻¹, t _D = 3.9 d) than in darkness (μ = 0.236 d⁻¹, t _D = 2.9 d), it accumulated the highest amount (p < 0.05) of both phenolics (86.6 ± 0.01 mg gallic acid equivalents/g) and flavonoids (339.6 ± 0.06 mg catechin equivalents/g). Similarly, antioxidant activity was significantly higher (p < 0.05) when callus was cultured in period light than when grown in extended darkness. Antioxidant activity measured with a 2,20-azinobis (3-ethylbenzothiazoline-6-sulphonic acid) diammonium salt (ABTS)-based assay was 350.5 ± 15.8 mmol Trolox/g extract for callus cultured under a defined photoperiod compared to 129.1 ± 7.5 mmol Trolox/g extract from callus cultured in darkness. Content of phenolic compounds and flavonoids was in agreement with a better antioxidant power (EC₅₀ = 450 μg extract/mg 1,1-diphenyl-2-picrylhydrazyl) and antiradical efficiency. Results of the present study show that calli of T. stans are a source of compounds with antioxidant activity that is favored by culture under a set photoperiod.     

Spatial and temporal interactions of sympatric mountain lions in Arizona

Spatial and temporal interactions among individual members of populations can have direct applications to habitat management of mountain lions (Puma concolor). Our objectives were to evaluate home range overlap and spatial/temporal use of overlap zones (OZ) of mountain lions in Arizona. We incorporated spatial data with genetic analyses to assess relatedness between mountain lions with overlapping home ranges. We recorded the space use patterns of 29 radio-collared mountain lions in Arizona from August 2005 to August 2008. We genotyped 28 mountain lions and estimated the degree of relatedness among individuals. For 26 pairs of temporally overlapping mountain lions, 18 overlapped spatially and temporally and eight had corresponding genetic information. Home range overlap ranged from 1.18% to 46.38% ( [`(x)] = \text24.\text43 \overline x = {\text{24}}.{\text{43}} , SE = 2.96). Male–male pairs were located within 1 km of each other on average, 0.04% of the time, whereas male–female pairs on average were 3.0%. Two male–male pairs exhibited symmetrical spatial avoidance and two symmetrical spatial attractions to the OZ. We observed simultaneous temporal attraction in three male–male pairs and four male–female pairs. Individuals from Tucson were slightly related to one another within the population (n = 13, mean R = 0.0373 ± 0.0151) whereas lions from Payson (n = 6, mean R = −0.0079 ± 0.0356) and Prescott (n = 9, mean R = −0.0242 ± 0.0452) were not as related. Overall, males were less related to other males (n = 20, mean R = −0.0495 ± 0.0161) than females were related to other females (n = 8, mean R = 0.0015 ± 0.0839). Genetic distance was positively correlated with geographic distance (r ² = 0.22, P = 0.001). Spatial requirements and interactions influence social behavior and can play a role in determining population density.     

Chronic Fluoride Exposure Has a Role in Etiology of Coronary Artery Ectasia: Sialic Acid/Glycosaminoglycan Ratio

The sialic acid/glycosaminoglycan ratio was determined in 35 coronary artery ectasia patients and 35 control subjects to determine the possible role of fluoride in the etiology of the disease. The coronary artery ectasia patients and controls were selected from subjects who underwent coronary angiography. The mean serum sialic acid level was significantly lower in patients with coronary artery ectasia (CAE) than in controls (340.3 ± 28.6 vs. 427.0 ± 15.9 μg/mL, respectively; p < 0.001). The mean serum glycosaminoglycan level was significantly higher in patients with CAE than in controls (5,013.1 ± 158.6 vs. 3,833.6 ± 237.1 μg/mL, respectively; p < 0.001). The sialic acid/glycosaminoglycan ratio in patients with coronary artery ectasia was significantly lower than in controls (0.068 ± 0.007 vs. 0.111 ± 0.005; p < 0.001). There was more than 38.7% reduction in this ratio in patients with CAE when compared with controls. We demonstrated that chronic fluoride exposure has an important role in pathogenesis of coronary artery ectasia.