bluuebunny/crossref_metadata_2025_split huggingface dataset:
Altered Fatty Acid Profile of Polar Lipids in Maize Seedlings in Response to Excess Copper
Authors: Chaffai R. , Elhammadi M. A. , Seybou T. N. , Tekitek A. , Marzouk B. , El Ferjani E. 
Published: March 2007

AbstractA wide range of cellular responses occur when plants are exposed to heavy metal stress, including changes in the membrane fatty acid composition. In this study, we examined the effect of excess copper (100 μm) on the degree of unsaturation [double bond index (DBI) of 18‐C fatty acids] and the polar lipid profiles in maize (Zea mays L.). The level of unsaturation of total fatty acids decreased from 1.42 to 1.28 in maize roots. However, copper‐induced compositional changes of polar fatty acid composition show a general trend of increasing DBI. These responses suggest that individual 18‐C fatty acid classes may have specific roles in maintaining optimal membrane function, enabling plant growth under copper stress. The results also reveal key changes including marked decrease in total root phospholipid levels and consistent increase in the steryl lipid/phospholipid (SL/PL) ratio, as well as a decrease in monogalactosyldiacylglycerol/digalactosyldiacylglycerol (MGDG/DGDG) ratio, reflecting alteration of membrane permeability and fluidity. In shoots, the DBI obtained from phosphatidylcholine (PC), sulphoquinovosyldiacylglycerol (SQDG) and monogalactosyldiacylglycerol (MGDG) was increased. In contrast, these indices were decreased in phosphatidylinositol (PI) and phosphatidylglycerol (PG). However, the PI, PC, PG, MGDG and DGDG contents in shoots were significantly decreased, suggesting alterations in the photosynthetic membranes.
Effects of Zinc Deficiency and Drought on Grain Yield of Field‐grown Wheat Cultivars in Central Anatolia
Authors: Bagci S. A. , Ekiz H. , Yilmaz A. , Cakmak I. 
Published: March 2007

AbstractDrought stress and zinc (Zn) deficiency are serious abiotic stress factors limiting crop production in Turkey, especially in Central Anatolia. In this study, the effects of Zn deficiency and drought stress on grain yield of 20 wheat cultivars (16 bread wheat, Triticum aestivum; four durum wheat, Triticum durum cultivars) were investigated over 2 years under rainfed and irrigated conditions in Central Anatolia where drought and Zn deficiency cause substantial yield reductions. Plants were treated with (+Zn: 23 kg Zn ha−1, as ZnSO4·7H2O) and without (−Zn) Zn under rainfed and irrigated conditions. Both Zn deficiency and rainfed treatments resulted in substantial decreases in grain yield. Significant differences were determined between both bread wheat and durum wheat cultivars in terms of drought stress tolerance. Considering drought sensitivity indices over 2 years, the bread wheat cultivars Yayla‐305, Gerek‐79, Dagdas‐94 and Bolal‐2973 were found to be more drought‐tolerant than the other cultivars under both −Zn and +Zn treatments. Especially the durum wheat cultivars Cakmak 79 and Selcuklu 97 showed much greater drought susceptibility under Zn deficiency, and irrigation alone was not sufficient to obtain satisfying grain yield without Zn application. The results indicate that sensitivity to Zn deficiency stress became more pronounced when plants were drought‐stressed. The effect of irrigation on grain yield was maximized when Zn was adequately supplied, leading to the suggestion that efficient water use in Central Anatolia seems to be highly dependent on the Zn nutritional status of plants.
Soya Bean (Glycine max L. Merr.) Genotype Response to Early‐season Flooding: I. Root and Nodule Development
Authors: Henshaw T. L. , Gilbert R. A. , Scholberg J. M. S. , Sinclair T. R. 
Published: March 2007

