Conservation status of parrot populations in an Atlantic rainforest area of southeastern Brazil

A census of four species of syntopic parrots was carried out using distance sampling methods on São Sebastião island, SE Brazil. Most of the 33593 ha island is covered by mature and secondary Atlantic rainforest. Almost 80% of these forests are within the Ilhabela Park. Although the species counted have marked differences in size and weight, density (individuals/km²) and estimated population size in 23500 ha of well-preserved forests were similar: Amazona farinosa (13.82±5.94; 3247±1395), Pionus maximiliani (15.79±7.04; 3712±1654), Brotogeris tirica (15.05±4.87; 3537±1143) and Pyrrhura frontalis (13.06±5.53; 3068±1298). Encounter rates of Forpus crassirostris and Pionopsitta pileata were very low, which suggests that there is only a small population of these species on the island. The São Sebastião forests still support healthy populations of parrots. Although woodpecker population estimates on the island are large enough to provide nesting sites for parrots, competition for holes with other secondary cavity nesters such as toucans, flycatchers and tytiras, and the selective cutting of dead trees for canoe construction, which is a common practice on the island, may limit hole availability for parrots.     

<Emphasis Type="Italic">In vitro</Emphasis> screening of sugarcane to evaluate smut susceptibility

Tissue-cultured plantlets of three sugarcane (Saccharum spp.) cultivars having a known field smut reaction were screened for susceptibility to Ustilago scitaminea H&P Sydow. Plantlets were inoculated with 0.5 l of a suspension of equally mixed quantities of plus and minus mating type sporidia of U. scitaminea at concentrations ranging from 1×10¹ to 1×10⁶ cells. Fungal sori (whips) were produced in cultivar N12 (intermediate) 6weeks following inoculation with 1×10⁵ mixed sporidia and thereafter in cultivar NCo310 (susceptible) but not in cultivar N19 (resistant). Sori bearing teliospores were produced up to 3months following inoculation and incubation at 26°C. No sori were produced at mixed sporidial concentrations lower than 1×10⁵cells. The in vitro soral production in cultivars N19, N12 and NCo310 was 0, 27.5 and 47.5% respectively. Plantlets inoculated with 1×105sporidia of only one mating-type did not produce sori in any of the three cultivars tested. Blind scoring of an unknown sugarcane cultivar by this method corresponded exactly with its field smut rating.     

Defective remethylation of homocysteine is related to decreased synthesis of coenzymes B2 in thyroidectomized rats

Summary. We investigated the influence of hypothyroidism on homocysteine metabolism in rats, focusing on a hypothetical deficient synthesis of FAD by riboflavin kinases. Animals were allocated in control group (n=7), thyroidectomized rats (n=6), rats with diet deficient in vitamin B2, B9, B12, choline and methionine (n=7), thyroidectomized rats with deficient diet (n=9). Homocysteine was decreased in operated rats (2.6±1.01 vs. 4.05±1.0mol/L, P=0.02) and increased in deficient diet rats (29.56±4.52 vs. 4.05±1.0mol/L, P=0.001), when compared to control group. Erythrocyte-Glutathione-Reductase-Activation-Coefficient (index of FAD deficiency) was increased in thyroidectomized or deficient diet rats (P=0.004 for both). Methylenetetrahydrofolate-reductase and methionine-synthase activities were decreased in thyroidectomized rats but not in those subjected to deficient diet. Cystathionine--synthase was increased only in operated rats. Taken together, these results showed a defective re-methylation in surgical hypothyroidism, which was due in part to a defective synthesis of vitamin B2 coenzymes. This defective pathway was overcompensated by the increased Cystathionine--synthase activity.     

