bluuebunny/crossref_metadata_2025 huggingface dataset:
Linear and nonlinear quantum dust ion acoustic wave with dust size distribution effect
Authors: El-Labany S. K. , El-Siragy N. M. , El-Taibany W. F. , El-Shamy E. F. , Behery E. E.
Published: May 2010

Both linear and nonlinear quantum dust ion acoustic waves (QDIAWs) are analyzed using two fluid quantum hydrodynamics model including the dust size distribution (DSD) effect. Two different DSD functions are applied (the power law DSD and the polynomial DSD). A new dispersion relation is derived. Using the reductive perturbation technique, a quantum Zakharov–Kuzentsov equation is evaluated for the QDIAW description. The relevance of the wave velocity, amplitude, and width to the DSD and quantum effects is illustrated both analytically and numerically. Moreover, it is found that both linear and nonlinear wave properties are affected by increasing the matter density; the more dense the material the less the wave frequency. The accuracy of controlling coefficients presented in the polynomial DSD is examined numerically for both linear and nonlinear QDIAWs. A brief conclusion is presented to the current findings and their relevance to astrophysics data is also discussed.
Whispering gallery modes of microspheres in the presence of a changing surrounding medium: A new ray-tracing analysis and sensor experiment
Authors: Ioppolo Tindaro , Das Nirod , Ötügen M. Volkan
Published: May 2010

A simple plane wave, ray-tracing approach was used to derive approximate equations for the dielectric microsphere whispering gallery mode (WGM) resonant wavenumber and quality factor, as dependent on the surrounding medium’s refractive index. These equations are then used to determine the feasibility of a micro-optical sensor for species concentration. Results indicate that the WGMs are not sensitive enough to refractive index changes in the case of gas media. However, they can be sufficiently sensitive for measurements in liquids. Experiments were carried out to validate the analysis and to provide an assessment of this sensor concept.
Precision Lamb-dip infrared spectra of the C–N stretching band of CH3NH2 with a CO2-laser/microwave-sideband spectrometer
Authors: Sun Zhen-Dong , Lees Ronald M. , Xu Li-Hong
Published: May 2010

We report saturation dip spectroscopy in the C–N stretching band of CH3NH2 with a resolution of 0.4 MHz and an accuracy of 0.1 MHz by use of a CO2-laser/microwave-sideband spectrometer. The wide tunability, Lamb-dip resolution, absolute frequency accuracy, and high sensitivity of our dual-mode instrument were all key features in making precise measurements for a range of lines in the densely crowded spectrum with its complex pattern of splittings arising from the large-amplitude CH3 torsion and NH2 inversion. We focused on achieving resolution and assignment of transitions within the highly blended Q branch of the C–N stretch and on observations of the important K=0 sequences of Aa and Ea torsion-inversion symmetry. Term values of the latter were fitted to J(J+1) power-series expansions to obtain the K=0 C–N stretching effective B values and substate origins, from which calculated ground-state substate energies were subtracted to yield values of 1044.7061 and 1044.8011 cm−1 for the Aa and Ea subband origins, respectively. We thereby estimate a mean value of 1044.75(5) cm−1 for the vibrational band origin and 0.7323(5) cm−1 for the effective upper-state B value for the C–N stretching fundamental of CH3NH2.
Multiphonon transitions in the biomolecular energy transfer dynamics
Authors: Nalbach P. , Thorwart M.
Published: May 2010

We show that the biomolecular exciton dynamics under the influence of slow polarization fluctuations in the solvent cannot be described by lowest order, one-phonon approaches which are perturbative in the system-bath coupling. Instead, nonperturbative multiphonon transitions induced by the slow bath yield significant contributions. This is shown by comparing results for the decoherence rate of the exciton dynamics of a resumed perturbation theory with numerically exact real-time path-integral data. The exact decoherence rate for realistically slow solvent environments is significantly modified by multiphonon processes even in the weak coupling regime, while a one-phonon description is satisfactory only for fast environmental noise. Slow environments inhibit bath modes that are resonant with the exciton dynamics, thereby suppressing one-phonon transitions and enhancing multiphonon processes, which are typically not captured by lowest order perturbative treatments, such as Redfield or Lindblad approaches, even in more refined variants.
Numerical simulation of atmospheric-pressure helium discharge driven by combined radio frequency and trapezoidal pulse sources
Authors: Wang Qi , Sun Jizhong , Zhang Jianhong , Ding Zhenfeng , Wang Dezhen
Published: May 2010

Atmospheric-pressure capacitive discharges driven by combined radio frequency (rf) and trapezoidal pulse sources are investigated using a one-dimensional self-consistent fluid model. The results show that the plasma intensity in the rf discharge can be enhanced drastically when a low duty ratio short pulse source is additionally applied. The mechanism for the increase in the plasma density can be attributed to a strong localized electric field induced by the applied short pulse; the strong electric field generates a great number of high energy electrons and chemically active particles, which subsequently generate more electrons and ions. The rf capacitive discharges with the aid of externally applied short pulses can achieve a high plasma density with better power efficiency.
Hysteresis in photoelectric charging of dust particles in a complex plasma
Authors: Sodha M. S. , Mishra S. K. , Misra Shikha , Srivastava Sweta
Published: May 2010

