bluuebunny/crossref_metadata_2025 huggingface dataset:
Virulent Shigella flexneri subverts the host innate immune response through manipulation of antimicrobial peptide gene expression
Authors: Sperandio Brice , Regnault Béatrice , Guo Jianhua , Zhang Zhi , Stanley Samuel L. , Sansonetti Philippe J. , Pédron Thierry
Published: April 2008

Antimicrobial factors are efficient defense components of the innate immunity, playing a crucial role in the intestinal homeostasis and protection against pathogens. In this study, we report that upon infection of polarized human intestinal cells in vitro, virulent Shigella flexneri suppress transcription of several genes encoding antimicrobial cationic peptides, particularly the human β-defensin hBD-3, which we show to be especially active against S. flexneri. This is an example of targeted survival strategy. We also identify the MxiE bacterial regulator, which controls a regulon encompassing a set of virulence plasmid-encoded effectors injected into host cells and regulating innate signaling, as being responsible for this dedicated regulatory process. In vivo, in a model of human intestinal xenotransplant, we confirm at the transcriptional and translational level, the presence of a dedicated MxiE-dependent system allowing S. flexneri to suppress expression of antimicrobial cationic peptides and promoting its deeper progression toward intestinal crypts. We demonstrate that this system is also able to down-regulate additional innate immunity genes, such as the chemokine CCL20 gene, leading to compromised recruitment of dendritic cells to the lamina propria of infected tissues. Thus, S. flexneri has developed a dedicated strategy to weaken the innate immunity to manage its survival and colonization ability in the intestine.
Essential role of Notch signaling in effector memory CD8+ T cell–mediated airway hyperresponsiveness and inflammation
Authors: Okamoto Masakazu , Takeda Katsuyuki , Joetham Anthony , Ohnishi Hiroshi , Matsuda Hiroyuki , Swasey Christina H. , Swanson Bradley J. , Yasutomo Koji , Dakhama Azzeddine , Gelfand Erwin W.
Published: April 2008

Adoptive transfer of in vivo–primed CD8+ T cells or in vitro–generated effector memory CD8+ T (TEFF) cells restores airway hyperresponsiveness (AHR) and airway inflammation in CD8-deficient (CD8−/−) mice. Examining transcription levels, there was a strong induction of Notch1 in TEFF cells compared with central memory CD8+ T cells. Treatment of TEFF cells with a γ-secretase inhibitor (GSI) strongly inhibited Notch signaling in these cells, and after adoptive transfer, GSI-treated TEFF cells failed to restore AHR and airway inflammation in sensitized and challenged recipient CD8−/− mice, or to enhance these responses in recipient wild-type (WT) mice. These effects of GSI were also associated with increased expression of the Notch ligand Delta1 in TEFF cells. Treatment of sensitized and challenged WT mice with Delta1-Fc resulted in decreased AHR and airway inflammation accompanied by higher levels of interferon γ in bronchoalveolar lavage fluid. These results demonstrate a role for Notch in skewing the T cell response from a T helper (Th)2 to a Th1 phenotype as a consequence of the inhibition of Notch receptor activation and the up-regulation of the Notch ligand Delta1. These data are the first to show a functional role for Notch in the challenge phase of CD8+ T cell–mediated development of AHR and airway inflammation, and identify Delta1 as an important regulator of allergic airway inflammation.
Oceanographic gradients and patterns in invertebrate assemblages on offshore oil platforms
Authors: Page Henry M. , Culver Carolynn S. , Dugan Jenifer E. , Mardian Brent
Published: April 2008

Page, H. M., Culver, C. S., Dugan, J. E., and Mardian, B. 2008. Oceanographic gradients and patterns in invertebrate assemblages on offshore oil platforms. – ICES Journal of Marine Science, 65: 851–861. We explored variability in the composition and cover of subtidal macroinvertebrate assemblages, and the recruitment and growth rates of selected invertebrate species, on seven offshore oil and gas platforms arrayed across a gradient in oceanographic conditions in the Santa Barbara Channel, CA, USA. The major macroinvertebrate taxa (sea anemones, mussels, barnacles, tubiculous amphipods, hydroids, and sponges) were common to all platforms. However, discriminant function analysis (DFA) revealed that the assemblages of two platforms (Gilda and Gail) clearly differed from the other platforms, a pattern attributable, in part, to the presence of conspicuous exotic species (the anemone, Diadumene sp., and encrusting bryozoan, Watersipora subtorquata) on these platforms. If these exotic species were excluded from the analysis, platforms in proximity to each other generally tended to have invertebrate assemblages more similar to each other than to platforms located farther away. Spatial variation in barnacle recruitment onto ceramic plates and mussel growth rate reflected prevailing oceanographic gradients. The existence of along-channel patterns in the composition of platform invertebrate assemblages, and in invertebrate recruitment and growth associated with oceanographic gradients, suggests that assemblages attached to platforms or other artificial structures may be useful barometers of short and perhaps longer term change in ocean climate.
Can economic and biological management objectives be achieved by the use of MSY-based reference points? A North Sea plaice (Pleuronectes platessa) and sole (Solea solea) case study
Authors: Pilling Graham M. , Kell Laurence T. , Hutton Trevor , Bromley Peter J. , Tidd Alex N. , Bolle Loes J.
Published: April 2008

