bluuebunny/crossref_metadata_2025 huggingface dataset:
Towards ultra-subwavelength optical latches
Authors: Mu Jianwei , Han Zhaohong , Grillanda Stefano , Melloni Andrea , Michel Jurgen , Kimerling L. C. , Agarwal Anu
Published: July 2013

We propose an electrically driven nanometer scale plasmonic optical latch integrated with Ge2Sb2Te5 chalcogenide glasses. For an effective switching length of 167 nm, the extinction ratio between the ON and OFF states of the proposed switch is as large as 10 dB, with net operation energy as low as 30.4 pJ per cycle.
Intra- and interspecific agonistic behaviour in hatchling Australian freshwater crocodiles (Crocodylus johnstoni) and saltwater crocodiles (Crocodylus porosus)
Authors: Brien Matthew L. , Webb Grahame J. , Lang Jeffrey W. , Christian Keith A.
Published: July 2013

We examined agonistic behaviour in hatchling Australian freshwater crocodiles (Crocodylus johnstoni) at 2 weeks, 13 weeks, and 50 weeks after hatching, and between C. johnstoni and saltwater crocodiles (Crocodylus porosus) at 40–50 weeks of age. Among C. johnstoni, agonistic interactions (15–23 s duration) were well established by two weeks old and typically involved two and occasionally three individuals, mostly between 17 : 00 and 24 : 00 hours in open-water areas of enclosures. A range of discrete postures, non-contact and contact movements are described. The head is rarely targeted in contact movements with C. johnstoni because they exhibit a unique ‘head raised high’ posture, and engage in ‘push downs’. In contrast with C. porosus of a similar age, agonistic interactions between C. johnstoni were conducted with relatively low intensity and showed limited ontogenetic change; there was also no evidence of a dominance hierarchy among hatchlings by 50 weeks of age, when the frequency of agonistic interactions was lowest. Agonistic interactions between C. johnstoni and C. porosus at 40–50 weeks of age were mostly low level, with no real exclusion or dominance observed. However, smaller individuals of both species moved slowly out of the way when a larger individual of either species approached. When medium- or high-level interspecific interactions did occur, it was between similar-sized individuals, and each displayed species-specific behaviours that appeared difficult for contestants to interpret: there was no clear winner or loser. The nature of agonistic interactions between the two species suggests that dominance may be governed more strongly by size rather than by species-specific aggressiveness.
Activation-induced cytidine deaminase (AID) is necessary for the epithelial–mesenchymal transition in mammary epithelial cells
Authors: Muñoz Denise P. , Lee Elbert L. , Takayama Sachiko , Coppé Jean-Philippe , Heo Seok-Jin , Boffelli Dario , Di Noia Javier M. , Martin David I. K.
Published: July 2013

Significance

The epithelial to mesenchymal transition (EMT) is a driving force behind normal morphogenesis and tumor metastasis. We have found evidence that the EMT in both malignant and nonmalignant mammary epithelial cells requires the enzyme activation-induced cytidine deaminase (AID). AID is induced in mammary epithelial cell lines by inflammatory stimuli that also induce the EMT. Deficiency of AID in these cells blocks morphological and transcriptional changes typical of the EMT and increases promoter cytosine methylation in genes encoding key EMT factors. These findings suggest that AID regulates gene expression in a complex developmental process that involves epigenetic reprogramming.
Multiparametric approach for the evaluation of lipid nanoparticles for siRNA delivery
Authors: Alabi Christopher A. , Love Kevin T. , Sahay Gaurav , Yin Hao , Luly Kathryn M. , Langer Robert , Anderson Daniel G.
Published: July 2013

Nanoparticle-mediated siRNA delivery is a complex process that requires transport across numerous extracellular and intracellular barriers. As such, the development of nanoparticles for efficient delivery would benefit from an understanding of how parameters associated with these barriers relate to the physicochemical properties of nanoparticles. Here, we use a multiparametric approach for the evaluation of lipid nanoparticles (LNPs) to identify relationships between structure, biological function, and biological activity. Our results indicate that evaluation of multiple parameters associated with barriers to delivery such as siRNA entrapment, pK
a
, LNP stability, and cell uptake as a collective may serve as a useful prescreening tool for the advancement of LNPs in vivo. This multiparametric approach complements the use of in vitro efficacy results alone for prescreening and improves in vitro–in vivo translation by minimizing false negatives. For the LNPs used in this work, the evaluation of multiple parameters enabled the identification of LNP pK
a
as one of the key determinants of LNP function and activity both in vitro and in vivo. It is anticipated that this type of analysis can aid in the identification of meaningful structure–function–activity relationships, improve the in vitro screening process of nanoparticles before in vivo use, and facilitate the future design of potent nanocarriers.
Determining complete electron flow in the cofactor photoreduction of oxidized photolyase
Authors: Liu Zheyun , Tan Chuang , Guo Xunmin , Li Jiang , Wang Lijuan , Sancar Aziz , Zhong Dongping
Published: July 2013