Starting with the basic equations of number and energy balance along with charge neutrality it is shown that the charge on the particle versus irradiance of incident radiation plot in a complex plasma, illuminated by radiation with periodic irradiance displays hysteresis.
Miniaturized transportable evaporator for molecule deposition inside cryogenic scanning probe microscopes
Authors: Lämmle K. , Schwarz A. , Wiesendanger R.
Published: May 2010

Here, we present a very small evaporator unit suitable to deposit molecules onto a sample in a cryogenic environment. It can be transported in an ultrahigh vacuum system and loaded into Omicron-type cantilever stages. Thus, molecule deposition inside a low temperature force microscope is possible. The design features an insulating base plate with two embedded electrical contacts and a crucible with low power consumption, which is thermally well isolated from the surrounding. The current is supplied via a removable power clip. Details of the manufacturing process as well as the used material are described. Finally, the performance of the whole setup is demonstrated.
On morphological selection rule of noisy character applied to model (dis)orderly protein formations
Authors: Siódmiak Jacek , Santamaría-Holek Ivan , Gadomski Adam
Published: May 2010

We propose that the main mechanism controlling the selection rule of model (dis)orderly protein formations, such as non-Kossel crystal growth and aggregation of lysozyme from aqueous solution, is an ion-channeling filter having flicker-noise properties. This filter is originated at the interfaces between growing solidlike object and its external liquid-type phase, and it can be considered as a series of voltage gated ion subchannels. The dynamics of each channel is studied by using both simulation and analytic argumentation lines, and represents a novel thought on how to utilize the presence of constructive-noise sources in protein formation, a field of utmost experimental and technological interest.
Surface-enhanced Raman spectroscopy on coupled two-layer nanorings
Authors: Hou Yumin , Xu Jun , Wang Pengwei , Yu Dapeng
Published: May 2010

A reproducible quasi-three-dimensional structure, composed of top and bottom concentric nanorings with same periodicity but different widths and no overlapping at the perpendicular direction, is built up by a separation-layer method, which results in huge enhancement of surface-enhanced Raman spectroscopy (SERS) due to the coupling of plasmons. Simulations show plasmonic focusing with “hot arcs” of electromagnetic enhancement meeting the need of quantitative SERS with extremely high sensitivities. In addition, the separation-layer method opens a simple and effective way to adjust the coupling of plasmons among nanostructures which is essential for the fabrication of SERS-based sensors.
New free energy density functional and application to core-softened fluid
Authors: Zhou Shiqi
Published: May 2010

A new free energy density functional is advanced for general nonhard sphere potentials characterized by a repulsive core with a singular point at zero separation. The present functional is characterized by several features. (i) It does not involve with dividing the potentials into hard-sphere-like contribution and tail contribution in sharp contrast with usual effective hard sphere model+mean field approximation for tail contribution. (ii) It has no recourse to the use of weighted density and is computationally modest; it also does not resort to an equation of state and/or an excess Helmholtz free energy of bulk fluid over a range of density as input. Consequently, all of input information can be obtained by numerical solution of a bulk Ornstein–Zernike integral equation theory (OZ IET). Correspondingly, despite the use of bulk second-order direct correlation function (DCF) as input, the functional is applicable to the subcritical region. (iii) There is no any adjustable parameter associated with the present functional, and an effective hard sphere diameter entering the functional can be determined self-consistently and analytically once the input information, i.e., the second-order DCF and pressure of the coexistence bulk fluid, are obtained by the OZ IET. The present functional is applied to a core-softened fluid subject to varying external fields, and the density distributions predicted by the present functional are more self-consistent with available simulation results than a previous third-order+second-order perturbation density functional theory.
Isolation, phylogeny and evolutionary analysis of Pto-type disease resistance gene analogues from a Cucumis hystrix introgression line of cucumber (C. sativus)
Authors: Wan Hongjian , Qian Chuntao , Malik Ahmed Abbas , Zhao Zhenguo , Chen Jinfeng
Published: May 2010

Multiple resistances to bacterial and fungal pathogens due to Pto-type serine/threonine kinase (STK) has made this protein a promising candidate for resistance breeding and provided motivation to identify functional Pto-type genes from other plant species. In our present paper, eight classes of STKs were isolated from the cucumber (Cucumis sativus L.) introgressed line 5211S that shows downy mildew resistance. Phylogenetic analysis revealed six classes of cucumber Pto-type resistance gene analogues (RGAs). Multiple sequence alignment of deduced amino acid sequences from these Pto-type RGAs and Pto showed the typical structure of a Pto protein. Non-synonymous to synonymous nucleotide substitution (Ka : Ks) ratios for these Pto-type RGAs were less than 1, indicating that purifying selection played an important role in the evolutionary process. The Pto-type RGAs identified in this study will permit further genetic characterisation that may lead to the development of specific or even broad-spectrum pathogen resistance in 5211S.
Disturbance is required for CO2-dependent promotion of woody plant growth in grasslands
Authors: Loveys Beth R. , Egerton John J. G. , Bruhn Dan , Ball Marilyn C.
Published: May 2010

