Preparation of a composite film electrochemically deposited with chitosan and gold nanoparticles for the determination of α-1-fetoprotein

A novel amperometric immunosensor based on chitosan–gold nanoparticles (Chit–GNPs) composite film and thionine (Thi) was prepared for the determination of α-1-fetoprotein (AFP). The immunosensor was prepared by electro-depositing a Chit–GNPs composite matrix on the surface of the glass carbon electrode, then Thi was immobilized onto the Chit–GNPs film using glutaraldehyde as a cross-linker. Furthermore, the GNPs were chemisorbed onto Thi film for immobilization of α-1-fetoprotein antibody. The procedure of the immunosensor was characterized by means of cyclic voltammograms. The performance and influencing factors of the resulting immunosensor were studied in details. Under optimal conditions, the immunosensor was highly sensitive to AFP and the linear range covered from 0.40 to 200.0 ng mL⁻¹ with a detection limit of 0.24 ng mL⁻¹ at three times background noise. Moreover, the simple and controllable electro-deposition method overcame the irreproducibility for preparing Chit-based immunosensor systems and the proposed immunosensor displayed a satisfactory reproducibility and stability.     

Subcellular distribution of aluminum, bismuth, cadmium, chromium, copper, iron, manganese, nickel, and lead in cultivated mushrooms (Agaricus bisporus and Pleurotus ostreatus)

In this work, the distribution of nine metals in two types of cultivated mushroom had been investigated. For Agaricus bisporus, the biomass was separated into caps and stalks, and for Pleurotus ostreatus, the entire mushrooms were taken for analysis. Electrothermal atomic absorption spectrometry was used for total element determination in acid digests. For accuracy checking, the certified reference material (NIST 1571, citrus leaves) was analyzed. The results obtained for the two fungi species were within the ranges of concentration reported previously by other authors. Subcellular fractionation was accomplished by centrifugation of cell homogenates, which has been suspended in Tris-HCl buffer. In the first centrifugation (7300g, 4°C, 10 min), cell walls were separated (pellet I), and the second centrifugation (147,000g, 4°C, 60 min) yielded mixed membrane fraction (pellet II) and cytosol (supernatant II). Recoveries of the fractionation procedure were in the range 70–100% (with the exception of Fe). For all elements studied, the highest relative contributions were found in cytosol fractions of the fruiting bodies (63–72%, 49–76%, 44–93%, 26–87pc, 55–85%, 50–68%, 41–78%, 39–78%, 54–67% respectively for Al, Bi, Cd, Cr, Cu, Fe, Mn, Ni, and Pb. Lower contributions were found in cell walls (respectively 22–32%, 24–44%, 6.1–47%, 12–52%, 7.3–37%, 7.9–32%, 19–52%, 20–42%, and 25–38%) and only minute amounts in the mixed membrane fraction (3.0–5.8%, 0.7–7.0%, 0.7–8.3%, 1.0–22%, 7.5–14%, 16–24%, 1.1–19%, and 5.1–7.7%). The results obtained indicate that small water-soluble molecules were the primary forms of nine elements in two mushroom species studied. On the other hand, the evidence has been provided on elements binding to larger, water-insoluble molecules contained in the structures of cell wall and membranes. The relative distribution was both element and fungi dependent. Thus, in P. ostreatus, total element levels were higher than in A. bisporus, with the preference for their accumulation in cytosol. On the contrary, total element content in the latter fungi was lower; however, a clear tendency toward more efficient element incorporation to the water-insoluble structures was observed (no apparent differences between stalks and caps). These findings might contribute in a better understanding of the accumulation of metals in mushrooms.     