Pilling, G. M., Kell, L. T., Hutton, T., Bromley, P. J., Tidd, A. N., and Bolle, L. J. 2008. Can economic and biological management objectives be achieved by the use of MSY-based reference points? A North Sea plaice (Pleuronectes platessa) and sole (Solea solea) case study. – ICES Journal of Marine Science, 65: 1069–1080. We examined the biological and economic impact of changing from management based on single-species limit reference points to one based on alternative targets, using the multispecies multifleet North Sea flatfish fishery. The robustness of reference points was tested against identified changes in plaice and sole biology. Current ICES single-species limit and precautionary biomass and fishing mortality reference points were seldom consistent with each other. Although they were generally robust to biological uncertainty, fishing at Fpa for sole could lead to stock collapse under one biological scenario. Adoption of alternative targets would reduce reliance on current reference points as stocks moved to a more sustainable state. Maximum sustainable yield (MSY), maximum economic yield (MEY), and maximum employment conditions implied different effort levels in the two fleets modelled, and different profits. Ftarget could be achieved with equal effort reductions in both fleets. Changes in stock biology affected the fishing effort required to maximize employment within the fishery, whereas MSY, Fmax, and MEY targets were robust to this uncertainty. Resulting profits and yields did vary widely, however. The selection of target reference points therefore requires stakeholders to define fishery objectives explicitly, against which targets can be evaluated for the resulting trade-offs between risk to stocks, yield, employment, and other social objectives.
Current techniques for single-cell lysis
Authors: Brown Robert B , Audet Julie
Published: April 2008

Owing to the small quantities of analytes and small volumes involved in single-cell analysis techniques, manipulation strategies must be chosen carefully. The lysis of single cells for downstream chemical analysis in capillaries and lab-on-a-chip devices can be achieved by optical, acoustic, mechanical, electrical or chemical means, each having their respective strengths and weaknesses. Selection of the most appropriate lysis method will depend on the particulars of the downstream cell lysate processing. Ultrafast lysis techniques such as the use of highly focused laser pulses or pulses of high voltage are suitable for applications requiring high temporal resolution. Other factors, such as whether the cells are adherent or in suspension and whether the proteins to be collected are desired to be native or denatured, will determine the suitability of detergent-based lysis methods. Therefore, careful selection of the proper lysis technique is essential for gathering accurate data from single cells.
Synchrony and entrainment properties of robust circadian oscillators
Authors: Bagheri Neda , Taylor Stephanie R , Meeker Kirsten , Petzold Linda R , Doyle Francis J
Published: April 2008

Systems theoretic tools (i.e. mathematical modelling, control, and feedback design) advance the understanding of robust performance in complex biological networks. We highlight phase entrainment as a key performance measure used to investigate dynamics of a single deterministic circadian oscillator for the purpose of generating insight into the behaviour of a population of (synchronized) oscillators. More specifically, the analysis of phase characteristics may facilitate the identification of appropriate coupling mechanisms for the ensemble of noisy (stochastic) circadian clocks. Phase also serves as a critical control objective to correct mismatch between the biological clock and its environment. Thus, we introduce methods of investigating synchrony and entrainment in both stochastic and deterministic frameworks, and as a property of a single oscillator or population of coupled oscillators.
How much of protein sequence space has been explored by life on Earth?
Authors: Dryden David T.F , Thomson Andrew R , White John H
Published: April 2008

We suggest that the vastness of protein sequence space is actually completely explorable during the populating of the Earth by life by considering upper and lower limits for the number of organisms, genome size, mutation rate and the number of functionally distinct classes of amino acids. We conclude that rather than life having explored only an infinitesimally small part of sequence space in the last 4 Gyr, it is instead quite plausible for all of functional protein sequence space to have been explored and that furthermore, at the molecular level, there is no role for contingency.
Quantitative approaches to the study of bistability in the
lac
operon of
Escherichia coli
Authors: Santillán Moisés , Mackey Michael C
Published: April 2008

In this paper, the history and importance of the
lac
operon in the development of molecular and systems biology are briefly reviewed. We start by presenting a description of the regulatory mechanisms in this operon, taking into account the most recent discoveries. Then we offer a survey of the history of the
lac
operon, including the discovery of its main elements and the subsequent influence on the development of molecular and systems biology. Next the bistable behaviour of the operon is discussed, both with respect to its discovery and its molecular origin. A review of the literature in which this bistable phenomenon has been studied from a mathematical modelling viewpoint is then given. We conclude with some brief remarks.
Event-driven feedback tracking and control of tapping-mode atomic force microscopy
Authors: Misra Sambit , Dankowicz Harry , Paul Mark R
Published: April 2008

This paper presents an event-driven, discrete-in-time feedback strategy for tracking and stabilizing naturally occurring periodic oscillations in the probe-tip dynamics of atomic force microscope (AFM) cantilevers in tapping-mode operation. Specifically, robust dynamic tracking and stabilization is achieved by the imposition of discrete changes in the vertical offset between the cantilever support and the sample surface based on an estimated linearization of the system dynamics about a dynamically generated reference trajectory. Here, use is made not only of the oscillation amplitude, as is typical in commercial control implementations for AFMs, but also of the instantaneous phase information. It is shown that stabilization and desirable performance during surface scanning is possible, even in the presence of uncertainty and limited state access. In particular, the methodology enables robust tracking and use of low-contact-velocity periodic system responses that are unstable in the absence of control.
Bounds on the mean power-weighted nearest neighbour distance
Authors: Liitiäinen Elia , Lendasse Amaury , Corona Francesco
Published: April 2008

