bluuebunny/crossref_metadata_2025 huggingface dataset:
Predicting the brain response to treatment using a Bayesian hierarchical model with application to a study of schizophrenia
Authors: Guo Ying , DuBois Bowman F. , Kilts Clinton
Published: October 2007

In vivo functional neuroimaging, including functional magnetic resonance imaging (fMRI) and positron emission tomography (PET), is becoming increasingly important in defining the pathophysiology of psychiatric disorders such as schizophrenia, major depression, and Alzheimer's disease. Furthermore, recent studies have begun to investigate the possibility of using functional neuroimaging to guide treatment selection for individual patients. By studying the changes between a patient's pre‐ and post‐treatment brain activity, investigators are gaining insights into the impact of treatment on behavior‐related neural processing traits associated with particular psychiatric disorders. Furthermore, these studies may shed light on the neural basis of response and nonresponse to specific treatments. The practical limitation of such studies is that the post‐treatment scans offer little guidance to treatment selection in clinical settings, since treatment decisions precede the availability of post‐treatment brain scans. This shortcoming represents the impetus for developing statistical methodology that would provide clinicians with predictive information concerning the effect of treatment on brain activity and, ultimately, symptom‐related behaviors. We present a prediction algorithm that uses a patient's pretreatment scans, coupled with relevant patient characteristics, to forecast the patient's brain activity following a specified treatment regimen. We derive our predictive method from a Bayesian hierarchical model constructed on the pre‐ and post‐treatment scans of designated training data. We perform estimation using the expectation–maximization algorithm. We evaluate the accuracy of our proposed prediction method usingK‐fold cross‐validation, quantifying the error using two new measures that we propose for neuroimaging data. The proposed method is applicable to both PET and fMRI studies. We illustrate its use with a PET study of working memory in patients with schizophrenia and an fMRI data example is also provided. Hum Brain Mapp 29:1092–1109, 2007. © 2007 Wiley‐Liss, Inc.
Activation of septal 5‐HT1A receptors alters spatial memory encoding, interferes with consolidation, but does not affect retrieval in rats subjected to a water‐maze task
Authors: Koenig Julie , Cosquer Brigitte , Cassel Jean‐Christophe
Published: October 2007

Using Long‐Evans rats tested in a water maze, this study assessed the role of 5‐HT1A/5‐HT7 receptors of the medial septum in encoding, consolidation, and retrieval of spatial information. The testing protocol (acquisition: daily four‐trial sessions over three consecutive days; retention: probe trial on day 4) was first validated by showing that intraseptal infusions of lidocaine (LIDO; 40 μg/0.5 μL) disrupted acquisition and retrieval of the task. 8‐OH‐DPAT (4 μg/0.5 μL) infused before each acquisition session prevented learning/retention of the platform location, an effect attenuated by pretreatment with the 5‐HT1A receptor antagonist WAY 100635. With the 5‐HT7 antagonist SB 269970, the 8‐OH‐DPAT‐induced acquisition deficit seemed attenuated, but there was no subsequent retention. When infused immediately, 1, 4, or 6 h after each acquisition session, 8‐OH‐DPAT did not hinder consolidation. When the infusions were performed 2 h postacquisition, however, consolidation was disrupted. Finally, when infused before a probe trial after drug‐free acquisition, 8‐OH‐DPAT had no effect, suggesting no interference with retrieval processes. We also established that 8‐OH‐DPAT had no effects when the platform was visible, and altered neither home‐cage activity nor anxiety‐related behavior (elevated plus‐maze). Altogether, these results show that 5‐HT1A receptors in the septal region contribute both to declarative‐like information encoding and subsequently, within a given postacquisition time window, to its consolidation. They do not participate in the retrieval of recently learned declarative‐like information. These observations suggest that 5‐HT1A receptors of the medial septum contribute to a serotonin‐mediated mechanism involved in the encoding and consolidation, not the retrieval of spatial hippocampal‐ dependent knowledge. These results might have some relevance to approaches aimed at modifying serotonergic functions in the brain for the treatment of disorders such as depression, anxiety, post‐traumatic stress, and amnesia. © 2007 Wiley‐Liss, Inc.
An epigenetic induction of a right‐shift in hippocampal asymmetry: Selectivity for short‐ and long‐term potentiation but not post‐tetanic potentiation
Authors: Tang Akaysha C. , Zou Bende , Reeb Bethany C. , Connor John A.
Published: October 2007