The flavin cofactor in photoenzyme photolyase and photoreceptor cryptochrome may exist in an oxidized state and should be converted into reduced state(s) for biological functions. Such redox changes can be efficiently achieved by photoinduced electron transfer (ET) through a series of aromatic residues in the enzyme. Here, we report our complete characterization of photoreduction dynamics of photolyase with femtosecond resolution. With various site-directed mutations, we identified all possible electron donors in the enzyme and determined their ET timescales. The excited cofactor behaves as an electron sink to draw electron flow from a series of encircling aromatic molecules in three distinct layers from the active site in the center to the protein surface. The dominant electron flow follows the conserved tryptophan triad in a hopping pathway across the layers with multiple tunneling steps. These ET dynamics occur ultrafast in less than 150 ps and are strongly coupled with local protein and solvent relaxations. The reverse electron flow from the flavin is slow and in the nanosecond range to ensure high reduction efficiency. With 12 experimentally determined elementary ET steps and 6 ET reaction pairs, the enzyme exhibits a distinct reduction–potential gradient along the same aromatic residues with favorable reorganization energies to drive a highly unidirectional electron flow toward the active-site center from the protein surface.
Use of Stable Isotopes to Identify Redds of Putative Hatchery and Wild Atlantic Salmon and Evaluate Their Spawning Habitat and Egg Thiamine Status in a Lake Ontario Tributary
Authors: Fitzsimons John D. , Dalton Alex , MacVeigh Brydon , Heaton Mark , Wilson Chris , Honeyfield Dale C.
Published: July 2013

Both wild and hatchery Atlantic Salmon Salmo salar can contribute to restoration but can exhibit differences in spawning habitat selection (e.g., water depth, current speed) and egg nutritional quality (e.g., thiamine), which affect reproductive success. Hence, there is a need to be able to differentiate the spawning contribution of the two groups in the wild. As diets of wild and hatchery-reared spawners are markedly dissimilar and diet is known to influence stable isotope signature, egg stable isotope signatures offer the potential to discriminate redds of each. Using stable isotope analysis of carbon and nitrogen (δ13C and δ 15N) of naturally spawned Atlantic Salmon eggs, we were able to discriminate the redds of putative wild (i.e., previously stocked life stage feeding in Lake Ontario; EWSR) from putative hatchery-reared Atlantic Salmon (EHSR). Eggs of EWSR were significantly more enriched in nitrogen (δ15N: 15.0 ± 0.5‰ [mean ± SE]) but more depleted in carbon (δ13C: −26.6 ± 0.3‰) than eggs of EHSR (δ15N = 9.8 ± 0.6‰; δ13C = −17.5 ± 0.0‰). Eggs of EHSR were indistinguishable from eggs of known hatchery Atlantic Salmon for both δ13C and δ 15N. Using stable isotopes to discriminate redd type, few differences were found between the spawning habitat of putative wild and hatchery spawners. Similarly using the same criteria, thiamine levels in eggs of EWSR (8,474 ± 840 pmol/g) were not significantly different from eggs of known wild Atlantic Salmon (3,691 ± 782 pmol/g) or of eggs of EHSR (14,865 ± 1,050 pmol/g), whose thiamine levels were indistinguishable from eggs of known hatchery Atlantic Salmon (14,200 ± 1,167 pmol/g). Egg thiamine levels for all groups were above established mortality thresholds. Our results indicate that both hatchery and wild Atlantic Salmon can make reproductive contributions, which can be differentiated and quantified using stable isotope signatures.

Received August 24, 2012; accepted May 15, 2013
A Comparison of Methods to Estimate Shovelnose Sturgeon Mortality in the Mississippi River Adjacent to Missouri and Illinois
Authors: Phelps Quinton E. , Vining Ivan , Herzog David P. , Dames Ross , Travnichek Vince H. , Tripp Sara J. , Boone Mark
Published: July 2013

Mortality is a key parameter in understanding the dynamics of any fish population. We examined three methods to evaluate Shovelnose Sturgeon Scaphirhynchus platorynchus mortality (e.g., ratio of first year recruits to all recruits [Heincke's method], a linearized weighted catch curve, and an open system mark–recapture mortality approach). The Mississippi River was sampled in two distinct but connected geomorphic sections: upper Mississippi River (UMR; river kilometer 323–587) and the middle Mississippi River (MMR; river kilometer 0–322). All analyses were pooled across these areas due to potential emigration or immigration throughout both study reaches. Heincke's method estimated annual mortality at 16.9% for the full range of ages (9–23 years) with generally increasing estimates with decreasing age ranges considered (10–23, 11–23, 12–23, and so on). A linearized weighted catch curve that considered increasing estimates of mortality for the shorter age ranges generated an annual mortality estimate of 29.0%.d Four mark–recapture models were considered using the program MARK. The model with the greatest support was the model that provided estimates of annual mortality for each year and a single recapture probability. The annual mortality estimates from this model varied from 2.7% to 70.7% after correcting for tag loss. The best fit model with a single estimate of annual mortality was the one that estimated annual recapture probabilities for each year and had a mortality estimate of 34.6% (after correcting for tag loss, but not for immigration, emigration, or sampling effort). The three methods provided varying results, and our data indicated that a single method to estimate Shovlenose Sturgeon mortality rate may not be appropriate. As such, biologists must recognize that disparities in Shovelnose Sturgeon mortality rates may exist using various methods and should use caution when choosing which method will be employed to estimate sturgeon mortality.

