Spatial distribution of aquatic birds in Anavilundawa Ramsar wetland sanctuary in Sri Lanka

Biotic and abiotic factors that influence the avian distribution in a dry zone wetland was investigated by studying the distribution of Asian Openbill (Anastomus oscitans), Cotton Pygmy-goose (Nettapus coromandelianus) and Pheasant-tailed Jacana (Hydrophasianus chirurgus) in Anavilundawa Ramsar sanctuary in Sri Lanka in 2006. Their distribution was recorded in Anavilundawa, Suruwila and Maiyawa reservoirs, their catchments and respective paddy fields, through line transects. The floral cover of surface water was recorded by floating quadrates. Water lily (Nymphea spp.) was the dominant flora in Anavilundawa reservoir, invasive water hyacinth (Eichhornia crassipes) in Suruwila reservoir and a native lotus (Nelumbo nucifera) in Maiyawa reservoir, respectively. Anavilundawa area had a higher distribution of birds than in the other two areas. Among the three species observed, Asian Openbill distribution was mainly restricted to Anavilundawa whereas Pheasant-tailed Jacana was present in all three areas. Nesting of Asian Openbill occurred only in Anavilundawa while nesting of Pheasant-tailed Jacana was only observed in Maiyawa. Among the three species recorded, Cotton Pygmy-goose numbers were the least. Asian Openbill preferred dead trees and trees with no leaves for nesting and perching over live trees. It is concluded that the spread of invasives such as Water hyacinth and Salvinia (Salvinia molesta) forming mats over surface water have reduced the abundance of habitat specialists like Cotton Pygmy-goose.     

Combined measurements of egg fatty acids and stable isotopes as indicators of feeding ecology in lake-dwelling birds

1. We examined whether egg fatty acid (FA) profiles and stable isotopes (SIA) could be used in a comparative way to infer the diet of two aquatic bird species with contrasting feeding habits: a surface forager, the pheasant-tailed jacana ( Hydrophasianus chirurgus ), and a pursuit-diving forager, the little cormorant ( Phalacrocorax niger ), at Haleji Lake (Pakistan).
2. The species differed markedly in the overall percentage of saturated and polyunsaturated fatty acids. Moreover, among jacanas, two groups of birds had relatively high or low concentrations of long-chain essential PUFAs (such as 18:2 n-6 and 20:4 n-6), suggesting differing contributions from animal prey and plant material.
3. These trophic differences were corroborated by δ¹⁵N values which indicated both a higher trophic position in cormorants relative to jacanas, and differences in trophic position for the two groups of jacanas. In this latter species δ¹³C values in both groups also pointed to differing diets, involving mainly grazing plants or a contribution from animal resources (aquatic invertebrates or insects).
4. Both lower values of δ¹³C and higher percentages of 18:1 n-7 detected in little cormorants may indicate the influence of the anoxic water, typical of a freshwater system densely covered by macrophytes.
5. These results indicate how both biomarkers offer complementary information in studies of feeding ecology, refining interpretations of trophic pathways which are usually based on FA or SIA alone. Comparisons of FA profiles and SIA among species also proved to be a reliable approach for inferring the diet of species for which information is scarce or contradictory, as is the case for the pheasant-tailed jacana.     

Detection of chromosomal aneuploidy in endometriosis by multi-color fluorescence in situ hybridization (FISH)

Endometriosis affects 10–15% of women of reproductive age and is a common cause of infertility and pelvic pain. Although endometriosis is characterized by abnormal growth or turn-over of cells, the genetic changes involved remain unclear. We employed a multi-color fluorescence in situ hybridization (FISH) strategy to determine the incidence of somatic chromosomal numeric alterations in severe/late stage endometriosis. Using alpha-satellite sequence-specific DNA probes for chromosomes 7, 8, 11, 12, 16, 17, and 18, simultaneous two- and three-color FISH were performed to evaluate the frequency of monosomic, disomic, and trisomic cells in normal control and endometriotic tissue specimens. In one of four endometriosis samples studied, a significantly higher frequency of monosomy for chromosome 17 (14.8%, χ² ₄ = 53.3, P < 0.0001) and 16 (8.8%, χ² ₄ = 11.4, P < 0.05) was observed. An increased number of cells with chromosome 11 trisomy (14.8%, χ² ₄ = 96.2, P < 0.0001) were detected in a second case. In a third case, a distinct colony of nuclei with chromosome 16 monosomy (14.1%, χ² ₄ = 21.39, P < 0.005) was detected. Acquired chromosome-specific aneuploidy may be involved in endometriosis, reflecting clonal expansion of chromosomally abnormal cells. That candidate tumor suppressor genes and oncogenes have been mapped to chromosomes 11, 16, and 17 suggests that chromosomal loss or gain plays a role in the development and/or progression of endometriosis. Received: 27 December 1997 / Accepted: 14 April 1997     