In this paper, bounds on the mean power-weighted nearest neighbour distance are derived. Previous work concentrates mainly on the infinite sample limit, whereas our bounds hold for any sample size. The results are expected to be of importance, for example in statistical physics, non-parametric statistics and computational geometry, where they are related to the structure of matter as well as properties of statistical estimators and random graphs.
The bandcount increment scenario. II. Interior structures
Authors: Avrutin Viktor , Eckstein Bernd , Schanz Michael
Published: April 2008

Bifurcation structures in the two-dimensional parameter spaces formed by chaotic attractors alone are still far away from being understood completely. In a series of three papers, we investigate the chaotic domain without periodic inclusions for a map, which is considered by many authors as some kind of one-dimensional canonical form for discontinuous maps. In this second part, we investigate fine substructures nested into the basic structures reported and explained in part I. It is demonstrated that the overall structure of the chaotic domain is caused by a complex interaction of bandcount increment, bandcount adding and bandcount doubling structures, whereby some of them are nested into each other ad infinitum leading to self-similar structures in the parameter space.
Oscillations in self-aware networks
Authors: Gellman Michael
Published: April 2008

Adaptive routing is once again of interest owing to the possibility to couple online probing in networks with real-time dynamic and distributed control of paths and flows. Wireless networks, with their rapidly changing network conditions also create a need to revisit this issue. This paper uses measurements in a wired adaptive network test bed, the cognitive packet network (CPN), to investigate the pros and cons of adaptive routing. CPN routes packet flows through a store and forward network according to their quality of service (QoS) needs through an online distributed reinforcement learning mechanism. This paper investigates routing oscillations that occur due to the interaction of multiple flows and studies their effect on QoS in the context of CPN. Our results indicate that routing oscillations can be easily controlled by randomizing the route switching, and that from an overall QoS viewpoint increased switching can also lead to improved performance.
Decomposition of functions into pairs of intrinsic mode functions
Authors: Vatchev Vesselin , Sharpley Robert
Published: April 2008

The intrinsic mode functions (IMFs) arise as basic modes from the application of the empirical mode decomposition (EMD) to functions or signals. In this procedure, instantaneous frequencies are subsequently extracted from the IMFs by the simple application of the Hilbert transform, thereby providing a multiscale analysis of the signal's nonlinear phases. The beauty of this redundant representation method is in its simplicity and extraordinary effectiveness in many important and diverse settings. A fundamental issue in the field is to better understand these demonstrated qualities of the EMD procedures and the elementary modes they produce. For example, it is easily observed that when an EMD procedure is applied to the sum of two arbitrary IMFs, the original modes are rarely reproduced in the generated collection of IMFs. An interesting question from a representation point of view may be stated as follows: for any given sufficiently smooth function and fixed
n
≥2, when is it possible to represent the function as a sum of (at most)
n
intrinsic modes? A more interesting question is whether such a decomposition is possible when the extracted modes are constructed from a common formulation of the intrinsic properties of the function being analysed.

We provide an answer to these questions for a relaxed version of IMFs, called
weak IMFs
, which has been shown to be characterized in terms of eigenfunctions of Sturm–Liouville operators. The objective of this study is to further extend that analogy to the relationship between sums of weak IMFs and coupled Sturm–Liouville
systems
. The construction of this decomposition also provides a guide to an alternate characterization of the instantaneous frequency and bandwidth.
Implications from the ratio of surface tension to bulk modulus and nearest neighbour distance, for planar surfaces
Authors: Weir Graham
Published: April 2008

The theory of impact between nano-sized particles leads to the important non-dimensional grouping
γ
/
aB
, where
γ
,
a
and
B
are the effective surface energy, effective near neighbour distance, and effective bulk modulus for the impacting surfaces. A general, though formal, expression for
γ
/
aB
is obtained for a planar surface, and a modified Lennard-Jones analysis suggests that this grouping is of the order of several per cent. Bounds are suggested on this ratio, which are verified for many of the elements about their melting points, for several liquids at 298 K, and for the liquified noble gases. It is suggested that, at the atomic scale, the ratio between yield stress and the bulk modulus is also approximately equal to this grouping, which would make impacts between nano-scaled surfaces very much harder than for macroscopic impacts. However,
γ
/
aB
is material dependent and can vary by a factor of two or more about its median value. Subject to such variation, it is suggested that, to leading order, collisions between pure nanoscale particles depend primarily on the number of atoms in the clusters, and on a non-dimensional velocity scale, for low-velocity impacts. The expression for
γ
/
aB
is evaluated approximately in planar geometry by assuming that interactions between surface atoms (or molecules) only involve radial pair surface interactions.
Optimal tracking control of nonlinear dynamical systems
Authors: Udwadia Firdaus E
Published: April 2008