Microbial population dynamics, especially stress tolerant Bacillus thuringiensis, in partially anaerobic rice field soils during post-harvest period of the Himalayan, island, brackish water and coastal habitats of India

Population ( × 10⁷ c.f.u./g dr. soil) of the aerobic (30.5–154.1) and anaerobic (5.9–91.4) heterotrophic, aerobic (24.0–56.0) and anaerobic (2.4–4.2) spore forming, Gram (-)ve (1.6–2.9), phosphate solubilizing (10–20), asymbiotic N₂-fixing (0.5–0.9), sulfur oxidizing (1.1–2.0), nitrifying (1.0–5.8) and denitrifying (12.1–18.7) bacteria; as well as, the actinomycetes (about 10⁴ c.f.u./g dr. soil) and fungi (about 10⁵ c.f.u./g dr. soil) were variable in the partially anaerobic, saline and drain out flooded rice soils during the post harvest period of the Himalayan, brackish water flooded, island and coastal habitats of India. The aerobic heterotrophic and spore forming bacteria were more than the anaerobic counterparts in the soils. Population (0.51–3.51 × 10⁶ c.f.u./g dr. soil) and crystal morphotype (spherical, bipyramidal and polymorphic) of the Bacillus thuringiensis (Bt) isolates of different soils were variable. Bt index was 0.002 at Mahe but 0.006 in other soils. The Bt isolates tolerated 5–12% NaCl. The osmolytes (mg/g dr. wt.) like the amino acids (0.38–99.45) and proline (0.38–0.80); and the antioxidative enzymes (units (U)/mg protein/min) viz. the catalase (0.17–5.59) and superoxide dismutase (0.35–74.46) were related with intrinsic osmotic stress tolerance of the Bt but they formed spores to overcome anoxic stress. Two Bt isolates were potent tolerant to both osmotic and anoxic stresses.     

Embryonic, larval and juvenile development of the roughskin sculpin,Trachidermus fasciatus (Scorpaeniformes: Cottidae)

Embryonic, larval and juvenile development of the catadromous roughskin sculpin,Trachidermus fasciatus, were described using eggs spawned in an aquarium. The eggs, measuring 1.98–2.21 mm in diameter, were light reddish-yellow and had many oil globules, 0.05–0.18 mm in diameter. Hatching occurred 30 days after spawning at 2.3–11.3°C. The newly-hatched larvae, measuring 6.9–7.3 mm BL, had a single oil globule, 9–10+25–26=34–36 myomeres and 6 or 7 large stellate melanophores dorsally along the gut. The yolk was almost resorbed, number of pectoral-fin rays attained 16–17, and two parietal, one nuchal and four preopercular spines were formed, 5 days after hatching, at 8.2–8.4 mm BL. The oil globule disappeared, and one supracleithral spine was formed, 11 days after hatching, at 8.9–9.5 mm BL. Notochord flexion began 15 days after hatching, at 9.7–10.3 mm BL. A posttemporal spine was formed 20 days after hatching, at 10.7–10.9 mm BL. The first dorsal fin spines (VII–VIII), second dorsal fin and anal fin rays (18–19, 16–18, respectively) appeared 23 days after hatching, at 12.0–13.7 mm BL. The pelvic fin spine and rays (I, 4) were formed and black bands on the head and sides of the body began to develop 27 days after hatching, at 13.8–15.8 mm BL. Newly-hatched larvae swam just below the surface in the aquaria. Preflexion larvae (8.9–9.5 mm BL), in which the oil globule had disappeared, swam in the middle layer, while juveniles (13.8–15.8 mm BL) began swimming on the bottom of the aquaria. Swimming behavior observed in the aquaria suggested that the fish started to change to a demersal existence at the juvenile stage.     