In humans, it is well established that major psychological functions are asymmetrically represented between the left and right cerebral cortices. The developmental origin of such functional lateralization remains unknown. Using the rat as a model system, we examined whether exposing neonates briefly to a novel environment can differentially affect synaptic plasticity in the left and right hippocampi during adulthood. During the first 3 weeks of life, one half of the pups from a litter spent 3 min daily away from their familiar home environment (Novel) while their littermates remained in that familiar environment (Home). At adulthood (7‐months old), post‐tetanic potentiation (PTP) of excitatory post‐synaptic potentials (EPSPs), a very short‐lasting form of plasticity, was greater among the Novel than the Home rats in both left and right hippocampi. In contrast, the novelty‐induced increases in short‐ and long‐term potentiation (STP, LTP), two relatively longer‐lasting forms of plasticity, were found only in the right hippocampus. These findings demonstrate that a phase‐selective asymmetry in hippocampal synaptic plasticity can be induced epigenetically by seemingly small systematic differences in early life environment. The selectivity of this asymmetry for the longer‐lasting forms of synaptic plasticity suggests that the observed asymmetry in plasticity may contribute specifically to an asymmetric learning process which, in turn, may contribute to a functional asymmetry in the neocortex. © 2007 Wiley‐Liss, Inc.
Sexual orientation‐related differences in allocentric spatial memory tasks
Authors: Rahman Qazi , Koerting Johanna
Published: October 2007

Spatial memory in mammals, including humans, appears highly sexually dimorphic. The present investigation sought to examine if spatial learning and spatial memory in humans is also linked to sexual orientation. This was achieved by using virtual reality versions of two classic paradigms developed in animal models of hippocampal functioning, the Morris Water Maze (MWM) and Radial Arm Maze (RAM). Here, we show that in contrast to heterosexual men, and in congruence with heterosexual women, homosexual men displayed significantly greater search latencies (spatial learning) during a virtual Morris Water Maze. During a virtual 8‐arm Radial Arm Maze, heterosexual males had significantly shorter search latency than heterosexual females, and did not differ from homosexual males. Statistical modeling revealed that variations in neurodevelopmental markers previously associated with human sexual orientation (2nd to 4th finger length ratios and older fraternal siblings) differentially predicted MWM probe trial performance and RAM search latencies only. These data may limit the number of possible neurodevelopmental pathways responsible for sexual variation in components of spatial learning and memory. © 2007 Wiley‐Liss, Inc.
Differential long‐term neurotoxicity of HIV‐1 proteins in the rat hippocampal formation: A design‐based stereological study
Authors: Fitting Sylvia , Booze Rosemarie M. , Hasselrot Ulla , Mactutus Charles F.
Published: October 2007

