bluuebunny/crossref_metadata_2025 huggingface dataset:
The Contingency of Corporatist Influence: Incomes Policy in the Netherlands
Authors: WOLDENDORP JAAP , KEMAN HANS
Published: October 2006

This paper examines the hypothesis that corporatist intermediation by party governments facilitates incomes policy formation and is effective in reaching agreements between employers and trade unions as well. A social democratic party in government would positively enhance this process. Investigating this for the Netherlands between 1965–2000, two puzzles emerge. The first puzzle is that coalition governments of Social and Christian Democracy fall short of expectations despite their commitment to corporatism. The second puzzle is that the relationship between Social Democracy and effective corporatist intermediation is positive but cannot sufficiently account for the variation in agreements on Dutch incomes policy. That variation can be better understood as induced by institutional change, economic development and external vulnerabilities. The Dutch case study shows that the performance of a social democratic party in government in a corporatist context is less directly effective than the literature often has suggested.
A Comparison of Two Versions of the Cognitive Therapy Scale
Authors: Gordon P. Kenneth
Published: November 2006

The Cognitive Therapy Scale is a well-established tool for assessing skills in delivering cognitive therapy, but has been subject to criticism. It has recently been updated by two groups, producing the Revised version or CTS-R (Blackburn, James, Milne and Reichelt, 2000) and a version designed for therapy of psychosis, the CTS-Psy (Haddock et al., 2001). The present study made a direct comparison of these scales to evaluate their inter-rater reliability, the extent to which they measure the same therapist qualities, and their utility for assessment of skills in trainee therapists working with different client-types. Twenty-six trainees submitted tapes of therapy with clients suffering either personality disorder or psychosis. Each tape was rated by two independent assessors on each of the two scales. Results suggest the scales are both fairly easy to use and produce highly similar estimates of student competence. Client diagnosis has no significant influence on the scores obtained by the therapist. However, inter-rater reliability is relatively low. It is concluded that safeguards are needed where these scales are used as a training outcome measure.
Gallium Phase Formation in Cu During 30kV Ga+ FIB Milling
Authors: Michael JR
Published: October 2006

Extended abstract of a paper presented at Microscopy and Microanalysis 2006 in Chicago, Illinois, USA, July 30 – August 3, 2006
Automating the Collection of Ultrathin Serial Sections for Large Volume TEM Reconstructions
Authors: Hayworth KJ , Kasthuri N , Schalek R , Lichtman JW
Published: October 2006

Extended abstract of a paper presented at Microscopy and Microanalysis 2006 in Chicago, Illinois, USA, July 30 – August 3, 2005
Al and Mg Kα Shifts in Common Silicate and Oxide Minerals: Relevance to Achieving the Goal of 1% Accuracy in EPMA
Authors: Fournelle J
Published: October 2006

Extended abstract of a paper presented at Microscopy and Microanalysis 2006 in Chicago, Illinois, USA, July 30 – August 3, 2006
Scanning Electron Microscopy Methods for Analysis of Polymer Nanocomposites
Authors: Dikin D , Kohlhaas K , Dommett G , Stankovich S , Ruoff R
Published: October 2006

Extended abstract of a paper presented at Microscopy and Microanalysis 2006 in Chicago, Illinois, USA, July 30 – August 3, 2005
Equilibrium constant of the HO2‐H2O complex formation and kinetics of HO2 + HO2‐H2O: Implications for tropospheric chemistry
Authors: Kanno Nozomu , Tonokura Kenichi , Koshi Mitsuo
Published: October 2006

Complex formation between HO2 and H2O and kinetics of the HO2‐H2O complex were investigated using near‐infrared two‐tone frequency modulation spectroscopy at 250–350 K and 50 torr with N2 diluent. From the depletion of the HO2 signal in the presence of water, the equilibrium constant of the HO2‐H2O complex formation was estimated. The stabilized energy of the HO2‐H2O complex formation was estimated to be 31 ± 4 kJ mol−1, and it was suggested that the complex has two hydrogen bonds. Using the equilibrium constant obtained from spectral measurements, the rate constant of the reaction HO2 + HO2‐H2O was estimated at 297–350 K and 50 torr with N2 diluent. Weak dependence of the rate constant on temperature indicated that the temperature dependence of water effects on HO2 self‐reaction kinetics was mainly controlled by that of the equilibrium constant of the HO2‐H2O complex formation. Altitude profiles of HO2‐H2O complexes and HO2 self‐reaction rate were also estimated in the northwest Pacific Ocean. The importance of HO2‐H2O complexes in the lower troposphere was suggested.
Valley formation and methane precipitation rates on Titan
Authors: Perron J. Taylor , Lamb Michael P. , Koven Charles D. , Fung Inez Y. , Yager Elowyn , Ádámkovics Máté
Published: November 2006

Branching valley networks near the landing site of the Huygens probe on Titan imply that fluid has eroded the surface. The fluid was most likely methane, which forms several percent of Titan's atmosphere and can exist as a liquid at the surface. The morphology of the valley networks and the nature of Titan's surface environment are inconsistent with a primary valley formation process involving thermal, chemical, or seepage erosion. The valleys were more likely eroded mechanically by surface runoff associated with methane precipitation. If mechanical erosion did occur, the flows must first have been able to mobilize any sediment accumulated in the valleys. We develop a model that links precipitation, open‐channel flow, and sediment transport to calculate the minimum precipitation rate required to mobilize sediment and initiate erosion. Using data from two monitored watersheds in the Alps, we show that the model is able to predict precipitation rates in small drainage basins on Earth. The calculated precipitation rate is most sensitive to the sediment grain size. For a grain diameter of 1–10 cm, a range that brackets the median size observed at the Huygens landing site, the minimum precipitation rate required to mobilize sediment in the nearby branching networks is 0.5–15 mm hr−1. We show that this range is reasonable given the abundance of methane in Titan's atmosphere. These minimum precipitation rates can be compared with observations of tropospheric cloud activity and estimates of long‐term methane precipitation rates to further test the hypothesis that runoff eroded the valleys.
Alkenone temperature anomalies in the Brazil‐Malvinas Confluence area caused by lateral advection of suspended particulate material
Authors: Rühlemann Carsten , Butzin Martin
Published: October 2006