Maternal and neonatal scalp hair concentrations of zinc, copper, cadmium, and lead

Postpartum scalp hair samples from 82 term-pregnancy mother/neonate pairs were analyzed for their concentration of zinc (Zn), copper (Cu), cadmium (Cd), and lead (Pb), using inductively coupled plasma-mass spectrometry. Maternal and neonatal Zn concentrations had geometric means (and 99% confidence intervals) of 122.5 μg/g (117.9–131.5 μg/g) and 146.9 μg (141.5–156.7 μg/g) respectively. Corresponding Cu values were 18.4 μg/g (17.6–23.8 μg/g) and 6.7 μg/g (6.3–7.6 μg/g). Those of Cd were 0.49 μg/g (0.47–0.69 μg/g) in the mothers and 0.57 μg/g (0.55–0.86 μg/g) in the neonates. For Pb, they were 7.95 μg/g (7.60–9.32 μg/g) and 4.56 μg/g (4.39–5.56 μg/g). Cigaret smoking, despite its relatively low prevalence (19.5%), was associated with lower Zn and higher Cd and Pb concentrations and in lower Zn/Cd and Zn/Pb molar concentration ratios. Smoking also altered interelemental relationships, particularly those of Zn with Cd and Pb and those between Cd and Pb. Smoking frequency appeared to show negative dose-response effects on maternal and neonatal Zn concentrations, Zn/Pb molar concentration ratios, and birth weight. Mothers with a history of oral contraceptive (OC) usage had significantly higher Cu concentrations and lower Zn/Cu molar concentration ratios than nonusers, with the highest Cu concentrations and lowest Zn/Cu values being associated with third-generation OCs. No similar effects were elicited in the respective neonatal Cu concentrations. Neither alcohol consumption nor prenatal supplementation with iron and/or folic acid had discernible effects on the maternal or neonatal elemental concentrations. The data from this study suggest that in a given population of term-pregnancy mothers and neonates, significant interindividual variations in hair trace element concentrations can occur, irrespective of commonality of general environment, and that lifestyle factors, including cigaret smoking and OC usage history, can be significant contributory factors to such variations. The data are discussed in relation to the effects of smoking-associated exposure to Cd and Pb exposure on Zn availability for placental transfer, as well as on the quantitative maternal Zn supply levels to the fetus resulting from the known tendency of smokers to have lower dietary intakes of Zn. The higher Cu concentrations in OC users are discussed in relation to altered Cu metabolism, characterized by increased synthesis of the Cu-binding protein, ceruloplasmin, as an acute-phase antioxidant response to altered lipid profile and increased lipid oxidation.     

Dynamic calibration of mechanically, air- and electromagnetically braked cycle ergometers

In this study we measured the accuracy of the following types of cycle ergometer against the criterion of a dynamic calibration rig (DCR): 35 friction-braked (Monark), 5 research-grade air-braked (Repco) and 5 electromagnetically braked (2 Siemens, 1 Elema-Schonander, 1 Ergoline, l Warren E. Collins). Monark ergometer power outputs over the range 58.9–353.2 W significantly (P < 0.001) underestimated those registered by the DCR with mean accuracies of 91.7–97.8%. The least accurate individual reading for each of the six up-scale (0–353.2 W) power outputs ranged from 81.6␣to␣91.6%; corresponding down-scale (353.2–0 W) accuracies were 85.1–92.5%. A hysteresis effect was furthermore evident for this ergometer in that up-scale measurements were significantly (P < 0.05) greater than down-scale ones. In addition, when the oldest [mean (SD): 11.3 (2.3) years old] and newest [1.4 (0.8) years old] eight ergometers were compared, the latter were significantly (P < 0.05) more accurate over the range 117.7–294.3 W. Apart from the two lowest power outputs of 47␣W (62.2–96.0% accuracy) and 127 W (88.0–97.7% accuracy), the individual up-scale and down-scale accuracies of the Repco ergometers ranged from 98.0 to 104.2% for power outputs of 272.7–1137.8 W and the means were not significantly different from those of the DCR. There was also no evidence of hysteresis. Except for the initial power output of 50 W (40 rev/min: 83.8–99.2% accuracy; 60 rev/min: 93.2–122.6% accuracy), the␣individual accuracies of the electromagnetically braked ergometers ranged from 89.3 to 101.4% over the up-scale range of 100–400 W, and none of the means were significantly different from those of the DCR. The variability of individual errors for the preceding data emphasises that all cycle ergometers should be validated against the criterion of a DCR if accurate power outputs are required. Accepted: 19 February 1998     