The human immunodeficiency virus type 1 (HIV‐1) proteins, gp120 and Tat, are believed to play a role in mediating central nervous system (CNS) pathology in HIV‐1 infected patients. Using design‐based stereology, we examined the role of neonatal intrahippocampal injections of gp120 and Tat on the adult hippocampus (∼7½ month). Postnatal day (P)1‐treated Sprague‐Dawley rats were bilaterally injected with vehicle (VEH, 0.5 μl sterile buffer), gp120 (100 ng), Tat (25 μg) or combined gp120 + Tat (100 ng + 25 μg). Using Nissl‐stained tissue sections, we quantified total neurons in five subregions of the rat hippocampus [granual layer (GL), hilus of the dentate gyrus (DGH), cornu ammonis fields (CA)2/3, CA1, and subiculum (SUB)], and total glial cells (astrocytes and oligodendrocytes) in two subregions (DGH and SUB). Estimates of cell area and cell volume were taken in the DGH. There was a significant reduction of neuron number in the CA2/3 subfield by Tat and gp120, and a significant reduction in the DGH by Tat only. For glial cells, numbers of astrocytes in the DGH and SUB were increased by the Tat protein, whereas no effects were noted for gp120. Finally, for oligodendrocytes Tat increased cell number in the DGH but not in any other region; gp120 had no detectable effect in any brain region. Estimates of cell area and cell volume of the three different cell types revealed no significant differences between treatments. Collectively, these results suggest differential effects of gp120 and Tat on the estimated total number of neurons, as well as on the number of glial cells. © 2007 Wiley‐Liss, Inc.
Immunogenicity of bioactive magnetic nanoparticles: Natural and acquired antibodies
Authors: Ziv Ofra , Avtalion Ramy R. , Margel Shlomo
Published: October 2007

Uniform magnetic nanoparticles (MNP) were prepared by nucleation followed by controlled growth of maghemite thin films onto porcine gelatin nuclei. The formed gelatin containing MNP (Gel‐MNP) were then coated with dextran (Gel‐MNP‐Dex) followed by human serum albumin (Gel‐MNP‐Dex‐HSA). Since these MNP are designated for clinical applications, studies concerning the immunogenicity of their antigenic components (porcine gelatin, dextran, and HSA) have been performed in BALB‐C mice. These studies demonstrated that plasma of nonimmunized mice already contains basal levels of natural antibodies against all of these antigenic components. This work also demonstrated that the conjugated gelatin is a weak immunogen: Intraperitoneal injection of the various MNP (Gel‐MNP, Gel‐MNP‐Dex dispersed in PBS emulsified with Incomplete Freund's Adjuvant (IFA) mineral oil and Gel‐MNP‐Dex‐HSA dispersed in PBS) did not increase significantly the acquired anti‐gelatin antibody titers. Exceptional behavior was observed following immunization with Gel‐MNP‐Dex‐HSA dispersed in PBS emulsified with IFA, which exhibited an adjuvant effect and turned gelatin into a stronger immunogen. In contrast to gelatin, the conjugated HSA and dextran were found to be strong immunogens. The possibility that the various MNP will not induce an autoimmune response as a result of their clinical use is discussed in the contest of the protective role of the natural antibodies. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res, 2008
A novel multiphase anodic spark deposition coating for the improvement of orthopedic implant osseointegration: An experimental study in cortical bone of sheep
Authors: Giavaresi Gianluca , Fini Milena , Chiesa Roberto , Giordano Carmen , Sandrini Enrico , Bianchi Andrea E. , Ceribelli Paolo , Giardino Roberto
Published: October 2007

The effect of a new three‐step anodic spark deposition process, labeled TiSpark, including two consecutive treatments performed first in a P solution and second in Ca solution, followed by an additional alkali etching step, was investigated for the improvement of osseointegration of commercial grade 2 titanium, machined (Ti) or Al2O3 sandblasted (Ti‐SA), cylindrical implants (12 mm in length and 4 mm in diameter) in cortical bone of 12 adult sheep. Histomorphometric and microhardness measurements were carried out at each experimental time (4, 8, and 12 weeks) to quantify the bone‐to‐implant contact around the implants as well as the newly bone hardness and bone maturation index. TiSpark treated surfaces were covered by a thick layer of crystalline anatase TiO2 and by a further Ca/P layer. Bone tissue extends and grows on the surface of the TiSpark treated implants without any fibrous tissue, enhancing the short‐term osseointegration properties of implant. Bone mineralization rate was also influenced by the chemical composition of implants and sandblasted materials presented the lowest bone maturation rate at the interface. Data suggests that the TiSpark treatment produces a modification of the Ti surface, which presents good bioactivity and may be suitable for achieving a stable implant osseointegration. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res, 2008
Volumes of normal ovaries, ovaries with benign lesions, and ovaries with cancer in menopausal women: Is there an optimal cut‐off value to predict malignancy?
Authors: Aviram Rami , Gassner Gilad , Markovitch Ofer , Cohen Ilan , Fishman Ami , Tepper Ronnie
Published: October 2007