Alkenone temperatures derived from suspended particulate organic material which was collected in austral summer 2001 from surface waters (5 m) south of the Brazil‐Malvinas Confluence deviate from measured temperatures by −4° to −7°C when UK′37 ratios are converted to temperature using the Müller et al. (1998) calibration and up to −3°C when using the calibration of Conte et al. (2006). In contrast, alkenone temperatures determined from particulate material sampled north of the confluence reveal close correspondence to in situ temperatures or show slightly higher values. We suggest that the southern samples are biased by suspended organic detritus originating from the cold subpolar waters of the northward flowing Malvinas Current, whereas the northern samples carry an UK′37 signal of tropical/subtropical origin, transported southward with the Brazil Current. On the basis of surface ocean transport pathways and velocities simulated with the large‐scale geostrophic (LSG) ocean general circulation model, we identify areas of the world ocean where alkenone temperatures are potentially biased to higher or lower values due to long particle residence times and lateral advection by surface currents.
Comparison of in situ bottom pressure data with GRACE gravimetry in the Crozet‐Kerguelen region
Authors: Rietbroek R. , LeGrand P. , Wouters B. , Lemoine J.‐M. , Ramillien G. , Hughes C. W.
Published: November 2006

Two time series of deep ocean bottom pressure records (BPRs) in between the Crozet Islands and Kerguelen are compared with GRACE (Gravity Recovery And Climate Experiment) equivalent water heights. An analysis of the correlation is performed for four time series: 1) monthly averages of the equivalent water height at the Crozet Islands, 2) the same near the Kerguelen Islands, 3) the mean of the two preceding series and 4) the difference between the two locations expressed in terms of geostrophic transport. We find that smoothed GRACE solutions are strongly correlated with the BPR data with correlation coefficients in the order of 0.7–0.8. Consequently GRACE measures real oceanic mass variations in this region.
Temporal change in site response caused by earthquake strong motion as revealed from coda spectral ratio measurement
Authors: Sawazaki Kaoru , Sato Haruo , Nakahara Hisashi , Nishimura Takeshi
Published: November 2006

The spectral ratios of coda waves of local earthquakes have been often used as measures of relative amplification factors of different sites. Applying this method to coda waves registered by seismometers installed on the surface and at the bottom of a borehole, we succeeded in stably measuring the temporal change in site response associated with the occurrence of a large earthquake strong motion. A remarkable drop of coda spectral ratio and a shift of the peak frequency were observed during strong shake at two sites by the 2000 Western Tottori Earthquake and at a site by the 2003 Tokachi‐Oki Earthquake in Japan. The reduction of the peak frequency reached 30–70% at all the sites. After that, the peak frequency logarithmically recovered to the value before the strong motions for a few years at two sites, whereas the other one quickly recovered in a few tens of minutes.
Change in thermal conductivity of cylindrical silicon nanowires induced by surface bonding modification
Authors: Gu M. X. , Au Yeung T. C. , Tan C. M. , Nosik V.
Published: November 2006

The impact of bond order loss of surface atoms on thermal conductivity of cylindrical silicon nanowires has been examined using the isotropic elastic continuum model. A core-shell structure with a modified Young’s modulus in the surface skin of the wire has been used. Thermal conductivity is calculated from modified phonon dispersion relations based on recent developed bond-order-length-strength (BOLS) correlation. This work extends the previous linear approximation [Yeung et al. Phys. Rev. B 74, 155317 (2006)] to calculate the phonon dispersion relation of torsional mode and longitudinal mode using the nonlinear approach. A significant increase in thermal conductivity is found compared to the case without using BOLS correlation.
Improvement of dichroic polymer dispersed liquid crystal performance using lift-off technique
Authors: Masutani A. , Roberts T. , Schüller B. , Hollfelder N. , Kilickiran P. , Nelles G. , Yasuda A. , Sakaigawa A.
Published: November 2006

A lift-off method has been developed for the fabrication of polymer dispersed liquid crystal (PDLC) displays. A polymer matrix template can be prefabricated by lifting off a PDLC film from a fluorosilanized antisticking substrate. Desirable liquid crystal can then be backfilled/infiltrated into the template. Applying this technique to fabricate dichroic PDLC yielded a reflectivity of 66% and a contrast ratio of 13.8:1 in 3.8in. quarter video graphics array reflective thin film transistor (TFT) displays. A diffuse layer with melamine-formaldehyde nanoparticles was employed to suppress the metallic glare caused by the reflective back plane. The technique is suitable for various back planes such as flexible, solvent/UV-sensitive, organic TFTs.
High field emission reproducibility and stability of carbon nanosheets and nanosheet-based backgated triode emission devices
Authors: Wang Sigen , Wang Jianjun , Miraldo Peter , Zhu Mingyao , Outlaw Ronald , Hou Kun , Zhao Xin , Holloway Brian C. , Manos Dennis , Tyler Talmage , Shenderova Olga , Ray Mark , Dalton Jay , McGuire Gary
Published: October 2006