Sequence Analysis of a 34.7-kb DNA Segment from the Genome of Buchnera aphidicola (Endosymbiont of Aphids) Containing groEL, dnaA, the atp operon, gidA, and rho

Buchnera aphidicola is a prokaryotic endosymbiont of the aphid Schizaphis graminum. From past and present nucleotide sequence analyses of the B. aphidicola genome, we have assembled a 34.7-kilobase (kb) DNA segment. This segment contains genes coding for 32 open reading frames (ORFs), which corresponded to 89.9% of the DNA. All of these ORFs could be identified with homologous regions of the Escherichia coli genome. The order of the genes with established functions was groELS–trmE–rnpA–rpmH–dnaA–dnaN–gyrB–atpCDGAHFEB–gidA–fdx–hscA– hscB–nifS–ilvDC–rep–trxA–rho. The order of genes in small DNA fragments was conserved in both B. aphidicola and E. coli. Most of these fragments were in approximately the same region of the E. coli genome. The latter organism, however, contained many additional inserted genes within and between the fragments. The results of the B. aphidicola genome analyses indicate that the endosymbiont has many properties of free-living bacteria. Received: 15 August 1997 / Accepted: 29 August 1997     

Activity,movements, and sociality of newborn Mongolian gazelle calves in the Eastern Steppe

We hand-captured, fitted with motion-sensitive VHF transmitters, and monitored 19 newborn (1–2 days old) Mongolian gazelle Procapra gutturosa Pallas, 1777 calves in Dornod, Mongolia during the 2000 and 2003 calving seasons to identify changes in activity, movements, and sociality with age. Overall, activity was highly variable throughout the day, regardless of age or year. Calf activity increased, however, from day 2 (age = 2 days; 18% total activity) to day 7 (29%), and 3-fold by day 25 (54%). By days 5–8, calves had moved an average of 6.6 km (range: 2–21 km) from capture sites but were still only seen alone or with their mother. By day 24–26, however, they were located an average of 41 km (range: 24–63 km) away from their capture site, and most (7 of 9) were in aggregations of >1000 animals. Mongolian gazelles do not display behaviour associated with “hiders” after about 2–3 weeks. This reflects the wide-ranging, nomadic existence of the species.     

Origin of Life and Definition of Life,from Buffon to Oparin

Many theories on origin of life at the end of the XIXth century and the beginning of the XXth, generally use conceptions of life instead of explicit definitions of life. This paper presents ideas on the origin of life as studied by Buffon (1707–1788), Lamarck (1744–1829), Darwin (1809–1882), Huxley (1825–1895), Oparin (1894–1980) and Haldane (1892–1964). We show that their conceptions on the evolution of matter and life reveal their conceptions of life rather than their definitions of life.     

Coloured hailnets alter light transmission,spectra and phytochrome,as well as vegetative growth,leaf chlorophyll and photosynthesis and reduce flower induction of apple

In view of alleged positive effects of coloured (red) hailnets on phytochrome, photosynthesis, yield and fruit quality, the objective of the present work was to investigate a range of red and green hailnets using apple as a model crop with cvs. ‘Pinova’ and ‘Fuji Kiku 8’. Light transmission of green or red hailnets peaked between 500 and 570 nm (green) or above 570 nm (red–orange) and was reduced by 12% (white) or 14% (red–white), 18% (red–black) and 23% (green–black) hailnets; there were no effects on phytochrome. Leaf chlorophyll concentration increased under coloured hailnets by up to 46% under the green–black hailnet, while air temperature was reduced by 0.2°C. Under sunny conditions, photosynthesis of ca. 18 μmol CO₂ m⁻² s⁻¹ was not reduced under coloured hailnets, in contrast with a 21% reduction under cloudy conditions with a concomitant reduction in transpiration by 13%. Vegetative growth was affected in different ways: shaded trees showed smaller trunk diameter, but increased the number and length of their 1-year shoots under coloured hailnets, particularly with cv. ‘Fuji’ when grown under green–black hailnet. Hailnets reduced flower induction in June and return bloom in the next spring to the same extent as they reduced the light transmission. Overall, tree growth under coloured hailnets was genetically influenced, with cv. ‘Fuji’ being more prone and sensitive to adverse effects of coloured hailnets than cv. ‘Pinova’, but is also influenced by the environment. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