Role of tissue plasminogen activator and plasminogen activator inhibitor polymorphism in myocardial infarction

A case–control association study on 229 Myocardial Infarction (MI) patients and 217 healthy controls was carried out to determine the role of tissue-plasminogen activator (t-PA) (Alu-repeat insertion (I)/deletion (D)) and plasminogen activator inhibitor (PAI-1) (4G/5G insertion/deletion) polymorphisms with MI in the Pakistani population. In MI patients the genotype distribution of the PAI-1 gene was not found to be different when compared with the unaffected controls (P > 0.05, χ² = 1.03). The risk allele 4G was also not associated with MI (P > 0.05, χ² = 0.46, odds ratio (OR) = 1.1 (95% confidence interval (CI) = 0.84–1.43), P > 0.05). Similarly, the genotype frequencies of t-PA I/I, I/D and D/D were not different from the unaffected controls (P > 0.05, χ² = 1.60), and the risk allele “I” was not found to be associated with MI (P > 0.05, χ² = 1.35, OR = 0.86 (95% CI = 0.66–1.11), P > 0.05). However, when the data were distributed along the lines of gender a significant association of the 4G/4G PAI-1 genotype was observed with only the female MI patients (P < 0.05, z-test = 2.21). When the combined genotypes of both the polymorphisms were analyzed, a significant association of MI was observed with the homozygous DD/4G4G genotype (P < 0.01, z-test = 2.61), which was specifically because of the female samples (P = 0.01, z-test = 2.53). In addition smoking (P < 0.001, χ² = 13.52, OR = 3.45 (95% CI = 1.77–6.94)), diabetes (P < 0.001, χ² = 22.45, OR = 8.89 (95% CI = 2.96–29.95)), hypertension (OR = 7.76 (95% CI = 2.88–22.68), P < 0.001) family history (P < 0.001, χ² = 13.72, OR = 3.7 (95% CI = 1.71–8.18)) and lower HDL levels (P < 0.05) were found to be significantly associated with the disease. In conclusion the PAI-1 gene polymorphism was found to have a gender specific role in the female MI patients.     

Cardiovascular risk in rheumatoid arthritis versus osteoarthritis: acute phase response related decreased insulin sensitivity and high-density lipoprotein cholesterol as well as clustering of metabolic syndrome features in rheumatoid arthritis

Rheumatoid arthritis (RA) patients experience a markedly increased frequency of cardiovascular disease. We evaluated cardiovascular risk profiles in 79 RA patients and in 39 age-matched and sex-matched osteoarthritis (OA) patients. Laboratory tests comprised ultrasensitive C-reactive protein (CRP) and fasting lipids. Insulin sensitivity (IS) was determined by the Quantitative Insulin Sensitivity Check Index (QUICKI) in all OA patients and in 39 of the RA patients. Ten RA patients were on glucocorticoids. RA patients exercised more frequently than OA patients (χ² = 3.9, P < 0.05). Nine RA patients and one OA patient had diabetes (χ² = 4.5, P < 0.05). The median CRP, the mean QUICKI and the mean high-density lipoprotein (HDL) cholesterol were 9 mg/l (range, 0.5–395 mg/l), 0.344 (95% confidence interval [CI], 0.332–0.355) and 1.40 mmol/l (95% CI, 1.30–1.49 mmol/l) in RA patients, respectively, as compared with 2.7 mg/l (range, 0.3–15.9 mg/l), 0.369 (95% CI, 0.356–0.383) and 1.68 mmol/l (95% CI, 1.50–1.85 mmol/l) in OA patients. Each of these differences was significant (P < 0.05). After controlling for the CRP, the QUICKI was similar in RA and OA patients (P = 0.07), while the differences in HDL cholesterol were attenuated but still significant (P = 0.03). The CRP correlated with IS, while IS was associated with high HDL cholesterol and low triglycerides in RA patients and not in OA patients. A high CRP (≥ 8 mg/l) was associated with hypertension (χ² = 7.4, P < 0.05) in RA patients. RA glucocorticoid and nonglucocorticoid users did not differ in IS and lipids (P > 0.05). Excess cardiovascular risk in RA patients as compared with OA patients includes the presence of decreased IS and HDL cholesterol in RA patients. The latter is only partially attributable to the acute phase response. The CRP, IS, HDL cholesterol, triglycerides and hypertension are inter-related in RA patients, whereas none of these relationships were found in OA patients.     