Thermophilic and mesophilic bacteria in biofilms associated with corrosion in a heat exchanger

Biofilm development on AISI-1020 carbon steel coupons installed at the outlet of a heat exchanger was evaluated at the thirtieth and the sixtieth days of exposure. Water temperature varied between 41 and 60°C. The most probable number technique (MPN) was applied to quantify mesophilic and thermophilic species of aerobic, anaerobic, and sulphate-reducing bacteria (SRB) in planktonic and sessile phases. The results showed predominance of thermophilic aerobic bacteria in both phases, corresponding to 9.5±0.8×10⁶cells/ml in the planktonic phase. In biofilms, maximal aerobic cell concentration, 7.8±0.6×10⁸cells/cm2, was registered at the sixtieth day. An increase in the number of thermophilic anaerobic and SRB with elapsed time was also observed. The results obtained after 60 days were 5.8±0.4×10⁷ and 8.9±0.9×10⁴cells/cm² for anaerobic and sulphate-reducing bacteria, respectively. Scanning electron microscopy showed a varied composition of species in the biofilms and corrosion on the carbon steel surfaces after biofilm removal.     

Relation between trace element levels in plasma and myocardium during coxsackievirus B3 myocarditis in the mouse

During most infections the plasma levels of trace elements change, but it is not clear if this reflects changes in the infected tissues. Coxsackievirus B3 (CB3) infection may result in viral replication, subsequent inflammation and changed trace element levels in the myocardium. In the present study, the trace element levels in the plasma and heart of adult male A/J mice were determined during the pre-inflammatory stage (day 4) of CB3 myocarditis for the following trace elements: aluminium (Al), arsenic (As), calcium (Ca), cobalt (Co), copper (Cu), iron (Fe), magnesium (Mg), manganese (Mn), selenium (Se), silver (Ag), vanadium (V) and zinc (Zn). The severity of the infection was assessed through clinical signs of disease and trace element levels were measured through inductively-coupled plasma mass-spectrometry (ICP-MS). In the heart, the levels decreased for V (59%; p<0.01), Co (38%; p<0.01), Al (81%; p< 0.01), As (66%; p<0.01) and Se (16%; p<0.01). Increased levels were detected for Mn (13%; p<0.05), Fe (48%; p<0.01), Cu (34%; p<0.01) and Ag (46%; p< 0.01). In the plasma, decreases were detected in the level of Zn (32%; p<0.05), whereas increases were seen in Mn (362%; p<0.05), Fe (272%; p<0.01), Co (71%; p<0.05), Cu (25%; n.s.) and Mg (43%; p<0.01) levels. A correlation was found between the levels in plasma and myocardium for Co (r _s=–0.636; p<0.05), Fe (r _s=0.764; p<0.05), Mn (r _s=0.682; p<0.05) and Mg (r _s=–0.791; p<0.05). Thus, determination of some of these trace elements in the plasma may be useful to indicate target tissue involvement in the early pre- inflammatory stage of an infectious disease. Some of these elements are important nutrients for the immune system, while others may be associated with the development of disease complications, such as cardiac arrhythmias.     

Transposome Insertional Mutagenesis and Direct Sequencing of Microbial Genomes

Preformed transposase-transposon complexes called Transposomes have been electroporated into bacterial cells. The magnesium dependent process of insertion of the transposable element into bacterial chromosomal DNA occurs in vivo. The transposition efficiency of a Transposome containing a kanamycin marker was between 1.0×10⁴and 1.0×10⁷kanamycin resistant clones per microgram of transposon DNA in three gram-negative enteric bacterial species. Transposon integration sites were examined by direct genome sequencing of chromosomal DNA. Genomic DNA was isolated from transposition clones and directly cycle sequenced with primers specific for the ends of the transposon. The precise location of genome interruption for a transposition clone was identified by homology to known genes or sequences. Mutant phenotypes were rapidly correlated with genomic insertions sites.     

Improved production of ginseng polysaccharide by adding conditioned medium to Panax notoginseng cell cultures

By adding 50% (v/v) filtered culture broth to fresh MS medium, the specific growth rate of Panax notoginseng was increased from 0.046 d–1 to 0.068 d–1, and the polysaccharide production and productivity reached 1.21 g l–1 and 61 mg/(ld), respectively, which were 1.3- and 2.3-fold of the control. Further supplementation of the conditioned medium with sucrose, ammonium, nitrate and phosphate gave a cell density of 13.7 g l–1 and a specific growth rate of 0.086 d–1. Polysaccharide production was 1.65 g l–1 and the productivity was 78 mg/(ld).     