Received August 1, 2012; accepted May 16, 2013
Differentiability of quermassintegrals: A classification of convex bodies
Authors: Hernández Cifre M. , Saorín E.
Published: July 2013

In this paper we characterize the convex bodies in

R

n

\mathbb {R}^n

whose quermassintegrals satisfy certain differentiability properties, which answers a question posed by Bol in 1943 for the

3
3

-dimensional space. This result will have unexpected consequences on the behavior of the roots of the Steiner polynomial: we prove that there exist many convex bodies in

R

n

\mathbb {R}^n

, for

n
≥
3

n\geq 3

, not satisfying the inradius condition in Teissier’s problem on the geometric properties of the roots of the Steiner polynomial.
Control of Phytophthora nicotianae with Mefenoxam, Fresh Brassica Tissues, and Brassica Pellets
Authors: Morales-Rodríguez Carmen , Palo Carolina , Palo Eloy , Rodríguez-Molina M. Carmen
Published: July 2013

Sensitivity to mefenoxam, fresh Brassicaceae tissues, and Brassica pellets was evaluated in several isolates of Phytophthora nicotianae recovered from pepper and tomato plants. The isolates of P. nicotianae studied were classified as sensitive to mefenoxam, showing great variability among isolates in the 50 and 90% effective concentrations (EC50 and EC90, respectively). Sensitivity differentiated isolates from the two hosts of origin, being isolates from tomato plants more resistant to fungicide than those from pepper plants. This differentiation also occurred in the case of fresh Brassicaceae tissues assay. The most effective biofumigant in inhibiting mycelial growth of P. nicotianae isolates was Brassica nigra. The effectiveness of B. carinata, Sinapis alba, and B. oleracea varied depending on the dose. Isolates differed in susceptibility to compounds released by the Brassica pellets and then in the EC50 and EC90. No significant difference was found between the isolates depending on the host of origin. Greenhouse tests demonstrated the effectiveness of treatments with mefenoxam and with Brassica pellets to control P. nicotianae in pepper plants. Mefenoxam application could be a solution to the disease caused by P. nicotianae in tomato and pepper crops in this region but its use could increase resistance in populations. Biofumigation is a promising technique which can be further developed to form part of integrated pest management strategies.
First Report of Rice yellow mottle virus in Rice in the Central African Republic
Authors: Longué D. R. S. , Galzi-Pinel A. , Semballa S. , Zinga I. , Fargette D. , Traoré O.
Published: July 2013

Rice yellow mottle virus (RYMV, genus Sobemovirus) is a major biotic constraint to rice production in Africa. First reported in Kenya in 1966, RYMV was later found in most countries in Africa where rice (Oryza sativa, O. glaberrima) is grown (4). In the Central African Republic, the disease has never been reported in rice fields. In October 2011, plants with leaf yellowing and mottling symptoms were observed in large irrigated rice production schemes about 30 km west of Bangui, the capital of the Central African Republic, and in lowland subsistence fields in Bangui outskirts. Disease incidence was estimated at 5 to 10%, causing small patches in the fields. Mechanical inoculation with extracts of symptomatic leaves reproduced the typical yellow mottle symptoms on the susceptible O. sativa cultivar BG90-2 6 to 9 days after inoculation. Symptomatic leaves of 12 cultivated plants collected in seed beds or in fields reacted positively when tested by ELISA with polyclonal antisera raised against a Madagascan isolate of RYMV (1). Discriminating monoclonal antibodies showed that the samples contained RYMV serotype 1, a serotype found in West and Central Africa (1). Total RNA was extracted by the RNeasy Plant Mini kit (QIAGEN, Hilden, Germany) from six samples. The 720-nt RYMV coat protein gene was amplified by reverse transcriptase (RT)-PCR with primers 5′CTCCCCCACCCATCCCGAGAATT3′ and 5′CAAAGATGGCCAGGAA3′ (2). RT-PCR products were directly sequenced and sequences were deposited in GenBank (Accession Nos. KF054740 through KF054745). These six sequences showed over 98% identity with each other, and were found to be closely related to sequences of isolates from Chad and Cameroon in Central Africa (3). Knowledge of the presence of RYMV in the Central African Republic is important since rice cultivation has intensified in this country. In addition, rice is also increasingly considered as one of the main staple crops in the country.

References: (1) D. Fargette et al. Arch. Virol. 147:583, 2002. (2) A. Pinel et al. Arch. Virol. 145:1621, 2000. (3) O. Traoré et al. Plant Dis. 96:1230, 2001. (4) O. Traoré et al. Virus Res. 141:258, 2009.
First Report of Sweet potato chlorotic fleck virus Infecting Sweet Potato in Sichuan Province, China
Authors: Deng X.-G. , Zhu F. , Zhu T. , Lin H.-H. , Xi D.-H.
Published: July 2013

Sweet potato chlorotic fleck virus (SPCFV) is one of several viruses naturally infecting sweet potato (Ipomoea batatas L.), and it has recently been classified as a new member of the genus Carlavirus (family Flexiviridae) (1). However, SPCFV is distantly related to typical carlaviruses, as most of its putative gene products share amino acid sequence identities of <40% with those of typical carlaviruses (1). China is the largest sweet potato producing country in the world. So far, SPCFV has been reported in eastern China, such as Jiangsu, Anhui, Henan (3), and Guangdong (2) provinces, but no reports exist in western China. Sichuan Province, located in southwestern China, is the largest sweet potato producing area in the country. There are big differences between the environment and climate conditions between Sichuan and eastern China. During 2012, a survey was constructed to determine the genetic diversity and distribution of sweet potato viruses in Sichuan. Forty-seven sweet potato samples exhibiting virus-like symptoms were collected from four different geographic areas of the province. Western blotting using the antisera obtained from the International Potato Center showed that two samples were positive for SPCFV, whereas with reverse transcription (RT)-PCR, only one isolate of SPCFV was obtained from a sample exhibiting symptoms of chlorosis, leaf distortion, and vein clearing. Serological detection indicated that the plant was co-infected with SPCFV, Sweet potato feathery mottle virus (SPFMV), and Sweet potato virus G (SPVG). Total RNA was extracted from symptomatic leaves using Trizol reagent (Invitrogen) according to the manufacturer's protocol, and RT-PCR was performed by using primer pairs SPCFV-CP F (5′-ATGGCGGCGAAGGAGGCTGATA-3′) and SPCFV-CP R (5′-TCACTTGCACTTCCCATTAC-3′) corresponding to the entire coat protein (CP) gene of SPCFV. Expected DNA fragments of 900 bp were obtained from the symptomatic plant but not from control plants. The obtained fragments were purified and cloned into the PMD19-T vector (TaKaRa). Recombinant plasmids were then transformed into competent cells of Escherichia coli strain DH5α. Nucleotide BLAST analysis revealed that the 900-bp fragment (GenBank Accession No. KC414676) shared 87 to 91% nucleotide identities with other SPCFV isolates available in the GenBank database. To our knowledge, this is the first report of the co-infection between SPCFV and other sweet potato viruses including SPFMV and SPVG in China, and this is the first molecular report of SPCFV in Sichuan, western China. It shows that SPCFV is spreading to a new ecological area of China, and the spread of the virus may affect sweet potato crop yields in western China. Some measures must be carried out quickly to control the virus.