The relative effects of disturbance (here defined as bare soil), competition for edaphic resources, thermal interference and elevated [CO2] on growth of tree seedlings in grasslands were studied under field conditions. Snow gum (Eucalyptus pauciflora Sieb. ex Spreng.) seedlings were grown in open-top chambers flushed with either ambient or elevated [CO2] from March 2004 to January 2005 (autumn to summer). These seedlings were planted into three treatments (i.e. bare soil, soil covered with straw or soil supporting a sward of live pasture grass) to separate effects of grass on seedling growth into those due to competition with grass for soil resources or to alteration of the thermal environment caused by a grassy surface (Ball et al. 2002). After the first major autumn frost, seedlings growing in competition with grass lost 59% of their canopy area, whereas those growing in bare soil or straw suffered negligible damage. These results reveal the complexity of competitive inhibition of plant growth in which ineffective competition for resources such as soil water enhances the vulnerability of the plant to abiotic stress, in this case frost. Tree seedlings growing in bare soil and straw commenced growth earlier in spring than those growing in competition with grass, where soil moisture was consistently lowest. Under ambient [CO2], growth was greater in bare soil than in straw, consistent with thermal interference, but these differences disappeared under elevated [CO2]. Elevated [CO2] significantly increased biomass accumulation for seedlings growing in bare soil and straw treatments, but not in grass. Thus, elevated [CO2] alleviated apparent thermal interference of seedling growth in spring but did not overcome adverse effects on seedling growth of either competitive reduction in soil resources or competitive enhancement of environmental stress. Nevertheless, elevated [CO2] could promote invasion of grasslands due to enhancement of woody plant growth in bare soil created by disturbances.
Viewing leaf structure and evolution from a hydraulic perspective
Authors: Brodribb Tim J. , Feild Taylor S. , Sack Lawren
Published: May 2010

More than 40 000 km3 year–1 of water flows through the intricate hydraulic pathways inside leaves. This water not only sustains terrestrial productivity, but also constitutes nearly 70% of terrestrial evapotranspiration, thereby influencing both global and local climate (Chapin et al. 2002). Thus, the central role played by leaf vascular systems in terrestrial biology provides an important context for research into the function and evolution of water transport in leaves. Significant progress has been made recently towards understanding the linkages between anatomy and water transport efficiency in leaves, and these discoveries provide a novel perspective to view the evolution of land plants.
The central role of the VERNALIZATION1 gene in the vernalization response of cereals
Authors: Trevaskis Ben
Published: May 2010

Many varieties of wheat (Triticum spp.) and barley (Hordeum vulgare L.) require prolonged exposure to cold during winter in order to flower (vernalization). In these cereals, vernalization-induced flowering is controlled by the VERNALIZATION1 (VRN1) gene. VRN1 is a promoter of flowering that is activated by low temperatures. VRN1 transcript levels increase gradually during vernalization, with longer cold treatments inducing higher expression levels. Elevated VRN1 expression is maintained in the shoot apex and leaves after vernalization, and the level of VRN1 expression in these organs determines how rapidly vernalized plants flower. Some alleles of VRN1 are expressed without vernalization due to deletions or insertions within the promoter or first intron of the VRN1 gene. Varieties of wheat and barley with these alleles flower without vernalization and are grown where vernalization does not occur. The first intron of the VRN1 locus has histone modifications typically associated with the maintenance of an inactive chromatin state, suggesting this region is targeted by epigenetic mechanisms that contribute to repression of VRN1 before winter. Other mechanisms are likely to act elsewhere in the VRN1 gene to mediate low-temperature induction. This review examines how understanding the mechanisms that regulate VRN1 provides insights into the biology of vernalization-induced flowering in cereals and how this will contribute to future cereal breeding strategies.
Prediction and validation of cell alignment along microvessels as order principle to restore tissue architecture in liver regeneration
Authors: Hoehme Stefan , Brulport Marc , Bauer Alexander , Bedawy Essam , Schormann Wiebke , Hermes Matthias , Puppe Verena , Gebhardt Rolf , Zellmer Sebastian , Schwarz Michael , Bockamp Ernesto , Timmel Tobias , Hengstler Jan G. , Drasdo Dirk
Published: May 2010

Only little is known about how cells coordinately behave to establish functional tissue structure and restore microarchitecture during regeneration. Research in this field is hampered by a lack of techniques that allow quantification of tissue architecture and its development. To bridge this gap, we have established a procedure based on confocal laser scans, image processing, and three-dimensional tissue reconstruction, as well as quantitative mathematical modeling. As a proof of principle, we reconstructed and modeled liver regeneration in mice after damage by CCl
4
, a prototypical inducer of pericentral liver damage. We have chosen the regenerating liver as an example because of the tight link between liver architecture and function: the complex microarchitecture formed by hepatocytes and microvessels, i.e. sinusoids, ensures optimal exchange of metabolites between blood and hepatocytes. Our model captures all hepatocytes and sinusoids of a liver lobule during a 16 days regeneration process. The model unambiguously predicted a so-far unrecognized mechanism as essential for liver regeneration, whereby daughter hepatocytes align along the orientation of the closest sinusoid, a process which we named “hepatocyte-sinusoid alignment” (HSA). The simulated tissue architecture was only in agreement with the experimentally obtained data when HSA was included into the model and, moreover, no other likely mechanism could replace it. In order to experimentally validate the model of prediction of HSA, we analyzed the three-dimensional orientation of daughter hepatocytes in relation to the sinusoids. The results of this analysis clearly confirmed the model prediction. We believe our procedure is widely applicable in the systems biology of tissues.
Conversion of a yeast prion protein to an infectious form in bacteria
Authors: Garrity Sean J. , Sivanathan Viknesh , Dong Jijun , Lindquist Susan , Hochschild Ann
Published: May 2010