Age and composition of carbonate shoreface sediments, Kailua Bay, Oahu, Hawaii

The origin, age, and dynamics of carbonate sediments in Kailua Bay on Oahu, Hawaii, are described. The shoreface (from shoreline to 4 km offshore) consists of a broad (5 km²) fringing coral reef ecosystem bisected by a sinuous, shore-normal, sand-filled paleostream channel 200–300 m wide. The median grain diameter of surface sands is finest on the beach face (<0.3 mm) and increases offshore along the channel axis. Kailua sands are >90% biogenic carbonate, dominated by skeletal fragments of coralline algae (e.g. Porolithon, up to 50%) followed by the calcareous green alga Halimeda (up to 32%), coral fragments (1–24%), mollusc fragments (6–21%), and benthic foraminifera (1–10%). Sand composition and age across the shoreface are correlated to carbonate production. Corals and coralline algae, principal builders of the reef framework, are younger and more abundant in sands along the channel axis and in offshore reefal areas, while Halimeda, molluscs, and foraminifera are younger and more dominant in nearshore waters shoreward of the main region of framework building. Shoreface sediments are relatively old. Of 20 calibrated radiocarbon dates on skeletal constituents of sand, only three are younger than 500 years b.p.; six are 500–1000 years b.p.; six are 1000–2000 years b.p.; and five are 2000–5000 years b.p. Dated fine sands are older than medium to coarse sands and hence may constitute a reservoir of fossil carbonate that is distributed over the entire shoreface. Dominance of fossiliferous sand indicates long storage times for carbonate grains, which tend to decrease in size with age, such that the entire period of relative sea-level inundation (∼5000 years) is represented in the sediment. Despite an apparently healthy modern coral ecosystem, the surficial sand pool of Kailua Bay is dominated by sand reflecting an antecedent system, possibly one that existed under a +1–2 m sea-level high stand during the mid- to late Holocene. Accepted: 20 December 1999     

Pharmacokinetics and Pharmacodynamic Effects of Flunixin after Intravenous,Intramuscular and Oral Administration to Dairy Goats

The pharmacokinetics and the prostaglandin (PG) synthesis inhibiting effect of flunixin were determined in 6 Norwegian dairy goats. The dose was 2.2 mg/kg body weight administered by intravenous (i.v.), intramuscular (i.m.) and oral (p.o.) routes using a cross-over design. Plasma flunixin content was analysed by use of liquid chromatography and the PG synthesis was evaluated by measuring plasma 15-ketodihydro-PGF_2α by a radioimmuno-assay. Results are presented as median (range). The elimination half-lives (t_1/2·λ) were 3.6 (2.0–5.0), 3.4 (2.6–6.8) and 4.3 (3.4–6.1) h for i.v., i.m. and p.o. administration, respectively. Volume of distribution at steady state (Vd_ss) was 0.35 (0.23–0.41) L/kg and clearance (CL), 110 (60–160) mL/h/kg. The plasma concentrations after oral administration showed a double-peak phenomenon with the two peaks occurring at 0.37 (0.25–1) and 3.5 (2.5–5.0) h, respectively. Both peaks were in the same order of magnitude. Bioavailability was 79 (53–112) and 58 (35%–120)% for i.m. and p.o. administration, respectively. 15-Ketodihydro-PGF_2α plasma concentrations decreased after flunixin administration independent of the route of administration.     