References: (1) V. Aritua et al. Arch. Virol. 152:813, 2007. (2) V. Aritua et al. Plant Dis. 93:87, 2009. (3) Q. Wang et al. Crop. Prot. 29:110, 2010.
Modeling the Effects of Environmental Conditions on HT2 and T2 Toxin Accumulation in Field Oat Grains
Authors: Xu Xiangming , Madden Laurence V. , Edwards Simon G.
Published: July 2013

Fusarium head blight (FHB) of wheat and barley has been extensively researched worldwide; in contrast, there is limited information on the effects of environmental conditions on Fusarium toxin accumulation in oat grains. More than 300 samples of oat grain from various regions of the United Kingdom from 2006 to 2008 were analyzed for mycotoxin contamination due to infection by Fusarium spp. HT2 and T2 toxins were the two most commonly detected, and their concentrations in individual samples were highly correlated. Hourly weather data were obtained from meteorological recording stations near most of the sampling sites. Statistical modeling was applied to both the original toxin (HT2 plus T2) data and the toxin data adjusted for oat cultivars and number of cereal crops in the previous four seasons. Accumulation of HT2 and T2 toxin was positively correlated with warm and wet conditions during early May and dry conditions thereafter. Using a collection of 51 environmental variables summarized over three lengths (10, 15, and 20 days) of time periods encompassing early May, late May, and early July, all-subsets regression showed that many models, consisting of three to six predictor variables, could be identified with similar explanatory strength for the effect of environmental conditions on toxin accumulation. Most important predictor variables were related to wet conditions during the early-May period, which was before anthesis. These results suggest that the predominant period for Fusarium langsethiae infection of oat is likely to be before rather than during anthesis, as for other head blight pathogens. These empirical models may be further improved by using quantified pathogen biomass within the grains and weather predictor variables summarized in relation to plant growth stages (instead of calendar times).
Viability of ‘Candidatus Liberibacter asiaticus’ Prolonged by Addition of Citrus Juice to Culture Medium
Authors: Parker Jennifer K. , Wisotsky Sarah R. , Johnson Evan G. , Hijaz Faraj M. , Killiny Nabil , Hilf Mark E. , De La Fuente Leonardo
Published: July 2013

Huanglongbing, or citrus greening disease, is associated with infection by the phloem-limited bacterium ‘Candidatus Liberibacter asiaticus’. Infection with ‘Ca. L. asiaticus’ is incurable; therefore, knowledge regarding ‘Ca. L. asiaticus’ biology and pathogenesis is essential to develop a treatment. However, ‘Ca. L. asiaticus’ cannot currently be successfully cultured, limiting its study. To gain insight into the conditions conducive for growth of ‘Ca. L. asiaticus’ in vitro, ‘Ca. L. asiaticus’ inoculum obtained from seed of fruit from infected pomelo trees (Citrus maxima ‘Mato Buntan’) was added to different media, and cell viability was monitored for up to 2 months using quantitative polymerase chain reaction in conjunction with ethidium monoazide. Media tested included one-third King's B (K), K with 50% juice from the infected fruit, K with 50% commercially available grapefruit juice, and 100% commercially available grapefruit juice. Results show that juice-containing media dramatically prolong viability compared with K in experiments reproduced during 2 years using different juice sources. Furthermore, biofilm formed at the air–liquid interface of juice cultures contained ‘Ca. L. asiaticus’ cells, though next-generation sequencing indicated that other bacterial genera were predominant. Chemical characterization of the media was conducted to discuss possible factors sustaining ‘Ca. L. asiaticus’ viability in vitro, which will contribute to future development of a culture medium for ‘Ca. L. asiaticus’.
Conventional and Kilohertz-frequency Spinal Cord Stimulation Produces Intensity- and Frequency-dependent Inhibition of Mechanical Hypersensitivity in a Rat Model of Neuropathic Pain
Authors: Shechter Ronen , Yang Fei , Xu Qian , Cheong Yong-Kwan , He Shao-Qiu , Sdrulla Andrei , Carteret Alene F. , Wacnik Paul W. , Dong Xinzhong , Meyer Richard A. , Raja Srinivasa N. , Guan Yun
Published: July 2013

Background:

Spinal cord stimulation (SCS) is a useful neuromodulatory technique for treatment of certain neuropathic pain conditions. However, the optimal stimulation parameters remain unclear.