This paper presents a simple methodology for obtaining the entire set of continuous controllers that cause a nonlinear dynamical system to exactly track a given trajectory. The trajectory is provided as a set of algebraic and/or differential equations that may or may not be explicitly dependent on time. Closed-form results are also provided for the real-time optimal control of such systems when the control cost to be minimized is any given weighted norm of the control, and the minimization is done not just of the integral of this norm over a span of time but also at each instant of time. The method provided is inspired by results from analytical dynamics and the close connection between nonlinear control and analytical dynamics is explored. The paper progressively moves from mechanical systems that are described by the second-order differential equations of Newton and/or Lagrange to the first-order equations of Poincaré, and then on to general first-order nonlinear dynamical systems. A numerical example illustrates the methodology.
Harmonic cosmology: how much can we know about a universe before the big bang?
Authors: Bojowald Martin
Published: April 2008

Quantum gravity may remove classical space–time singularities and thus reveal what a universe at the big bang could be like. In loop quantum cosmology, an exactly solvable model is available, which allows one to address precise dynamical coherent states and their evolution in such a setting. It is shown here that quantum fluctuations before the big bang are generically unrelated to those after the big bang. While this is derived only in the solvable model, it presents the case of the strongest control on coherence properties; adding ingredients to a realistic model could only increase the complexity. A reliable determination of pre-big bang quantum fluctuations of geometry would thus require exceedingly precise observations.
Localized waves along a line of masses on a plate: propagation and sub-exponential attenuation
Authors: Chakraborty Ishita , Mohanty Atanu K , Chatterjee Anindya
Published: April 2008

We have studied waves propagating in an infinite plate with a line of equally spaced point masses on it. In particular, we consider waves that are laterally decaying, i.e. waves that exist due to the point masses, not in spite of them. We begin with a simple continuum limit and then study the discrete case using a suitable Green function and a superposition method used earlier for other structures by Mead. The superposition involves a slowly decaying series that we transform to a rapidly converging one using the Poisson summation formula. The system has two non-dimensional parameters, and on this parameter plane we find a propagation zone and its boundary. The boundary involves successive point masses vibrating
π
radians out of phase, a situation far from the continuum limit. Outside the propagation zone, waves get attenuated; however, unlike common examples of linear periodic structures, and contrary to the usual assumption made in studies thereof, here the waves show
sub-exponential
attenuation. In particular, the eventual decay of the wave amplitude is like the 3/2 power of distance from the point of excitation. We conclude with a theoretical explanation of the 3/2 power in the decay.
Progressive island colonization and ancient origin of Hawaiian
Metrosideros
(Myrtaceae)
Authors: Percy Diana M , Garver Adam M , Wagner Warren L , James Helen F , Cunningham Clifford W , Miller Scott E , Fleischer Robert C
Published: April 2008

Knowledge of the evolutionary history of plants that are ecologically dominant in modern ecosystems is critical to understanding the historical development of those ecosystems.
Metrosideros
is a plant genus found in many ecological and altitudinal zones throughout the Pacific. In the Hawaiian Islands,
Metrosideros polymorpha
is an ecologically dominant species and is also highly polymorphic in both growth form and ecology. Using 10 non-coding chloroplast regions, we investigated haplotype diversity in the five currently recognized Hawaiian
Metrosideros
species and an established out-group,
Metrosideros collina
, from French Polynesia. Multiple haplotype groups were found, but these did not match morphological delimitations. Alternative morphologies sharing the same haplotype, as well as similar morphologies occurring within several distinct island clades, could be the result of developmental plasticity, parallel evolution or chloroplast capture. The geographical structure of the data is consistent with a pattern of age progressive island colonizations and suggests
de novo
intra-island diversification. If single colonization events resulted in a similar array of morphologies on each island, this would represent parallel radiations within a single, highly polymorphic species. However, we were unable to resolve whether the pattern is instead explained by ancient introgression and incomplete lineage sorting resulting in repeated chloroplast capture. Using several calibration methods, we estimate the colonization of the Hawaiian Islands to be potentially as old as 3.9 (−6.3) Myr with an ancestral position for Kaua'i in the colonization and evolution of
Metrosideros
in the Hawaiian Islands. This would represent a more ancient arrival of
Metrosideros
to this region than previous studies have suggested.
Perceptual uncertainty and line-call challenges in professional tennis
Authors: Mather George
Published: April 2008

Fast-moving sports such as tennis require both players and match officials to make rapid accurate perceptual decisions about dynamic events in the visual world. Disagreements arise regularly, leading to disputes about decisions such as line calls. A number of factors must contribute to these disputes, including lapses in concentration, bias and gamesmanship. Fundamental uncertainty or variability in the sensory information supporting decisions must also play a role. Modern technological innovations now provide detailed and accurate physical information that can be compared against the decisions of players and officials. The present paper uses this psychophysical data to assess the significance of perceptual limitations as a contributor to real-world decisions in professional tennis. A detailed analysis is presented of a large body of data on line-call challenges in professional tennis tournaments over the last 2 years. Results reveal that the vast majority of challenges can be explained in a direct highly predictable manner by a simple model of uncertainty in perceptual information processing. Both players and line judges are remarkably accurate at judging ball bounce position, with a positional uncertainty of less than 40 mm. Line judges are more reliable than players. Judgements are more difficult for balls bouncing near base and service lines than those bouncing near side and centre lines. There is no evidence for significant errors in localization due to image motion.
Progress in the pathogenesis and genetics of Parkinson's disease
Authors: Mizuno Yoshikuni , Hattori Nobutaka , Kubo Shin-ichiro , Sato Shigeto , Nishioka Kenya , Hatano Taku , Tomiyama Hiroyuki , Funayama Manabu , Machida Yutaka , Mochizuki Hideki
Published: April 2008

