bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effects of leaf‐cutting ant refuse on native plant performance under two levels of grazing intensity in the Monte Desert of Argentina
Authors: Cerda Noelia V. , Tadey Mariana , Farji‐Brener Alejandro G. , Navarro María C. 
Published: February 2012

AbstractQuestionLow quantities of soil nutrients often restrict plant establishment and growth in arid lands and have been partially attributed to the scarcity of organic matter in these ecosystems. Refuse dumps from leaf‐cutting ants are a natural source of organic matter; however, their effects on native plant performance have received limited attention to date. Do refuse dumps from leaf‐cutting ants (Acromyrmex lobicornis) enhance the germination and growth of several native plant species and what is the potential influence of heavy grazing on this practice?LocationMonte Desert, Neuquén Province, Argentina.MethodsWe collected fruits of five plant species and two types of substrate (ant refuse dump vs control soil) from two known paddocks with different livestock densities (high vs low). We sowed seeds, previously weighed, of each species in both substrates from both paddocks and monitored their development. We harvested emerged seedlings, documenting their age and measured their height, weight, number of leaves, root weight and root length.ResultsSeed weight was lower in the highly grazed paddock for all the plant species studied. However, seed weight did not affect germination rate. Refuse dumps from the less grazed paddock (i.e. with higher nutrient content) enhanced the vigour of seedlings from smaller seeds more often than those from the highly grazed paddock. Also, germination improved when both seeds and substrate were from the less grazed paddock. Vigour variables showed more complex results, but seedlings growing in refuse dumps tended to be more vigorous. Refuse dumps from the less grazed paddock (i.e. with higher nutrient content) enhanced the vigour of seedlings from the highly grazed paddock (smaller) more than the seeds from the less grazed paddock (larger).ConclusionsOur results demonstrated that ant refuse dumps increased plant germination rate and improved performance of the most representative vegetation in the Monte Desert. Given that external refuse dumps from leaf‐cutting ants are a renewable resource, very abundant and easy to collect, this substrate could be used as a free natural fertilizer in arid regions to restore and manage vegetation cover, especially in heavily grazed sites.
Diethyl Phthalate Enhances Apoptosis Induced by Serum Deprivation in PC12 Cells
Authors: Sun Yongkun , Takahashi Kumiko , Hosokawa Toshiyuki , Saito Takeshi , Kurasaki Masaaki 
Published: February 2012

AbstractIn this study, to examine the mechanism of diethyl phthalate toxicity to cells, the effects of diethyl phthalate on apoptosis in a PC12 cell system were investigated by assaying apoptotic factors such as caspase‐3, Bax, cytochrome c and DNA damage. Diethyl phthalate was shown to enhance the apoptosis induced by serum deprivation according to the results of DNA electrophoresis and TUNEL signal assays, although it could not induce apoptosis itself in the cells. This enhancement was thought to be because of an increase in caspase‐3‐like activity. In addition, the expression of bax and contents of cytochrome c in the cytosol showed a tendency to increase the cells exposed to diethyl phthalate. These results indicated that diethyl phthalate, a potential endocrine disrupter, affects the apoptotic system in PC12 cells. Diethyl phthalate may enhance oxidative stress such as that induced by reactive oxygen species in PC12 cells.
ABO‐incompatible organ transplantation
Authors: Subramanian V. , Ramachandran S. , Klein C. , Wellen J. R. , Shenoy S. , Chapman W. C. , Mohanakumar T. 
Published: February 2012

SummaryIncreases in the patients on the organ transplant wait list have far out paced the number of available organs. This has lead to longer time awaiting transplantation and thus increased morbidity and mortality associated with it. Making more organs available for transplantation remains critical, and hence, extended criteria donors and ABO‐incompatible organs are being utilized. Recent reports on the use of conventional immunosuppressive regimens for ABO‐incompatible grafts suggest outcomes can be obtained similar to those of ABO‐compatible transplants. The delay in the development of natural antibodies to ABO antigens in infants provides an ‘immunological window’ that allows for successful ABO‐incompatible transplants in this age group. This also allows for a unique mechanism long‐term tolerance to the graft in infants. ABO incompatibility may no longer be a contraindication in case of kidney transplantation and paediatric heart transplantation. Increased utilization of ABO‐incompatible grafts can alleviate the shortage for organs and decrease waitlist times and associated morbidity. In this review, we will discuss the current status of ABO‐incompatible transplantation in adult and paediatric solid organ transplantation with attention on recent developments on understanding the mechanisms of graft acceptance in these ABO‐incompatible organs.
Metabolic Engineering of Plant‐derived (E)‐β‐farnesene Synthase Genes for a Novel Type of Aphid‐resistant Genetically Modified Crop PlantsF
Authors: Yu Xiu‐Dao , Pickett John , Ma You‐Zhi , Bruce Toby , Napier Johnathan , Jones Huw D. , Xia Lan‐Qin 
Published: February 2012