Magnesium,Calcium, and Trace Elements Excretion in 24-h Urine

Urine is a clinical specimen often used in medical diagnostics for monitoring of elements concentrations and kidneys function. We determined the contents of magnesium (Mg), calcium (Ca), zinc (Zn), copper (Cu), iron (Fe), lead (Pb), and cadmium (Cd) in 74 samples of 24-h urine (from 46 women and 28 men). The measurements were realized by the atomic absorption spectrometry (AAS) with atomization in the flame (FAAS) and in the graphite furnace (GFAAS). The received results were the subject of statistical analysis including the sex and age of volunteers. Moreover, correlations between the elements and the relationships between age and amounts of excreted elements with urine were tested. We found the statistically significant higher content of Zn in men’s urine than in women^’s one. Moreover, both adult women and men (>18 years) excreted much more Ca in urine in comparison to young subjects. Only in case of Pb the significant positive correlation between its amount in 24-h urine of all donors and age was stated. The correlation analysis has shown the significant positive relationships between Ca–Mg, Ca–Fe, Mg–Fe, Cu–Fe, Cu–Cd, Fe–Cd, and Pb–Cd in total samples of urine. Basing on our results, we concluded that the gender and age of donors may impact on the elemental status of 24-h urine.     

Distribution of dissolved organic carbon and dissolved fulvic acid in mesotrophic Lake Biwa, Japan

The dissolved organic carbon (DOC) concentrations in mesotrophic Lake Biwa were determined by a total organic carbon (TOC) analyzer, and DOC molecular size distributions were determined by size exclusion chromatography (SEC) using a fluorescence detector at excitation/emission (Ex/Em) levels of 300/425 nm with the eluent at pH 9.7. The fluorescence wavelengths for detection were chosen from the result of excitation–emission matrix spectrometry (EEM) analysis for dissolved fulvic acid (DFA) extracted from Ado River (peak A, Ex/Em = 260–270/430–440 nm; peak B, Ex/Em = 300–310/420–430 nm). Ado River DFA was eluted with a retention time (RT) of 7.4–8.9 min and the apparent molecular weight was estimated at 22–87 kDa based on the elution curve for the spherical protein molecular weight standard. A DFA peak eluted at the same retention time as Ado River DFA also appeared in all the samples of Lake Biwa water. From the linear relationship between the peak areas with an RT of 7.4–8.9 min by SEC analysis and DOC values of DFA by TOC analysis of a series of DFA samples (r² = 0.9995), the concentrations of DFA in the lake water were roughly calculated. DFA was distributed within the range 0.25–0.43 mg C l⁻¹ and accounted for 15%–41% of DOC, with the highest ratios observed at a depth of 70 m in August and the lowest at 2.5 m in May.     

Effect of Diets Supplemented with Different Levels of Manganese,Zinc, and Copper from their Organic or Inorganic Sources on Egg Production and Quality Characteristics in Laying Hens

This experiment was conducted to evaluate the effect of zinc, manganese, and copper sources (inorganic vs. organic) in the diet on laying performance and eggshell quality characteristics. One hundred and eighty Hy-Line W-36 layers at 38 weeks of age were allocated to 36-layer cages of five hens each. Each six cages were randomly assigned to one of the six experimental diets fed from 38 to 53 week of age. In three experimental treatments, the basal diet was supplemented with 65–75–7 or 65–75–7 or 40–40–7 mg/kg of Zn, Mn, and Cu, respectively, from their oxide or sulfate sources. Three other groups were fed diets supplemented with 20–20–3.5 or 40–40–7.5 or 60–60–10.5 mg/kg of organic forms of Zn, Mn, and Cu, respectively. Dietary treatments significantly did affect feed intake (P < 0.001), feed conversion ratio (P < 0.001) and percentage of broken eggs (P < 0.05). Substitution of Zn and Mn oxides (65 and 75 mg kg⁻¹, respectively) with equal amounts of their sulfate forms significantly improved feed intake, feed conversion ratio, percentage of broken eggs, and Haugh Unit (P < 0.05). In addition, laying hens maintained their performance when substitution of Zn and Mn oxides and Cu sulfate (65, 75, and 7 mg kg⁻¹, respectively) reduced up to 20, 20, and 3.5 mg kg⁻¹ by amino acid complexes of the microelements. The results showed that a corn–soybean diet supplemented with the organic forms of Zn, Mn, and Cu at a dosage 50% to 75% lower than NRC recommendation is sufficient to maintain laying performance and can improve eggshell and albumen qualities of the egg in laying hens.     