AbstractSoya bean is often grown in regions subject to periodic flooding, with the rooting zone most affected by flooding due to its proximity to the source of stress. Our objectives were to examine the effects of flooding soya bean on its primary roots, adventitious roots and root nodules, and to determine relationships between root morphological changes and early‐season flood tolerance. The experiment was conducted in Belle Glade, FL with 11 soya bean genotypes subjected to (i) no flood, (ii) 2‐week flood 21–35 days after sowing (DAS) or (iii) 4‐week flood 21–49 DAS. All plants were harvested 49 DAS. Flooding reduced soya bean primary root weight, length and volume across genotypes. Adventitious root length and volume were greater in the 4‐week than the 2‐week flood. Soya bean nodule dry weight was threefold higher in the non‐flooded treatments. Genotypic differences in root development and tolerance to flooding were noted, with early‐season flood tolerance correlated with primary root dry weight, length and surface area, and adventitious root dry weight. However, there was no correlation between this study's early‐season root development and late‐season flood tolerance based on seed yield from previous studies. Our results indicate that full season trials may be necessary to identify flood‐tolerant soya bean germplasm.
Dietary nucleotides improve the immune status of puppies at weaning
Authors: Romano V. , Martinez‐Puig D. , Torre C. , Iraculis N. , Vilaseca Ll. , Chetrit C. 
Published: March 2007

SummaryAnimals have a continuous requirement for nucleotides, especially for systems that present a high rate of cell turnover‐like the immune system. Nucleotides may become conditionally essential nutrients under certain circumstances (e.g. weaning period) because endogenous synthesis may be insufficient to sustain normal function. In this case the immune function depends upon dietary nucleotide sources. The aim of the present study was to test the impact of a nucleotide supplement, specifically designed to mimic nucleotide composition in bitch's milk, on the immune function of weaned puppies. A total of 21 beagle puppies weaned at 8 weeks of age were allocated to three balanced groups and fed one of the following diets: standard commercial puppy diet (control diet); control diet supplemented with 900 p.p.m. of nucleotides or control diet supplemented with 1350 p.p.m. of nucleotides. One week later weaning puppies were vaccinated with an heptavalent vaccine. During the study blood samples were taken in order to analyse plasmatic concentrations of C‐reactive protein (CRP), non‐specific immunoglobulins and antibody titre against parvovirus. Peripheral blood mononuclear cells (PBMC) stimulation test was also performed. Supplemented groups showed higher antibody titre against parvovirus 14 days after vaccination and higher unspecific immunoglobulin levels. PBMC stimulation test at 35 days also showed higher results in the supplemented groups. CRP 1 day after vaccination and haematocrit after 35 days showed better results for the supplemented groups. In conclusion, dietary supplementation with nucleotides mimicking nucleotide composition of bitch's milk, improved the immune response capacity of puppies at weaning.
Effects of periodic desiccation on the synthesis of the UV‐screening compound, scytonemin, in cyanobacteria
Authors: Fleming Erich D. , Castenholz Richard W. 
Published: March 2007

SummaryScytonemin is an ultraviolet radiation (UVR)‐screening compound synthesized by some sheathed cyanobacteria exposed to high solar and sky radiation. It is primarily produced in response to UVA radiation, but certain environmental stresses can enhance synthesis. This study focuses on the effects of periodic desiccation on scytonemin synthesis in three desiccation‐tolerant cyanobacterial strains, Nostoc punctiforme PCC 73102, Chroococcidiopsis CCMEE 5056 and Chroococcidiopsis CCMEE 246. Nostoc punctiforme and Chroococcidiopsis CCMEE 5056 exposed to UVA radiation produced more concentrated scytonemin screens when experiencing periodic desiccation (i.e. 1 day desiccated for every 2 days hydrated) than when continuously hydrated. A more concentrated scytonemin screen would reduce the amount of UVR damage accrued when cells are desiccated and metabolically inactive. This might allow the cyanobacteria to allocate more energy to systems other than UVR damage repair during rehydration, which would facilitate recovery. The scytonemin screen is extremely stable, remaining largely intact in the sheaths of desiccated N. punctiforme even when continuously exposed to UVA radiation for about 2 months. In contrast to the above findings, scytonemin synthesis in Chroococcidiopsis CCMEE 246, a strain that produces scytonemin constitutively under low visible light (no UVA), was partially inhibited by periodic desiccation.
Polyphyletic photosynthetic reaction centre genes in oligotrophic marine Gammaproteobacteria
Authors: Cho Jang‐Cheon , Stapels Martha D. , Morris Robert M. , Vergin Kevin L. , Schwalbach Michael S. , Givan Scott A. , Barofsky Douglas F. , Giovannoni Stephen J. 
Published: March 2007

