Effects of waterlogging on soil aeration and on root and shoot growth and yield of winter oats (Avena sativa L.)

Summary Winter oats were grown outdoors in lysimeters containing monoliths of a sandy loam soil. The soil was either freely-drained throughout the experiment or waterlogged to the soil surface from mid-January until mid-April. After the start of waterlogging the oxygen flux density decreased most rapidly nearer the soil surface and in the upper 50 cm declined to zero. At 80 cm depth the oxygen flux density at the end of the waterlogging still had not diminished to zero. While the soil was waterlogged root growth was negligible in the 20–50 cm zone of the soil profile, whereas below that depth root growth continued, reaching 95 cm by the end of the treatment. During the latter part of the waterlogging period root growth resumed in the upper 10 cm, and in the upper 2.5 cm was greater than in the freelydrained treatment.At the end of the waterlogging period, the total root length and shoot dry weights were 77 and 60% of those in the freely-drained treatment, tillering was restricted and leaf area index diminished. However, by anthesis, root length and shoot weights of the plants that had been waterlogged were only 10 and 12% less respectively than for the freely-drained plants. At harvest, total dry matter and grain yields were only 9% less, the latter largely through fewer grains per panicle.     

Mobilising mosques? The role of service attendance for political participation of Turkish and Moroccan minorities in the Netherlands

Religious service attendance has been identified as an important source of political participation among Christians and Muslims in the USA. In Europe, where religion is seen as a barrier rather than a bridge to Muslims’ integration, the role of mosque attendance for the political participation of Muslims remains understudied. This study asks whether the politically mobilizing role of service attendance extends to Muslim minorities in Europe. We examine direct and indirect effects of the frequency of religious service attendance on organizational participation, political trust and voting intentions among large nationwide samples of Turkish and Moroccan minorities in the Netherlands using multi-group structural equation modelling. Our results show that service attendance relates positively to engagement in both co-ethnic and mainstream organizations. These two forms of civic engagement translate into a greater intention to vote among Turks, but not Moroccans.     

Cloning and sequence analysis of a cDNA for barley ferredoxin-dependent glutamate synthase and molecular analysis of photorespiratory mutants deficient in the enzyme

The NH₂-terminal sequences of ferredoxin-dependent glutamate synthase (Fd-GOGAT; EC 1.4.7.1) purified from barley (Hordeum vulgare L.) and Chlamydomonas reinhardtii (Dangeard), and of a barley peptide, were determined and the barley sequences were used to design oligonucleotide primers for the polymerase chain reaction. A specific 1.3-kilobase (kb) cDNA fragment specifying the NH₂-terminal one-third of the mature barley polypeptide, was amplified, cloned and sequenced. The NH₂-terminus of plant Fd-GOGAT is highly conserved and homologous to the NH₂-terminus of the heavy subunit of Escherichia coli NADPH-GOGAT. Based on sequence homologies, we tentatively identified the NH₂-terminal region of Fd-GOGAT as the glutamine-amidotransferase domain, which is related to the corresponding domain of the purF-type amidotransferases. The Fd-GOGAT cDNA clone, and polyclonal antibodies raised against the barley enzyme, were used to analyse four Fd-GOGAT-deficient photorespiratory mutants. Three mutants (RPr 82/1, RPr 82/9 and RPr 84/82) had no detectable Fd-GOGAT protein in leaves, while the fourth (RPr 84/42) had a small amount of cross-reacting material. Hybridization to Northern blots of total leaf RNA revealed that both RPr 82/9 and RPr 84/82 were indistinguishable from the parental line (Maris Mink), having normal amounts of a 5.7-kb mRNA species. On the other hand, RPr 82/2 and RPr 84/42 each contained two distinct hybridizing RNA species, one of which was larger than 5.7 kb, the other smaller. Using a set of wheat-barley telosomic addition lines we have assigned the Fd-GOGAT structural locus to the short arm of chromosome 2.Abbreviations bp kbase pairs - cDNA copy DNA - Fd ferredoxin - GOGAT glutamate synthase - GAT glutamine amidotransferase - kb kilobase - PCR polymerase chain reaction C.A. was the holder of a Fleming award from the British Council and the Spanish Ministry of Education and Science. A.J.M. was for part of the work the recipient of a European Molecular Biology Organization postdoctoral fellowship. The research was also partly supported by contract no. BAP/O354/E of the Biotechnology Action Programme of the E.C., by an Acciones Integradas award (no. 40/125) from the British Council and the Spanish Ministry of Education and Science, by the Junta de Andalucia (to Group 3263) and by project PB91-0613 from DGICYT (Spain). We thank Daryl Pappin (Department of Biochemistry, University of Leeds) for amino-acid sequencing, and Martin Cornelius (Rothamsted Experimental Station, Harpenden, Herts., UK) for synthesis of oligonuleotides.     