Purpose:

To evaluate different ovarian volume cut‐off values to distinguish between normal ovaries, benign lesions, and malignant lesions in menopausal women.

Methods:

Transvaginal sonographic ovarian volume measurements were performed in 362 menopausal patients prior to gynecologic surgery. Based on the histopathologic results, a total of 466 ovaries were divided into 3 groups: normal ovary, benign lesion, and malignant tumor. Different ovarian volume cut‐off values were analyzed via receiver operating characteristic curves to determine the optimal cut‐off value.

Results:

The mean ovarian volumes in the normal ovary, benign lesion, and malignant tumor groups were 3.4 ± 2.2 cm3 (range, 0.6–9.6 cm3), 102 ± 308 cm3 (range, 0.3–3543 cm3), and 368 ± 1176 cm3 (range, 8.1–9908) cm3, respectively. Cut‐off values of 8 cm3 and 10 cm3 to distinguish between malignant and nonmalignant lesions had a sensitivity of 100% and 97% and a specificity of 39% and 45%, respectively.

Conclusion:

In menopausal patients, any ovary with a volume >8 cm3 can potentially harbor a cancer. © 2007 Wiley Periodicals, Inc. J Clin Ultrasound, 2008
The contingent effect of constructive confrontation on the relationship between shared mental models and decision quality
Authors: Kellermanns Franz W. , Floyd Steven W. , Pearson Allison W. , Spencer Barbara
Published: October 2007

Work teams are being utilized more frequently to give organizations access to the broader knowledge and skill base of employees, as well as to provide for adaptive, efficient decision‐making. In teams, we argue that constructive confrontation norms are an important contingency variable in the relationship between mental model similarity and decision quality. Mental model similarity helps team members understand one another's perspectives and reduces the likelihood of conflict. Accordingly, mental model similarity improves decision quality. When strong norms of constructive confrontation are in place, however, teams are in a better position to reap the benefits of conflict (greater diversity of inputs) without experiencing its negative consequences. Thus, when constructive confrontation norms are strong, less mental model similarity (i.e., more diversity of perspectives) is likely to improve decision quality. Copyright © 2007 John Wiley & Sons, Ltd.
Soils and land use in the Tigray highlands (Northern Ethiopia)
Authors: Nyssen J. , Naudts J. , De Geyndt K. , Haile Mitiku , Poesen J. , Moeyersons J. , Deckers J.
Published: October 2007

Land use in a 208 ha representative catchment in the Tigray Highlands, Dogu'a Tembien district in Northern Ethiopia was studied in relation to soil geography. Typical soils are Vertisols, Vertic Cambisols, Cumulic Regosols, Calcaric Regosols and Phaeozems. Patterns of land use vary greatly within the catchment and results from χ2‐tests showed strong associations (p < 0·001) between soil type and land use and crop production system. There is a strong association between cropland and colluvium high in basaltic content because the most fertile soils, such as Vertisols and Vertic Cambisols, have developed on this material. Preference is for autochthonous soils on in situ parent material, irrespective of the rock type, to be put under rangeland. Land use by smallholders in Dogu'a Tembien appears to be the result primarily of the interaction between environmental and social factors. Copyright © 2007 John Wiley & Sons, Ltd.
Influence of the chemical composition of 20MoCrS4 and low‐alloyed TRIP steel on the intensity of high temperature corrosion
Authors: Mašek B. , Staňková H. , Meyer L.W. , Krüger L.
Published: October 2007