The authors have characterized field emission properties of freestanding, 1nm thick graphene layers, called carbon nanosheets (CNSs), which were grown perpendicular to the growth surface using a radio-frequency plasma-enhanced chemical vapor deposition technique. The CNSs are metallic impurity-free and have uniform height distribution (standard deviation of <10%). The authors have demonstrated reproducibility and stability of the CNSs for a period of >200h at 1.3mA emission current level. Over this time, no degradation has been observed, the variability of the individual I-V curves is small among 7216 voltage cycles, and the standard deviation at the maximum current was no more than 2.3%. A nanosheet-based backgated triode emission device has been developed to take advantage of the nanosheet field emission performance. Prototype devices have confirmed triode operation and stable electron emission.
Kinetics of gallium adsorption and desorption on (0001) gallium nitride surfaces
Authors: Choi Soojeong , Kim Tong-Ho , Brown April , Everitt Henry O. , Losurdo Maria , Bruno Giovanni , Moto Akihiro
Published: November 2006

In situ spectroscopic ellipsometry kinetic characterization is used to monitor the behavior of Ga atoms during and after Ga flux impingement upon a (0001) GaN surface at various temperatures in the range of 680–750°C. The observed saturation of the pseudodielectric function verifies the existence of a critical thickness for the Ga wetting layer, while the observed desorption delay after the Ga flux is terminated indicates the presence of two Ga phases, one acting as a Ga reservoir to compensate the desorption of the wetting layer until the other phase is depleted.
Spin polarization of oxygen atoms in ferromagnetic Co-doped rutile TiO2
Authors: Nefedov A. , Akdogan N. , Zabel H. , Khaibullin R. I. , Tagirov L. R.
Published: November 2006

Of central interest in the research of dilute magnetic semiconductors is the coupling mechanism leading to a ferromagnetic ground state. Using x-ray resonant magnetic scattering, we have analyzed the element specific magnetic hysteresis curves of Co, Ti, and oxygen in Co-doped TiO2 synthesized by ion implantation. Magnetic dichroism was observed at the Co L2,3 edges, as well as at the O K edge, indicative of a spin polarization of oxygen atoms in the TiO2 host matrix. The hysteretic shapes and the coercive field values measured at the Co L3 and O K edges are identical (1.9kOe at 30K).
Wnt and TGF-β signaling are required for the induction of an
in vitro
model of primitive streak formation using embryonic stem cells
Authors: Gadue Paul , Huber Tara L. , Paddison Patrick J. , Keller Gordon M.
Published: November 2006

The establishment of the primitive streak and its derivative germ layers, mesoderm and endoderm, are prerequisite steps in the formation of many tissues. To model these developmental stages
in vitro
, an ES cell line was established that expresses CD4 from the
foxa2
locus in addition to GFP from the
brachyury
locus. A GFP-Bry
+
population expressing variable levels of CD4-Foxa2 developed upon differentiation of this ES cell line. Analysis of gene-expression patterns and developmental potential revealed that the CD4-Foxa2
hi
GFP-Bry
+
population displays characteristics of the anterior primitive streak, whereas the CD4-Foxa2
lo
GFP-Bry
+
cells resemble the posterior streak. Using this model, we were able to demonstrate that Wnt and TGF-β/nodal/activin signaling simultaneously were required for the generation of the CD4-Foxa2
+
GFP-Bry
+
population. Wnt or low levels of activin-induced a posterior primitive streak population, whereas high levels of activin resulted in an anterior streak fate. Finally, sustained activin signaling was found to stimulate endoderm commitment from the CD4-Foxa2
+
GFP-Bry
+
ES cell population. These findings demonstrate that the early developmental events involved in germ-layer induction in the embryo are recapitulated in the ES cell model and uncover insights into the signaling pathways involved in the establishment of mesoderm and endoderm.
A critical role for IκB kinase α in the development of human and mouse squamous cell carcinomas
Authors: Liu Bigang , Park Eunmi , Zhu Feng , Bustos Tracie , Liu Jinsong , Shen Jianjun , Fischer Susan M. , Hu Yinling
Published: November 2006

IKK (IκB kinase) α is essential for embryonic skin development in mice. Mice deficient in IKKα display markedly hyperplasic epidermis that lacks terminal differentiation, and they die because of this severely impaired skin. However, the function of IKKα in human skin diseases remains largely unknown. To shed light on the role of IKKα in human skin diseases, we examined IKKα expression and
Ikk
α mutations in human squamous cell carcinomas (SCCs). We found a marked reduction in IKKα expression in poorly differentiated human SCCs and identified
Ikk
α mutations in exon 15 of
Ikk
α in eight of nine human SCCs, implying that IKKα is involved in development of this human skin cancer. Furthermore, in a chemical carcinogen-induced skin carcinogenesis setting, mice overexpressing human IKKα in the epidermis under the control of a truncated loricrin promoter developed significantly fewer SCCs and metastases than did wild-type mice. The IKKα transgene altered the skin microenvironment conditions, leading to elevated terminal differentiation in the epidermis, reduced mitogenic activity in the epidermis, and decreased angiogenic activity in the skin stroma. Thus, overexpression of IKKα in the epidermis antagonized chemical carcinogen-induced mitogenic and angiogenic activities, repressing tumor progression and metastases.
Quantum dot/peptide-MHC biosensors reveal strong CD8-dependent cooperation between self and viral antigens that augment the T cell response
Authors: Anikeeva Nadia , Lebedeva Tatiana , Clapp Aaron R. , Goldman Ellen R. , Dustin Michael L. , Mattoussi Hedi , Sykulev Yuri
Published: November 2006