Electrochemical detection of DNA hybridization amplified by nanoparticles

Detection of specific oligonucleotide (ODN) fragments has become an important field in many areas of biomedicine. We describe a novel ODN sensor based on electropolymerization of a conducting polymer (polypyrrole) in the presence of a sample containing ODN(s). The resulting trapped ODN(s) are then probed by addition of complimentary sequence ODN. By incorporating CdS nanoparticles with the probe, a significant improvement in sensor sensitivity was observed. Impedance spectroscopy suggested that optimal detection of hybridization occurred at frequencies>or=3000 Hz (for a 0.07 cm2 85 nm thick film). At these frequencies, the impedance signal was almost linear with the logarithm of ODN concentration in the range 3.7-370 nM with a detection limit of approximately 1 nM ODN (for the sensor fabricated). Importantly, the sensor could be regenerated by removing hybridized ODN with NaOH suggesting possibility of the sensor re-use.     

Induction of T cell responses and recruitment of an inflammatory dendritic cell subset following tumor immunotherapy with Mycobacterium smegmatis

Mycobacteria and their cell wall components have been used with varying degrees of success to treat tumors, and Mycobacterium bovis BCG remains in use as a standard treatment for superficial bladder cancer. Mycobacterial immunotherapy is very effective in eliciting local immune responses against solid tumors when administered topically; however, its effectiveness in eliciting adaptive immune responses has been variable. Using a subcutaneous mouse thymoma model, we investigated whether immunotherapy with Mycobacterium smegmatis, a fast-growing mycobacterium of low pathogenicity, induces a systemic adaptive immune response. We found that M. smegmatis delivered adjacent to the tumor site elicited a systemic anti-tumor immune response that was primarily mediated by CD8⁺ T cells. Of note, we identified a CD11c⁺CD40^intCD11b^hiGr-1⁺ inflammatory DC population in the tumor-draining lymph nodes that was found only in mice treated with M. smegmatis. Our data suggest that, rather than rescuing the function of the DC already present in the tumor and/or tumor-draining lymph node, M. smegmatis treatment may promote anti-tumor immune responses by inducing the involvement of a new population of inflammatory cells with intact function.     

Prosopis pod production—Comparison of North American,South American,Hawaiian, and African germplasm in young plantations

Prosopispod production was compared in 3 field trials in southern California, i.e., a typical orchard planting, an irrigation trial, and a heat/drought stress trial. Thirteen species representing North American, South American, Hawaiian, and African germplasm were evaluated. Hawaiian and African accessions were eliminated from the irrigation trial by a minus 5°C temperature. The most productive pod producers were P. velutinaaccessions from southern Arizona. In the fifth season, 5 trees of the most productive accession, i.e., P. velutina32 had a mean pod production of 7.2 kg/tree with a range of 3.2–12.2 kg/tree. P. chilensisand P. albatrees of the same age were much larger but had less pod production. Trees in the driest irrigation treatment had the greatest pod production. Pod production estimates of 3,000–4,000 kg/ha were obtained in the dry irrigation treatment by P. velutina20 which received 370 mm rainfall in the year preceding harvest.     

Mortality in sickle cell anemia in Africa: a prospective cohort study in Tanzania

Background

The World Health Organization has declared Sickle Cell Anemia (SCA) a public health priority. There are 300,000 births/year, over 75% in Africa, with estimates suggesting that 6 million Africans will be living with SCA if average survival reaches half the African norm. Countries such as United States of America and United Kingdom have reduced SCA mortality from 3 to 0.13 per 100 person years of observation (PYO), with interventions such as newborn screening, prevention of infections and comprehensive care, but implementation of interventions in African countries has been hindered by lack of locally appropriate information. The objective of this study was to determine the incidence and factors associated with death from SCA in Dar-es-Salaam.