Investigation of the early mineralisation on collagen in dentine of rat incisors by quantitative electron spectroscopic diffraction (ESD)

The earliest crystallites in dentine appear as chains of dots in ultra-thin sections viewed by transmission electron microscopy. These dots rapidly coalesce along the longitudinal directions of the collagen microfibrils to form needle-like structures that coalesce preferentially in lateral directions to form ribbon-like or plate-like crystallites. This morphological interpretation is supported by line-scans of the corresponding zero-loss filtered electron spectroscopic diffraction patterns, which demonstrate the crystalline structure of the dentine mineral (apatite). The intensity ratio of the Debye-Scherrer rings of the characteristic Bragg-reflections (002 to 300, together with 1 or 2 unresolved reflections) shows a maximum in the region of early chain-like and needle-like crystallites, decreasing with maturation of the dentine mineral to the ribbon-plate-like crystallites. Detailed investigations using line-scans of the zero-loss filtered electron spectroscopic diffraction patterns through the dentine zone show that the intensity ratio found near the mineralisation front is repeated 3–5 times at distances of about 10–20 m. This may represent a circadian pattern of mineralisation corresponding to light microscopically visible incremental lines in dentine.     

<Emphasis Type="Italic">Uncisudis posteropelvis</Emphasis>, a new species of barracudina (Aulopiformes: Paralepididae) from the western North Pacific Ocean

Six specimens (2 flexion larvae: 9.5–10.4mm in notochord length; 4 postflexion larvae: 12.3–18.2mm in standard length) collected from the western North Pacific are tentatively ascribed to the genus Uncisudis of the tribe Lestidiini of the subfamily Paralepidinae (Paralepididae) in sharing remarkably elongate and filamentous pelvic fin rays, their tips reaching the origin of the anal fin. They are described as Uncisudis posteropelvis sp. nov. in uniquely having the insertion of pelvic fins closer to the origin of anal fin than to the posterior end of dorsal fin base among lestidiine species. Addition to this character, the new species has remarkably elongate and filamentous dorsal fin rays, the short distance between anus and origin of anal fin (4.2–6.1% of standard length, SL), the posteriorly located pelvic fins (prepelvic length 69.4–71.5% SL), dorsal fin rays 10, anal fin rays 28–29, myomeres 41–42+38–40=80–81 (vertebrae 38+41=79), and peritoneal pigment spots 11–12. The occurrence of larvae differing in pigment pattern from the present new species suggests another undescribed species of Uncisudis in the western South Pacific.     

Evidence of downstream migration of Sakhalin taimen, <Emphasis Type="Italic">Hucho perryi</Emphasis>, as revealed by Sr : Ca ratios of otolith

The migratory history of Sakhalin taimen, Hucho perryi, was examined in terms of strontium (Sr) and calcium (Ca) uptake in the otolith by using wavelength dispersive X-ray spectrometry on an electron microprobe. Otolioth Sr:Ca ratios of freshwater-reared samples remained consistently at low levels throughout the otolith. The Sr:Ca ratios of samples from Lake Aynskoye of Sakhalin Island showed a low value from the core up to a point of 700–2140µm. Thereafter, the ratios increased sharply and remained at higher levels up to the outermost regions. The difference in Sr:Ca ratio might be the result of the presence of individuals that underwent seawater and freshwater life history phases, probably reflecting the ambient salinity or the seawater–freshwater gradient in Sr concentration. Otolith Sr:Ca ratio analysis revealed downstream migration history in H. perryi.     

Growth and Reproduction of Double-Ended Pipefish, Syngnathoides biaculeatus, in Moreton Bay, Queensland, Australia