Methods:

In rats after L5 spinal nerve ligation, the authors compared the inhibitory effects on mechanical hypersensitivity from bipolar SCS of different intensities (20, 40, and 80% motor threshold) and frequencies (50, 1 kHz, and 10 kHz). The authors then compared the effects of 1 and 50 Hz dorsal column stimulation at high- and low-stimulus intensities on conduction properties of afferent Aα/β-fibers and spinal wide-dynamic–range neuronal excitability.

Results:

Three consecutive daily SCS at different frequencies progressively inhibited mechanical hypersensitivity in an intensity-dependent manner. At 80% motor threshold, the ipsilateral paw withdrawal threshold (% preinjury) increased significantly from pre-SCS measures, beginning with the first day of SCS at the frequencies of 1 kHz (50.2 ± 5.7% from 23.9 ± 2.6%, n = 19, mean ± SEM) and 10 kHz (50.8 ± 4.4% from 27.9 ± 2.3%, n = 17), whereas it was significantly increased beginning on the second day in the 50 Hz group (38.9 ± 4.6% from 23.8 ± 2.1%, n = 17). At high intensity, both 1 and 50 Hz dorsal column stimulation reduced Aα/β-compound action potential size recorded at the sciatic nerve, but only 1 kHz stimulation was partially effective at the lower intensity. The number of actions potentials in C-fiber component of wide-dynamic–range neuronal response to windup-inducing stimulation was significantly decreased after 50 Hz (147.4 ± 23.6 from 228.1 ± 39.0, n = 13), but not 1 kHz (n = 15), dorsal column stimulation.

Conclusions:

Kilohertz SCS attenuated mechanical hypersensitivity in a time course and amplitude that differed from conventional 50 Hz SCS, and may involve different peripheral and spinal segmental mechanisms.
Nestling telomere length does not predict longevity, but covaries with adult body size in wild barn swallows
Authors: Caprioli Manuela , Romano Maria , Romano Andrea , Rubolini Diego , Motta Rosita , Folini Marco , Saino Nicola
Published: July 2013

Telomere length and dynamics are increasingly scrutinized as ultimate determinants of performance, including age-dependent mortality and fecundity. Few studies have investigated longevity in relation to telomere length (TL) in the wild and none has analysed longevity in relation to TL soon after hatching, despite the fact that telomere shortening may mostly occur early in life. We show that TL in nestling barn swallows (
Hirundo rustica
) in the wild does not predict longevity. However, TL positively covaries with body size, suggesting that individuals with large TL can afford to grow larger without paying the cost of reduced TL, and/or that benign rearing conditions ensure both large body size and low rates of telomere shortening. Overall, our study hints at a role of TL in developmental processes, but also indicates a need for further analyses to assess the expectation that TL in young individuals predicts longevity in the wild.
Reciprocal feeding facilitation between above- and below-ground herbivores
Authors: McKenzie Scott W. , Vanbergen Adam J. , Hails Rosemary S. , Jones T. Hefin , Johnson Scott N.
Published: July 2013

Interspecific interactions between insect herbivores predominantly involve asymmetric competition. By contrast, facilitation, whereby herbivory by one insect benefits another via induced plant susceptibility, is uncommon. Positive reciprocal interactions between insect herbivores are even rarer. Here, we reveal a novel case of reciprocal feeding facilitation between above-ground aphids (
Amphorophora idaei
) and root-feeding vine weevil larvae (
Otiorhynchus sulcatus
), attacking red raspberry (
Rubus idaeus
). Using two raspberry cultivars with varying resistance to these herbivores, we further demonstrate that feeding facilitation occurred regardless of host plant resistance. This positive reciprocal interaction operates via an, as yet, unreported mechanism. Specifically, the aphid induces compensatory growth, possibly as a prelude to greater resistance/tolerance, whereas the root herbivore causes the plant to abandon this strategy. Both herbivores may ultimately benefit from this facilitative interaction.
In vivo
optic nerve head biomechanics: performance testing of a three-dimensional tracking algorithm
Authors: Girard Michaël J. A. , Strouthidis Nicholas G. , Desjardins Adrien , Mari Jean Martial , Ethier C. Ross
Published: July 2013

Measurement of optic nerve head (ONH) deformations could be useful in the clinical management of glaucoma. Here, we propose a novel three-dimensional tissue-tracking algorithm designed to be used
in vivo
. We carry out preliminary verification of the algorithm by testing its accuracy and its robustness. An algorithm based on digital volume correlation was developed to extract ONH tissue displacements from two optical coherence tomography (OCT) volumes of the ONH (undeformed and deformed). The algorithm was tested by applying artificial deformations to a baseline OCT scan while manipulating speckle noise, illumination and contrast enhancement. Tissue deformations determined by our algorithm were compared with the known (imposed) values. Errors in displacement magnitude, orientation and strain decreased with signal averaging and were 0.15 µm, 0.15° and 0.0019, respectively (for optimized algorithm parameters). Previous computational work suggests that these errors are acceptable to provide
in vivo
characterization of ONH biomechanics. Our algorithm is robust to OCT speckle noise as well as to changes in illumination conditions, and increasing signal averaging can produce better results. This algorithm has potential be used to quantify ONH three-dimensional strains
in vivo
, of benefit in the diagnosis and identification of risk factors in glaucoma.
The cost of sensitive response and accurate adaptation in networks with an incoherent type-1 feed-forward loop
Authors: Lan Ganhui , Tu Yuhai
Published: July 2013