AbstractAphids are major agricultural pests that cause significant yield losses of crop plants each year. Excessive dependence on insecticides for long‐term aphid control is undesirable because of the development of insecticide resistance, the potential negative effects on non‐target organisms and environmental pollution. Transgenic crops engineered for resistance to aphids via a non‐toxic mode of action could be an efficient alternative strategy. (E)‐β‐Farnesene (EβF) synthases catalyze the formation of EβF, which for many pest aphids is the main component of the alarm pheromone involved in the chemical communication within these species. EβF can also be synthesized by certain plants but is then normally contaminated with inhibitory compounds. Engineering of crop plants capable of synthesizing and emitting EβF could cause repulsion of aphids and also the attraction of natural enemies that use EβF as a foraging cue, thus minimizing aphid infestation. In this review, the effects of aphids on host plants, plants’ defenses against aphid herbivory and the recruitment of natural enemies for aphid control in an agricultural setting are briefly introduced. Furthermore, the plant‐derived EβF synthase genes cloned to date along with their potential roles in generating novel aphid resistance via genetically modified approaches are discussed.
image

[ Lan‐Qin Xia (Corresponding author)]
A Sequential Quantitative Trait Locus Fine‐Mapping Strategy Using Recombinant‐Derived ProgenyF
Authors: Yang Qin , Zhang Dongfeng , Xu Mingliang 
Published: February 2012

Abstract
image
[ Mingliang Xu ]A thorough understanding of the quantitative trait loci (QTLs) that underlie agronomically important traits in crops would greatly increase agricultural productivity. Although advances have been made in QTL cloning, the majority of QTLs remain unknown because of their low heritability and minor contributions to phenotypic performance. Here we summarize the key advantages and disadvantages of current QTL fine‐mapping methodologies, and then introduce a sequential QTL fine‐mapping strategy based on both genotypes and phenotypes of progeny derived from recombinants. With this mapping strategy, experimental errors could be dramatically diminished so as to reveal the authentic genetic effect of target QTLs. The number of progeny required to detect QTLs at various R2 values was calculated, and the backcross generation suitable to start QTL fine‐mapping was also estimated. This mapping strategy has proved to be very powerful in narrowing down QTL regions, particularly minor‐effect QTLs, as revealed by fine‐mapping of various resistance QTLs in maize. Application of this sequential QTL mapping strategy should accelerate cloning of agronomically important QTLs, which is currently a substantial challenge in crops.
An Integrated Approach to Crop Genetic ImprovementF
Authors: Parry Martin A. J. , Hawkesford Malcolm J. 
Published: February 2012

Abstract
image
[ Martin A. J. Parry ]The balance between the supply and demand of the major food crops is fragile, fueling concerns for long‐term global food security. The rising population, increasing wealth and a proliferation of non‐food uses (e.g. bioenergy) has led to growing demands on agriculture, while increased production is limited by greater urbanization, and the degradation of land. Furthermore, global climate change with increasing temperatures and lower, more erratic rainfall is projected to decrease agricultural yields. There is a predicted need to increase food production by at least 70% by 2050 and therefore an urgent need to develop novel and integrated approaches, incorporating high‐throughput phenotyping that will both increase production per unit area and simultaneously improve the resource use efficiency of crops. Yield potential, yield stability, nutrient and water use are all complex multigenic traits and while there is genetic variability, their complexity makes such traits difficult to breed for directly. Nevertheless molecular plant breeding has the potential to deliver substantial improvements, once the component traits and the genes underlying these traits have been identified. In addition, interactions between the individual traits must also be taken into account, a demand that is difficult to fulfill with traditional screening approaches. Identified traits will be incorporated into new cultivars using conventional or biotechnological tools. In order to better understand the relationship between genotype, component traits, and environment over time, a multidisciplinary approach must be adopted to both understand the underlying processes and identify candidate genes, QTLs and traits that can be used to develop improved crops.
Design of Potent, Non‐Toxic Antimicrobial Agents Based upon the Structure of the Frog Skin Peptide, Temporin‐1CEb from Chinese Brown Frog, Rana chensinensis
Authors: Shang Dejing , Li Xiaofan , Sun Yue , Wang Che , Sun Li , Wei Shi , Gou Meng 
Published: February 2012