Life-history characteristics of the double-ended pipefish, Syngnathoides biaculeatus (Bloch), were investigated to determine growth rate, degree of sexual dimorphism, size at maturity, and reproductive biology. Growth rates of wild juveniles and adults calculated from monthly progression of length-frequency modes ranged from 0.8mmd^–1 (fish lengths 120–145mm standard length (SL)) in summer to 0.2mmd^–1 in winter (185–200mm SL). Growth of laboratory-reared juveniles up to 63d old was greater, ranging from 0.8 to 2.3mmd^-1. The von Bertalanffy growth constant K was estimated at 0.0076d^{- 1}, or 2.8year^–1. Morphological differentiation between the sexes based upon abdominal pattern was possible for fish larger than 120mm SL, with females possessing a zigzag pattern on the abdomen. The association between this pattern and sex was confirmed by histological gonad analysis. Males were significantly longer than females during four of seven seasons examined, and a 1:1 sex ratio was determined for all seasons except autumn when the ratio was female biased. The breeding season was marked by the appearance of pregnant males between October and April, and during courtship both species exhibited increased pigmentation. The minimum paternal size at maturity was 185mm, the maximum length recorded 260mm. Clutch size ranged between 60 and 200 eggs, with a mean of 153. Ovaries had a sequential pattern of egg development, resulting in egg batches that approximated the number of eggs carried by brooding males. Additionally, all eggs in a brood were at the same developmental stage. This suggests that one female provides all of the eggs for one male per breeding event in a monogamous mating system.     

Plastid Sequence Evolution: A New Pattern of Nucleotide Substitutions in the Cucurbitaceae

Nucleotide substitutions (i.e., point mutations) are the primary driving force in generating DNA variation upon which selection can act. Substitutions called transitions, which entail exchanges between purines (A=adenine, G=guanine) or pyrimidines (C=cytosine, T=thymine), typically outnumber transversions (e.g., exchanges between a purine and a pyrimidine) in a DNA strand. With an increasing number of plant studies revealing a transversion rather than transition bias, we chose to perform a detailed substitution analysis for the plant family Cucurbitaceae using data from several short plastid DNA sequences. We generated a phylogenetic tree for 19 taxa of the tribe Benincaseae and related genera and then scored conservative substitution changes (e.g., those not exhibiting homoplasy or reversals) from the unambiguous branches of the tree. Neither the transition nor (A+T)/(G+C) biases found in previous studies were supported by our overall data. More importantly, we found a novel and symmetrical substitution bias in which Gs had been preferentially replaced by A, As by C, Cs by T, and Ts by G, resulting in the GACTG substitution series. Understanding this pattern will lead to new hypotheses concerning plastid evolution, which in turn will affect the choices of substitution models and other tree-building algorithms for phylogenetic analyses based on nucleotide data.     

Root traits, nutrient uptake, multi-location grain yield and benefit–cost ratio of two lentil (Lens culinaris, Medikus.) varieties

Lentil is a protein-rich pulse, grown mainly in developing countries as a rain-fed crop in nutrient-poor soils. Hence, the importance of root traits for efficient capture of soil nutrients and water can be crucial to its economical yield. Little is known about the lentil root system and even less about its relationship to grain yield. We compared the root system of two Bangladeshi lentil varieties, Barimasur-3 (BM-3) and Barimasur-4 (BM-4), in a pot experiment and related it to their multi-location grain yield in the fields. BM-4 maintained faster root development both at an early growth stage (20days after sowing) and at flowering (60days) compared to BM-3. The roots of BM-4 penetrated the 25cm depth of the soil profile after 19±1days and while those of BM-3 took 24±2days to reach the same depth. The roots of BM-4 were covered with denser (26±3mm^–1) and longer (0.48±0.11) root hairs than BM-3 (density 17±2mm^–1, length 0.32±0.09mm). The differential presence of root hairs increased the effective length of root system of BM-4 by 12 times and that of BM-3 by five times. The lentil varieties did not differ in their ability to induce pH change and acid phosphatase activity in rhizosphere. In the pot experiment, the uptake of macro-nutrients (K, P, Ca, and Mg) as well as micro-nutrients (Fe, Mn, Zn, Cu, B and Mo) by BM-4 was significantly higher, compared to BM-3. The varieties produced the same amount of shoot biomass. At five of six agro-ecological distinct field locations in Bangladesh, BM-4 gave significantly higher (10–20%) grain yield than BM-3. Linked with the higher grain yield, the benefit-cost ratio (BCR) of BM-4 was 3.14 and that of BM-3 were 2.62, indicating that BM-4 provided better return per unit investment, compared to BM-3, supported by the better root morphology and higher nutrient uptake. This may be one of the reasons supporting the popularity and preferred adoption of BM-4 among the Bangladeshi farmers, who grow lentil mainly on nutrient-poor soils. The results indicate the benefits of selection and breeding for superior root traits for better agro-economics.     