SummaryEcological studies indicate that aerobic anoxygenic phototrophic bacteria (AAP) that use bacteriochlorophyll to support phototrophic electron transport are widely distributed in the oceans. All cultivated marine AAP are alpha‐3 and alpha‐4 Proteobacteria, but metagenomic evidence indicates that uncultured AAP Gammaproteobacteria are important members of ocean surface microbial communities. Here we report the description of obligately oligotrophic, marine Gammaproteobacteria that have genes for aerobic anoxygenic photosynthesis. Three strains belonging to the OM60 clade were isolated in autoclaved seawater media. Polymerase chain reaction assays for the pufM gene show that these strains contain photosynthetic reaction centre genes. DNA sequencing and phylogenetic analysis indicate that the pufM genes are polyphyletic, suggesting multiple instances of lateral gene transfer. Peptide sequences from six photosynthesis genes (pufL, pufM, pufC, pufB, pufA and puhA) were detected by proteomic analyses of strain HTCC2080 cells grown aerobically in seawater. They closely match predicted peptides from an environmental seawater bacterial artificial chromosome clone of gammaproteobacterial origin, thus identifying the OM60 clade as a significant source of gammaproteobacterial AAP genes in marine systems. The cell yield and rate of growth of HTCC2080 in autoclaved, aerobic seawater increased in the light. These findings identify the OM60 clade as a source of Gammaproteobacteria AAP genes in coastal oceans, and demonstrate that aerobic, anoxygenic photosynthetic metabolism can enhance the productivity of marine oligotrophic bacteria that also grow heterotrophically in darkness.
Assessing diversity and biogeography of aerobic anoxygenic phototrophic bacteria in surface waters of the Atlantic and Pacific Oceans using the Global Ocean Sampling expedition metagenomes
Authors: Yutin Natalya , Suzuki Marcelino T. , Teeling Hanno , Weber Marc , Venter J. Craig , Rusch Douglas B. , Béjà Oded 
Published: March 2007

SummaryAerobic anoxygenic photosynthetic bacteria (AAnP) were recently proposed to be significant contributors to global oceanic carbon and energy cycles. However, AAnP abundance, spatial distribution, diversity and potential ecological importance remain poorly understood. Here we present metagenomic data from the Global Ocean Sampling expedition indicating that AAnP diversity and abundance vary in different oceanic regions. Furthermore, we show for the first time that the composition of AAnP assemblages change between different oceanic regions, with specific bacterial assemblages adapted to open ocean or coastal areas respectively. Our results support the notion that marine AAnP populations are complex and dynamic, and compose an important fraction of bacterioplankton assemblages in certain oceanic areas.
Ecophysiology of Defluviicoccus‐related tetrad‐forming organisms in an anaerobic–aerobic activated sludge process
Authors: Wong Man‐Tak , Liu Wen‐Tso 
Published: March 2007

SummaryA group of uncultured tetrad‐forming organisms (TFOs) was enriched in an acetate‐fed anaerobic–aerobic sequencing membrane bioreactor showing deteriorated enhanced biological phosphorus removal capacity. Based on 16S rRNA gene clone library and fluorescence in situ hybridization (FISH) analyses, these TFOs were identified as novel members of the Defluviicoccus cluster in the Alphaproteobacteria, accounting for 90 ± 5% of the EUBmix FISH‐detectable bacterial cell area in the reactor biomass. Microautoradiography in combination with FISH and polyhydroxyalkanoate (PHA) staining revealed that these Defluviicoccus‐related TFOs could take up and transform acetate, lactate, propionate and pyruvate, but not aspartic acid and glucose, into PHA under anaerobic conditions. In contrast, under continuous anaerobic–aerobic cultivation, Defluviicoccus vanus, the only cultured strain from the cluster, was able to take up glucose with concurrent glycogen consumption and PHA production under anaerobic conditions. Under subsequent aerobic conditions, the accumulated PHA was utilized and the biomass glycogen levels were restored. These findings not only re‐confirmed these Defluviicoccus‐related TFOs as glycogen‐accumulating organisms, but also revealed unexpected levels of physiological, phylogenetic and morphological diversity among members of the Defluviicoccus cluster.
An Acanthamoeba sp. containing two phylogenetically different bacterial endosymbionts
Authors: Heinz Eva , Kolarov Irina , Kästner Christian , Toenshoff Elena R. , Wagner Michael , Horn Matthias 
Published: March 2007