Geographic variation in malarial parasite lineages in the common yellowthroat (<Emphasis Type="Italic">Geothlypis trichas</Emphasis>)

Our current understanding of migration routes of many birds is limited and researchers have employed various methods to determine migratory patterns. Recently, parasites have been used to track migratory birds. The objective of this study was to determine whether haemosporidian parasite lineages detect significant geographic structure in common yellowthroats (Geothlypis trichas). We examined liver tissue or blood from 552 birds sampled from multiple locations throughout the continental United States, southern Canada, and the Bahamas. We found a 52.7% overall prevalence of haematozoan infection. We identified 86.1% of these infections to genus: 81% were Plasmodium; 5% were Haemoproteus; and 0.1% were Leucocytozoon. There were significant differences in the prevalence of different parasite genera among regions (χ² = 36.82, P < 0.0001) and in the proportion of Plasmodium infections versus other parasites among regions (χ² = 35.52, P < 0.0001). Sequence information identified three Haemoproteus lineages, two Leucocytozoon lineages, and thirteen Plasmodium lineages. Due to the low number of Haemoproteus and Leucocytozoon, only Plasmodium lineages were used in the geographic comparison of lineages. Six Plasmodium lineages were found in eight or more birds and the prevalence of these varied significantly among regions (χ² = 172.33, P < 0.0001). Additionally, 45 juvenile birds were sampled to determine what parasites could be obtained in the breeding grounds and we found only one lineage. In conclusion, parasite lineages show some geographic structure, with some lineages being more geographically specific than others, but are not useful for determining migratory connectivity in this species. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users. The U.S. Government’s right to retain a non-exclusive, royalty-free license in and to any copyright is acknowledged.     

Identification of QTL underlying vitamin E contents in soybean seed among multiple environments

Vitamin E (VE) in soybean seed has value for foods, medicines, cosmetics, and animal husbandry. Selection for higher VE contents in seeds along with agronomic traits was an important goal for many soybean breeders. In order to map the loci controlling the VE content, F₅-derived F₆ recombinant inbred lines (RILs) were advanced through single-seed-descent (SSD) to generate a population including 144 RILs. The population was derived from a cross between ‘OAC Bayfield’, a soybean cultivar with high VE content, and ‘Hefeng 25’, a soybean cultivar with low VE content. A total of 107 polymorphic simple sequence repeat markers were used to construct a genetic linkage map. Seed VE contents were analyzed by high performance liquid chromatography for multiple years and locations (Harbin in 2007 and 2008, Hulan in 2008 and Suihua in 2008). Four QTL associated with α-Toc (on four linkage groups, LGs), eight QTL associated with γ-Toc (on eight LGs), four QTL associated with δ-Toc (on four LGs) and five QTL associated with total VE (on four LGs) were identified. A major QTL was detected by marker Satt376 on linkage group C2 and associated with α-Toc (0.0012 > P > 0.0001, 5.0% < R ² < 17.0%, 25.1 < α-Toc < 30.1 μg g⁻¹), total VE (P < 0.0001, 7.0% < R ² < 10.0%, 118.2 < total VE < 478.3 μg g⁻¹). A second QTL detected by marker Satt286 on LG C2 was associated with γ-Toc (0.0003 > P > 0.0001, 6.0% < R ² < 13.0%, 141.5 < γ-Toc < 342.4 μg g⁻¹) and total VE (P < 0.0001, 2.0% < R ² < 9.0%, 353.9 < total VE < 404.0 μg g⁻¹). Another major QTL was detected by marker Satt266 on LG D1b that was associated with α-Toc (0.0002 > P > 0.0001, 4.0% < R ² < 6.0%, 27.7 < α-Toc < 43.7 μg g⁻¹) and γ-Toc (0.0032 > P > 0.0001, 3.0% < R ² < 10.0%, 69.7 < γ-Toc < 345.7 μg g⁻¹). Since beneficial alleles were all from ‘OAC Bayfield’, it was concluded that these three QTL would have great potential value for marker assisted selection for high VE content.     