Cytotoxic T lymphocytes (CTL) can respond to a few viral peptide-MHC-I (pMHC-I) complexes among a myriad of virus-unrelated endogenous self pMHC-I complexes displayed on virus-infected cells. To elucidate the molecular recognition events on live CTL, we have utilized a self-assembled biosensor composed of semiconductor nanocrystals, quantum dots, carrying a controlled number of virus-derived (cognate) and other (noncognate) pMHC-I complexes and examined their recognition by antigen-specific T cell receptor (TCR) on anti-virus CD8+T cells. The unique architecture of nanoscale quantum dot/pMHC-I conjugates revealed that unexpectedly strong multivalent CD8–MHC-I interactions underlie the cooperative contribution of noncognate pMHC-I to the recognition of cognate pMHC-I by TCR to augment T cell responses. The cooperative, CD8-dependent spread of signal from a few productively engaged TCR to many other TCR can explain the remarkable ability of CTL to respond to virus-infected cells that present few cognate pMHC-I complexes.
Ownerbuilt Housing and Resources: Implications for Self-Help Policies
Authors: O'Connell Lenahan
Published: October 2006

This note looks at the resources used by 101 non-rural people who built their own homes, saving an estimated 34 per cent of the home's market value.
Killing controversy
Authors: Williams Ruth
Published: October 2006

How do neutrophils kill pathogens? A 1967 paper by Seymour Klebanoff provided a neat answer. But far from being resolved, the question still provokes vehement arguments.
Sternocleidomastoid Myofascial Flap for Reconstruction After Composite Resection of Invasive Squamous Cell Carcinoma of the Tonsillar Region: Technique and Outcome
Authors: Laccourreye Ollivier , Ménard Madeleine , Behm Eva , Garcia Dominique , Cauchois Régis , Holsinger F Christopher
Published: November 2006

Objective: To present the surgical technique and determine the efficacy of sternocleidomastoid myofascial (SCMF) flap reconstruction after composite resection with intent to cure.

Study Design: Retrospective review of 73 consecutive patients with a previously isolated and untreated moderately to well‐differentiated invasive squamous cell carcinoma of the tonsillar region and a minimum of 3 years follow‐up, managed at a tertiary referral care center during the years 1970 to 2002, with an ipsilateral superiorly based SCMF flap after composite resection.

Methods: The surgical procedure is presented in detail. Potential technical pitfalls are highlighted. Survival, mortality, and morbidity are documented. Univariate analysis for potential correlation between the incidence for postoperative flap complications and various variables is also performed.

Results: The 1, 3, and 5 year Kaplan‐Meier actuarial survival estimates were 82.2%, 64.4%, and 49.3%, respectively. Death never appeared to be related to the completion of the SCMF flap. Thirty‐three (45.2%) patients had some kind of significant postoperative surgical complication, and nine (12.3%) patients had some kind of significant postoperative medical complication. The most common significant postoperative complication was partial SCMF flap necrosis and pharyngocutaneous fistula noted in 30.1% and 10.9% of patients, respectively. Complete SCMF flap necrosis was never encountered. No patient developed carotid artery rupture or died as a result of the SCMF flap, and none required additional surgery. In univariate analysis, no significant statistical relation was noted between the significant postoperative surgical complications related to the use of the SCMF flap and the variables under analysis.

Conclusions: The superiorly based SCMF flap appears to be simple to perform and useful for reconstruction of defects after composite resection.
Securing the Nasogastric Tube in Head and Neck Cancer Patients
Authors: Leong Samuel Chee , Mahanta Vibhuti
Published: November 2006

The nasogastric tube (NGT) remains an important method of enteral feeding in head and neck cancer patients and those who are critically ill. The NGT is normally secured to the skin with adhesive tapes. This method carries a high risk of accidental dislodgement, either by the patient or during nursing care. Replacement of the tubes is costly, time and effort intensive, uncomfortable to the patient, and potentially dangerous. We present a technique that is effective and safe. This entails securing the NGT to a fine bore suction catheter looped around the nasal septum.

Summary

The NGT is an important method of enteral feeding in the short and intermediate term.

Various methods of securing the NGT have been described, but the risk of accidental extubation is high.

We describe a simple method of securing the NGT to a fine bore suction catheter looped around the nasal septum.

This method should be considered for patients in the critical care setting or head and neck cancer patients, in whom accidental extubation and repeated re‐insertion of NGT may be hazardous.
Efficacy of Tonsillectomy in Treatment of Recurrent Group A β‐Hemolytic Streptococcal Pharyngitis
Authors: Orvidas Laura J. , St. Sauver Jennifer L. , Weaver Amy L.
Published: November 2006

Objective: The objective of this study was to determine whether children with tonsillectomies experienced fewer recurrent group A β‐hemolytic streptococcal (GABHS) infections after surgery compared with children who did not receive tonsillectomies.

Study Design/Methods: The authors conducted a retrospective cohort study of 290 children 4 to <16 years who experienced three or more episodes of group A β‐hemolytic streptococcal pharyngitis at least 1 month apart in 12 months.

