bluuebunny/crossref_metadata_2025 huggingface dataset:
Multiple paternity and sperm competition in the sibling species Drosophila buzzatii and Drosophila koepferae
Authors: Hurtado J. , Iglesias P. P. , Lipko P. , Hasson E.
Published: August 2013

Sperm competition (SC) is a major component of sexual selection that enhances intra‐ and intersexual conflicts and may trigger rapid adaptive evolution of sexual characters. The actual role of SC on rapid evolution, however, is poorly understood. Besides, the relative contribution of distinctive features of the mating system to among species variation in the strength of SC remains unclear. Here, we assessed the strength of SC and mating system factors that may account for it in the closely related species Drosophila buzzatii and Drosophila koepferae. Our analyses reveal higher incidence of multiple paternity and SC risk in D. buzzatii wild‐inseminated females. The estimated number of fathers per brood was 3.57 in D. buzzatii and 1.95 in D. koepferae. In turn, the expected proportion of females inseminated by more than one male was 0.89 in D. buzzatii and 0.58 in D. koepferae. Laboratory experiments show that this pattern may be accounted for by the faster rate of stored sperm usage observed in D. koepferae and by the greater female remating rate exhibited by D. buzzatii. We also found that the male reproductive cost of SC is also higher in D. buzzatii. After a female mated with a second male, first‐mating male fertility was reduced by 71.4% in D. buzzatii and only 33.3% in D. koepferae. Therefore, we may conclude that postmating sexual selection via SC is a stronger evolutionary force in D. buzzatii than in its sibling.
Starch synthase 4 is essential for coordination of starch granule formation with chloroplast division during Arabidopsis leaf expansion
Authors: Crumpton‐Taylor Matilda , Pike Marilyn , Lu Kuan‐Jen , Hylton Christopher M. , Feil Regina , Eicke Simona , Lunn John E. , Zeeman Samuel C. , Smith Alison M.
Published: August 2013

Arabidopsis thaliana mutants lacking the SS4 isoform of starch synthase have strongly reduced numbers of starch granules per chloroplast, suggesting that SS4 is necessary for the normal generation of starch granules. To establish whether it plays a direct role in this process, we investigated the circumstances in which granules are formed in ss4 mutants.

Starch granule numbers and distribution and the accumulation of starch synthase substrates and products were investigated during ss4 leaf development, and in ss4 mutants carrying mutations or transgenes that affect starch turnover or chloroplast volume.

We found that immature ss4 leaves have no starch granules, but accumulate high concentrations of the starch synthase substrate ADPglucose. Granule numbers are partially restored by elevating the capacity for glucan synthesis (via expression of bacterial glycogen synthase) or by increasing the volumes of individual chloroplasts (via introduction of arc mutations). However, these granules are abnormal in distribution, size and shape.

SS4 is an essential component of a mechanism that coordinates granule formation with chloroplast division during leaf expansion and determines the abundance and the flattened, discoid shape of leaf starch granules.
Trait stacking via targeted genome editing
Authors: Ainley William M. , Sastry‐Dent Lakshmi , Welter Mary E. , Murray Michael G. , Zeitler Bryan , Amora Rainier , Corbin David R. , Miles Rebecca R. , Arnold Nicole L. , Strange Tonya L. , Simpson Matthew A. , Cao Zehui , Carroll Carley , Pawelczak Katherine S. , Blue Ryan , West Kim , Rowland Lynn M. , Perkins Douglas , Samuel Pon , Dewes Cristie M. , Shen Liu , Sriram Shreedharan , Evans Steven L. , Rebar Edward J. , Zhang Lei , Gregory Phillip D. , Urnov Fyodor D. , Webb Steven R. , Petolino Joseph F.
Published: August 2013

Modern agriculture demands crops carrying multiple traits. The current paradigm of randomly integrating and sorting independently segregating transgenes creates severe downstream breeding challenges. A versatile, generally applicable solution is hereby provided: the combination of high‐efficiency targeted genome editing driven by engineered zinc finger nucleases (ZFNs) with modular ‘trait landing pads’ (TLPs) that allow ‘mix‐and‐match’, on‐demand transgene integration and trait stacking in crop plants. We illustrate the utility of nuclease‐driven TLP technology by applying it to the stacking of herbicide resistance traits. We first integrated into the maize genome an herbicide resistance gene, pat, flanked with a TLP (ZFN target sites and sequences homologous to incoming DNA) using WHISKERS™‐mediated transformation of embryogenic suspension cultures. We established a method for targeted transgene integration based on microparticle bombardment of immature embryos and used it to deliver a second trait precisely into the TLP via cotransformation with a donor DNA containing a second herbicide resistance gene, aad1, flanked by sequences homologous to the integrated TLP along with a corresponding ZFN expression construct. Remarkably, up to 5% of the embryo‐derived transgenic events integrated the aad1 transgene precisely at the TLP, that is, directly adjacent to the pat transgene. Importantly and consistent with the juxtaposition achieved via nuclease‐driven TLP technology, both herbicide resistance traits cosegregated in subsequent generations, thereby demonstrating linkage of the two independently transformed transgenes. Because ZFN‐mediated targeted transgene integration is becoming applicable across an increasing number of crop species, this work exemplifies a simple, facile and rapid approach to trait stacking.
Development of AS‐PCR marker based on a key mutation confirmed by resequencing of Wx‐mp in Milky Princess and its application in japonica soft rice (Oryza sativa L.) breeding
Authors: Yang Jie , Wang Jun , Fan Fang‐Jun , Zhu Jin‐Yan , Chen Tao , Wang Cai‐Lin , Zheng Tian‐Qing , Zhang Jian , Zhong Wei‐Gong , Xu Jian‐Long
Published: August 2013