Staphylococcal cassette chromosome mec (SCCmec) characterization and panton-valentine leukocidin gene occurrence for methicillin-resistant Staphylococcus aureus in Turkey, from 2003 to 2006

Methicillin-resistant Staphylococcus aureus (MRSA) cause serious community-acquired and nosocomial diseases all over the world. We determined the SCCmec types and occurrence of the PVL gene by using TaqMan real-time PCR method, and correlated these with phenotypic antibiotic susceptibility patterns for MRSA strains collected from Gulhane Military Medical Academy Hospital (GMMAH) during 4 years study period. To our knowledge, this is the first report from Turkey of molecular SCCmec typing analysis of MRSA stains. A total of 385 clinical MRSA isolates collected in the clinical and Microbiology Laboratory at GMMAH between 2003 and 2006 were included in the study. Overall, SCCmec types-I, II, III, IV, V, nontypeable and PVL occurrence were detected in 11 (2.8%), 3 (0.8%), 316 (82.1%), 20 (5.1%), 20 (5.1%), 15 (3.9%) and 5 (1.3%) isolates, respectively. A total of 330 (85.5%) were SCCmec-I/II/III and 40 (10.3%) were SCCmec IV/V. SCCmec-I/II/III isolates were recovered more from patients with serious infections in surgical departments especially those with intensive care units than the SCCmec-IV/V isolates (χ² = 13.560, P < 0.001). SCCmec-I/II/III MRSA strains were predominantly recovered from blood stream (53.0%, P = 0.014), while SCCmec-IV/V strains were predominately isolated from skin and soft tissue and abscess (55.0%, P < 0.001). The PVL gene was detected in 10.0% of SCCmec-IV/V isolates in contrast to 0.3% in SCCmec-I/II/III (χ² = 25.164, P < 0.001). SCCmec-I/II/III MRSA strains were more resistant to clindamycin (χ² = 5.078, P = 0.024), amoxicillin-clavulanate (χ² = 84.912, P < 0.001), erythromycin (χ² = 4.651, P = 0.031), gentamicin (χ² = 24.869, P < 0.001), and rifampin (χ² = 18.878, P < 0.001) than SCCmec-IV/V MRSA strains. This data indicates that SCCmec-III MRSA strains that do not carry the PVL gene are the predominant MRSA strains in our hospital setting in Ankara, capital of Turkey and that SCCmec-I/II/III MRSA strains may cause serious infections in surgical departments especially those with intensive care units.     

Clinical implications of activated leukocyte cell adhesion molecule expression in breast cancer

In the study, we enrolled 150 breast cancer cases to investigate the expression status of activated leukocyte cell adhesion molecule (ALCAM), and the relationships between ALCAM expression and clinical-pathological characteristics and prognosis of breast cancer. It was observed that ALCAM was expressed at higher levels in breast cancer tissue compared to levels observed for tumor-adjacent tissue. Compared to cancers with low membranous ALCAM expression, cancers with high membranous ALCAM expression were prone to lymph node metastasis (χ² = 15.910, P = 0.010) and metastasis in general (χ² = 5.211, P = 0.029). High cytoplasmic ALCAM expression was noticeably correlated with local recurrence (χ² = 7.379, P = 0.012), especially for short-term recurrence (interval <2 years) (χ² = 5.562, P = 0.037), while not associated to long-term local recurrence (interval >2 years). The content of ALCAM protein is closely associated with the expression of estrogen receptor (ER) (P = 0.024). The disease-free survival of patients with high cytoplasmic ALCAM expression was significantly shorter compared to the cases with low cytoplasmic ALCAM expression (P = 0.036). In conclusion, ALCAM expressed at high levels in breast cancer. High membranous expression of ALCAM probably resulted in weakened adherent ability and metastasis. In addition, high cytoplasmic ALCAM expression strengthened invasive ability of malignant cells and then promoted tumor development.     