Nutrient content of tropical edible seaweeds, Eucheuma cottonii, Caulerpa lentillifera and Sargassum polycystum

The proximate composition, vitamin C, α-tocopherol, dietary fibers, minerals, fatty acid and amino acid profiles of three tropical edible seaweeds, Eucheuma cottonii (Rhodophyta), Caulerpa lentillifera (Chlorophyta) and Sargassum polycystum (Phaeophyta) were studied. The seaweeds were high in ash (37.15–46.19%) and dietary fibers (25.05–39.67%) and low in lipid content (0.29–1.11%) on dry weight (DW) basis. These seaweeds contained 12.01–15.53% macro-minerals (Na, K, Ca and Mg) and 7.53–71.53 mg.100 g⁻¹ trace minerals (Fe, Zn, Cu, Se and I). The crude protein content of E. cottonii (9.76% DW) and C. lentillifera (10.41% DW) were higher than that of S. polycystum (5.4% DW), and protein chemical scores are between 20 and 67%. The PUFA content of E. cottonii was 51.55%, C. lentillifera 16.76% and S. polycystum 20.34%. Eicosapentaenoic acid (EPA), accounted for 24.98% of all fatty acids in E. cottonii. These seaweeds have significant vitamin C (∼35 mg.100 g⁻¹) and α-tocopherol (5.85–11.29 mg.100 g⁻¹) contents.     

Phosphorus speciation in Myall Lake sediment, NSW, Australia

The amount of phosphorus and its fractions in the sediment of Lake Myall, NSW, Australia, was assessed using a sequential extraction technique. Five sedimentary phosphorus reservoirs were measured, namely loosely sorbed phosphorus (NH₄Cl–P), iron associated phosphorus (BD–P), calcium bound phosphorus (HCl–P), metal oxide bound phosphorus (NaOH–P) and residual phosphorus (organic and refractory P, Res-P). Samples were taken from the deep and shallow sites of the lake. During the analysis, the average concentrations of each fraction of phosphorus was calculated. The results depicted that the total phosphorus (TP) content and chemically extractable phosphorus in both fine and coarse sediment fractions from the deep sites of the lake were significantly higher than those of the shallow sites, except for HCl–P extracted from the fine sediment fraction. Sediment TP was also strongly and positively correlated to sediment Fe. The phosphorus in the sediment mainly consisted of BD–P and Res-P, while NH₄Cl–P and HCl–P only contributed a minor part. The rank order of the different phosphorus extracts was similar for the two sites, namely Residual-P > BD–P > NaOH–P > HCl–P > NH₄Cl–P.     

Altitudinal Zonation of Pteridophytes on Mt. Banahaw de Lucban,Luzon Island,Philippines