Enhanced acetyl esterase production by Fusarium oxysporum

Production of acetyl esterase (EC 3.1.1.6) by Fusarium oxysporum strain F3 was enhanced by optimization of growth conditions. Under optimal conditions, activities as high as 0.89U/ml of culture medium were obtained. The culture filtrate was equally active on p-nitrophenyl acetate and acetylxylan. The enzyme produced 71% deacetylation of acetylxylan in 2h at 40C. Activity was optimized at pH6.5 and at 55^C. The respective K_m values for p-nitrophenyl acetate and acetylxylan were 0.25mM and 1.05% (w/v) and the V_m values were 0.65 and 0.43mol acetate/min/mg protein.     

A Cytogenetic Study of the Leaf Beetle Genus Cyrtonus (Coleoptera, Chrysomelidae)

The chromosomes of ten species of Cyrtonus and the genome sizes of six are surveyed. Among the total of 15 chromosomally studied species, 11 have 2n=28 chromosomes and a 13+Xy_p male meioformula, three have 2n=40 and 19+Xy_p and one 2n=46 and 22+Xy_p. All but one species with 28 chromosomes show only metacentric or submetacentric chromosomes, whereas the species with 40 and 46 chromosomes display some telocentrics or subtelocentrics, that are probably derived from the former by centric fissions. However, since the number of major chromosome arms is strikingly higher in these latter species (NF=70 and 78) than in the 28-chromosome species (mostly NF=56), other chromosomal rearrangements such as pericentric inversions or heterochromatin accretions could also be involved. The genome sizes display a narrow range, from 1C=0.6–1.22pg, and they are not significantly correlated with the chromosome numbers. Some possible factors implied in the rough chromosomal evolution of Cyrtonus are discussed in relation to a few other genera of the subfamily Chrysomelinae.     

Biotransformation of codeine to morphine in freely suspended cells and immobilized cultures of Spirulina platensis

Both freely suspended cells and immobilized cultures of Spirulina platensis, a blue-green alga, biotransformed exogenously fed codeine, an opium alkaloid, to morphine. The external addition of codeine to the culture medium did not affect the growth of S. platensis. Immobilization of Spirulina in a calcium alginate gel matrix was optimized by using 2% (w/v) sodium alginate and reducing the concentration of nutrients of Zarrouk's medium, which caused destabilization of the calcium alginate gel. The accumulation of morphine increased gradually and reached maxima of 330g 100ml^–1 culture at 105h in freely suspended and 351g 100ml^–1 at 96h in immobilized Spirulina cultures. Accumulation of morphine was detected only in the medium, whereas cells did not show accumulation. The immobilized Spirulina cultures showed marginally higher conversion of codeine to morphine over freely suspended cultures.     

Diel Movements of Bat Rays, Myliobatis californica, in Tomales Bay, California: Evidence for Behavioral Thermoregulation?

We used ultrasonic telemetry to examine movement patterns of 11 bat rays, Myliobatis californica, in Tomales Bay, California. Tomales Bay is long (20km) and narrow (1.4km), and is hydrographically separated into outer and inner bay regions. The outer bay (the outermost 8km) is characterized by oceanic conditions while the shallow inner bay (the innermost 12km) features wide seasonal temperature shifts. Five rays were tracked monthly from October 1990 to November 1991 and six rays (four of which carried temperature-sensing transmitters) were tracked daily from 30 June to 16 July 1992. Mean bat ray movement rate was 8.84mmin^–1 (range 4.49 to 13.40mmin^–1) and was not significantly affected by size (p=0.592), tidal stage (p=0.610), or time of day (p=0.327). Movement direction was unrelated to tidal stage (p=0.472) but showed a highly significant diel pattern (p<0.001). From 2:50–14:50h, rays moved toward the warmer and shallower inner bay, while from 14:50–2:50h they moved toward the cooler and deeper outer bay. These telemetry data, along with known bat ray foraging patterns and respiratory temperature-sensitivity, argue for behavioral thermoregulation as the primary influence on this movement pattern.     