Prions are infectious, self-propagating protein aggregates that have been identified in evolutionarily divergent members of the eukaryotic domain of life. Nevertheless, it is not yet known whether prokaryotes can support the formation of prion aggregates. Here we demonstrate that the yeast prion protein Sup35 can access an infectious conformation in
Escherichia coli
cells and that formation of this material is greatly stimulated by the presence of a transplanted [
PSI
+
] inducibility factor, a distinct prion that is required for Sup35 to undergo spontaneous conversion to the prion form in yeast. Our results establish that the bacterial cytoplasm can support the formation of infectious prion aggregates, providing a heterologous system in which to study prion biology.
Small heat-shock proteins interact with a flanking domain to suppress polyglutamine aggregation
Authors: Robertson Amy L. , Headey Stephen J. , Saunders Helen M. , Ecroyd Heath , Scanlon Martin J. , Carver John A. , Bottomley Stephen P.
Published: May 2010

Small heat-shock proteins (sHsps) are molecular chaperones that play an important protective role against cellular protein misfolding by interacting with partially unfolded proteins on their off-folding pathway, preventing their aggregation. Polyglutamine (polyQ) repeat expansion leads to the formation of fibrillar protein aggregates and neuronal cell death in nine diseases, including Huntington disease and the spinocerebellar ataxias (SCAs). There is evidence that sHsps have a role in suppression of polyQ-induced neurodegeneration; for example, the sHsp alphaB-crystallin (αB-c) has been identified as a suppressor of SCA3 toxicity in a
Drosophila
model. However, the molecular mechanism for this suppression is unknown. In this study we tested the ability of αB-c to suppress the aggregation of a polyQ protein. We found that αB-c does not inhibit the formation of SDS-insoluble polyQ fibrils. We further tested the effect of αB-c on the aggregation of ataxin-3, a polyQ protein that aggregates via a two-stage aggregation mechanism. The first stage involves association of the N-terminal Josephin domain followed by polyQ-mediated interactions and the formation of SDS-resistant mature fibrils. Our data show that αB-c potently inhibits the first stage of ataxin-3 aggregation; however, the second polyQ-dependent stage can still proceed. By using NMR spectroscopy, we have determined that αB-c interacts with an extensive region on the surface of the Josephin domain. These data provide an example of a domain/region flanking an amyloidogenic sequence that has a critical role in modulating aggregation of a polypeptide and plays a role in the interaction with molecular chaperones to prevent this aggregation.
Assembly of large-area, highly ordered, crack-free inverse opal films
Authors: Hatton Benjamin , Mishchenko Lidiya , Davis Stan , Sandhage Kenneth H. , Aizenberg Joanna
Published: May 2010

Whereas considerable interest exists in self-assembly of well-ordered, porous “inverse opal” structures for optical, electronic, and (bio)chemical applications, uncontrolled defect formation has limited the scale-up and practicality of such approaches. Here we demonstrate a new method for assembling highly ordered, crack-free inverse opal films over a centimeter scale. Multilayered composite colloidal crystal films have been generated via evaporative deposition of polymeric colloidal spheres suspended within a hydrolyzed silicate sol-gel precursor solution. The coassembly of a sacrificial colloidal template with a matrix material avoids the need for liquid infiltration into the preassembled colloidal crystal and minimizes the associated cracking and inhomogeneities of the resulting inverse opal films. We discuss the underlying mechanisms that may account for the formation of large-area defect-free films, their unique preferential growth along the 〈110〉 direction and unusual fracture behavior. We demonstrate that this coassembly approach allows the fabrication of hierarchical structures not achievable by conventional methods, such as multilayered films and deposition onto patterned or curved surfaces. These robust SiO
2
inverse opals can be transformed into various materials that retain the morphology and order of the original films, as exemplified by the reactive conversion into Si or TiO
2
replicas. We show that colloidal coassembly is available for a range of organometallic sol-gel and polymer matrix precursors, and represents a simple, low-cost, scalable method for generating high-quality, chemically tailorable inverse opal films for a variety of applications.
Impacts of climate change on biodiversity - consolidated knowledge and research gaps.
Authors: Vohland K.
Published: May 2010

Climate change is one of the main drivers impacting biodiversity. The spatial and temporal distribution of temperature and precipitation as well as the increasing CO
2
concentration of the atmosphere are the main drivers substantially modifying the competitive success of species. Most information exists at the species level, and here studies to correlate future species distribution with climate change indicators prevail. Most information that concentrates on the species level is based on studies that correlate future species distribution with climate change indicators. However, the reliability of these findings is limited because only slowly adaptive processes are included into modelling frameworks (if any at all). Direct impacts of climate change are manifested by physiological processes in all organisms, but most information is available for plants only. Some plant species may benefit from increasing atmospheric CO
2
. Higher temperatures, especially in spring, might induce earlier budburst, which causes longer growing periods. Higher temperature and droughts, on the other hand, limit assimilation and growth. Changes in biodiversity at the ecosystem level are more difficult to capture, not the least because different scientific communities use different definitions. From a societal point of view, ecosystems provide vital services whose provision might change under climate change. While in some regions ecosystem services such as carbon sequestration might increase, in others they might decrease as a result of water limitations and heat stress. More integrated nature conservation strategies that combine the protection of specific species of common interest with minimizing land-use tradeoffs will increase. Research is needed to develop suitable strategies that ensure adaptive capacity at all biodiversity levels and satisfy human requirements.
Evolving vaccine choices for the continuously evolving avian influenza viruses.
Authors: Collisson E. W. , Singh S. , Drechsler Y.
Published: May 2010