Soft rice with low amylose content (AC) ranging by 5–15% is a unique type with special eating and appearance quality and has become popular in the rice market. We resequenced the Wx‐mp, a key allele from Milky Princess, a Japanese low AC variety, and found that the +473 mutation in exon 4 is the key mutation in both Wx‐mp and its ancestor allele, Wx‐mq from Milky Queen. Based on this functional mutation, an allele‐specific PCR (AS‐PCR) marker was developed and proven in a breeding population derived from a cross between a Chinese late variety Nan Keng 46 (Wx‐mp/Wx‐mp) and an early line Ning 63121(Wx‐b/Wx‐b). Based on the marker‐aided selection by our newly developed AS‐PCR marker for Wx‐mp and the known ST10 marker for Stvb‐i, a total of 12 Wx‐mp homozygotes were selected from 198 F2 progenies, and four of them were immune to rice stripe virus (RSV) with averagely 11.3 days earlier heading than Nan Keng 46 without significant change in grain yield.
Identification of glycogen synthase kinase 3α as a therapeutic target in melanoma
Authors: Madhunapantula SubbaRao V. , Sharma Arati , Gowda Raghavendra , Robertson Gavin P.
Published: August 2013

Deregulated expression or activity of kinases can lead to melanomas, but often the particular kinase isoform causing the effect is not well established, making identification and validation of different isoforms regulating disease development especially important. To accomplish this objective, an siRNA screen was undertaken that which identified glycogen synthase kinase 3α (GSK3α) as an important melanoma growth regulator. Melanocytes and melanoma cell lines representing various stages of melanoma tumor progression expressed both GSK3α and GSK3β, but analysis of tumors in patients with melanoma showed elevated expression of GSK3α in 72% of samples, which was not observed for GSK3β. Furthermore, 80% of tumors in patients with melanoma expressed elevated levels of catalytically active phosphorylated GSK3α (pGSK3αY279), but not phosphorylated GSK3β (pGSK3βY216). siRNA‐mediated reduction in GSK3α protein levels reduced melanoma cell survival and proliferation, sensitized cells to apoptosis‐inducing agents and decreased xenografted tumor development by up to 56%. Mechanistically, inhibiting GSK3α expression using siRNA or the pharmacological agent AR‐A014418 arrested melanoma cells in the G0/G1 phase of the cell cycle and induced apoptotic death to retard tumorigenesis. Therefore, GSK3α is a key therapeutic target in melanoma.
Reproductive ecology and genetic variability in natural populations of the wild potato, Solanum kurtzianum
Authors: Marfil C. F. , Masuelli R. W.
Published: August 2013

The cultivated potato (Solanum tuberosum ssp. tuberosum) has more than 200 related wild species distributed along the Andes, adapted to a wide range of geographical and ecological areas. Since the last century, several collection expeditions were carried out to incorporate genetic variability into the potato germplasm around the world. However, little is known about the reproductive ecology and genetic population structure of natural potato population from field studies. The aim of this work is to study, in the field, the genetic variability and reproductive strategies of populations of one of the most widely distributed potato species in Argentina, Solanum kurtzianum, growing in Mendoza province. AFLP markers showed that the genetic variability is mainly present among plants within populations, indicating that in the sampled populations, sexual reproduction is more relevant than clonal multiplication (by tubers). Additional evidence was obtained evaluating the genetic diversity in populations with a distribution in patches, where several genotypes were always detected. From a field study performed in the Villavicencio Natural Reserve, we found that the average number of plump seeds per fruit was 94.3, identified and calculated the foraging distance of four insect pollinators, and demonstrated the seed dispersal by storm water channels. We argue that the breeding system, the two modes of reproduction and the ecological interaction described here may have a prominent role in determining the genetic structure of S. kurtzianum populations, and discuss the importance of field studies on population genetics, reproductive biology and ecology to design collections and conservation strategies.
The comparative reproductive biology of a tetraploid species,Hedychium villosum, and its diploid progenitorH. tenuiflorum(Zingiberaceae)
Authors: Gao J. Y. , Liu Q. , Li Q. J.
Published: August 2013

The evolutionary advantages of polyploidy may result from a number of changes in floral traits and breeding system, which may enable polyploids to exploit new habitats and become widespread. In this study, we comparatively investigated the floral biology of the tetraploid speciesHedychium villosumand its diploid progenitorH. tenuiflorum, to assess reproductive divergence between the two species. The results showed that flowers of the tetraploid species last longer and produce more nectar than did diploid species. The flowering times of the two species did not overlap at all. Observations of floral visitors in natural populations demonstrated that butterflies and hawkmoths were effective pollinators of both species, but there was a significant difference in butterfly and hawkmoth assemblages between the two species. The hand‐pollination experiments and pollen tube growth experiments suggested that diploidH. tenuiflorumwas self‐incompatible, while tetraploidH. villosumwas completely self‐compatible.H. villosumhas a much wider distribution range and occupies more diverse habitats thanH.tenuiflorum. Polyploidisation may enable tetraploidH. villosumto exploit new habitats previously unavailable to diploidH.tenuiflorum.
Identification, characterisation and molecular modelling of two AP endonucleases from base excision repair pathway in sugarcane provide insights on the early evolution of green plants
Authors: Maira N. , Torres T. M. , de Oliveira A. L. , de Medeiros S. R. B. , Agnez‐Lima L. F. , Lima J. P. M. S. , Scortecci K. C.
Published: August 2013