The incoherent type-1 feed-forward loop (I1-FFL) is ubiquitous in biological regulatory circuits. Although much is known about the functions of the I1-FFL motif, the energy cost incurred in the network and how it affects the performance of the network have not been investigated. Here, we study a generic I1-FFL enzymatic reaction network modelled after the GEF–GAP–Ras pathway responsible for chemosensory adaptation in eukaryotic cells. Our analysis shows that the I1-FFL network always operates out of equilibrium. Continuous energy dissipation is necessary to drive an internal phosphorylation–dephosphorylation cycle that is crucial in achieving strong short-time response and accurate long-time adaptation. In particular, we show quantitatively that the energy dissipated in the I1-FFL network is used (i) to increase the system's initial response to the input signals; (ii) to enhance the adaptation accuracy at steady state; and (iii) to expand the range of such accurate adaptation. Moreover, we find that the energy dissipation rate, the catalytic speed and the maximum adaptation accuracy in the I1-FFL network satisfy the same energy–speed–accuracy relationship as in the negative-feedback-loop (NFL) networks. Because the I1-FFL and NFL are the only two basic network motifs that enable accurate adaptation, our results suggest that a universal cost–performance trade-off principle may underlie all cellular adaptation processes independent of the detailed biochemical circuit architecture.
Enhanced signal-to-noise ratios in frog hearing can be achieved through amplitude death
Authors: Ahn Kang-Hun
Published: July 2013

In the ear, hair cells transform mechanical stimuli into neuronal signals with great sensitivity, relying on certain active processes. Individual hair cell bundles of non-mammals such as frogs and turtles are known to show spontaneous oscillation. However, hair bundlesin vivomust be quiet in the absence of stimuli, otherwise the signal is drowned in intrinsic noise. Thus, a certain mechanism is required in order to suppress intrinsic noise. Here, through a model study of elastically coupled hair bundles of bullfrog sacculi, we show that a low stimulus threshold and a high signal-to-noise ratio (SNR) can be achieved through the amplitude death phenomenon (the cessation of spontaneous oscillations by coupling). This phenomenon occurs only when the coupled hair bundles have inhomogeneous distribution, which is likely to be the case in biological systems. We show that the SNR has non-monotonic dependence on the mass of the overlying membrane, and find out that the SNR has maximum value in the region of amplitude death. The low threshold of stimulus through amplitude death may account for the experimentally observed high sensitivity of frog sacculi in detecting vibration. The hair bundles' amplitude death mechanism provides a smart engineering design for low-noise amplification.
Post-hatch heat warms adult beaks: irreversible physiological plasticity in Japanese quail
Authors: Burness Gary , Huard Jacqueline R. , Malcolm Emily , Tattersall Glenn J.
Published: July 2013

Across taxa, the early rearing environment contributes to adult morphological and physiological variation. For example, in birds, environmental temperature plays a key role in shaping bill size and clinal trends across latitudinal/thermal gradients. Such patterns support the role of the bill as a thermal window and in thermal balance. It remains unknown whether bill size and thermal function are reversibly plastic. We raised Japanese quail in warm (30°C) or cold (15°C) environments and then at a common intermediate temperature. We predicted that birds raised in cold temperatures would develop smaller bills than warm-reared individuals, and that regulation of blood flow to the bill in response to changing temperatures would parallel the bill's role in thermal balance. Cold-reared birds developed shorter bills, although bill size exhibited ‘catch-up’ growth once adults were placed at a common temperature. Despite having lived in a common thermal environment as adults, individuals that were initially reared in the warmth had higher bill surface temperatures than cold-reared individuals, particularly under cold conditions. This suggests that blood vessel density and/or the control over blood flow in the bill retained a memory of early thermal ontogeny. We conclude that post-hatch temperature reversibly affects adult bill morphology but irreversibly influences the thermal physiological role of bills and may play an underappreciated role in avian energetics.
Peer‐mediated interventions with elementary and secondary school students with emotional and behavioural disorders: a literature review
Authors: Kaya Cahit , Blake John , Chan Fong
Published: July 2013

Peer‐mediated interventions (PMIs) have been shown to be effective for increasing adaptive social and academic behaviours of children and youth. Although PMI efficacy is generally well supported, there have been relatively few published intervention studies that focus on elementary, middle and high school students with emotional and behavioural disorders (EBD). The present review examines selected empirical literature in order to identify characteristics and relative efficacy of PMI. Findings of 12 peer‐reviewed journal papers including research designs and outcomes were examined. Results provide support for the efficacy of PMI for improving behavioural and social skills of students with EBD. Recommendations include further research on PMI for high school students and longitudinal research of PMI.
Age Estimation Based on Pulp Cavity to Tooth Volume Ratio Using Postmortem Computed Tomography Images
Authors: Sakuma Ayaka , Saitoh Hisako , Suzuki Yoichi , Makino Yohsuke , Inokuchi Go , Hayakawa Mutsumi , Yajima Daisuke , Iwase Hirotaro
Published: July 2013

Pulp cavity size is known to decrease with age and can therefore serve as an indicator for age estimation. Here, we evaluated whether reconstructed images of multidetector‐row computed tomography (MDCT) acquired before forensic autopsy are useful for estimating age at death. Images of 136 mandibular first premolars obtained from bodies of known age at death were analyzed, and the volume of the regions corresponding to pulp cavity and that of the whole tooth were determined using a voxel counting function. The pulp cavity was clearly distinguishable from dental hard tissue on the reconstructed images when using a cutoff value of 1400 Hounsfield units. Regression analysis adjusted for sex showed that estimated age correlated significantly with the pulp cavity to tooth volume ratio (r = 0.76). MDCT is gaining more widespread use in forensic medicine, and analyzing dental images to obtain parameters for age prediction is a practical approach for postmortem identification.
Information‐Theoretical Assessment of the Performance of Likelihood Ratio Computation Methods
Authors: Ramos Daniel , Gonzalez‐Rodriguez Joaquin , Zadora Grzegorz , Aitken Colin
Published: July 2013