Avian influenza viruses (AIVs) are a continuously evolving group of RNA viruses with segmented genomes. Although AIV is thought to originate from wild bird populations, the capacity for ready mutation and adaptation to mammalian hosts makes AIV both a potential agricultural and public health risk. Worldwide spread of AIV is inevitable because of the ever-presence of infection in wild, especially migratory, bird reservoirs. Therefore, vaccine development is of high priority. The potential for genetic shift (reassortment) and drift (point mutations) is a concern for dependency on live, attenuated vaccine strategies, which were the first vaccines of wide use in poultry. Inactivated whole virus and subunit protein vaccines provide limited immune responses. The evolution of vaccine strategies is the result of creative applications of genetic engineering to develop plasmid and viral gene delivery vectors. Gene vaccines that include plasmid DNA and viral vector delivery of AIV genes allow for endogenous,
in vivo
amplification of proteins within cells. The viral vectors are Nature's specialists for cellular delivery of genetic information and, if replication-competent, also for the spread from host cell to cell, furthering opportunities for induction of immunity. Viral proteins that induce neutralizing antibodies are preferred to subunit vaccines. The replication-competent fowlpox virus vectors have been licensed and proved to be efficacious even in field situations. Several avian respiratory viruses, with DNA or RNA genomes, are being developed with promising practical application for poultry. Maximum exploitation of vectored vaccines may incorporate enhancing immune molecules. Future vaccines must also allow for differentiation of vaccinated birds from naturally infected birds.
How can producers access the modern agri-food chain? A Central and Eastern European perspective.
Authors: Ferto I.
Published: May 2010

This article reviews the empirical literature on how farmers can access the modern agri-food chain in Central and Eastern Europe, with special emphasis on small-scale producers. We focus on two questions: on farmer-buyer relationships and the credit market imperfections. We briefly describe common theoretical approaches including transaction costs economics, economics of enforceable contracts and augmented accelerator model. Empirical results suggest that after almost two decades since the beginning of transition, the adjustment problems of farmers in these countries are more general, and many of them are not specific to small-scale farms. However, some issues are more severe for small-scale farms as a lack of enforceable contract arrangements and cooperation among farmers, the low level of trust in trading partners and difficult access to credit markets. Note that empirical evidence is far from exhaustive, especially for small-scale farms. Thus we need more research on these fields focusing on more countries and more food chains, including more carefully developed theoretical models as a base for empirical research.
Probiotics and aquaculture.
Authors: Aly S. M.
Published: May 2010

Aquaculture has become the fastest growing sector of food production in the world. Despite the encouraging trends, several constraints have a negative impact on the growth of aquaculture. Among those, diseases are the primary limiting factors. Bacterial diseases are responsible for heavy mortality in both wild and cultured fish. Antibiotics are used to control such infection but may result in development and spread of antimicrobial-resistant bacteria and resistance genes and occurrence of antimicrobial residues in fish tissues. This may induce a negative impact on human health, fish performance and the environment. An alternative approach employed recently to control bacterial infection in fish is the use of vaccines. However, vaccines are not available in many countries, a tremendous amount of human labour is required to deliver the vaccines, and implementation is also associated with handling stress for the fish, which may impair the efficacy of the vaccines to a great extent. The concept of biological disease control, particularly using non-pathogenic biological agents (probiotics), has received widespread attention during the last decade. This review focused on the nature, sources, benefit, selection criteria, mode of action and efficiency of probiotics.
Distinguishing Suicidal from Non-Suicidal Deliberate Self-Harm Events in Women with Borderline Personality Disorder
Authors: Maddock Gillian R. , Carter Gregory L. , Murrell Elizabeth R. , Lewin Terry J. , Conrad Agatha M.
Published: May 2010

Objective: Deliberate self-harm (DSH) is common in Borderline Personality Disorder, may be due to a variety of reasons, and is associated with different degrees of suicidal intent. Understanding the reasons for episodes of DSH in this population may be helpful in developing interventions to reduce the rate of DSH or to assist in the clinical judgement of suicidal intention after DSH has occurred.

Methods: The Parasuicide History Interview, version 2 (PHI-2) was used to determine the reasons for DSH events in 70 Australian women diagnosed with Borderline Personality Disorder. Factor analysis of the responses identified four empirically derived component factors. Multivariate models were developed to identify the independent predictors of suicidal deliberate self-harm (S-DSH) versus non-suicidal deliberate self-harm (NS-DSH) events.