Unlike bacteria and mammals, plant DNA repair pathways are not well characterised, especially in monocots. The understanding of these processes in the plant cell is of major importance, since they may be directly involved in plant acclimation and adaptation to stressful environments. Hence, two sugarcane ESTs were identified as homologues of AP endonuclease from the base‐excision repair pathway: ScARP1 and ScARP3. In order to understand their probable function and evolutionary origin, structural and phylogenetic studies were performed using bioinformatics approaches. The two predicted proteins present a considerable amino acid sequence similarity, and molecular modelling procedures indicate that both are functional, since the main structural motifs remain conserved. However, inspection of the sort signal regions on the full‐length cDNAs indicated that these proteins have a distinct organelle target. Furthermore, variances in their promoter cis‐element motifs were also found. Although the mRNA expression pattern was similar, there were significant differences in their expression levels. Taken together, these data raise the hypothesis that the ScARP is an example of a probable gene duplication event that occurred before monocotyledon/dicotyledon segregation, followed by a sub‐functionalisation event in the Poaceae, leading to new intracellular targeting and different expression levels.
Root antioxidant responses of two Pisum sativum cultivars to direct and induced Fe deficiency
Authors: Jelali N. , Donnini S. , Dell'Orto M. , Abdelly C. , Gharsalli M. , Zocchi G.
Published: August 2013

The contribution of antioxidant defence systems in different tolerance to direct and bicarbonate‐induced Fe deficiency was evaluated in two pea cultivars (Kelvedon, tolerant and Lincoln, susceptible). Fe deficiency enhanced lipid peroxidation and H2O2 concentration in roots of both cultivars, particularly in the sensitive one grown under bicarbonate supply. The results obtained on antioxidant activities (SOD, CAT, POD) suggest that H2O2 accumulation could be due to an overproduction of this ROS and, at the same time, to a poor capacity to detoxify it. Moreover, under bicarbonate supply the activity of POD isoforms was reduced only in the sensitive cultivar, while in the tolerant one a new isoform was detected, suggesting that POD activity might be an important contributor to pea tolerance to Fe deficiency. The presence of bicarbonate also resulted in stimulation of GR, MDHAR and DHAR activities, part of the ASC‐GSH pathway, which was higher in the tolerant cultivar than in the sensitive one. Overall, while in the absence of Fe only slight differences were reported between the two cultivars, the adaptation of Kelvedon to the presence of bicarbonate seems to be related to its greater ability to enhance the antioxidant response at the root level.
Interethnic Factors as Predictors of the Subjective Well‐Being of Minority Individuals in a Context of Recent Societal Changes
Authors: Kus Larissa , Ward Colleen , Liu James
Published: August 2013

Our research examined the impact of contextual intergroup variables on the subjective well‐being of ethnic Russians in Estonia (N = 190) who have experienced major social changes with the demise of the Soviet Union. A mediational model was tested where aspects of intergroup relations (i.e., relative deprivation, status legitimization, and temporal comparisons) acted as mediators of the influence of cultural identity and representations of history on subjective well‐being. Preliminary analyses indicated polemical representations of history in which Estonian historical narratives are established around the struggle for independence, and Russian representations of history are consolidated around victory in World War II. Mediation analyses demonstrated that the importance of Russian history increased the perceptions of relative deprivation, status delegitimization, and the frequency of temporal comparisons, which negatively affected life satisfaction. At the same time, the importance of Estonian history led to positive perceptions of the intergroup situation and, in turn, to greater subjective well‐being. The effect of Russian identity on well‐being was mediated by delegitimizing beliefs, but not by relative deprivation and temporal comparisons. Estonian identity did not exert a significant effect on the proposed mediators. The research demonstrates the salience of the effects of contextual intergroup factors on subjective well‐being, and the article discusses implications for the study of intergroup relations and subjective well‐being.
Social Welfare and the Psychology of Food Sharing: Short‐Term Hunger Increases Support for Social Welfare
Authors: Petersen Michael Bang , Aarøe Lene , Jensen Niels Holm , Curry Oliver
Published: August 2013

Do politically irrelevant events influence important policy opinions? Previous research on social welfare attitudes has emphasized the role of political factors such as economic self‐interest and ideology. Here, we demonstrate that attitudes to social welfare are also influenced by short‐term fluctuations in hunger. Using theories in evolutionary psychology, we predict that hungry individuals will be greedier and take more resources from others while also attempting to induce others to share by signaling cooperative intentions and expressing support for sharing, including evolutionarily novel forms of sharing such as social welfare. We test these predictions using self‐reported hunger data as well as comparisons of subjects who participated in relevant online studies before and after eating lunch. Across four studies collected in two different welfare regimes—the United Kingdom and Denmark—we consistently find that hungry individuals act in a greedier manner but describe themselves as more cooperative and express greater support for social welfare.
Dynamic changes of the ethylene biosynthesis in ‘Jonagold’ apple
Authors: Bulens Inge , Van de Poel Bram , Hertog Maarten L. A. T. M. , Cristescu Simona M. , Harren Frans J. M. , De Proft Maurice P. , Geeraerd Annemie H. , Nicolai Bart M.
Published: August 2013