Temporin‐1CEb shows antimicrobial activity against Gram‐positive bacteria, but its therapeutic potential is limited by its haemolysis. In this study, eight temporin‐1CEb analogues with altered cationicities and hydrophobicities were synthesized. Increasing cationicity and amphipathicity by substituting neutral and non‐polar amino acid residues on the hydrophilic face of the α‐helix by five or six lysines increased antimicrobial potency approximately 10‐fold to 40‐fold, although when the number of positive charges was increased from +6 to +7, the antimicrobial potency was not additionally enhanced. The substitution of an l‐lysine with a d‐lysine, meanwhile maintaining the net charge and the mean hydrophobicity values, had only a minor effect on its antimicrobial activity, whereas significantly led a decrease in its haemolytic activity. Of all the peptides, l‐K6 has the best potential as an antimicrobial agent because its antimicrobial activity against both Gram‐positive and Gram‐negative bacteria is substantial, and its haemolytic activity is negligible. l‐K6 adopts an α‐helix in 50% trifluoroethanol/water and 30 mm SDS solutions. l‐K6 killed 99.9% of E. coli and S. aureus at 4× MIC in 60 min, and its postantibiotic effect was >5 h. l‐K6 affects the integrity of E. coli and S. aureus plasma membranes by rapidly inducing membrane depolarization.
Nitrogen starvation induces extensive changes in the redox proteome of Prochlorococcus sp. strain SS120
Authors: McDonagh Brian , Domínguez‐Martín Ma Agustina , Gómez‐Baena Guadalupe , López‐Lozano Antonio , Diez Jesús , Bárcena Jose A. , García Fernández Jose M. 
Published: February 2012

SummaryVery low nitrogen concentration is a critical limitation in the oligotrophic oceans inhabited by the cyanobacterium Prochlorococccus, one of the main primary producers on Earth. It is well known that nitrogen starvation affects redox homeostasis in cells. We have studied the effect of nitrogen starvation on the thiol redox proteome in the Prochlorococcus sp. SS120 strain, by using shotgun proteomic techniques to map the cysteine modified in each case and to quantify the ratio of reversibly oxidized/reduced species. We identified a number of proteins showing modified cysteines only under either control or N‐starvation, including isocitrate dehydrogenase and ribulose phosphate 3‐epimerase. We detected other key enzymes, such as glutamine synthetase, transporters and transaminases, showing that nitrogen‐related pathways were deeply affected by nitrogen starvation. Reversibly oxidized cysteines were also detected in proteins of other important metabolic pathways, such as photosynthesis, phosphorus metabolism, ATP synthesis and nucleic acids metabolism. Our results demonstrate a wide effect of nitrogen limitation on the redox status of the Prochlorococcus proteome, suggesting that besides previously reported transcriptional changes, this cyanobacterium responds with post‐translational redox changes to the lack of nitrogen in its environment.
A Backwards Design Method for Mechanical Conceptual Design
Authors: Burgess Stuart C. 
Published: February 2012

Abstract
This paper presents a backwards design method for mechanical conceptual design. The method involves starting with a very idealistic semiworking solution and then systematically solving the unworkable parts of the solution until a complete solution is found. The method can work in conjunction with other methods such as Theory of Inventive Problem Solving (TRIZ) or brainstorming. The method tries to exploit the principle that it is easier to critique and modify a design than it is to create a fully working solution in one go. The visual nature of the method means that it is suited to design problems where geometry is important such as mechanism design and machine design. Three case studies of conceptual design are presented. The case studies involve a novel clutch, a novel rotary damping mechanism and a novel worm gearbox. Each of these designs won at least one national design competition in the UK. A simple design experiment has been carried out which indicated that the backwards design method was at least as effective as the morphological chart method for a simple machine design exercise.
Employing a Recombinant Strain of Advenella mimigardefordensis for Biotechnical Production of Homopolythioesters from 3,3′-Dithiodipropionic Acid
Authors: Xia Yongzhen , Wübbeler Jan Hendrik , Qi Qingsheng , Steinbüchel Alexander 
Published: February 2012