Results: Participants and raters showed strong agreement in classifying S-DSH and NS-DSH events. Methods used that involved self-poisoning, jumping or stabbing showed increased risk for S-DSH, adjusted odds ratio 12.07 (95% CI 2.17, 67.29), compared to the referent group, external damage to skin with no rescue contact being sought. Although no grouping of reasons were independently significant, the lower the effectiveness of the DSH event to resolve the reasons for the event, the higher the risk of it having been a S-DSH event.

Conclusion: In clinical situations, any Borderline Personality Disorder patient seeking help or medical attention, using any method other than superficial external injury to skin, or reporting a failure to effectively resolve the reasons for the DSH event, should be considered as likely to have had a S-DSH event (greater suicidal intention). However, specific reasons for the DSH event, or individual subject characteristics, did not meaningfully distinguish S-DSH from NS-DSH events.
Frequent Multidrug-ResistantAcinetobacter baumanniiContamination of Gloves, Gowns, and Hands of Healthcare Workers
Authors: Morgan Daniel J. , Liang Stephen Y. , Smith Catherine L. , Johnson J. Kristie , Harris Anthony D. , Furuno Jon P. , Thorn Kerri A. , Snyder Graham M. , Day Hannah R. , Perencevich Eli N.
Published: May 2010

Background.

Multidrug-resistant (MDR) gram-negative bacilli are important nosocomial pathogens.

Objective.

To determine the incidence of transmission of MDRAcinetobacter baumanniiandPseudomonas aeruginosafrom patients to healthcare workers (HCWs) during routine patient care.

Design.

Prospective cohort study.

Setting.

Medical and surgical intensive care units.

Methods.

We observed HCWs who entered the rooms of patients colonized with MDRA. baumanniior colonized with both MDRA. baumanniiand MDRP. aeruginosa. We examined their hands before room entry, their disposable gloves and/or gowns upon completion of patient care, and their hands after removal of gloves and/or gowns and before hand hygiene.

Results.

Sixty-five interactions occurred with patients colonized with MDRA. baumanniiand 134 with patients colonized with both MDRA. baumanniiand MDRP. aeruginosa. Of 199 interactions between HCWs and patients colonized with MDRA. baumannii, 77 (38.7% [95% confidence interval {CI}, 31.9%–45.5%]) resulted in HCW contamination of gloves and/or gowns, and 9 (4.5% [95% CI, 1.6%–7.4%]) resulted in contamination of HCW hands after glove removal before hand hygiene. Of 134 interactions with patients colonized with MDRP. aeruginosa, 11 (8.2% [95% CI, 3.6%–12.9%]) resulted in HCW contamination of gloves and/or gowns, and 1 resulted in HCW contamination of hands. Independent risk factors for contamination with MDRA. baumanniiwere manipulation of wound dressing (adjusted odds ratio [aQR], 25.9 [95% CI, 3.1–208.8]), manipulation of artificial airway (aOR, 2.1 [95% CI, 1.1–4.0]), time in room longer than 5 minutes (aOR, 4.3 [95% CI, 2.0–9.1]), being a physician or nurse practitioner (aOR, 7.4 [95% CI, 1.6–35.2]), and being a nurse (aOR, 2.3 [95% CI, 1.1–4.8]).

Conclusions.

Gowns, gloves, and unwashed hands of HCWs were frequently contaminated with MDRA. baumannii. MDRA. baumanniiappears to be more easily transmitted than MDRP. aeruginosaand perhaps more easily transmitted than previously studied methicillin-resistantStaphylococcus aureusor vancomycin-resistantEnterococcus. This ease of transmission may help explain the emergence of MDRA. baumannii.
Large magnetocaloric effect in Ni50Mn33.66Cr0.34In16 alloy
Authors: Sharma V K , Chattopadhyay M K , Roy S B
Published: May 2010

A large isothermal magnetic entropy change with a peak value of 17.7 J kg−1 K−1 has been observed across the austenite–martensite phase transition in Ni50Mn33.66Cr0.34In16 alloy near 270 K. In comparison with the parent Ni50Mn34In16 alloy this temperature regime of the peak in isothermal entropy change is closer to the ambient temperature by nearly 30 K. The effective refrigerant capacity is calculated to be 254 J kg−1, which is 15% higher than that of the parent alloy.
Surface oxidation and charge transfer inducing dipole–dipole interactions for homogeneous liquid crystal orientation
Authors: Kim Jeong-Hwan , Kang Young-Gu , Lim Ji-Hun , Oh Byeong-Yun , Park Hong-Gyu , Kim Byoung-Yong , Kim Young-Hwan , Ok Chul-Ho , Hwang Jeong-Yeon , Han Jeong-Min , Kim Sung-Ho , Park Tae-Kyu , Seo Dae-Shik
Published: May 2010

Generally, liquid crystal (LC) orientation on rubbed polystyrene (PS) surfaces runs in the direction orthogonal to the rubbing process. In this study, homogeneous LC orientations were produced in the direction parallel to the ion beam (IB) process on PS surfaces using various IB exposure energies. Through x-ray photoelectron spectroscopy it was shown that IB irradiation resulted in the reformation of O=C bonds resulting from surface oxidation or charge transfer, reversely tracing out the produced pretilt angles of the homogeneous LC. Moreover, thermal tests on IB-irradiated PS surfaces were carried out which showed that a relatively high IB exposure energy induced a thermally stable LC alignment property. Finally, we determined the mechanism by which homogeneous LCs are aligned on IB-irradiated PS surfaces with electro-optical properties of twisted-nematic LC cells.
Properties and response of composite material with spheroidal superelastic shape memory alloy inclusions subject to three-dimensional stress state
Authors: Birman Victor
Published: May 2010