Recent progresses in the pathogenesis of sporadic Parkinson's disease (PD) and genetics of familial PD are reviewed. There are common molecular events between sporadic and familial PD, particularly between sporadic PD and
PARK1
-linked PD due to
α
-
synuclein
(
SNCA
) mutations. In sporadic form, interaction of genetic predisposition and environmental factors is probably a primary event inducing mitochondrial dysfunction and oxidative damage resulting in oligomer and aggregate formations of α-synuclein. In
PARK1
-linked PD, mutant α-synuclein proteins initiate the disease process as they have increased tendency for self-aggregation. As highly phosphorylated aggregated proteins are deposited in nigral neurons in PD, dysfunctions of proteolytic systems, i.e. the ubiquitin–proteasome system and autophagy–lysosomal pathway, seem to be contributing to the final neurodegenerative process. Studies on the molecular mechanisms of nigral neuronal death in familial forms of PD will contribute further on the understanding of the pathogenesis of sporadic PD.
Detection and characterization of silencers and enhancer-blockers in the greater CFTR locus
Authors: Petrykowska Hanna M. , Vockley Christopher M. , Elnitski Laura
Published: April 2008

Silencers and enhancer-blockers (EBs) are cis-acting, negative regulatory elements (NREs) that control interactions between promoters and enhancers. Although relatively uncharacterized in terms of biological mechanisms, these elements are likely to be abundant in the genome. We developed an experimental strategy to identify silencers and EBs using transient transfection assays. A known insulator and EB from the chicken beta-globin locus, cHS4, served as a control element for these assays. We examined 47 sequences from a 1.8-Mb region of human chromosome 7 for silencer and EB activities. The majority of functional elements displayed directional and promoter-specific activities. A limited number of sequences acted in a dual manner, as both silencers and EBs. We examined genomic data, epigenetic modifications, and sequence motifs within these regions. Strong silencer elements contained a novel CT-rich motif, often in multiple copies. Deletion of the motif from three regions caused a measurable loss of silencing ability in these sequences. Moreover, five duplicate occurrences of this motif were identified in the cHS4 insulator. These motifs provided an explanation for an uncharacterized silencing activity we measured in the insulator element. Overall, we identified 15 novel NREs, which contribute new insights into the prevalence and composition of sequences that negatively regulate gene expression.
Role of L-type Ca2+channel isoforms in the extinction of conditioned fear
Authors: Busquet Perrine , Hetzenauer Alfred , Sinnegger-Brauns Martina J. , Striessnig Jörg , Singewald Nicolas
Published: April 2008

Dihydropyridine (DHP) L-type Ca2+channel (LTCC) antagonists, such as nifedipine, have been reported to impair the extinction of conditioned fear without interfering with its acquisition. Identification of the LTCC isoforms mediating this DHP effect is an essential basis to reveal their role as potential drug targets for the treatment of specific anxiety disorders. CaV1.2 and CaV1.3 are the predominant LTCCs in the mammalian brain. However, since no isoform-selective DHP blockers are available, their individual contribution to fear memory extinction is unknown. We used a novel mouse model expressing DHP-insensitive CaV1.2 LTCCs (CaV1.2DHP−/−mice) to address this question. In line with previous studies, wild-type (WT) mice treated with systemic nifedipine displayed markedly impaired fear extinction. This DHP effect was completely abolished in CaV1.2DHP−/−mice, indicating that it is mediated by CaV1.2, but not by CaV1.3 LTCCs. Supporting this conclusion, CaV1.3-deficient mice (CaV1.3−/−) showed extinction identical to the respective WT mice. The inhibition of fear extinction was not observed after intracerebroventricular (i.c.v.) application of different doses of nifedipine, suggesting that this effect is secondary to inhibition of peripheral CaV1.2 channels. The LTCC activator BayK, which lacks neurotoxic effects in CaV1.2DHP−/−mice, did not influence the extinction time course. In summary, we demonstrate that LTCC signaling through the CaV1.2 isoform of LTCCs interferes with fear memory extinction, presumably via a peripherally mediated mechanism. Activation of other LTCC isoforms (predominantly CaV1.3) is not sufficient to accelerate extinction of conditioned fear in mice.
Enhanced distribution of NK012, a polymeric micelle‐encapsulated SN‐38, and sustained release of SN‐38 within tumors can beat a hypovascular tumor
Authors: Saito Yohei , Yasunaga Masahiro , Kuroda Junichiro , Koga Yoshikatsu , Matsumura Yasuhiro
Published: April 2008