Results: Children without tonsillectomy were 3.1 times (95% confidence interval, 1.9–4.9; P < .001) more likely to develop a subsequent group A β‐hemolytic streptococcal pharyngitis infection during follow up than children who underwent tonsillectomy after adjusting for the number of group A β‐hemolytic streptococcal pharyngitis infections per patient within the previous year and the presence of preexisting conditions. Among the children who developed a subsequent group A β‐hemolytic streptococcal pharyngitis infection, the children without a tonsillectomy developed a group A β‐hemolytic streptococcal pharyngeal infection sooner (median, 0.6 vs. 1.1 years).

Conclusions: Tonsillectomy is associated with a decrease in the number of group A β‐hemolytic streptococcal pharyngitis infections in children with a history of recurrent groups A β‐hemolytic streptococcal pharyngitis infection. Tonsillectomy also increased the amount of time before development of further GABHS pharyngitis.
Does the 43 bp sequence from an 800 000 year old Cretan dwarf elephantid really rewrite the textbook on mammoths?
Authors: Orlando Ludovic , Pagés Marie , Calvignac Sébastien , Hughes Sandrine , Hänni Catherine
Published: October 2006

Pigmy elephants inhabited the islands from the Mediterranean region during the Pleistocene period but became extinct in the course of the Holocene. Despite striking distinctive anatomical characteristics related to insularity, some similarities with the lineage of extant Asian elephants have suggested that pigmy elephants could be most probably seen as members of the genus
Elephas
. Poulakakis
et al.
(2006) have recently challenged this view by recovering a short mtDNA sequence from an 800 000 year old fossil of the Cretan pigmy elephant (
Elephas creticus
). According to the authors of this study, a deep taxonomic revision of Cretan dwarf elephants would be needed, as the sequence exhibits clear affinities with woolly mammoth haplotypes. However, we point here many aspects that seriously weaken the strength of the ancient DNA evidence reported.
Bacteriocin diversity and the frequency of multiple bacteriocin production in Escherichia coli
Authors: Gordon David M. , O'Brien Claire L.
Published: October 2006

A collection of 266 faecal isolates of Escherichia coli from humans was assayed for the production of mitomycin C-inducible bacteriocins and screened using a PCR-based method for the presence of eleven colicins and seven microcins. Eight different colicins were detected and all seven microcins. Of the strains examined, 38 % produced a bacteriocin, 24 % produced a colicin and 20 % produced a microcin. Of the 102 bacteriocin-producing strains, 42 % produced one type of bacteriocin, 41 % produced two, 16 % produced three and one strain was found to produce four different bacteriocins. Strains producing more than one bacteriocin were more likely to be members of E. coli genetic group B2 and less likely to belong to genetic groups A or D. Several of the bacteriocins were found to co-occur in a strain more often than would be expected by chance: microcins H47 and M; colicin Ia and microcin V; colicins B and M; colicins E1 and M; colicins E1 and Ia. No bacteriocins released as a consequence of cell lysis were found to co-associate more often than expected by chance. Three non-mutually exclusive hypotheses are presented that might explain the high frequency of multiple bacteriocin production in E. coli strains: (1) expanded killing range, (2) expanded receptor repertoire and (3) fitness benefits in different environments.
The predicted secretome of Lactobacillus plantarum WCFS1 sheds light on interactions with its environment
Authors: Boekhorst Jos , Wels Michiel , Kleerebezem Michiel , Siezen Roland J.
Published: October 2006

The predicted extracellular proteins of the bacterium Lactobacillus plantarum were analysed to gain insight into the mechanisms underlying interactions of this bacterium with its environment. Extracellular proteins play important roles in processes ranging from probiotic effects in the gastrointestinal tract to degradation of complex extracellular carbon sources such as those found in plant materials, and they have a primary role in the adaptation of a bacterium to changing environmental conditions. The functional annotation of extracellular proteins was improved using a wide variety of bioinformatics methods, including domain analysis and phylogenetic profiling. At least 12 proteins are predicted to be directly involved in adherence to host components such as collagen and mucin, and about 30 extracellular enzymes, mainly hydrolases and transglycosylases, might play a role in the degradation of substrates by L. plantarum to sustain its growth in different environmental niches. A comprehensive overview of all predicted extracellular proteins, their domains composition and their predicted function is provided through a database at http://www.cmbi.ru.nl/secretome, which could serve as a basis for targeted experimental studies into the function of extracellular proteins.
Mammalian sirtuins—emerging roles in physiology, aging, and calorie restriction
Authors: Haigis Marcia C. , Guarente Leonard P.
Published: November 2006

Sir2 is an NAD-dependent deacetylase that connects metabolism with longevity in yeast, worms and flies. Mammals contain seven homologs of yeast Sir2, SIRT1–7. Here, we review recent findings demonstrating the role of these mammalian sirtuins as regulators of physiology, calorie restriction, and aging. The current findings sharpen our understanding of sirtuins as potential pharmacological targets to treat the major diseases of aging.
Concurrent MPL515 and JAK2V617F mutations in myelofibrosis: chronology of clonal emergence and changes in mutant allele burden over time
Authors: Lasho Terra L. , Pardanani Animesh , McClure Rebecca F. , Mesa Ruben A. , Levine Ross L. , Gary Gilliland D. , Tefferi Ayalew
Published: November 2006

MPLW515L/K and JAK2V617F can co‐exist in myelofibrosis with myeloid metaplasia (MMM).The chronology of clonal emergence was studied in three such cases using serially stored bone marrow. At diagnosis, a major MPL515 mutant clone was accompanied by a minor JAK2V617F clone in all three instances. At 25 time points over a period of 4–8 years, allele burden fluctuated but remained high for MPLW515L/K and low for JAK2V617F. We conclude that MPLW515L/K and JAK2V617F are both early events in MMM and allele burden, rather than the mere presence of these mutations, might be relevant to phenotypic variation in myeloproliferative disorders.
Natural rubber latex and hymenoptera venoms share ImmunoglobinE‐epitopes accounting for cross‐reactive carbohydrate determinants
Authors: Mahler V. , Gutgesell C. , Valenta R. , Fuchs T.
Published: November 2006

Background
Epidemiological data on the prevalence and risk factors of latex sensitization have suggested a significant association between latex sensitization and the presence of one or more positive skin prick test responses to aeroallergens, food allergens and to one or more insect venoms. Xylose and core 3‐fucose are typical complex glycans in plants and are foreign to mammals. Plant N‐glycans and insect N‐glycans may cross‐react in humans.