SummaryAcanthamoebae are ubiquitous free‐living amoebae and important predators of microbial communities. They frequently contain obligate intracellular bacterial symbionts, which show a worldwide distribution. All Acanthamoeba spp. described so far harboured no or only a single specific endosymbiont phylotype, and in some cases evidence for coevolution between the symbiotic bacteria and the amoeba host has been reported. In this study we have isolated and characterized an Acanthamoeba sp. (strain OEW1) showing a stable symbiotic relationship with two morphologically different endosymbionts. 16S rRNA sequence analysis assigned these symbionts to the candidate genus Procabacter (Betaproteobacteria) and the genus Parachlamydia (Chlamydiae) respectively. Fluorescence in situ hybridization and transmission electron microscopy confirmed the affiliation of the endosymbionts and showed their co‐occurrence in the amoeba host cells and their intracellular location within separate compartments enclosed by host‐derived membranes. Further analysis of this stable relationship should provide novel insights into the complex interactions of intracellular multiple‐partner associations.
Mobile colonoscopic surveillance provides quality care for hereditary nonpolyposis colorectal carcinoma families in South Africa
Authors: Anderson D. W. , Goldberg P. A. , Algar U. , Felix R. , Ramesar R. S. 
Published: March 2007

AbstractBackground  It is difficult to provide a colonoscopic surveillance service for at‐risk family members with hereditary nonpolyposis colorectal carcinoma when many of those family members live in a remote area of South African far from endoscopic services. A mobile surveillance programme was established to service these individuals.Objective  The aim of this study was to compare the quality of the mobile service to that provided in established endoscopy units.Method  Ninety‐one asymptomatic subjects with known disease‐causing mutations underwent 259 colonoscopies. Of these, 171 colonoscopies were performed by a mobile colonoscopy service in small rural hospitals and 88 in established endoscopy units. The quality of the colonoscopic services was measured by completion rate, the rate of detection of colonoscopic abnormalities, histopathological analyses of biopsies, surgical intervention and colorectal cancer deaths.Results  The caecum was reached in 96% of all colonoscopies. A significant lesion was detected in 8.8% of colonoscopies. There was no difference in the rate of complete colonoscopy and detection rate of lesions in the established units and the mobile service (both P = 0.6). The rate of detection of early adenocarcinomas was similar (P = 0.17). The colonoscopic screening/surveillance programme meets international standards with a high accuracy (95.75%) and negative predictive value (100%).Conclusion  The mobile service provides access to colonoscopy in remote areas without compromising the quality of service.
Low anastomotic leak rate after colorectal surgery: a single‐centre study
Authors: Jones O. M. , John S. K. P. , Horseman N. , Lawrance R. J. , Fozard J. B. J. 
Published: March 2007

AbstractObjective  Anastomotic leak after colorectal surgery is a serious event associated with significant morbidity and mortality. There is little consensus regarding ‘acceptable’ rates of leakage, however. This study describes the experience of anastomotic leakage after both elective and emergency colorectal surgery in a district general hospital.Method  A prospectively collected database of all patients with a diagnosis of colorectal cancer in a single hospital formed the basis of the study. Leak was defined as breakdown of the anastomosis contributing to death or requiring reoperation or reintervention.Results  A total of 949 patients underwent surgery with an anastomosis between 1996 and 2004, including 331 patients treated with anterior resection. Anastomotic leaks requiring reoperation occurred in eight patients (0.8%). Thirty‐day and in‐hospital mortality was 4%.Conclusion  A very low rate of anastomotic leakage after colorectal surgery is possible in a district general hospital setting. Given the impact of anastomotic leakage on function, tumour recurrence and long‐term survival, it should be considered as a marker of surgical quality when evaluating surgical performance.
Laparoscopic colectomy is cheaper than conventional open resection
Authors: Ridgway P. F. , Boyle E. , Keane F. B. , Neary P. 
Published: March 2007