In this study, the short‐term and dynamic changes of the ethylene biosynthesis of Jonagold apple during and after application of controlled atmosphere (CA) storage conditions were quantified using a systems biology approach. Rapid responses to imposed temperature and atmospheric conditions were captured by continuous online photoacoustic ethylene measurements. Discrete destructive sampling was done to understand observed changes of ethylene biosynthesis at the transcriptional, translational and metabolic level. Application of the ethylene inhibitor 1‐methylcyclopropene (1‐MCP) allowed for the discrimination between ethylene‐mediated changes and ethylene‐independent changes related to the imposed conditions. Online ethylene measurements showed fast and slower responses during and after application of CA conditions. The changes in 1‐aminocyclopropane‐1‐carboxylate synthase (ACS) activity were most correlated with changes in ACS1 expression and regulated the cold‐induced increase in ethylene production during the early chilling phase. Transcription of ACS3 was found ethylene independent and was triggered upon warming of CA‐stored apples. Increased expression of ACO1 during shelf life led to a strong increase in 1‐aminocyclopropane‐1‐carboxylate oxidase (ACO) activity, required for the exponential production of ethylene during system 2. Expression of ACO2 and ACO3 was upregulated in 1‐MCP‐treated fruit showing a negative correlation with ethylene production. ACO activity never became rate limiting.
The novel HLA‐B*48:19 allele, identified by sequence‐based typing in a Chinese individual
Authors: Zhang W. D. , Li W. , Zhang K. Y. , Shan X. Y. , Jia Y. J.
Published: August 2013

HLA‐B*48:19 differs from HLA‐B*48:01:01 exon 3 2 nt at position 195 and 196 (C→T and T→G).
Identification of a novel HLA‐DRB1*13 variant allele: DRB1*13:154
Authors: Barbuti S. , Putignano A. L. , Rombolà G. , Marchetti L. , Curcio M. , Scatena F.
Published: August 2013

A newly identified allele, named HLA‐DRB1*13:154, differs from DRB1*13:13 by the single nucleotide substitution 227T‐A at codon 47 in exon 2.
Identification of a novel allele MICA*008:05 by sequence‐based typing
Authors: Du Z.‐H. , Jiao S.‐X. , Du B. , Liu X.‐H. , Wu Z.‐J.
Published: August 2013

The new allele differs from MICA*008:01:01 by a single nucleotide substitution at position 591 of exon 3.
Association of CXCL12 and CXCR4 gene polymorphisms with the susceptibility and prognosis of renal cell carcinoma
Authors: Cai C. , Wang L.‐H. , Dong Q. , Wu Z.‐J. , Li M.‐Y. , Sun Y.‐H.
Published: August 2013

CXCL12 and its unique receptor CXCR4, play important roles in inflammation and cancer metastasis. This study was undertaken to investigate the association of CXCL12 and CXCR4 polymorphisms with risk and prognosis of renal cell carcinoma (RCC) in the Chinese population. Blood was collected from 322 RCC patients and 402 healthy controls. The CXCL12 rs1801157G/A polymorphism and CXCR4 rs2228014C/T polymorphism were genotyped by polymerase chain reaction‐restriction fragment length polymorphism. Results showed that prevalence of CXCL12 rs1801157AA genotype was significantly increased in RCC cases than in controls [odds ratio (OR) = 3.07, 95% confidence interval (CI), 1.98–5.46, P = 6.1 × 10−6; data were adjusted for age and sex]. Similarly, subjects carrying CXCR4 rs2228014CT or TT genotypes showed significantly high risk of RCC (OR = 1.77, 95% CI, 1.28–2.71, P = 0.0003; OR = 4.01, 95% CI, 1.87–9.12, P = 7.8 × 10−4, respectively; data were adjusted for age and sex). When analyzing the survival time of RCC, patients with CXCL12 rs1801157AA genotype revealed significantly shorter survival time compared to cases with CXCL12 rs1801157GG and GA genotypes (P = 0.001), whereas RCC patients carrying CXCR4 rs2228014CT and TT genotypes showed shorter survival time than the wild type (P = 0.002). These data indicated that CXCL12 and CXCR4 may be new risk factors for RCC and could be used as prognostic markers for this malignancy.
Distribution patterns of variability for 18 immune system genes in Amerindians – relationship with history and epidemiology
Authors: Lindenau J. D. , Salzano F. M. , Guimarães L. S. P. , Callegari‐Jacques S. M. , Hurtado A. M. , Hill K. R. , Petzl‐Erler M. L. , Tsuneto L. T. , Hutz M. H.
Published: August 2013

Native American populations generally have a higher prevalence of infectious diseases than non‐Native populations and this fact can induce different pressures in their immune system. We investigated the patterns of population differentiation (FST) of 32 polymorphisms related to adaptive immune response in four Native American populations (Aché, Guarani‐Kaiowá, Guarani‐Ñandeva and Kaingang), and the results were compared with the three major world population data [Yoruba of Ibadan, Nigeria (YRI), Utah residents with northern and Western Europe ancestry (CEU) and Han Chinese of Beijing, China (CHB)] available in the HapMap database. The Aché clearly differentiated from the other Amerindians, but when all Native Americans were compared with the samples of other ethnic groups the lowest difference (0.08) was found with CHB (Asians), the second lowest (0.15) with YRI (Africans) and the most marked with CEU (European‐derived). The considerable intra and interethnic differences found can be explained both in terms of diverse evolutionary distances and more recent environmental pathogen exposures; and they should be appropriately considered prior to any specific public health action.
Algorithm for the diagnosis of smear‐negative pulmonary tuberculosis in high‐incidence resource‐constrained settings
Authors: Soto Alonso , Solari Lely , Agapito Juan , Gotuzzo Eduardo , Accinelli Roberto , Vargas Dante , Acurio Vilma , Matthys Francine , Van der Stuyft Patrick
Published: August 2013