Human pancreatic cancer is generally hypovascular in nature and rich in interstitium. These pathological barriers may contribute to the intractable nature of pancreatic cancer by binding the penetration of anticancer agents throughout the tumor tissue. The aim of the present study was to determine whether NK012 is an appropriate formulation for the treatment of hypovascular tumors. Among pancreatic tumor xenografts, PSN1 appeared to have the richest tumor vasculature and the least number of stromal cells and matrix. In contrast, Capan1 had the poorest tumor vasculature and most abundant stromal tissue. Fluorescence microscopy and high‐performance liquid chromatography analysis demonstrated that although NK012 accumulated and continued to be distributed for more than 48 h throughout the entire body of both tumors, CPT‐11 disappeared almost entirely from both tumors within 6 h. In addition, efficient sustained release of SN‐38 was maintained for more than 96 h in both tumors following administration of NK012. Following the administration of CPT‐11, SN‐38 was no longer detectable after 24 h in the Capan1 tumor or after 48 h in the PSN1 tumor. All tumors were eradicated in the mice treated with NK012 but not in those treated with CPT‐11. Because the antitumor activity of SN‐38 is time dependent, NK012, which combines enhanced distribution with sustained release of SN‐38 within tumors, may be ideal for the treatment of hypovascular tumors, such as pancreatic cancer. (Cancer Sci 2008; 99: 1258–1264)
Enhanced radiation response of a solid tumor with the artificial oxygen carrier ‘albumin‐heme’
Authors: Horinouchi Hirohisa , Yamamoto Hisashi , Komatsu Teruyuki , Huang Yubin , Tsuchida Eishun , Kobayashi Koichi
Published: April 2008

Tumor‐cell hypoxia is one of the main factors inducing radioresistance. Enhanced tumor oxygenation has previously been achieved in an animal model using the synthetic heme‐based oxygen carrier ‘albumin‐heme’ (recombinant human serum albumin‐Fe cyclohexanoil heme; rHSA‐FeP). The present study was done to determine whether rHSA‐FeP enhances the radiation response in an experimental tumor model. Male Donryu rats and LY80, a variant of the syngenic liver ascites tumor, were used. A total of 1 × 106 cells were injected into the subfascial tissue of the right thigh. The rats were divided randomly into five groups: sham (tumor implantation and sham operation); rHSA‐FeP; irradiation; rHSA + irradiation; and rHSA‐FeP + irradiation. Six days after, under general anesthesia, intra‐arterial administration of 10 mL/kg of either 5% rHSA solution or oxygenated rHSA‐FeP solution at 2.5 mL/min was done and a dose of 20 Gy was given. There were significant differences in tumor growth between the sham and irradiation groups, and between the sham and rHSA‐FeP + irradiation groups. Tumor growth delay was observed and differences were significant between the sham and irradiation groups, and between the irradiation and rHSA‐FeP + irradiation groups. In the present study, rHSA‐FeP itself had a slight effect on tumor growth without irradiation. Enhancing the effect of rHSA‐FeP on the radiation response is responsible in part for the oxygen‐carrying property of rHSA‐FeP. In conclusion, rHSA‐FeP is a candidate radiation‐enhancing drug. Arterial infusion of rHSA‐FeP may serve as a local oxygenation method that enhances the radiation effect. (Cancer Sci 2008; 99: 1274–1278)
Age‐related Epstein–Barr virus‐associated B‐cell lymphoproliferative disorders: Special references to lymphomas surrounding this newly recognized clinicopathologic disease
Authors: Shimoyama Yoshie , Yamamoto Kazuhito , Asano Naoko , Oyama Takashi , Kinoshita Tomohiro , Nakamura Shigeo
Published: April 2008

Epstein–Barr virus (EBV) is associated with some disease entities of malignant lymphomas, including Burkitt lymphoma, Hodgkin lymphoma, immunodeficiency‐associated lymphoproliferative disorders (LPD), and a part of diffuse large B‐cell lymphoma. We have recently identified a series of elderly patients with EBV‐associated (or EBV+) B‐cell LPD (B‐LPD) showing similarities in many respects to immunodeficiency‐associated LPD, although no evidence of underlying immunodeficiency was found. Therefore, the nosological category of senile or age‐related EBV+ B‐LPD has been proposed for those patients. A larger series of patients with this disease revealed that the relative ratios of such EBV+ B‐LPD to all diffuse large B‐cell lymphoma cases were higher with increasing with age, reaching a peak (20–30%) at ≥90 years of age, with a median of 71 years, providing additional evidence for our assertion that this disease may be related to immunological deterioration as a result of the aging process. This new disease entity is characterized pathologically by centroblasts, immunoblasts, and Hodgkin and Reed–Sternberg‐like giant cells with a varying degree of reactive components, often posing therapeutic and diagnostic problems for hematologists and pathologists, respectively. The aim of the present review is to briefly summarize the overall clinicopathological profile of this newly recognized age‐related (also called ‘senile’) EBV+ B‐LPD and EBV+ Hodgkin lymphoma for a practical diagnostic approach. (Cancer Sci 2008; 99: 1085–1091)
Application de pesticides à bas et ultra‐bas volume en Yougoslavie
Authors: Topalovic G.
Published: April 2008

Summaire

Les considérations d'ordre économique sont la principale raison qui a orienté l'Aviation agricole de la JAT à introduire dans la pratique l'application de pesticides à bas et ultra‐bas volume en équipant les avions d'appareils rotatifs « micronair » et « turbair». Cette technique a été mise au point au cours des deux dernières années et dès maintenant elle va être mise en pratique en agriculture, en sylviculture et pour la protection de la santé publique.