Objective
The aim of our study was to investigate whether there are cross‐reactive IgE‐binding structures in natural rubber latex (NRL) and hymenoptera venoms and to examine their nature.

Methods
Hundred and twenty‐five consecutive patients with insect venom allergy were screened for coincidental latex‐specific IgE. IgE‐binding components in the venoms from Apis mellifera and/or vespula species and in NRL extracts were characterized by IgE‐immunoblotting to the natural allergen sources and determination of specific IgE to recombinant allergens. Cross‐reactive components were investigated by inhibition experiments. The involvement of carbohydrates in the constitution of cross‐reactive IgE‐epitopes was further examined by specific IgE‐binding to cross‐reactive carbohydrate determinants (CCD) in bromelain and horseradish peroxidase as well as by periodate treatment.

Results
NRL glove extracts inhibited patients' serum IgE‐binding to venom allergens. Vice versa, the IgE‐binding to latex glove extracts could be inhibited by pre‐incubation with the insect venoms. Specific IgE‐binding to recombinant latex allergens was absent, whereas the cross‐reactive IgE‐epitopes were sensitive to periodate treatment and specific IgE to CCD (MMXF and MUXF type) could be detected.

Conclusion
Insect venoms and NRL share IgE‐binding CCD that may be responsible for positive serological test results to NRL in patients with insect venom allergy. This copositivity occurs frequently (13.6%) among venom‐allergic individuals and did not elicit clinical symptoms upon contact to latex in the patients examined. In contrast, true cosensitization to insect venoms and NRL allergens can occur and may not be missed.
Do shrimp‐allergic individuals tolerate shrimp‐derived glucosamine?
Authors: Villacis J. , Rice T. R. , Bucci L. R. , El‐Dahr J. M. , Wild L. , DeMerell D. , Soteres D. , Lehrer S. B.
Published: November 2006

Background
There is concern that shrimp‐allergic individuals may react to glucosamine‐containing products as shrimp shells are a major source of glucosamine used for human consumption.

Objective
The purpose of this study was to determine whether shrimp‐allergic individuals can tolerate therapeutic doses of glucosamine.

Methods
Subjects with a history of shrimp allergy were recruited and tested for both shrimp reactivity via a prick skin test and shrimp‐specific IgE by an ImmunoCAP assay. Fifteen subjects with positive skin tests to shrimp and an ImmunoCAP class level of two or greater were selected for a double‐blind placebo‐controlled food challenge (DBPCFC) using glucosamine‐chondroitin tablets containing 1500 mg of synthetically produced (control) or shrimp‐derived glucosamine. Immediate reactions, including changes in peak flow and blood pressure, and delayed reactions (up to 24 h post‐challenge) via questionnaire were noted and assessed.

Results
All subjects tolerated 1500 mg of both shrimp‐derived or synthetic glucosamine without incident of an immediate hypersensitivity response. Peak flows and blood pressures remained constant, and no subject had symptoms of a delayed reaction 24 h later.

Conclusion
This study demonstrates that glucosamine supplements from specific manufacturers do not contain clinically relevant levels of shrimp allergen and therefore appear to pose no threat to shrimp‐allergic individuals.
Regulation of the T cell response
Authors: Romagnani S.
Published: November 2006

The T cell branch of the immune system can respond to a virtually infinite variety of exogenous antigens, thus including the possibility of self‐antigen recognition and dangerous autoimmune reactions. Therefore, regulatory mechanisms operate both during ontogeny within the thymus and after birth in the periphery. The control of self‐reactive T cells occurs through a process of negative selection that results in apoptosis of T cells showing high affinity for self‐peptides expressed at the thymic level by means of promiscuous gene expression. Self‐reactive T cells escaped to negative selection are controlled in the periphery by other regulatory mechanisms, the most important being natural Foxp3+ T regulatory (Treg) cells. Regulation is also required to control excessive effector T cell responses against exogenous antigens, when they become dangerous for the body. Three types of effector T cells have been recognized: T helper 1 (Th1) cells, which are protective against intracellular bacteria; Th2 cells, which play some role in the protection against nematodes, but are responsible for allergic reactions; Th17 cells, which are probably effective in the protection against extracellular bacteria, but also play a role in the amplification of autoimmune disorders. Abnormal or excessive Th effector responses are regulated by different mechanisms. Redirection or immune deviation of Th1‐ or Th2‐dominated responses is provided by cytokines [interferon‐γ (IFN‐γ) vs. interleukin‐4 (IL‐4)] produced by the same cell types and by the CXCR3‐binding chemokines CXCL4 and CXCL10. Moreover, both Th1 and Th2 responses can be suppressed by adaptive Treg cells through contact‐dependent mechanisms and/or the production of IL‐10 and transforming growth factor‐β (TGF‐β). Finally, TGF‐β1 can promote the development of both Th17 effector and adaptive Treg cells, while the contemporaneous production of IL‐6 contributes to the development of Th17 cells, but inhibits Treg cells. The development of Th17 cells is also down‐regulated by IL‐4 produced by Th2 cells and by IFN‐γ produced by Th1 cells.
Nutrient availability constrains the hydraulic architecture and water relations of savannah trees
Authors: BUCCI SANDRA J. , SCHOLZ FABIAN G. , GOLDSTEIN GUILLERMO , MEINZER FREDERICK C. , FRANCO AUGUSTO C. , CAMPANELLO PAULA I. , VILLALOBOS‐VEGA RANDOL , BUSTAMANTE MERCEDES , MIRALLES‐WILHELM FERNANDO
Published: November 2006