Objectives

Diagnosis of smear‐negative pulmonary tuberculosis (SNPT) remains a challenge, particularly in resource‐constrained settings. We evaluated a diagnostic algorithm that combines affordable laboratory tools and a clinical prediction rule (CPR).

Methods

We derived, based on published evidence, a diagnostic algorithm for SNPT. Sputum concentration constitutes its first step. In suspects with negative results, SNPT probability is classified with a CPR as low (excluded), high (confirmed) or intermediate. For intermediate patients, sputum Middlebrook 7H9 liquid culture is performed, and they are assessed after 2 weeks. If clinically deteriorated, with still negative liquid culture, bronchoscopy is offered. Otherwise, results of Middlebrook 7H9 culture are awaited. We prospectively evaluated this algorithm against a reference standard of solid and liquid cultures in two reference hospitals in Lima, Peru.

Results

670 SNPT suspects were included from September 2005 to March 2008. The prevalence of SNPT was 27% according to the reference standard. The algorithm's overall accuracy was 0.94 (95% CI 0.91–0.95), its sensitivity was 0.88 (95% CI 0.82–0.92) and its specificity, 0.96 (95% CI 0.94–0.98). Sputum concentration, the CPR, Middlebrook 7H9 sputum culture and bronchoscopic samples defined a diagnosis of SNPT according to the algorithm in 57 (37%), 25 (16%), 63 (41%) and 8(5%) of patients, respectively. 65% of patients were diagnosed within 3 weeks.

Conclusions

The algorithm was accurate for SNPT diagnosis. Sputum concentration, CPR and selective Middlebrook 7H9 culture are essential components.
Studies on the inactivation of human parvovirus 4
Authors: Baylis Sally A. , Tuke Philip W. , Miyagawa Eiji , Blümel Johannes
Published: August 2013

Background

Human parvovirus 4 (PARV4) is a novel parvovirus, which like parvovirus B19 (B19V) can be a contaminant of plasma pools used to prepare plasma‐derived medicinal products. Inactivation studies ofB19Vhave shown that it is more sensitive to virus inactivation strategies than animal parvoviruses. However, inactivation ofPARV4 has not yet been specifically addressed.

Study Design and Methods

Treatment of parvoviruses by heat or low‐pHconditions causes externalization of the virus genome. Using nuclease treatment combined with real‐time polymerase chain reaction, the extent of virusDNAexternalization was used as an indirect measure of the inactivation ofPARV4, B19V, and minute virus of mice (MVM) by pasteurization of albumin and by low‐pHtreatment. Infectivity studies were performed in parallel forB19VandMVM.

Results

PARV4 showed greater resistance to pasteurization and low‐pHtreatment thanB19V, althoughPARV4 was not as resistant asMVM. There was a 2‐ to 3‐log reduction of encapsidatedPARV4DNAafter pasteurization and low‐pHtreatment. In contrast,B19Vwas effectively inactivated whileMVMwas stable under these conditions. Divalent cations were found to have a stabilizing effect onPARV4 capsids. In the absence of divalent cations, even at neutralpH, there was a reduction ofPARV4 titer, an effect not observed forB19VorMVM.

Conclusion

In the case of heat treatment and incubation at lowpH, PARV4 shows intermediate resistance when compared toB19VandMVM. Divalent cations seem important for stabilizingPARV4 virus particles.
Hydroxyl and Nitric Oxide Distribution in Waste Rice Bran Biofuel-Octanol Flames
Authors: Desmira Nelfa , Kitagawa Kuniyuki , Gupta Ashwani K.
Published: August 2013

Two-dimensional (2-D) visualization of hydroxyl (OH) radical in combustion of biofuel made of waste rice bran oil (called W) mixed with octanol (called O) at different mixture ratios were examined in a laboratory scale facility using planar laser-induced fluorescence (PLIF) diagnostics. Rice bran oil has a composition similar to that of peanut oil, with 38% monounsaturated, 37% polyunsaturated, and 25% saturated fatty acids. The ratio of this biofuel to octanol fuel examined was W90/O10, W75/O25, and W60/O40. The chemical species generated from within the combustion zone were analyzed from the spontaneous emission spectra of the flame in the ultraviolet to visible (Uv-Vis) range. The spatial distribution of Nitric Oxide (NO) and OH, denoted as OH*, were identified from the spectra. Two-dimensional (2-D) distributions of flame temperature were obtained using a thermal video camera. The experimental results showed the temperatures to range from 600 °C to 1400 °C. The highest temperature was obtained using W60/O40 waste/octanol fuel mixture. A practical burner commonly used in Indonesia, called semawar, that have a built-in preheating system was used for the combustion of biofuels.
Cooling Systems for Power Plants in an Energy-Water Nexus Era
Authors: Wong Kaufui V. , Johnston James
Published: August 2013