Performance of likelihood ratio (LR) methods for evidence evaluation has been represented in the past using, for example, Tippett plots. We propose empirical cross‐entropy (ECE) plots as a metric of accuracy based on the statistical theory of proper scoring rules, interpretable as information given by the evidence according to information theory, which quantify calibration of LR values. We present results with a case example using a glass database from real casework, comparing performance with both Tippett and ECE plots. We conclude that ECE plots allow clearer comparisons of LR methods than previous metrics, allowing a theoretical criterion to determine whether a given method should be used for evidence evaluation or not, which is an improvement over Tippett plots. A set of recommendations for the use of the proposed methodology by practitioners is also given.
Novel technique of cytolithotripsy for large bladder stones
Authors: Toktas Gokhan , Sacak Vural , Erkan Erkan , Kocaaslan Ramazan , Demiray Murat , Unluer Erdinc , Ozyalvacli M Emin
Published: July 2013

Introduction

We evaluated a minimally invasive surgical technique involving a single percutaneous access with a laparoscopic trocar under video‐cystoscopic vision for managing large bladder stones. All patients were candidates for open surgery.

Materials and Surgical Technique

Fourteen patients with bladder stones larger than 3 cm in diameter or multiple stones were treated with this technique. The procedure involved the percutaneous placement of a laparoscopic trocar under cystoscopic control and the introduction of a rigid nephroscope into the bladder. Stones were cleansed via fragmentation or direct removal.

Discussion

The technique was successful in all cases, resulting in controlled, stone‐free bladders; there were no surgical complications. The mean operation time was comparable to that of standard management. All patients discharged uneventfully. None reported urethral stricture during the 24‐month follow‐up period. Percutaneous cystolithotripsy under endoscopic control is easy to perform and should be considered as an alternative for large or multiple bladder stones as it decreases the risk of urethral stricture.
Single‐port endo‐laparoscopic surgery in combined abdominal procedures
Authors: Kim Guowei , Lomanto Davide , Lawenko Michael M , Lopez‐Gutierrez Javier , Lee‐Ong Alembert , Iyer Shridhar Ganpathi , Cheah Wei Keat , So Jimmy Bok Yan , Tsang Charles Bih Shiou , Fong Yoke Fai
Published: July 2013

Single‐port endo‐laparoscopic surgery has gained support in the surgical community because it is perceived to offer a better postoperative outcome as it requires only a single incision. We write this prospective observational study to ascertain the feasibility and safety of this technique in patients otherwise requiring two operations. Five patients who underwent double procedures with a single‐port device were reviewed: Case 1, a transabdominal preperitoneal hernia repair and gastric wedge resection; Case 2, cholecystectomy and diaphragmatic hernia repair; Case 3, oophorectomy and incisional hernia repair; Case 4, anterior resection of the rectum and hepatic segmentectomy; and Case 5, left adrenalectomy and cholecystectomy. Patient demographics, type of port used, operative time, complications and incision length were collected. Mean operative time for the cases ranged from 100 to 315 min. Incision length for the single‐port device was 2 cm. In Case 2, an additional 5‐mm port was used and an intraoperative complication involving a laceration of the liver occurred during the suturing of the gallbladder fundus. An additional 8‐cm lower abdominal incision (Pfannenstiel) was required in Case 4 to complete the colonic anastomosis and for specimen retrieval. Single‐port endo‐laparoscopic surgery is a feasible and safe technique for approaching double procedures. It drastically reduces the number of scars that a double procedure creates, and if difficulty arises, another port can always be added to ease the operation. It can also potentially reduce the number of admissions and anesthesia that a patient undergoes.
Prospects for the provision of genotyped blood for transfusion
Authors: Denomme Gregory A.
Published: July 2013

Blood group genotyping is gaining widespread adoption in blood centres and transfusion services. The current interest for a blood centre is its use as a screening tool to accurately predict donor phenotypes. However, not only is blood group genotyping used to screen for uncommon and rare types on a mass‐scale, it can be used to optimize the inventory of multiple antigen‐negative screened units. In addition, blood group genotyping provides blood types when antisera are not available, it can predict weak and variant antigens, and can aid in the resolution of ABO discrepancies. There are quality improvement benefits in blood group genotyping because it can screen for RHD alleles in Rh‐negative blood donors and can be used to confirm that donors are suitable for reagent red cell production. It is possible that blood group genotyping information may be used as a donor recruitment tool. Given that genotyping can convey much more information about the expression of some complex antigens, e.g. hrB, Uvar, and Duffy, clinical trials are probably needed to show that genotyped or ‘dry matched’ transfusions are superior to phenotyped blood.
Mutations in SETBP1 are recurrent in myelodysplastic syndromes and often coexist with cytogenetic markers associated with disease progression
Authors: Fernandez‐Mercado Marta , Pellagatti Andrea , Di Genua Cristina , Larrayoz Maria Jose , Winkelmann Nils , Aranaz Paula , Burns Adam , Schuh Anna , Calasanz Maria Jose , Cross Nicholas C. P. , Boultwood Jacqueline
Published: July 2013