Methods and Findings

A hospital-based cohort study was conducted, with prospective surveillance of 1,725 SCA patients recruited from 2004 to 2009, with 209 (12%) lost to follow up, while 86 died. The mortality rate was 1.9 (95%CI 1.5, 2.9) per 100 PYO, highest under 5-years old [7.3 (4.8–11.0)], adjusting for dates of birth and study enrollment. Independent risk factors, at enrollment to the cohort, predicting death were low hemoglobin (<5 g/dL) [3.8 (1.8–8.2); p = 0.001] and high total bilirubin (≥102 µmol/L) [1.7 (1.0–2.9); p = 0.044] as determined by logistic regression.

Conclusions

Mortality in SCA in Africa is high, with the most vulnerable period being under 5-years old. This is most likely an underestimate, as this was a hospital cohort and may not have captured SCA individuals with severe disease who died in early childhood, those with mild disease who are undiagnosed or do not utilize services at health facilities. Prompt and effective treatment for anemia in SCA is recommended as it is likely to improve survival. Further research is required to determine the etiology, pathophysiology and the most appropriate strategies for management of anemia in SCA.     

Phase Ia clinical evaluation of the safety and immunogenicity of the Plasmodium falciparum blood-stage antigen AMA1 in ChAd63 and MVA vaccine vectors

Background

Traditionally, vaccine development against the blood-stage of Plasmodium falciparum infection has focused on recombinant protein-adjuvant formulations in order to induce high-titer growth-inhibitory antibody responses. However, to date no such vaccine encoding a blood-stage antigen(s) alone has induced significant protective efficacy against erythrocytic-stage infection in a pre-specified primary endpoint of a Phase IIa/b clinical trial designed to assess vaccine efficacy. Cell-mediated responses, acting in conjunction with functional antibodies, may be necessary for immunity against blood-stage P. falciparum. The development of a vaccine that could induce both cell-mediated and humoral immune responses would enable important proof-of-concept efficacy studies to be undertaken to address this question.

Methodology

We conducted a Phase Ia, non-randomized clinical trial in 16 healthy, malaria-naïve adults of the chimpanzee adenovirus 63 (ChAd63) and modified vaccinia virus Ankara (MVA) replication-deficient viral vectored vaccines encoding two alleles (3D7 and FVO) of the P. falciparum blood-stage malaria antigen; apical membrane antigen 1 (AMA1). ChAd63-MVA AMA1 administered in a heterologous prime-boost regime was shown to be safe and immunogenic, inducing high-level T cell responses to both alleles 3D7 (median 2036 SFU/million PBMC) and FVO (median 1539 SFU/million PBMC), with a mixed CD4⁺/CD8⁺ phenotype, as well as substantial AMA1-specific serum IgG responses (medians of 49 µg/mL and 41 µg/mL for 3D7 and FVO AMA1 respectively) that demonstrated growth inhibitory activity in vitro.

Conclusions

ChAd63-MVA is a safe and highly immunogenic delivery platform for both alleles of the AMA1 antigen in humans which warrants further efficacy testing. ChAd63-MVA is a promising heterologous prime-boost vaccine strategy that could be applied to numerous other diseases where strong cellular and humoral immune responses are required for protection.

Trial Registration

ClinicalTrials.gov {"type":"clinical-trial","attrs":{"text":"NCT01095055","term_id":"NCT01095055"}}NCT01095055     

Effects of artificial social stimuli on the reproductive schedule and hormone levels of yellow-eyed penguins (Megadyptes antipodes)

The effects of social stimuli on avian reproductive behaviors such as breeding schedules and courtship behaviors are well known due to numerous field studies. However, studies that have simultaneously examined the effects of social stimuli on reproductive behavior and the mediating endocrine mechanisms have been largely restricted to captive populations, which may not be representative of free-living populations. This study, conducted over two breeding seasons, aimed to simultaneously measure the effects of experimentally increasing auditory stimuli on the breeding schedule and endocrinology (levels of total androgen, estradiol, progesterone and prolactin) on free-living yellow-eyed penguins (Megadyptes antipodes). The yellow-eyed penguin is the least colonial of all penguins, nesting far apart from each other under dense vegetation, and, therefore, is presumed to experience much lower levels of social stimuli than other penguins. Egg laying was significantly more synchronous and tended to be earlier when birds were exposed to playbacks of the calls of conspecifics in 1 year of the study. We also found that levels of total androgen and estradiol of males in 1 year, and prolactin in another year, were proportionally higher among treated birds compared control birds that received no artificial auditory stimuli. These results show that even among supposedly solitary nesters, social stimuli could still play a role in influencing reproductive behavior and physiology. For the first time in free-living seabirds, we have demonstrated that behavioral responses to increased social stimuli are associated with hormonal changes.