Species Richness and Patterns of Invasion in Plants, Birds, and Fishes in the United States*

We quantified broad-scale patterns of species richness and species density (mean # species/km²) for native and non-indigenous plants, birds, and fishes in the continental USA and Hawaii. We hypothesized that the species density of native and non-indigenous taxa would generally decrease in northern latitudes and higher elevations following declines in potential evapotranspiration, mean temperature, and precipitation. County data on plants (n = 3004 counties) and birds (n=3074 counties), and drainage (6 HUC) data on fishes (n = 328 drainages) showed that the densities of native and non-indigenous species were strongly positively correlated for plant species (r = 0.86, P < 0.0001), bird species (r = 0.93, P<0.0001), and fish species (r = 0.41, P<0.0001). Multiple regression models showed that the densities of native plant and bird species could be strongly predicted (adj. R² = 0.66 in both models) at county levels, but fish species densities were less predictable at drainage levels (adj. R² = 0.31, P<0.0001). Similarly, non-indigenous plant and bird species densities were strongly predictable (adj. R² = 0.84 and 0.91 respectively), but non-indigenous fish species density was less predictable (adj. R² = 0.38). County level hotspots of native and non-indigenous plants, birds, and fishes were located in low elevation areas close to the coast with high precipitation and productivity (vegetation carbon). We show that (1) native species richness can be moderately well predicted with abiotic factors; (2) human populations have tended to settle in areas rich in native species; and (3) the richness and density of non-indigenous plant, bird, and fish species can be accurately predicted from biotic and abiotic factors largely because they are positively correlated to native species densities. We conclude that while humans facilitate the initial establishment, invasions of non-indigenous species, the spread and subsequent distributions of non-indigenous species may be controlled largely by environmental factors. The U.S. Government’s right to retain a non-exclusive, royalty-free licence in and to any copyright is acknowledged.     

Cardiorespiratory power across adolescence in male soccer players

Despite the recognition of the beneficial role of cardiorespiratory power (CRP) for health and sport performance, the development of this physical fitness parameter in adolescent soccer players was not well studied. Aim of this cross-sectional study was to investigate the effect of age on CRP of adolescent soccer players, the influence of anthropometric characteristics and body composition on it, and to establish normative data. Male adolescent (N = 274; aged 12.07–20.98 y), classified in nine one-year age-groups, child (N = 12, aged 7.71–11.8 y) and adult players (N = 22; aged 21.12–31.59 y), all members of competitive soccer clubs, were examined for anthropometric characteristics and body composition and they performed Physical Working Capacity in heart rate 170 test (PWC₁₇₀) on cycle ergometer. Analysis of variance revealed significant difference between age groups with respect to PWC170 in absolute (F _10,.297 = 29.58, P < 0.001, η² = 0.5), relative to body mass (F _10,.297 = 5.28, P < 0.001, η² = 0.15) and relative to fat free mass values (F _10.297 = 4.98, P < 0.001, η²= 0.14). In addition, age was in positive association with these parameters (r = 0.6, P < 0.001, r = 0.24, P < 0.001 and r = 0.23, P < 0.001, correspondingly). The main finding of this study was that CRP increased during developmental period in soccer players, even when it was adjusted to body mass or FFM, which increased during development. This documentation of the development of CRP provided useful tool for coaches and fitness trainers in order to apply optimal exercise interventions for health and performance.     