Whole exome sequencing was performed in a patient with myelodysplastic syndrome before and after progression to acute myeloid leukaemia. Mutations in several genes, including SETBP1, were identified following leukaemic transformation. Screening of 328 patients with myeloid disorders revealed SETBP1 mutations in 14 patients (4·3%), 7 of whom had −7/del(7q) and 3 had i(17)(q10), cytogenetic markers associated with shortened overall survival and increased risk of leukaemic evolution. SETBP1 mutations were frequently acquired at the time of leukaemic evolution, coinciding with increase of leukaemic blasts. These data suggest that SETBP1 mutations may play a role in MDS and chronic myelomonocytic leukaemia disease progression.
Primary treatment of the prostate improves local palliation in men who ultimately develop castrate‐resistant prostate cancer
Authors: Won Andy C.M. , Gurney Howard , Marx Gavin , De Souza Paul , Patel Manish I.
Published: July 2013

Objectives

To determine whether local treatment of primary prostate cancer gives palliative benefit to men who later develop castrate‐resistant prostate cancer (CRPC).

Local treatments of primary prostate cancer are defined as radical retropubic prostatectomy (RRP) or external beam radiation therapy (EBRT).

Patients and Methods

Patient records were reviewed in five different hospitals in Sydney, Australia, and 263 men with CRPC were identified.

Eligible patients comprised men who had progressive disease during androgen deprivation therapy with castrate levels of testosterone.

Clinical and pathological data were reviewed and evaluated using the chi‐squared test and relative risk analysis to determine the relationship between previous local prostate treatment and complications secondary to local disease.

The end‐point was complications and morbidity attributed to cancer progression locally (i.e. from the prostate).

Results

Primary treatment of the prostate by either RRP or EBRT significantly reduces the incidence of local complications compared to no primary treatment (32.6% vs 54.6%; P = 0.001).

RRP showed a significantly lower level of local complications compared to EBRT (20.0% vs 46.7%; P = 0.007).

The most common local complications were bladder outlet obstruction (35.0%) and ureteric obstruction (15.2%).

Conclusions

The present retrospective analysis supports the hypothesis that primary local prostatic treatment gives palliative benefit to men who later develop CRPC.

RRP was associated with the lowest local complication rate experienced at the stage of metastatic disease.
High‐throughput Screening for Identification of Inhibitors of EpCAM‐Dependent Growth of Hepatocellular Carcinoma Cells
Authors: Henrich Curtis J. , Budhu Anuradha , Yu Zhipeng , Evans Jason R. , Goncharova Ekaterina I. , Ransom Tanya T. , Wang Xin W. , McMahon James B.
Published: July 2013

The cancer stem cell marker, EpCAM, is an important indicator of Wnt/β‐catenin signaling activation and a functional component of hepatocellular tumor‐initiating cells. A high‐throughput screening assay was developed to identify inhibitors of EpCAM‐dependent growth of hepatocellular carcinoma (HCC) cells. EpCAM(+) and EpCAM(−) HCC cell lines were assessed for differential sensitivity to a Wnt/β‐catenin pathway inhibitor. Libraries comprising 22 668 pure compounds and 107 741 crude or partially purified natural product extracts were tested, and 12 pure compounds and 67 natural product extracts were identified for further study. Three active compounds and the positive control were further characterized in terms of effects on EpCAM expression. Treatment of EpCAM(+) Hep3B cells resulted in loss of EpCAM expression as assessed by flow cytometry. This reduction was incomplete (most cells continued to express EpCAM), but resulted in generation of cell populations expressing lower levels of EpCAM. Sublethal concentrations (~IC50) reduced median EpCAM expression to 28% of control after 1 day and 19% of control after 2 days. Reduction in EpCAM expression preceded growth inhibition suggesting that a threshold of EpCAM expression may be required for growth of EpCAM‐dependent cells. The identification of compounds with a variety of possible molecular targets suggests a likelihood of multiple mechanisms for modulation of EpCAM‐dependent cell growth.
Which aspects of an oral health–related quality of life measure are mainly associated with global ratings of oral health in children?
Authors: Krisdapong Sudaduang , Sheiham Aubrey
Published: July 2013

Objectives

To assess the associations of global subjective ratings of oral health with different aspects of an oral health–related quality of life measure, namely total Oral Impacts on Daily Performances (OIDP) and Child‐Oral Impacts on Daily Performances (Child‐OIDP) scores, extent and intensity of oral impacts, the different performance scores and oral impacts attributed to certain groups of oral conditions.

Methods

This study was part of the Sixth Thailand National Oral Health Survey. One thousand and sixty‐six 12‐year‐olds and 815 15‐year‐olds were interviewed on their OHRQoL using Child‐OIDP and OIDP indices, respectively, and rated their overall oral problems on 3‐point and 5‐point scales, respectively. Associations of global rating of oral health with different Child‐OIDP/OIDP outcome variables were estimated using Spearman's rank correlations and logistic regressions.

Results

Child‐OIDP/OIDP scores were significantly associated with global ratings. Intensity was associated with global ratings, whereas extent was not. Impacts of ‘very little’ intensity were associated with a slightly higher chance of having poorer oral health perceptions. Global ratings were associated most with oral impacts attributed to dental caries, but not with the impacts related to natural process, such as eruption. Eating, cleaning teeth, emotional stability and smiling, plus social contact in 15‐year‐olds were performances associated with global ratings. Fifteen‐year‐old girls were more likely to perceive more oral problems than boys.

Conclusions

Associations of global ratings of oral health with Child‐OIDP/OIDP scores were mainly due to the intensity of impacts. Global ratings were related to multidimensional aspects of children's quality of life.