This communication illustrates the method of evaluation of the stiffness tensor and the stress–strain relationship of a particulate composite material with randomly distributed spheroidal superelastic shape memory alloy (SMA) inclusions that is subject to three-dimensional stresses. The Mori–Tanaka homogenization technique in conjunction with the Tanaka phenomenological SMA theory is applied to develop relations between the properties of the composite material and the applied stresses. In addition, the composite stress–strain loop reflecting hysteresis within the SMA material is generated. It is shown that the energy dissipation within a metal matrix composite with spherical SMA inclusions is comparable to that observed in composites with SMA fibres. The solution is exact within the framework of the assumptions of the Mori–Tanaka and phenomenological SMA theories.
The Arf-like GTPase Arl8 Mediates Delivery of Endocytosed Macromolecules to Lysosomes inCaenorhabditis elegans
Authors: Nakae Isei , Fujino Tomoko , Kobayashi Tetsuo , Sasaki Ayaka , Kikko Yorifumi , Fukuyama Masamitsu , Gengyo-Ando Keiko , Mitani Shohei , Kontani Kenji , Katada Toshiaki
Published: May 2010

Late endocytic organelles including lysosomes are highly dynamic acidic organelles. Late endosomes and lysosomes directly fuse for content mixing to form hybrid organelles, from which lysosomes are reformed. It is not fully understood how these processes are regulated and maintained. Here we show that the Caenorhabditis elegans ARL-8 GTPase is localized primarily to lysosomes and involved in late endosome-lysosome fusion in the macrophage-like coelomocytes. Loss of arl-8 results in an increase in the number of late endosomal/lysosomal compartments, which are smaller than wild type. In arl-8 mutants, late endosomal compartments containing endocytosed macromolecules fail to fuse with lysosomal compartments enriched in the aspartic protease ASP-1. Furthermore, loss of arl-8 strongly suppresses formation of enlarged late endosome-lysosome hybrid organelles caused by mutations of cup-5, which is the orthologue of human mucolipin-1. These findings suggest that ARL-8 mediates delivery of endocytosed macromolecules to lysosomes by facilitating late endosome-lysosome fusion.
Automated analysis of protein subcellular location in time series images
Authors: Hu Yanhua , Osuna-Highley Elvira , Hua Juchang , Nowicki Theodore Scott , Stolz Robert , McKayle Camille , Murphy Robert F.
Published: May 2010

Motivation: Image analysis, machine learning and statistical modeling have become well established for the automatic recognition and comparison of the subcellular locations of proteins in microscope images. By using a comprehensive set of features describing static images, major subcellular patterns can be distinguished with near perfect accuracy. We now extend this work to time series images, which contain both spatial and temporal information. The goal is to use temporal features to improve recognition of protein patterns that are not fully distinguishable by their static features alone.

Results: We have adopted and designed five sets of features for capturing temporal behavior in 2D time series images, based on object tracking, temporal texture, normal flow, Fourier transforms and autoregression. Classification accuracy on an image collection for 12 fluorescently tagged proteins was increased when temporal features were used in addition to static features. Temporal texture, normal flow and Fourier transform features were most effective at increasing classification accuracy. We therefore extended these three feature sets to 3D time series images, but observed no significant improvement over results for 2D images. The methods for 2D and 3D temporal pattern analysis do not require segmentation of images into single cell regions, and are suitable for automated high-throughput microscopy applications.

Availability: Images, source code and results will be available upon publication at http://murphylab.web.cmu.edu/software

Contact:  murphy@cmu.edu
Effects of mangrove removal on benthic communities and sediment characteristics at Mangawhai Harbour, northern New Zealand
Authors: Alfaro Andrea C.
Published: May 2010

Alfaro, A. C. 2010. Effects of mangrove removal on benthic communities and sediment characteristics at Mangawhai Harbour, northern New Zealand. – ICES Journal of Marine Science, 67: 1087–1104. The spread of mangroves at many locations in temperate northern New Zealand provides a stark contrast to the well-documented trend in mangrove forest decline recorded through the tropics and subtropics. To explore this difference, improved understanding is needed of New Zealand's mangrove ecosystems and how they respond to anthropogenic disturbance. The effect of mangrove removal on the community ecology of mangrove stands and adjacent habitats was investigated within Mangawhai Estuary, northern New Zealand, between March 2004 and September 2006. The vegetation, benthic macrofauna, and sediments were sampled within habitats (marshgrass, mangrove stands, pneumatophore zones, sandflats, and channels) at a treatment site (mangroves removed) and two undisturbed sites, before and after mangrove-removal activities. Mature mangrove habitats had less total abundance and fewer taxa than all the other habitats sampled and were dominated by pulmonate snails (Amphibola crenata) and mud crabs (Helice crassa). Whereas faunal composition varied seasonally as a result of life-history dynamics, temporal changes could be attributed to mangrove-removal activities. Mangrove eradication was followed by immediate changes in the sediment from a muddy to sandier environment, which favoured an overall increase in the abundance of crabs, snails, and bivalves. However, unexpected topographic catchment reconfigurations in late 2005 may have caused a subsequent increase in the delivery of silt and organic content to the study area and an overall decrease in faunal density in March and September 2006. The study provides direct evidence of the effect of mangroves on sediment and benthic faunal characteristics and the importance of catchment-derived imports to estuarine ecosystems.
Linking sperm length and velocity: the importance of intramale variation
Authors: Fitzpatrick John L. , Garcia-Gonzalez Francisco , Evans Jonathan P.
Published: May 2010