Potable water is becoming scarce in many areas of the planet as the human population pushes past 7 × 109. There is an increasing need for electric power since electricity is essential for modern development and progress. Traditionally, condenser cooling systems for power plants use seawater or freshwater in conjunction with cooling tower technology. Seawater is used in plants near the sea or ocean, and seawater condenser cooling systems are typically open systems. More recently, air-cooling has been implemented and undergoing evaluations. Predictably, during the summer season in hot, semidesert and desert areas, air-cooling would not prove very efficient. Ironically, these areas would require the most fresh, potable water if the population and/or population density is large. The need for additional power generation units to satisfy consumer demands, and hence more cooling capacities, creates a problem for utilities. The current work researches the feasibility of using seawater cooling systems in the United States of America that are far from the sea. Five such locations have been identified as possibilities. Such a system has proven successful in South Florida. This system utilizes a series of cooling canals, used to dissipate the condenser heat to the surroundings. Relevant statistics of such a canal include water flow rate, total capacity, and MW of generators (both fossil-fueled and nuclear steam generators) the system is designed to cool. Additional statistics include the possible need to top-up (both amount and frequency of water required to maintain canal surface levels) or whether local natural rain water is adequate to replace evaporation and loss. Logistical information includes the estimated size of land required to accommodate the cooling canals. In estimating the canal system size and concomitantly the land required in other parts of the country, there is the tacit assumption that the thermal capacity of the surrounding land is about the same, and that the thermal conductivities of the different types of soil, and the heat transfer coefficients between the seawater and the canal are similar.
Fundamentals of PV efficiency interpreted by a two-level model
Authors: Alam Muhammad A. , Ryyan Khan M.
Published: August 2013

We consider the physics of photovoltaic (PV) energy conversion in a two-level, atomic PV and explain the conditions for which the Carnot efficiency is reached and how it can be exceeded. The loss mechanisms—thermalization, angle entropy, and below-bandgap transmission—explain the gap between Carnot efficiency and the Shockley-Queisser limit. Techniques developed to reduce these losses (e.g., solar concentrators, tandem cells, etc.) are reinterpreted using a simple two-level model. Remarkably, this simple model captures the essence of PV operation and reproduces the key results and important insights that that have been previously obtained using more complicated derivations.
Extra Dimensions of Space
Authors: Lincoln Don
Published: August 2013

They say that there is no such thing as a stupid question. In a pedagogically pure sense, that's probably true. But some questions do seem to flirt dangerously close to being really quite ridiculous. One such question might well be, “How many dimensions of space are there?” I mean, it's pretty obvious that there are three: left/right, up/down, and forward/backward. No matter how you express an object's coordinate, be it Cartesian, spherical, cylindrical, or something exotic, it's eminently clear that we live in a three-dimensional universe.
Hockey, iPads, and Projectile Motion in a Physics Classroom
Authors: Hechter Richard P.
Published: August 2013

With the increased availability of modern technology and handheld probeware for classrooms, the iPad1 and the Video Physics2 application developed by Vernier are used to capture and analyze the motion of an ice hockey puck within secondary-level physics education. Students collect, analyze, and generate digital modes of representation of physics phenomena using modern technologies to complement theoretical plots. This activity acknowledges hockey players' implicit understanding of the launch angle and initial velocity of a saucer pass as basic projectile motion while engaging students in authentic physics-based problem solving.
Vacuum Energy and Inflation: 1. A Liter of Vacuum Energy
Authors: Huggins Elisha
Published: August 2013

In the popular press, diagrams showing the evolution of the universe begin with a great jump in size labeled “inflation.” Can we explain the basic ideas behind inflation to our students who have taken our introductory physics course? Probably not. In our standard introductory physics courses, even those with special relativity, something is missing. We do not talk about how space behaves, and that is a key component in modern astronomy. This is the first of four papers dealing with the behavior of space. They focus on basic cosmology and a discussion of inflation, building on the ideas and experiments covered in introductory physics.
The Frahm Resonance Apparatus: Variations on a Theme
Authors: Daffron John A. , Greenslade Thomas B.
Published: August 2013

The Frahm resonance principle, in which resonating reeds indicate the frequency of mechanical or electrical oscillations, is a hardy perennial. In this note we will give some history, show some original apparatus, and show how it may be reproduced with relatively little effort.
Corrected Launch Speed for a Projectile Motion Laboratory
Authors: Sanders Justin M. , Boleman Michael W.
Published: August 2013

At our university, students in introductory physics classes perform a laboratory exercise to measure the range of a projectile fired at an assigned angle. A set of photogates is used to determine the initial velocity of the projectile (the launch velocity). We noticed a systematic deviation between the experimentally measured range and the range calculated using the speed as determined by the photogates. In this paper, we will discuss the origin of this systematic error and derive a simple formula to correct it. In particular, we find that the launch speed given by our instrument is significantly different from the actual launch speed of our projectile.
This Is Rocket Science!
Authors: Keith Wayne , Martin Cynthia , Veltkamp Pamela
Published: August 2013