ABSTRACT

Advenella mimigardefordensis
strain DPN7
T
was genetically modified to produce poly(3-mercaptopropionic acid) (PMP) homopolymer by exploiting the recently unraveled process of 3,3′-dithiodipropionic acid (DTDP) catabolism. Production was achieved by systematically engineering the metabolism of this strain as follows: (i) deletion of its inherent 3MP dioxygenase-encoding gene (
mdo
), (ii) introduction of the
buk-ptb
operon (genes encoding the butyrate kinase, Buk, and the phosphotransbutyrylase, Ptb, from
Clostridium acetobutylicum
), and (iii) overexpression of its own polyhydroxyalkanoate synthase (

phaC
Am

). These measures yielded the potent PMP production strain
A. mimigardefordensis
strain SHX22. The deletion of
mdo
was required for adequate synthesis of PMP due to the resulting accumulation of 3MP during utilization of DTDP. Overexpression of the plasmid-borne
buk-ptb
operon caused a severe growth repression. This effect was overcome by inserting this operon into the genome. Polyhydroxyalkanoate (PHA) synthases from different origins were compared. The native PHA synthase of
A. mimigardefordensis
(

phaC
Am

) was obviously the best choice to establish homopolythioester production in this strain. In addition, the cultivation conditions, including an appropriate provision of the carbon source, were further optimized to enhance PMP production. The engineered strain accumulated PMP up to approximately 25% (wt/wt) of the cell dry weight when cultivated in mineral salts medium containing glycerol as the carbon source in addition to DTDP as the sulfur-providing precursor. According to our knowledge, this is the first report of PMP homopolymer production by a metabolically engineered bacterium using DTDP, which is nontoxic, as the precursor substrate.
Lytic Activity of LysH5 Endolysin Secreted by Lactococcus lactis Using the Secretion Signal Sequence of Bacteriocin Lcn972
Authors: Rodríguez-Rubio Lorena , Gutiérrez Dolores , Martínez Beatriz , Rodríguez Ana , García Pilar 
Published: February 2012

ABSTRACT

Bacteriophage endolysins have an interesting potential as antimicrobials. The endolysin LysH5, encoded by
Staphylococcus aureus
phage vB_SauS-phi-IPLA88, was expressed and secreted in
Lactococcus lactis
using the signal peptide of bacteriocin lactococcin 972 and lactococcal constitutive and inducible promoters. Up to 80 U/mg of extracellular active endolysin was detected in culture supernatants, but most of the protein (up to 323 U/mg) remained in the cell extracts.
Emergence and Stability of High-Pressure Resistance in Different Food-Borne Pathogens
Authors: Vanlint Dietrich , Rutten Nele , Michiels Chris W. , Aertsen Abram 
Published: February 2012

ABSTRACT

High hydrostatic pressure (HHP) processing is becoming a valuable nonthermal food pasteurization technique, although there is reasonable concern that bacterial HHP resistance could compromise the safety and stability of HHP-processed foods. While the degree of natural HHP resistance has already been shown to vary greatly among and within bacterial species, a still unresolved question remains as to what extent different food-borne pathogens can actually develop HHP resistance. In this study, we therefore examined and compared the intrinsic potentials for HHP resistance development among strains of
Escherichia coli
,
Shigella flexneri
,
Salmonella enterica
serovars Typhimurium and Enteritidis,
Yersinia enterocolitica
,
Aeromonas hydrophila
,
Pseudomonas aeruginosa
, and
Listeria innocua
using a selective enrichment approach. Interestingly, of all strains examined, the acquisition of extreme HHP resistance could be detected in only some of the
E. coli
strains, indicating that a specific genetic predisposition might be required for resistance development. Furthermore, once acquired, HHP resistance proved to be a very stable trait that was maintained for >80 generations in the absence of HHP exposure. Finally, at the mechanistic level, HHP resistance was not necessarily linked to derepression of the heat shock genes and was not related to the phenomenon of persistence.
Establishment of a Tractable Genetic Transformation System in Veillonella spp
Authors: Liu Jinman , Xie Zhoujie , Merritt Justin , Qi Fengxia 
Published: February 2012