Association of chronotype and social jetlag with human non-verbal intelligence

The aim of this study was to evaluate the effects of chronotype and social jetlag (SJL) on intelligence. Subjects were aged 14–25 years (n = 1008). A significant effect of intelligence on academic performance, as measured by the Raven’s Standard Progressive Matrices test, was found (F_2,917 = 11.75, P < 0.0001, η² = 0.03). When SJL was less than 2 hours, the intelligence of people with late chronotype was found to be higher than that of subjects with early and intermediate chronotypes (F_2,305 = 3.12, P < 0.05, η² = 0.02). A negative effect of SJL on the results of intelligence testing was noted only in subjects with late chronotype (F_2,536 = 2.61, P < 0.05, η² = 0.02). Our data suggest that people with late chronotype have a higher level of intelligence, but these advantages disappear when SJL ≥2 hours.     

Effects of a School‐based Weight Maintenance Program for Mexican‐American Children: Results at 2 Years

The prevalence of childhood overweight has increased significantly, with the highest rates noted among Mexican Americans. Many negative health outcomes are associated with overweight; thus, there is a need for effective weight‐loss interventions tailored to this group. This study evaluated 24‐month outcomes of a randomized, controlled trial involving an intensive lifestyle‐based weight maintenance program targeting overweight Mexican‐American children at a charter school in Houston, Texas. A total of 60 children (33 males, 55%) between the ages of 10 and 14 at or >85th percentile for BMI were recruited. Participants were randomized to an instructor‐led intervention (ILI) or a self‐help (SH) program, both aimed at modifying eating and physical activity behaviors using behavior modification strategies. Changes in participants' standardized BMI (zBMI) were assessed at baseline, 1, and 2 years. Tricep skinfold, total cholesterol, triglycerides, high‐density lipoprotein cholesterol, and calculated low‐density lipoprotein were assessed at baseline and 1 year. ILI participants showed significantly greater decreases in zBMI at 1 and 2 years (F = 26.8, P < 0.001, F = 4.1, P < 0.05, respectively) compared to SH controls. ILI participants showed greater improvements in body composition, as measured by tricep skinfold (F = 9.75, P < 0.01). Children in the ILI condition experienced benefits with respect to total cholesterol (F = 7.19, P < 0.05) and triglycerides (F = 4.35, P < 0.05) compared to children in the SH condition. Overall, the school‐based intervention resulted in improved weight and clinical outcomes in overweight Mexican‐American children, and zBMI was maintained over 2 years.     

Fecundity and fitness in cross-compatible pollinations of tristylous North American Lythrum salicaria populations

As heterostyly and self incompatibility are linked in tristylous L. salicaria, all cross-compatible pollinations – those between anthers and styles of the same level – should produce viable seed. The rigor of this theory was tested using seed set and germination of cross-compatible pollinations in 18 naturalized L. salicaria populations in Minnesota/Wisconsin (n=342 genotypes; n=86 shorts, n=127 mids, and n=129 longs). Seed set for short-styled genotypes ranged from zero to 135 (36+38); mids–0–156, (53+39), and longs–0–151 (59+39). Mean seed set per capsule was not significantly different for mids and longs, but both were significantly greater than that of shorts (F=14, P<0.0001). Zero seed set frequently occurred in most compatible crosses, in contrast with theoretical expectations. The high percentage of populations deviating from normality must be due to incompatibility. An incompatibility system independent of heterostyly could cause this, where failed crosses result from matches of incompatibility specificities in pollen and pistil. This independence is questionable, however, given the non-significant difference in failed outcrosses for pooled χ² comparing within and between populations (χ²=0.395, P>0.5). A sporophytic incompatibility model is proposed with a minimum of three specificities. Zero seed set in compatible crosses is due to the addition of alleles from L. alatum, a distylous species that forms introgressive hybrids with L. salicaria. Reduced fecundity could increase the deficiency of shorts, and significantly greater seed germination of shorts could explain the continued presence of short-styled individuals in L. salicaria populations. Received: 3 February 2000 / Accepted: 25 March 2000     

Linkage of a RAPD marker with powdery mildew resistance <Emphasis Type="Italic">er-1</Emphasis> gene in <Emphasis Type="Italic">Pisum sativum</Emphasis> L.