Leaf and whole plant‐level functional traits were studied in five dominant woody savannah species from Central Brazil (Cerrado) to determine whether reduction of nutrient limitations in oligotrophic Cerrado soils affects carbon allocation, water relations and hydraulic architecture. Four treatments were used: control, N additions, P additions and N plus P additions. Fertilizers were applied twice yearly, from October 1998 to March 2004. Sixty‐three months after the first nutrient addition, the total leaf area increment was significantly greater across all species in the N‐ and the N + P‐fertilized plots than in the control and in the P‐fertilized plots. Nitrogen fertilization significantly altered several components of hydraulic architecture: specific conductivity of terminal stems increased with N additions, whereas leaf‐specific conductivity and wood density decreased in most cases. Average daily sap flow per individual was consistently higher with N and N + P additions compared to the control, but its relative increase was not as great as that of leaf area. Long‐term additions of N and N + P caused midday ΨL to decline significantly by a mean of 0.6 MPa across all species because N‐induced relative reductions in soil‐to‐leaf hydraulic conductance were greater than those of stomatal conductance and transpiration on a leaf area basis. Phosphorus‐fertilized trees did not exhibit significant changes in midday ΨL. Analysis of xylem vulnerability curves indicated that N‐fertilized trees were significantly less vulnerable to embolism than trees in control and P‐fertilized plots. Thus, N‐induced decreases in midday ΨL appeared to be almost entirely compensated by increases in resistance to embolism. Leaf tissue water relations characteristics also changed as a result of N‐induced declines in minimum ΨL: osmotic potential at full turgor decreased and symplastic solute content on a dry matter basis increased linearly with declining midday ΨL across species and treatments. Despite being adapted to chronic nutrient limitations, Cerrado woody species apparently have the capacity to exploit increases in nutrient availability by allocating resources to maximize carbon gain and enhance growth. The cost of increased allocation to leaf area relative to water transport capacity involved increased total water loss per plant and a decrease in minimum leaf water potentials. However, the risk of increased embolism and turgor loss was relatively low as xylem vulnerability to embolism and leaf osmotic characteristics changed in parallel with changes in plant water status induced by N fertilization.
Photosynthetic capacity is related to the cellular and subcellular partitioning of Na+, K+ and Cl‐ in salt‐affected barley and durum wheat
Authors: JAMES RICHARD A. , MUNNS RANA , VON CAEMMERER SUSANNE , TREJO CARLOS , MILLER CELIA , CONDON TONY (A.G.)
Published: November 2006

The capacity of plants to tolerate high levels of salinity depends on the ability to exclude salt from the shoot, or to tolerate high concentrations of salt in the leaf (tissue tolerance). It is widely held that a major component of tissue tolerance is the capacity to compartmentalize salt into safe storage places such as vacuoles. This mechanism would avoid toxic effects of salt on photosynthesis and other key metabolic processes. To test this, the relationship between photosynthetic capacity and the cellular and subcellular distribution of Na+, K+ and Cl‐ was studied in salt‐sensitive durum wheat (cv. Wollaroi) and salt‐tolerant barley (cv. Franklin) seedlings grown in a range of salinity treatments. Photosynthetic capacity parameters (Vcmax, Jmax) of salt‐stressed Wollaroi decreased at a lower leaf Na+ concentration than in Franklin. Vacuolar concentrations of Na+, K+ and Cl‐ in mesophyll and epidermal cells were measured using cryo‐scanning electron microscopy (SEM) X‐ray microanalysis. In both species, the vacuolar Na+ concentration was similar in mesophyll and epidermal cells, whereas K+ was at higher concentrations in the mesophyll, and Cl‐ higher in the epidermis. The calculated cytoplasmic Na+ concentration increased to higher concentrations with increasing bulk leaf Na+ concentration in Wollaroi compared to Franklin. Vacuolar K+ concentration was lower in the epidermal cells of Franklin than Wollaroi, resulting in higher cytoplasmic K+ concentrations and a higher K+ : Na+ ratio. This study indicated that the maintenance of photosynthetic capacity (and the resulting greater salt tolerance) at higher leaf Na+ levels of barley compared to durum wheat was associated with the maintenance of higher K+, lower Na+ and the resulting higher K+ : Na+ in the cytoplasm of mesophyll cells of barley.
Declining hydraulic efficiency as transpiring leaves desiccate: two types of response*
Authors: BRODRIBB TIM J. , HOLBROOK N. MICHELE
Published: November 2006