AbstractObjective  International randomized trials have endorsed the routine use of laparoscopic techniques in colorectal surgery. The authors hypothesize that the overall care pathway in minimal access resection was cheaper than conventional open resection.Method  This was a case‐matched study of consecutive patients undergoing laparoscopic resection between July 2005 and February 2006. Intraoperative (costs, duration, incision length) and postoperative [morbidity, length of stay (LOS), readmission] parameters were examined. Institutional retrospective open controls and national validated figures were used for costings.Results  Thirty‐five laparoscopic and 53 open resections were evaluated. Median LOS was 5 days in the laparoscopic group vs 12 in the open group (P = 0.001). There were two conversions (5.7%) and two readmissions. Mean operative cost of laparoscopic resection was €1557.08, therefore 2.4 bed days need to be saved to recoup the increased cost compared with open resection. The actual median save is 7 days (P = 0.031). A mean of €4591.38 and 7 bed days per case is saved by performing the resection laparoscopically. Subgroup analysis of laparoscopic resections clearly demonstrates similar trends.Conclusion  The institutional saving is over €150 000 and 245 bed days during the study period. Despite higher operative spending, laparoscopic colorectal resections are significantly cheaper than conventional open resections.
With and Without End
Authors: Cave Peter 
Published: March 2007

AbstractWays and words about infinity have frequently hidden a continuing paradox inspired by Zeno. The basic puzzle is the tortoise's – Mr T's – Extension Challenge, the challenge being how any extension, be it in time or space or both, moving or still, can yet be of an endless number of extensions. We identify a similarity with Mr T's Deduction Challenge, reported by Lewis Carroll, to the claim that a conclusion can be validly reached in finite steps. Rejecting common solutions to both challenges, we use a Wittgensteinian approach for dissolution, noting also that other paradoxes, such as the Surprise Examination and Yablo's, trap us inconsistently into similar endlessnesses. In so doing, we encounter a hopping flea, generate a proportionality paradox and consider the knight's move in chess.
Iris Murdoch's Mortal Asymmetry
Authors: Milligan Tony 
Published: March 2007

AbstractIris Murdoch holds that the best sort of life is a figurative death of the self. This figurative death is informed by an acceptance of real mortality. A recognition of mortality is supposed to help redirect our attention away from self and towards others. Yet these others are also mortal but (unlike the self) remain worthy of love, care and consideration. That is to say, the significance of mortality for Murdoch depends on whose mortality is at issue, whether it is the mortality of the self or of the other that is in question. My rejection of two ways of making sense of this self/other asymmetry is used to motivate the view that her attitude towards death requires a prior commitment to unselfing. And this is a problematic moral project.
Long‐term survival of HIV‐infected patients treated with highly active antiretroviral therapy in Serbia and Montenegro
Authors: Jevtović DO , Salemović D , Ranin J , Pešić I , Žerjav S , Djurković‐Djaković O 
Published: March 2007

BackgroundHighly active antiretroviral therapy (HAART) has dramatically changed the prognosis of HIV disease, even in terminally ill patients. Although these patients may survive many years after the diagnosis of AIDS if treated with HAART, some still die during treatment.MethodsA retrospective study in a cohort of 481 HIV‐infected patients treated with HAART between January 1998 and December 2005 was conducted to compare subgroups of long‐term survivors (LTSs) and patients who died during treatment.ResultsA total of 48 patients survived for more than 72 months (mean 83.8±standard deviation 5.6 months). Thirty patients died during treatment (mean 35.3±25.0 months), of whom nine died from non‐AIDS‐related causes, 18 died from AIDS‐related causes, and three died as a result of HAART toxicity. Although LTSs were significantly (P=0.015) younger at HAART initiation, age below 40 years was not a predictor of long‐term survival. The subgroups did not differ in the proportion of clinical AIDS cases at HAART initiation, in the prevalence of hepatitic C virus (HCV) coinfection, or in pretreatment and end‐of‐follow‐up CD4 cell counts. In contrast, the viral load achieved during treatment was lower in the survivors (P=0.03), as was the prevalence of hepatitis B virus (HBV) coinfection (P=0.03). Usage of either protease inhibitor (PI)‐containing regimens [odds ratio (OR) 9.0, 95% confidence interval (CI) 2.2–35.98, P<0.001] or all three drug classes simultaneously (OR 7.4, 95% CI 2.2–25.1, P<0.001) was associated with long‐term survival. Drug holidays incorporated in structured treatment interruption (STI) were also associated with a good prognosis (OR 14.9, 95% CI 2.9–75.6, P<0.001).ConclusionsLong‐term survival was associated with PI‐based HAART regimens and lower viraemia, but not with the immunological status either at baseline or at the end of follow up. STI when CD4 counts reach 350 cells/μL, along with undetectable viraemia, was a strong predictor of long‐term survival.