Laboratory culture studies of Trichodesmium isolated from the Great Barrier Reef Lagoon, Australia

Cultures of Trichodesmium from the Northern and Southern Great Barrier Reef Lagoon (GBRL) have been established in enriched seawater and artificial seawater media. Some cultures have been maintained with active growth for over 6years. Actively growing cultures in an artificial seawater medium containing organic phosphorus (glycerophosphate) as the principal source of phosphorus have also been established. Key factors that contributed to the successful establishment of cultures were firstly, the seed samples were collected from depth, secondly, samples were thoroughly washed and thirdly, incubations were conducted under relatively low light intensities (PAR 40–50molquantam^–2s^–1). N₂ fixation rates of the cultured Trichodesmium were found to be similar to those measured in the GBRL. Specific growth rates of the cultures during the exponential growth phase in all enriched media were in the range 0.2–0.3day^–1 and growth during this phase was characterised by individual trichomes (filaments) or small aggregations of two to three trichomes. Characteristic bundle formation tended to occur following the exponential growth phase, which suggests that the bundle formation was induced by a lack of a necessary nutrient e.g. Fe. Results from some exploratory studies showed that filament-dominated cultures of Trichodesmium grew over a range of relatively low irradiances (PAR 5–120molquantam^–2s^–1) with the maximum growth occurring at 40–50molquantam^–2s^–1. These results suggest that filaments of the tested strain are well adapted for growth at depth in marine waters. Other studies showed that growth yields were dependent on salinity, with maximum growth occurring between 30 and 37psu. Also the cell yields decreased by an order of magnitude with the reduction of Fe additions from 450 to 45nM. No active growth was observed with the 4.5nM Fe addition.     

Gross nitrogen transformations in soils from uncut and cut boreal upland and peatland coniferous forest stands

Gross and net nitrogen (N) ammonification and nitrification were measured in soils from an uncut and recently cut upland and peatland conifer stand in northwestern Ontario, Canada. Rates of gross total inorganic N immobilization were similar to gross mineralization, resulting in low net mineralization rates in soils from all four upland and peatland conifer stands. Gross ammonification rates were variable but similar in soils from uncut and cut peatland hollows (18–19mgNkg^–1day^–1) and upland forest floor soils (14–19mgNkg^–1day^–1). Gross ammonium ( ) immobilization rates were also variable but similar to ammonification rates. Median gross nitrification rates were within 0–2mgNkg^–1day^–1 in soils from all four upland and peatland cut and uncut stands, although rates were consistently higher for the soils from the cut stands. Large variability in gross nitrification rates were observed in peatland soils, however the highest gross nitrification rates were measured in saturated peatland soils. Net rates remained low in the soils from all four stands due to high nitrate ( ) immobilization and very fast turnover (<0.2 day). Our results suggest that potential losses may be negated by high immobilization in uncut and cut boreal forest stands. This study reveals the potential for the interaction of N production and consumption processes in regulating N retention in upland and peatland conifer forests, and the resilience of the boreal forest to disturbance.     

Flexibility on the karyotype evolution in bitterlings (Pisces, Cyprinidae)

In bitterlings (Acheilognathinae) C- and Ag-banding karyotypes of 6 species-subspecies collected in China and South Korea were analyzed. The chromosomal constitution of 2n=46 (4SM+42ST) in Rhodeus atremius fangi was quite different from that of 2n=48 (8M+20SM+20ST) in other species-subspecies in Rhodeus. It was concluded from the analysis of banded chromosomes that the increase in number of ST during the karyotype change from 2n=48 to 2n=46 was achieved by a series of pericentric inversions from 24 M-SM to 24 ST, and the decrease in the diploid number was caused by an additional tandem fusion of 4 ST chromosomes, forming a new ST pair in the 2n=46 karyotype. The karyotype of Tanakia koreensis, T. signifer, and Acheilognathus macropterus is 2n=48 (8M+20SM+20ST), 2n=48 (8M+20SM+14–16ST+4–6 A), 2n=44 (14M+16SM+14ST), respectively. In R. ocellatus ocellatus, T. koreensis, T. signifer and A. macropterus, karyotype changes from 2n=48 to 2n=44 due to centric fusion and inversion have also been estimated. It was suggested that C-banding heterochromatin was greatly concerned with the karyotype evolution in bitterlings.