Using model rockets to teach physics can be an effective way to engage students in learning. In this paper, we present a curriculum developed in response to an expressed need for helping high school students review physics equations in preparation for a state-mandated exam. This required a mode of teaching that was more advanced and analytical than that offered by Estes Industries,1 but more basic than the analysis of Nelson et al.2,3 In particular, drag is neglected until the very end of the exercise, which allows the concept of conservation of energy to be shown when predicting the rocket's flight. Also, the variable mass of the rocket motor is assumed to decrease linearly during the flight (while the propulsion charge and recovery delay charge are burning) and handled simplistically by using an average mass value. These changes greatly simplify the equations needed to predict the times and heights at various stages of flight, making it more useful as a review of basic physics. Details about model rocket motors, range safety, and other supplemental information may be found online at Apogee Components4 and the National Association of Rocketry.5
Effects of Inoculum Additions in the Presence of a Preestablished Arbuscular Mycorrhizal Fungal Community
Authors: Janoušková Martina , Krak Karol , Wagg Cameron , Štorchová Helena , Caklová Petra , Vosátka Miroslav
Published: August 2013

Communities of arbuscular mycorrhizal fungi (AMF) are crucial for promoting plant productivity in most terrestrial systems, including anthropogenically managed ecosystems. Application of AMF inocula has therefore become a widespread practice. It is, however, pertinent to understand the mechanisms that govern AMF community composition and their performance in order to design successful manipulations. Here we assess whether the composition and plant growth-promotional effects of a synthetic AMF community can be altered by inoculum additions of the isolates forming the community. This was determined by following the effects of three AMF isolates, each inoculated in two propagule densities into a preestablished AMF community. Fungal abundance in roots and plant growth were evaluated in three sequential harvests. We found a transient positive response in AMF abundance to the intraspecific inoculation only in the competitively weakest isolate. The other two isolates responded negatively to intra- and interspecific inoculations, and in some cases plant growth was also reduced. Our results suggest that increasing the AMF density may lead to increased competition among fungi and a trade-off with their ability to promote plant productivity. This is a key ecological aspect to consider when introducing AMF into soils.
The D3 Bacteriophage α-Polymerase Inhibitor (Iap) Peptide Disrupts O-Antigen Biosynthesis through Mimicry of the Chain Length Regulator Wzz in Pseudomonas aeruginosa
Authors: Taylor Véronique L. , Udaskin Molly L. , Islam Salim T. , Lam Joseph S.
Published: August 2013

Lysogenic bacteriophage D3 causes seroconversion of
Pseudomonas aeruginosa
PAO1 from serotype O5 to O16 by inverting the linkage between O-specific antigen (OSA) repeat units from α to β. The OSA units are polymerized by Wzy to modal lengths regulated by Wzz
1
and Wzz
2
. A key component of the D3 seroconversion machinery is the
i
nhibitor of
α
-
p
olymerase (Iap) peptide, which is able to solely suppress α-linked long-chain OSA production in
P. aeruginosa
PAO1. To establish the target specificity of Iap for Wzy
α
, changes in OSA phenotypes were examined via Western immunoblotting for
wzz
1
and
wzz
2
single-knockout strains, as well as a
wzz
1
wzz
2
double knockout, following the expression of
iap
from a tuneable vector. Increased induction of Iap expression completely abrogated OSA production in the
wzz
1
wzz
2
double mutant, while background levels of OSA production were still observed in either of the single mutants. Therefore, Iap inhibition of OSA biosynthesis was most effective in the absence of both Wzz proteins. Sequence alignment analyses revealed a high degree of similarity between Iap and the first transmembrane segment (TMS) of either Wzz
1
or Wzz
2
. Various topology prediction analyses of the Iap sequence consistently predicted the presence of a single TMS, suggesting a propensity for Iap to insert itself into the inner membrane (IM). The compromised ability of Iap to abrogate Wzy
α
function in the presence of Wzz
1
or Wzz
2
provides compelling evidence that inhibition occurs after Wzy
α
inserts itself into the IM and is achieved through mimicry of the first TMS from the Wzz proteins of
P. aeruginosa
PAO1.
Invasive pneumococcal disease complicated by cerebral vasculitis, transient diabetes insipidus and spondylodiscitis
Authors: Ribeiro Sofia , Domingues Vital , Faria Raquel M , Mendonça Teresa
Published: August 2013

Invasive pneumococcal disease (IPD) is a potential life-threatening situation that requires immediate recognition and treatment. Cerebrovascular complications are uncommon and have been reported less frequently in adults than in children. We report a case of 59-year-old man with IPD complicated by cerebral vasculitis, transient central diabetes insipidus and spondylodiscitis. Each of these complications is rare and needs specific approach. Their association is even rarer and to the best of our knowledge this is the first case reported.
Delayed postirradiation camptocormia
Authors: Kelly Linda , Perju-Dumbrava Laura D , Thyagarajan Dominic , Lee Yong Chern
Published: August 2013

Radiotherapy may cause central or peripheral nervous system complications, reported examples being myelopathy, brachial/lumbosacral plexopathies or predominantly motor lumbosacral radiculopathy. In the literature some studies regard camptocormia as a paravertebral myopathy and others as of neurogenic origin. We present a patient who developed camptocormia, 42 years after radiation therapy to the para-aortic and inguinal area.
Idiopathic acquired dacryocystocele treated with endonasal endoscopic dacryocystorhinostomy
Authors: Koltsidopoulos Petros , Papageorgiou Elena , Konidaris Vasileios Efstathios , Skoulakis Charalambos
Published: August 2013