ABSTRACT

We have constructed the first
Escherichia coli-Veillonella
shuttle vector based on an endogenous plasmid (pVJL1) isolated from a clinical
Veillonella
strain. A highly transformable
Veillonella
strain was also identified. Both the shuttle vector and the transformable strain should be valuable tools for future
Veillonella
genetic studies.
Ecological Success of a Group of Saccharomyces cerevisiae/Saccharomyces kudriavzevii Hybrids in the Northern European Wine-Making Environment
Authors: Erny C. , Raoult P. , Alais A. , Butterlin G. , Delobel P. , Matei-Radoi F. , Casaregola S. , Legras J. L. 
Published: February 2012

ABSTRACT

The hybrid nature of lager-brewing yeast strains has been known for 25 years; however, yeast hybrids have only recently been described in cider and wine fermentations. In this study, we characterized the hybrid genomes and the relatedness of the Eg8 industrial yeast strain and of 24
Saccharomyces cerevisiae/Saccharomyces kudriavzevii
hybrid yeast strains used for wine making in France (Alsace), Germany, Hungary, and the United States. An array-based comparative genome hybridization (aCGH) profile of the Eg8 genome revealed a typical chimeric profile. Measurement of hybrids DNA content per cell by flow cytometry revealed multiple ploidy levels (2n, 3n, or 4n), and restriction fragment length polymorphism analysis of 22 genes indicated variable amounts of
S. kudriavzevii
genetic content in three representative strains. We developed microsatellite markers for
S. kudriavzevii
and used them to analyze the diversity of a population isolated from oaks in Ardèche (France). This analysis revealed new insights into the diversity of this species. We then analyzed the diversity of the wine hybrids for 12
S. cerevisiae
and 7
S. kudriavzevii
microsatellite loci and found that these strains are the products of multiple hybridization events between several
S. cerevisiae
wine yeast isolates and various
S. kudriavzevii
strains. The Eg8 lineage appeared remarkable, since it harbors strains found over a wide geographic area, and the interstrain divergence measured with a (δμ)
2
genetic distance indicates an ancient origin. These findings reflect the specific adaptations made by
S. cerevisiae/S. kudriavzevii
cryophilic hybrids to winery environments in cool climates.
Distribution Patterns and Phylogeny of Marine Stramenopiles in the North Pacific Ocean
Authors: Lin Yun-Chi , Campbell Tracy , Chung Chih-Ching , Gong Gwo-Ching , Chiang Kuo-Ping , Worden Alexandra Z. 
Published: February 2012

ABSTRACT

Marine stramenopiles (MASTs) are a diverse suite of eukaryotic microbes found in marine environments. Several MAST lineages are thought to contain heterotrophic nanoflagellates. However, MASTs remain uncultured and data on distributions and trophic modes are limited. We investigated MASTs in provinces on the west and east sides of the North Pacific Subtropical Gyre, specifically the East China Sea (ECS) and the California Current system (CALC). For each province, DNA was sampled from three zones: coastal, mesotrophic transitional, and more oligotrophic euphotic waters. Along with diatoms, chrysophytes, and other stramenopiles, sequences were recovered from nine MAST lineages in the six ECS and four CALC 18S rRNA gene clone libraries. All but one of these libraries were from surface samples. MAST clusters 1, 3, 7, 8, and 11 were identified in both provinces, with MAST cluster 3 (MAST-3) being found the most frequently. Additionally, MAST-2 was detected in the ECS and MAST-4, -9, and -12 were detected in the CALC. Phylogenetic analysis indicated that some subclades within these lineages differ along latitudinal gradients. MAST-1A, -1B, and -1C and MAST-4 size and abundance estimates obtained using fluorescence
in situ
hybridization on 79 spring and summer ECS samples showed a negative correlation between size of MAST-1B and MAST-4 cells and temperature. MAST-1A was rarely detected, but MAST-1B and -1C and MAST-4 were abundant in summer and MAST-1C and MAST-4 were more so at the coast, with maximum abundances of 543 and 1,896 cells ml
−1
, respectively. MAST-4 and
Synechococcus
abundances were correlated, and experimental work showed that MAST-4 ingests
Synechococcus
. Together with previous studies, this study helps refine hypotheses on distribution and trophic modes of MAST lineages.