The aim of this study was to investigate the inheritance of powdery mildew disease and to tag it with a DNA marker to utilize for the marker-assisted selection (MAS) breeding program. The powdery mildew resistant genotype Fallon ^er and susceptible genotype 11760-3 ^ER were selected from 177 genotypes by heavy infestation of germplasm with Erysiphe pisi through artificial inoculation The F₁ plants of the cross Fallon/11760-3 indicated the dominance of the susceptible allele, while F₂ plants segregated in 3: 1 ratio (susceptible: resistant) that fit for goodness of fitness by χ² (P > 0.07), indicating monogenic recessive inheritance for powdery mildew resistance in Pisum sativum. A novel RAPD marker OPB18 (5′-CCACAGCAGT-3′) was linked to the er-1 gene with 83% probability with a LOD score of 4.13, and was located at a distance of 11.2 cM from the er-1 gene.     

CYP46 T/C Polymorphism is not Associated with Alzheimer’s Dementia in a Population from Hungary

Multiple genetic and environmental factors regulate the susceptibility to Alzheimer’s disease (AD). Recently, several independent studies have reported that a locus on chromosome 14q32.1, where a gene encoding a cholesterol degrading enzyme of the brain, called 24-hydroxylase (CYP46A1) is located, has been linked with AD. The single nucleotide polymorphism (T/C) in intron 2 of CYP46 gene has been found to confer the risk for AD. The water soluble 24(S)-hydroxysterol is the product of the CYP46A1, and elevated plasma and cerebrospinal fluid hydroxysterol concentrations have been found in AD, reflecting increased brain cholesterol turnover or cellular degradation, due to the neurodegenerative process. A case–control study was performed on 125 AD and 102 age- and gender-matched control subjects (CNT) from Hungary, to test the association of CYP46 T/C and apolipoprotein E (ApoE) gene polymorphisms in AD. The frequency of the CYP46 C allele was similar (χ²=0.647, df=1, P=0.421, exact P=0.466, OR=0.845; 95% CI: 0.561–1.274) in both groups (CNT: 27%; 95% CI: 21.3–33.4; AD 30%; 95% CI: 25.0–36.3). The ApoE ɛ4 allele was significantly over-represented (χ²=11.029, df=2, P=0.004) in the AD population (23.2%; 95% CI: 18.2–29.0) when compared with the CNT (11.3%; 95% CI: 7.4–16.6). The presence or absence of one or two CYP46C alleles together with the ApoE ɛ4 allele did not increase the risk of AD (OR=3.492; 95% CI: 1.401–8.707; P<0.007 and OR=3.714; 95% CI: 1.549–8.908; P<0.003, respectively). Our results indicate that the intron 2 T/C polymorphism of CYP46 gene (neither alone, nor together with the ɛ4 allele) does not increase the susceptibility to late-onset sporadic AD in the Hungarian population.     

Photosynthetic response to precipitation/rainfall in predominant tree (<Emphasis Type="Italic">Ulmus pumila</Emphasis>) seedlings in Hunshandak Sandland,China

The responses of gas exchange and chlorophyll fluorescence of field-growing Ulmus pumila seedlings to changes in simulated precipitation were studied in Hunshandak Sandland, China. Leaf water potential (Ψ_wp), net photosynthetic rate (P _N), stomatal conductance (g _s), and transpiration rate (E) were significantly increased with enhancement of precipitation from 0 to 20 mm (p<0.01), indicating stomatal limitation of U. pumila seedlings that could be avoided when soil water was abundant. However, P _N changed slightly when precipitation exceeded 20 mm (p>0.05), indicating more precipitation than 20 mm had no significant effects on photosynthesis. Maximum photochemical efficiency of photosystem 2, PS 2 (F_v/F_m) increased from 0.53 to 0.78 when rainfall increased from 0 to 10 mm, and F_v/F_m maintained a steady state level when rainfall was more than 10 mm. Water use efficiency (WUE) decreased significantly (from 78–95 to 23–27 μmol mol⁻¹) with enhancement of rainfalls. P _N showed significant linear correlations with both g _s and Ψ_wp (p<0.0001), which implied that leaf water status influenced gas exchange of U. pumila seedlings. The 20-mm precipitation (soil water content at about 15 %, v/v) might be enough for the growth of elm seedlings. When soil water content (SWC) reached 10 %, down regulation of PS2 photochemical efficiency could be avoided, but stomatal limitation to photosynthesis remained. When SWC exceeded 15 %, stomatal limitation to photosynthesis could be avoided, indicating elm seedlings might tolerate moderate drought.     