Selection imposed through sperm competition is commonly thought to promote the evolution of longer sperm, since sperm length is assumed to be positively associated with sperm swimming velocity. Yet, the basis for this assumption remains controversial, and there is surprisingly little intraspecific evidence demonstrating such a link between sperm form and function. Here, we show that sperm length and velocity are highly correlated in the sea urchin
Heliocidaris erythrogramma
, but importantly we report that failure to account for within-male variation in these sperm traits can obscure this relationship. These findings, in conjunction with the mounting evidence for extremely high levels of intra-specific variance in sperm traits, suggest that a functional link between sperm morphology and velocity may be more prevalent than what current evidence suggests. Our findings also suggest that selection for faster swimming sperm may promote the evolution of longer sperm, thereby supporting recent findings from macroevolutionary studies.
Biomimetic coatings for bone tissue engineering of critical-sized defects
Authors: Liu Yuelian , Wu Gang , de Groot Klaas
Published: May 2010

The repair of critical-sized bone defects is still challenging in the fields of implantology, maxillofacial surgery and orthopaedics. Current therapies such as autografts and allografts are associated with various limitations. Cytokine-based bone tissue engineering has been attracting increasing attention. Bone-inducing agents have been locally injected to stimulate the native bone-formation activity, but without much success. The reason is that these drugs must be delivered slowly and at a low concentration to be effective. This then mimics the natural method of cytokine release. For this purpose, a suitable vehicle was developed, the so-called biomimetic coating, which can be deposited on metal implants as well as on biomaterials. Materials that are currently used to fill bony defects cannot by themselves trigger bone formation. Therefore, biological functionalization of such materials by the biomimetic method resulted in a novel biomimetic coating onto different biomaterials. Bone morphogenetic protein 2 (BMP-2)-incorporated biomimetic coating can be a solution for a large bone defect repair in the fields of dental implantology, maxillofacial surgery and orthopaedics. Here, we review the performance of the biomimetic coating bothin vitroandin vivo.
Ceramic microparticles and capsules via microfluidic processing of a preceramic polymer
Authors: Ye Congwang , Chen Anthony , Colombo Paolo , Martinez Carlos
Published: May 2010

We have developed a robust technique to fabricate monodispersed solid and porous ceramic particles and capsules from single and double emulsion drops composed of silsesquioxane preceramic polymer. A microcapillary microfluidic device was used to generate the monodispersed drops. In this device, two round capillaries are aligned facing each other inside a square capillary. Three fluids are needed to generate the double emulsions. The inner fluid, which flows through the input capillary, and the middle fluid, which flows through the void space between the square and inner fluid capillaries, form a coaxial co-flow in a direction that is opposite to the flow of the outer fluid. As the three fluids are forced through the exit capillary, the inner and middle fluids break into monodispersed double emulsion drops in a single-step process, at rates of up to 2000 drops s
−1
. Once the drops are generated, the silsesquioxane is cross-linked in solution and the cross-linked particles are dried and pyrolysed in an inert atmosphere to form oxycarbide glass particles. Particles with diameters ranging from 30 to 180 µm, shell thicknesses ranging from 10 to 50 µm and shell pore diameters ranging from 1 to 10 µm were easily prepared by changing fluid flow rates, device dimensions and fluid composition. The produced particles and capsules can be used in their polymeric state or pyrolysed to ceramic. This technique can be extended to other preceramic polymers and can be used to generate unique core–shell multimaterial particles.
Twenty-first century challenges for biomaterials
Authors: Hench Larry L. , Thompson Ian
Published: May 2010

During the 1960s and 1970s, a first generation of materials was specially developed for use inside the human body. These developments became the basis for the field of biomaterials. The devices made from biomaterials are called prostheses. Professor Bill Bonfield was one of the first to recognize the importance of understanding the mechanical properties of tissues, especially bone, in order to achieve reliable skeletal prostheses. His research was one of the pioneering efforts to understand the interaction of biomaterials with living tissues. The goal of all early biomaterials was to ‘achieve a suitable combination of physical properties to match those of the replaced tissue with a minimal toxic response in the host’. By 1980, there were more than 50 implanted prostheses in clinical use made from 40 different materials. At that time, more than three million prosthetic parts were being implanted in patients worldwide each year. A common feature of most of the 40 materials was biological ‘inertness’. Almost all materials used in the body were single-phase materials. Most implant materials were adaptations of already existing commercial materials with higher levels of purity to eliminate release of toxic by-products and minimize corrosion. This article is a tribute to Bill Bonfield's pioneering efforts in the field of bone biomechanics, biomaterials and interdisciplinary research. It is also a brief summary of the evolution of bioactive materials and the opportunities for tailoring the composition, texture and surface chemistry of them to meet five important challenges for the twenty-first century.