Material behaviour in a corroding medium varies depending on its properties. These properties are affected by the treatment, alloy elements and last but not least its surface condition. The sensitivity of a material to iron scale formation and decarburisation limits some technological processes, especially those where materials are exposed to a corroding medium at high temperatures for a very long time. A typical example is the heating of semi‐products to forming temperature. Considering that similar materials can react differently under the same heating conditions, it is important to know the characteristic behaviour of a material in certain production processes. A comparison of two kinds of steels during model treatment was carried out in order to be able to determine the influence of different heating parameters. The model treatment consisted of three different heating temperatures at three different time durations. The intensity of the oxidation process was analysed by means of mass increments and the thickness of the oxide layer was detected via metallography. The depth and intensity of the surface layer decarburisation was evaluated from the profile of the microhardness change curve.
The interaction of message frames and reference points in prosocial persuasive appeals
Authors: Loroz Peggy Sue
Published: October 2007

This research seeks to reconcile inconsistent results obtained in prior framing research in prosocial persuasion contexts by proposing that the reference point (self or self‐other) invoked in a persuasive appeal moderates the impact of a particular message frame (positive or negative) on attitudes and behavioral intentions. Two experiments were conducted in which frame and reference point were manipulated in persuasive messages promoting either recycling or prevention of HPV, a sexually transmitted disease. The results indicate that in persuasive social contexts, negative frames may be most persuasive with self‐referencing appeals while positive frames work best when benefits to self as well as others are emphasized. This suggests that developers of prosocial communications should be cognizant of both the message frame and the reference point invoked in these messages in order to have maximum persuasion impact. © 2007 Wiley Periodicals, Inc.
Synthesis of Polyelectrolytes Bearing Phosphorylcholine Moieties
Authors: Reisch Andreas , Voegel Jean‐Claude , Decher Gero , Schaaf Pierre , Mésini Philippe J.
Published: October 2007

We report on the modification of the polyelectrolytes poly(L‐glutamic acid) (PGA), poly(acrylic acid) (PAA), and poly(L‐lysine) (PLL) with side groups bearing phosphorylcholine (PC) groups. Two different side chains were synthesized from monoamino tri‐ or tetraethylene glycol, both with PC group linked to the OH end: the tert‐butyloxycarbonyl protected compounds BOCNH(EO)nPC (n = 2, 3) and the succinylated compound SucNH(EO)3PC. BOCNH(EO)nPC was deprotected and the resulting amine was condensed with PGA or PAA and SucNH(EO)3PC was directly coupled to PLL. Degrees of substitution as high as 80% were obtained with the method described. These polyelectrolytes are potential candidates to fabricate multilayers with protein repellent properties.

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Interactive effects of low temperature and roscovitine (ROS) on meiotic resumption and developmental potential of goat oocytes
Authors: Han Dong , Zhao Ben‐Tian , Liu Yong , Li Jing‐Jing , Wu Yan‐Guang , Lan Guo‐Cheng , Tan Jing‐He
Published: October 2007