L'application d'insecticides à ultra‐bas volume (ULV) sera faite surtout pour protéger la betterave à sucre contre les noctuelles (Noctuidae), Bothynoderes punctiventris Germ., et les pucerons (Aphididae), pour combattre Eurygaster spp., Lema spp., ainsi qu'un certain nombre de ravageurs des plantes forestières, notamment Lymantria dispar L., enfin pour lutter contre les moustiques. L'application de fongicides à bas volume (LV) est pour l'instant limitée essentiellement au traitement de la vigne contre le mildiou et de la betterave à sucre contre Cercospora, et aux besoins de l'arboriculture.
Réflexions sur la notion de pulvérlsation à dosage ultra‐bas
Authors: Bals E.J.
Published: April 2008

Summaire

L'application de traitements à dosage et à volume ultra‐bas en goutte‐lettes fines, uniformes et non volatiles s'est développée lorsque des expériences pratiques ont indiqué que leur efficacité se fondait sur une redistribution de la matière active à la surface des tissus végétaux non atteints à l'origine. Le choix s'est porté sur des gouttelettes de 70 microns, émises de préférence à partir d'appareils rotatifs. Des volumes de 1 à 8 1/ha semblent suffisants contre les cryptogames et les insectes stationnaires et 0.1 à 1 1/ha contre les insectes mobiles, mais il y a lieu de réduire encore le dosage en l'adaptant aux strictes nécessités.

Les risques de dérive des produits non volatils paraissent moindres que ceux des pulvérisations à base d'eau. Une étude suivie des formulations pourrait réduire les dangers de contamination mais la notion de traitements à dosage ultra‐bas mérite de retenir l'attention.
Recent Improvements in Pneumatic Aerial Spraying
Authors: Audibert M.
Published: April 2008

In experimental treatments of vineyards against downy mildew, a Pintagram pneumatic sprayer on a Bell G helicopter using 10–15 lit./ha. was compared with pressure spraying with ground equipment (200 lit./ha.) or from a helicopter (50 lit./ha.). The efficacy of the Pintagram was slightly less than that of the ground sprayer but was comparable to the conventionally equipped helicopter and allowed the profitability of treatments to be raised by some 30%.
Review of ULV‐Formulations for Drift Spraying
Authors: Holtmann H.
Published: April 2008

ULV‐formulations of lindane, BHC, dimethoate, bromophos, bromophosethyl and combinations have been developed. Results of field tests on a number of pest problems are summarized. Preliminary experiments on brushkilling by 2, 4, 5‐T ULV application are reported.
Note sur la lutte contre Dacus oleae (Gmel.) au moyen de pulvérisations d'appâts à bas et ultra‐bas volume
Authors: Orphanidis P.S. , Mourikis P.A. , Souliotis M.C.
Published: April 2008

Summaire

L'étude des données de trois années de recherches expérimentales (1967, 1968, 1969) sur la lutte préventive aérienne contre Dacus au moyen de pulvérisations d'appâts à ultra‐bas volume et de pulvérisations habituelles à bas volume permet de comparer l'efficacité des deux méthodes. L'évaluation effectuée au moyen de méthodes directes et indirectes (répartition des gouttelettes, attaque subie par le fruit de l'olivier, pièges, abattages sur collecteurs) fait ressortir qu'il n'y a pas de différence d'efficacité statistiquement significative entre les deux modes de traitement. Il est estimé opportun de poursuivre des résultats expérimentaux dans des conditions de forte attaque.
Some Opportunities for Pest Prevention by Ultra‐low Volume Spraying
Authors: Joyce R.J.V.
Published: April 2008

The needs of the modern system of integrated control, or pest management, are contrasted with those of the prevailing view that pest control is an individual responsibility. It is argued that a rational approach to pest management must be based on a knowledge of the scale on which it must be exercised. In the case of mobile insects the scale normally far exceeds the ecologically artificial boundaries represented by fields or private holdings. The argument is illustrated by the desert locust where numbers are reckoned in millions of millions and mobility in terms of hundreds and thousands of km., calling for international action, and the Tsetse fly where numbers are reckoned in less than 10 per ha. and mobility in terms of km. Experience in the control of paddy pests in Java is drawn on to show the contribution of synoptic survey to delimit the scale and time for appropriate action, followed by synchronous application of pesticides in achieving, through control of pests, yield increases in excess of what could be expected from small scale plot trials. The value of spraying at ultra‐low volume rates is that it provides the means of achieving more or less synchronous application of pesticides on the scale demanded by the problem.
Emploi de formules à base de Cidial et de Rogor dans le traitement à ultra‐bas volume par hélicoptère
Authors: Pinamonti F. , Vavassori A.
Published: April 2008

Summaire

Lorsque les différents problèmes techniques inhérents aux applications ULV par hélicoptères furent résolus, il a été possible d'introduire les traitements insecticides sur le plan pratique. Le Rogor L 30 (diméthoate) s'est révélé efficace contre Dacus oleae Gmel. et le Cidial 50 L (phenthoate) contre les moustiques. Les résultats obtenus à l'aide du Cidial contre Thaumetopoea pityocampa Schiff. sont considérés et les investigations portent également sur les possibilités d'appliquer les fongicides en ULV sur la vigne, les peupliers, le tabac et les betteraves.
The Use of Cidial and Rogor Formulations in Ultra‐low Volume Treatments from Helicopters
Authors: Pinamonti F. , Vavassori A.
Published: April 2008

When various technical problems connected with ULV spraying from helicopters had been solved the practical application of insecticides was started. Rogor L 30 (dimethoate) was successfully used against Dacus oleae Gmel. and Cidial 50 L (phenthoate) against mosquitoes. The results of the use of Cidial against Thaumetopoea pityocampa Schiff. are being analysed, and the possibilities of applying fungicides at ULV rates in vineyards and on poplars, tobacco and beet crops are being investigated.
Problems in the Formulation of Pesticides for ULV Application
Authors: Hope J.N.
Published: April 2008