A 64-year-old woman presented with a medial canthal mass in her left eye, which was accompanied only by mild epiphora. There was no history of dacryocystitis, bloody tears, midfacial trauma or surgery. Physical examination showed a non-inflammatory, subcutaneous, immobile mass below the level of the medial canthal tendon. Lacrimal irrigation demonstrated blockage at the nasolacrimal duct. A CT revealed a non-enhancing, low density, cystic lesion in the inferomedial aspect of the left orbit without bony erosion, which was compatible with an idiopathic acquired dacryocystocele. The patient underwent endonasal endoscopic dacryocystorhinostomy (DCR) and silicone intubation. Epiphora resolved immediately after surgery. Two years after surgery, the patient has had no recurrence of either the epiphora or the orbital. Idiopathic acquired dacryocystocele associated only with epiphora without accompanying dacryocystitis although rare should be considered in the differential diagnosis of acquired non-inflammatory medial canthal masses. Endonasal endoscopic DCR represents a safe and effective treatment.
A model study of topological trends in random sets of asphaltene hydrocarbons
Authors: Perkins Jeffery , Edwards Essex , Dyck Greg , Weinberg Noham
Published: August 2013

A model graph approach is proposed to discuss topological trends in representative sets of random isomeric hydrocarbon molecules generated on a two-dimensional hexagonal grid and to study the dependence of the dominant structural motifs on parameters of the model. The results of the study are used to infer a more likely structural organization of asphaltene molecules.
SPH BASED OPTIMIZATION OF ELECTROWETTING-DRIVEN DIGITAL MICROFLUIDICS WITH ADVANCED ACTUATION PATTERNS
Authors: WEIß DENNIS , GREINER ANDREAS , LIENEMANN JAN , KORVINK JAN G.
Published: August 2013

Fast and thorough mixing is a crucial operation of digital microfluidic devices, where discrete and small fluid portions are moved and processed. In this paper, we want to analyze and to optimize the mixing process by substituting conventional motion and superposing oscillatory and translational modes. An accurate multiphase smoothed particle hydrodynamics (SPH) discretization for incompressible flow is instantiated. Different harmonic excitation patterns for the solid–liquid surface energy are applied and their influence on droplet mode shapes, formation of eddies and the Shannon entropy of droplet fluid components are measured. We tailor enhanced actuation patterns which improve mixing grade and reduce mixing time.
AUDIO-VISUAL RECOGNITION OF GOOSE FLOCKING BEHAVIOR
Authors: STEEN KIM ARILD , THERKILDSEN OLE ROLAND , GREEN OLE , KARSTOFT HENRIK
Published: August 2013

Every year, agriculture experience significant economic loss due to wild geese, rooks and other flocks of birds. A wide range of devices to detect and deter animals causing conflict is used to prevent this, although their effectiveness is often highly variable, due to habituation to disruptive or disturbing stimuli. Automated recognition of behaviors could form a critical component of a system capable of altering the disruptive stimulus to avoid habituation. This paper presents an audio-visual-based approach for recognition of goose flocking behavior. The vocal communication and movement of the flock is used for the audio-visual recognition, which is accomplished through classifier fusion of an acoustic and a video-based classifier. Acoustic behavior recognition is based on generalized perceptual features and support vector machines, and visual behavior recognition is based on optical flow estimation and a Bayesian Rule-Based scheme. Classifier fusion is implemented using the product rule on the soft-outputs from both classifiers. The algorithm has been used to recognize goose flocking behaviors (landing, foraging and flushing) and have improved the performance compared to using audio- or video-based classifiers alone. The improvement of using classifier fusion is most evident in the case of flushing and landing behavior recognition, where it was possible to combine the advantages of both the audio- and video-based classifier.
INDIUM SELENIDE THIN FILMS BY LASER IRRADIATION OF In/Se LAYERED STRUCTURE
Authors: ORNELAS-ACOSTA R. E. , SHAJI S. , AVELLANEDA D. , CASTILLO G. A. , DAS ROY T. K. , KRISHNAN B.
Published: August 2013

In this work, we report the formation of In 6 Se 7 thin films by laser irradiation of In / Se layered structure. Indium layer was deposited on glass substrates by thermal evaporation on which selenium thin film was grown by chemical bath deposition from an aqueous solution containing 10 ml of sodium selenosulphate (0.1 M), 1.0 ml acetic acid (25%) and 70 ml distilled water during 5 min. The In / Se coated glass substrates were irradiated using a 532 nm continuous laser for 3–5 min. Structure, morphology, optical and electrical properties of the irradiated thin films were analyzed using various techniques. X-ray diffraction analysis showed that the irradiated thin films were In 6 Se 7 of monoclinic structure. X-ray photoelectron spectroscopic study on the laser irradiated samples provided uniform relative composition of In and Se in the thin films formed after laser irradiation. The morphology, optical and electrical properties of the irradiated samples were investigated. The optical band gap of the In 6 Se 7 thin films was 2.2 eV and also, the thin films were photoconductive.
HARDY INEQUALITIES ON RIEMANNIAN MANIFOLDS WITH NEGATIVE CURVATURE
Authors: YANG QIAOHUA , SU DAN , KONG YINYING
Published: August 2013

Let M be a complete, simply connected Riemannian manifold with negative curvature. We obtain the sharp constants of Hardy and Rellich inequalities related to the geodesic distance on M. Furthermore, if M is with strictly negative curvature, we show that the LpHardy inequalities can be globally refined by adding remainder terms like the Brezis–Vázquez improvement in case p ≥ 2, which is contrary to the case of Euclidean spaces.