In vitro and in vivo evaluation of the prebiotic activity of water-soluble blueberry extracts

The prebiotic effects of water extracts of two blueberry (BBE) cultivars (‘Centurion’ and ‘Maru’) were studied using pure and mixed cultures of human faecal bacteria. The results demonstrated for the first time that addition of BBE from both cultivars to broth media containing pure cultures of Lactobacillus rhamnosus and Bifidobacterium breve resulted in a significant increase (P < 0.05–0.0001) in the population size of these strains. Batch fermentation system was used to monitor the effect of BBE addition on the mixed faecal bacterial populations (obtained from healthy human donors). Addition of BBE from both cultivars to batch cultures inoculated with mixed human faecal cultures resulted in a significant increase in the number of lactobacilli (P < 0.01–0.0001) and bifidobacteria (P < 0.05–0.0001). Furthermore, a significant influence on the population size of lactobacilli and bifidobacteria was observed after administration of extracts from both cultivars to rats daily for 6 days in comparison with the control group. In rats gavaged orally with 4 ml kg⁻¹ day⁻¹ of BBE for 6 days, the population size of lactobacilli (P < 0.05) and bifidobacteria (P < 0.05–0.01) was increased significantly. We hypothesize that BBE could modify the bacterial profile by increasing the numbers of beneficial bacteria and thereby improving gut health.     

Water hyacinth productivity and detritus accumulation

Water hyacinth [Eichhornia crassipes (Mart) Solms] productivity and detritus accumulation were evaluated in eutrophic lake water with and without added nutrients (fertilized and control reservoirs, respectively). Seasonal changes in plant productivity and detritus accumulation were determined at monthly intervals for one year. Significant differences were observed in plant productivity between seasons and nutrient additions. Seasonal plant productivity ranged from 1.9 to 23.1 mg (dry wt) ha⁻¹ for the fertilized reservoir and −0.2 to 10.2 mg ha⁻¹ for the control reservoir. Detritus accumulation was not significantly different between seasons or nutrient additions. Seasonal N assimilation by plants ranged from 34 to 242 kg N ha⁻¹ for plants in the fertilized reservoir and < 0 to 104 kg N ha⁻¹ for plants in the control reservoir. Annual net N recovered in detritus represented 21 and 28% of the total N removed by plants in the fertilized and control reservoirs, respectively. Net N loading to the reservoirs from detritus was 92 to 148 kg N ha⁻¹ yr⁻¹.     

Application of Polyelectrolyte Theory to the Study of the B-Z Transition in DNA (1)

Abstract

We have used the polyelectrolyte theory to study the ionic strength dependence of the B-Z equilibrium in DNA. A DNA molecule is molded as an infinitely long continuously charged cylinder of radius a with reduced linear charge density q. The parameters a and q for the B and Z forms were taken from X-ray data: a _B = 1nm, q _B = 4.2, a _z = 0.9 nm and q _z = 3.9. A simple theory shows that at low ionic strengths (when Debye screening length r _D>>a) the electrostatic free energy difference F ^el _Bz = F ^el _Z - F ^el _B increases with increasing ionic strength since q _B>q_z. At high ionic strengths (when r _D<<a) the F ^el _BZ would go on growing with increasing ionic strength if the inequality q _B/^a _B<q_z/a _z were valid. In the converse case when q _z/q _B<a_z/a _B the F ^el _BZ value decreases with increasing salt concentration at high ionic strength. Since X-ray data correspond to the latter case, theory predicts that the F ^el _BZ value reaches a maximum at an intermediate ionic strength of about 0.1 M (where r _D～a). We also performed rigorous calculations based on the Poisson-Boltzmann equation. These calculations have confirmed the above criterion of nonmonotonous behaviour of the F ^el _BZ value as a function of ionic strength. Different theoretical predictions for the B-Z transition in linear and superhelical molecules are discussed. Theory predicts specifically that at a very low ionic strength the Z form may prove to be more stable than the B form. Thus, one can observe the Z-B-Z transition with increasing ionic strength. In the light of our theoretical findings we discuss numerous experimental data on the B-Z transition in linear and superhelical DNA.