The conductance of transpiring leaves to liquid water (Kleaf) was measured across a range of steady‐state leaf water potentials (Ψleaf). Manipulating the transpiration rate in excised leaves enabled us to vary Ψleaf in the range −0.1 MPa to less than −1.5 MPa while using a flowmeter to monitor the transpiration stream. Employing this technique to measure how desiccation affects Kleaf in 19 species, including lycophytes, ferns, gymnosperms and angiosperms, we found two characteristic responses. Three of the six angiosperm species sampled maintained a steady maximum Kleaf while Ψleaf remained above −1.2 MPa, although desiccation of leaves beyond this point resulted in a rapid decline in Kleaf. In all other species measured, declining Ψleaf led to a proportional decrease in Kleaf, such that midday Ψleaf of unstressed plants in the field was sufficient to depress Kleaf by an average of 37%. It was found that maximum Kleaf was strongly correlated with maximum CO2 assimilation rate, while Kleaf = 0 occurred at a Ψleaf slightly less negative than at leaf turgor loss. A strong linear correlation across species between Ψleaf at turgor loss and Ψleaf at Kleaf = 0 raises the possibility that declining Kleaf was related to declining cell turgor in the leaf prior to the onset of vein cavitation. The vulnerability of leaves rehydrating after desiccation was compared with vulnerability of leaves during steady‐state evaporation, and differences between methods suggest that in many cases vein cavitation occurs only as Kleaf approaches zero.
Plasticity to soil water deficit in Arabidopsis thaliana: dissection of leaf development into underlying growth dynamic and cellular variables reveals invisible phenotypes
Authors: AGUIRREZABAL LUIS , BOUCHIER‐COMBAUD SANDRINE , RADZIEJWOSKI AMANDINE , DAUZAT MYRIAM , COOKSON SARAH JANE , GRANIER CHRISTINE
Published: November 2006

Genetic variability in the plasticity of leaf area expansion in response to water deficit has been reported in Arabidopsis thaliana. Here, the objective was to identify the underlying dynamic and cellular processes involved in this variability. Twenty‐five accessions were subjected to identical soil water deficit treatments. In all accessions, the plasticity of leaf production was low compared with that of individual leaf expansion. A subset of accessions was selected for further dissection of individual leaf expansion into its underlying variables: the rate and duration of leaf expansion and epidermal cell number and area. In all accessions, water deficit had opposite effects on the rate and duration of leaf expansion. The accumulation of these effects was reflected in changes in final leaf area. At the cellular level, moderate water deficits had opposite effects on cell number and cell size, but more severe ones reduced both variables. The importance of these opposing effects is highlighted by the behaviour of the accession An‐1, for which the compensation between the decrease in leaf expansion rate and the increase in the duration of expansion is total. This dynamic plasticity in response to water deficit is not detectable when only final measurements are done.
The cytosolic Na+ : K+ ratio does not explain salinity‐induced growth impairment in barley: a dual‐tracer study using 42K+ and 24Na+
Authors: KRONZUCKER HERBERT J. , SZCZERBA MARK W. , MOAZAMI‐GOUDARZI MARYAM , BRITTO DEV T.
Published: November 2006

It has long been believed that maintenance of low Na+ : K+ ratios in the cytosol of plant cells is critical to the plant’s ability to tolerate salinity stress. Direct measurements of such ratios, however, have been few. Here we apply the non‐invasive technique of compartmental analysis, using the short‐lived radiotracers 42K+ and 22Na+, in intact seedlings of barley (Hordeum vulgare L.), to evaluate unidirectional plasma membrane fluxes and cytosolic concentrations of K+ and Na+ in root tissues, under eight nutritional conditions varying in levels of salinity and K+ supply. We show that Na+ : K+ ratios in the cytosol of root cells adjust significantly across the conditions tested, and that these ratios are poor predictors of the plant’s growth response to salinity. Our study further demonstrates that Na+ is subject to rapid and futile cycling at the plasma membrane at all levels of Na+ supply, independently of external K+, while K+ influx is reduced by Na+, from a similar baseline, and to a similar extent, at both low and high K+ supply. We compare our results to those of other groups, and conclude that the maintenance of the cytosolic Na+ : K+ ratio is not central to plant survival under NaCl stress. We offer alternative explanations for sodium sensitivity in relation to the primary acquisition mechanisms of Na+ and K+.
Large‐scale histological analysis of leaf mutants using two simple leaf observation methods: identification of novel genetic pathways governing the size and shape of leaves
Authors: Horiguchi Gorou , Fujikura Ushio , Ferjani Ali , Ishikawa Naoko , Tsukaya Hirokazu
Published: October 2006

Observations of cellular organization are essential in understanding the mechanisms underlying leaf morphogenesis. These observations require several preparative steps, such as fixation and clearing of organs, and such procedures are time‐consuming and labor‐intensive for large‐scale analyses. Thus, we have developed simple methods for the observation of leaf epidermal and mesophyll cells. To visualize the epidermis, a gel cast was made of the leaf surface, which was then observed under a light microscope. To visualize the leaf mesophyll cells, leaves were immersed in a solution containing Triton X‐100, briefly centrifuged, and then viewed under a light microscope. These methods allowed us to conduct a histological phenome analysis for a large number of known and newly isolated leaf‐shape/size mutants of Arabidopsis thaliana by measuring various parameters, including cell number, size, and distribution of cells within a leaf blade. Mutants showed changes in leaf size caused by specific increases or decreases in the number and/or size of cells. In addition, altered cell distributions in the leaf blade were observed, resulting from increases or decreases in the number of cells along the proximo‐distal or medio‐lateral axis, or recruitment of cells along a particular axis at the expense of other leaf parts. These results provide a phenomic view of the cellular behavior involved in organ size control and leaf‐shape patterning.