Five altitudinal pteridophyte zones are established along the northeastern altitudinal slopes of Mt. Banahaw de Lucban, Quezon, Luzon Is., Philippines using cluster- and ordination analyses, namely: Zone 1, Cyathea contaminans – Dicranopteris–Nephrolepis–Diplazium patches at 700–800 m a.s.l.; Zone 2, Sphaerostephanos hirsutus var. hirsutus – Selaginella delicatula patches at 750–900 m a.s.l.; Zone 3, Cyathea philippinensis – Selaginella patches at 900–1200 m a.s.l.; Zone 4, Cyathea philippinensis – Cyathea callosa–Asplenium cymbifolium–Selaginella cumingiana patches at 1200–1550 m a.s.l. and; Zone 5 which is further divided into Sub-zone 5A, Cyathea callosa – Cyathea loheri-Hymenophyllaceae patches at 1550–1800 m a.s.l. and Sub-zone 5B, Cyathea loheri – Cephalomanes apiifolia patches at 1800–1875 m a.s.l. These pteridophyte zones coincide with the woody species zones of Mt. Banahaw de Lucban but differ significantly with the altitudinal fern zones of Mt. Makiling. Stepwise multiple regression analysis reveals that altitude exhibits a linear relationship with pteridophyte species distribution. Altitude and soil pH influence 65% of the variation in principal component 1 [PC1 = 0.0839 + 0.0010(altitude) − 0.2072(soil pH); r = 0.8058] and 27% of the variation in principal component 2 [PC2 = 2.0453 − 0.0005(altitude) − 0.2560(soil pH); r = 0.5206]. Thirty-three (33) species are preferential to specific microenvironments along the altitudinal gradient, making them effective altitudinal zone markers and biodiversity conservation indicators for the forest ecosystem of Mt. Banahaw de Lucban.     

A new species, Polydactylus siamensis, from Thailand and redescription of P. plebeius (Broussonet, 1782) with designation of a neotype (Perciformes: Polynemidae)

A new species, Polydactylus siamensis, is described on the basis of eight specimens from Thailand. The species is similar to P. plebeius (Broussonet, 1782) in having five pectoral filaments and several dark stripes along the scale rows above and below the lateral line, but differs from the latter in having lower counts of pectoral fin rays (15 vs. 16–18 in P. plebeius), pored lateral line scales (54–58 vs. 60–68), scale rows above and below the lateral line (7 and 10 or 11, respectively vs. 8 or 9 and 12 or 13, respectively) and gill rakers (9 or 10 upper series, 13 or 14 lower and 22–24 total vs. 9–14, 13–18 and 24–32, respectively), and a longer upper jaw (mean 17% [range 16–17%] of standard length vs. 15% [13–16%]). Polydactylus siamensis is currently known only from Bangkok and Songkhla, Gulf of Thailand, and Phuket Island, Andaman Sea, whereas P. plebeius is widely distributed in the Indo-Pacific. Received: January 12, 2000 / Revised: September 15, 2000 / Accepted: January 12, 2001     

Validity of the gerreid fish,Gerres macracanthus Bleeker, 1854, with designation of a lectotype,and designation of a neotype forG. filamentosus Cuvier, 1829

Gerres macracanthus Bleeker, 1854, for many years having been explicitly or tentatively synonymized withG. filamentosus Cuvier, 1829, is redescribed as a valid species.Gerres macracanthus differs fromG. filamentosus in lacking vertical rows of dark ovoid spots on the body, having instead only indistinct vertical bands in both subadult and adult stages, in addition to shorter second and third anal fin spines (9.1–13.9% and 10.4–14.4% of standard length [SL] vs. 12.3–19.6% and 11.9–17.3% of SL), fewer ored lateral line scales (41–44 vs. 43–46) and fewer scales between the base of the 5th dorsal fin spine and the lateral line (4–5 vs. 4 1/2–5 1/2), and above and below the lateral line (5 1/2–6 1/2/9 1/2–10 1/2 vs. 6 1/2–7 1/2/10 1/2–11 1/2). AlthoughG. filamentosus has similarly, indistinct vertical bands on the body up to ca. 100 mm SL, specimens over ca. 100 mm SL develop diffuse ovoid spots in each vertical band. Furthermore,G. macracanthus is generally a smaller species, apparently attaining a maximum size of ca. 170 mm SL, compared with ca. 250 mm SL forG. filamentosus. Formerly known from the Philippines, Indonesia, New guinea, India and the Arabian Gulf,G. macracanthus is newly-recorded from Japan, China, the Gulf of Thailand, the Red Sea and South Africa. A lectotype and three paralectotypes are designated forG. macracanthus Bleeker, 1854, in addition to a neotype forG. filamentosus Cuvier, 1829.