The various factors affecting the production of satisfactory ULV formulations of common pesticides are discussed. Both the selection of carrier oils and the incorporation of active ingredients are examined and field workers are warned against possible misfortunes as the result of « on the spot » formulations. The importance of using machines capable of emitting the carefully controlled droplets necessary for satisfactory ULV spraying is stressed.
Problèmes relatifs à la formulation des pesticides pour les pulvérisations à ultra‐bas volume
Authors: Hope J.N.
Published: April 2008

Summaire

Après une étude des différents facteurs qui influent sur la mise au point de bonnes formulations ULV de pesticides, l'auteur souligne l'importance du choix judicieux des supports huileux et de l'incorporation des matières actives, et met en garde contre les aléas des formulations « sur place ». L'emploi de pulvérisateurs capables de produire des gouttelettes de dimension bien définie s'impose également.
Report on Olive Fly Control with Ultra‐low Volume Concentrate Bait Air Sprays
Authors: Psyllakis N. , Mikros L. , Androulakis J. , Loupasaki M.
Published: April 2008

In the 1968 olive fly control season the effectiveness of an ultra‐low volume concentrate bait consisting of 87% protein hydrolysate and 13% insecticide Malathion ULV 96% and of a standard type bait, consisting of 12% protein hydrolysate Atropaz, 1,57% malathion 57% (0.9% active ingredient) and 86.43% water, applied by air against the Dacus fly were compared. Both baits resulted in very good olive fly control and the olive fruit at the end of the season was completely free of any infestation. No differences in the effectiveness of the two baits tried could be established, however.
Evolution des techniques d'application antiparasitaire fongicide au cours de la décennie écoulée
Authors: Audibert M.
Published: April 2008

Summaire

L'auteur souligne, dans un premier temps, l'évolution des traitements antiparasitaires vers les techniques d'épandage à bas volume. Après avoir précisé l'intérêt de ces dernières, il retrace l'historique des matériels qui ont été successivement mis au point puis énonce les diverses cultures auxquelles ils s'appliquent en mentionnant les expérimentations effectuées depuis dix ans.
Technical Developments in Fungicide Applications in the Last Decade
Authors: Audibert M.
Published: April 2008

A description is given of the development of low volume applications, as well as of the spraying equipment which enabled its success to be achieved. Examples of the crops treated are cited.
Lutte chimique à bas et très bas volume effectuée par voie aérienne contre les principaux parasites des agrumes et de l'olivier en Tunisie et en Libye
Authors: Stancic J. , Yana A.
Published: April 2008

Summaire

Depuis quelques années, les services de la protection des végétaux et les organismes de recherche des pays de l'Afrique du Nord se penchent sur le problème de la technique de lutte chimique à appliquer dans les conditions climatiques et culturales spécifiques de cette zone. Les premiers essais de traitements aériens à bas et très bas volume contre Ceratitis capitata Wied. sur agrumes ont été entrepris en Tunisie en 1967. Ces essais ont été beaucoup intensifiés en 1968 et étendus également en Libye à la lutte contre Dacus oleae Gmel. sur l'olivier. Cette nouvelle technique a donné des résultats très encourageants. Les produits insecticides, qui ont été testés à bas et à très bas volume, sont le Malathion LV (96% m.a.) contre C. capitata et le Malarhion LV, le phosphamidon (50 et 100% m.a.) et le dicrotophos (100% m.a.) contre D. oleae. Le rapport insecticide/attractif a étéégalement étudié.
Aerial Application of Chemicals at Low and Ultra‐low Volume Against Main Pests of Citrus and Olive Trees in Tunisia and Libya
Authors: Stancic J. , Yana A.
Published: April 2008

Encouraging results were obtained in low and ultra‐low volume aerial applications against Ceratitis capitata Wied. in Tunisia (Malathion LV 96%) and against this pest and against Dacus oleae Gmel. in Libya (with Malathion LV, phosphamidon 50 and 100% a.i. and dicrotophos 100%). The mixture rates of insecticide and bait were also considered.
La cicadelle verte (Empoasca flavescens F.), cause d'importants rougissements du feuillage de la vigne
Authors: Baggiolini M. , Canevascini V. , Caccia R.
Published: April 2008

Summaire

L'étude de la symptomatologie des dégâts imputables àEmpoasca flavescens F. a conduit à une concordance de vues entre chercheurs italiens, français et suisses. Grandes sont les possibilités de confusion avec les altérations chromatiques des feuilles de vigne dues à d'autres causes comme les viroses, les acariens, les carences alimentaires, etc., et l'interprétation erronée des symptômes peut avoir des conséquences fâcheuses. C'est la raison pour laquelle il a paru utile de préciser les différentes natures des dégâts.
Pesticides and Wildlife: Retrospect and Prospect
Authors: Moriarty F.
Published: April 2008

The effects are described of organochlorine insecticides on two indigenous British species of wildlife: the peregrine falcon (Falco peregrinus Tunstall) and the small tortoiseshell butterfly (Aglais urticae [L.]). Four conclusions are drawn about the effects of pesticides on wildlife, which are then used to consider the possible risks from organophosphorus insecticides.