The objective of this article was to study the effects of low temperature and roscovitine (ROS) on meiotic resumption and developmental potential of goat oocytes. Goat oocytes were cultured at different temperatures in medium containing different concentrations of ROS, and at the end of culture, oocytes were either matured or processed for light/confocal microscopy. The matured oocytes were activated chemically or fertilized in vitro for embryo development. Meiotic arrest was successfully maintained for 24 hr with 0, 50, and 200 µM ROS at 5, 20, and 38.5°C, respectively. Following chemical activation, morulae/blastocysts (M/B) rates similar to untreated oocytes were obtained in oocytes that had been inhibited for 24 hr at 5°C without ROS (Protocol 5C) or at 20°C with 50 µM ROS (Protocol 20C) or for 8 hr at 38.5°C with 200 µM ROS (Protocol 8 hr), but no blastulation was observed after oocytes were inhibited at 38.5°C with 200 µM ROS for 24 hr. Following fertilization, however, while M/B rates similar to controls were achieved in oocytes treated with protocols 5C and 20C, few oocytes inhibited with Protocol 8 hr developed into morulae, due to a high incidence of polyspermy. Changes in GV chromatin configuration were not observed after inhibition with Protocol 5C, but were apparent after inhibition with protocols 20C and 8 hr, leading to a precocious germinal vesicle breakdown (GVBD) during subsequent maturation. Cortical granule (CG) migration and the formation of microtubule organizing centers occurred during inhibition and were more obvious in the absence of ROS. Significantly more oocytes inhibited by protocols 5C and 20C than by Protocol 8 hr completed CG migration after maturation. In conclusion, goat oocytes were tolerant to chilling and culture at lower temperatures with less ROS was better than culture at higher temperatures with more ROS for oocyte GVBD inhibition. Mol. Reprod. Dev. 75: 838–846, 2008. © 2007 Wiley‐Liss, Inc.
Changes in global histone acetylation pattern in somatic cell nuclei after their transfer into oocytes at different stages of maturation
Authors: Fulka Helena
Published: October 2007

In our study, we have examined the pattern of global histone modification changes in somatic cell nuclei after their transfer into mouse oocytes at different stages of maturation or after their parthenogenetic activation. While germinal vesicle (GV) staged immature oocytes are strongly labeled with anti‐acetylated histone H3 and H4 antibodies, the signal is absent in both metaphase I and metaphase II oocytes (MI, MII). In contrast, the oocytes of all maturation stages show a presence of trimethylated H3/K4 in their chromatin. When somatic cells were fused to intact or enucleated GV oocytes, both the GV and the somatic cell nucleus showed a very strong signal for all the antibodies used. On the other hand, when somatic cells nuclei that are AcH3 and AcH4 positive before fusion are introduced into either intact or enucleated MI or MII oocytes, their acetylation signal decreased rapidly and was totally absent after a prolonged culture. This was not the case when anti‐trimethyl H3/K4 antibody was used. The somatic cell chromatin showed only a slight decrease in the intensity of labeling after its transfer into MI or MII oocytes. This decrease was, however, evident only after a prolonged culture. These results suggest not only a relatively higher stability of the methylation modification but also some difference between the oocyte and somatic chromatin. The ability to deacetylate the chromatin of transferred somatic nuclei disappears rapidly after the oocyte activation. Our results indicate that at least some reprogramming activity appears in the oocyte cytoplasm almost immediately after GV breakdown (GVBD), and that this activity rapidly disappears after the oocyte activation. Mol. Reprod. Dev. 75: 556–564, 2008. © 2007 Wiley‐Liss, Inc.
Possible role for nitric oxide dysregulation in critical illness myopathy
Authors: Capasso Margherita , Muzio Antonio Di , Pandolfi Assunta , Pace Marta , Tomo Pamela Di , Ragno Michele , Uncini Antonino
Published: October 2007

Muscle fiber inexcitability and myosin loss underlie weakness in critical illness myopathy (CIM). Nitric oxide (NO) takes part in the maintenance of muscle fiber resting potential and, in pathological conditions accompanied by oxidative stress, may damage proteins through peroxynitrite generation. Sepsis and other conditions associated with CIM may differentially affect expression of NO synthases (NOSs), so that both downregulation and upregulation with excessive peroxynitrite production can be hypothesized. In six patients with CIM we studied NOS1, NOS2, and NOS3 protein expression by immunohistochemistry and Western blot. To investigate peroxynitrite production, we performed immunohistochemistry for nitrotyrosine and measured nitrotyrosine levels by enzyme‐linked immunosorbent assay. In three patients, sarcolemmal staining for NOS1 was selectively absent. In the others, it was absent in atrophic fibers and absent or reduced in non‐atrophic fibers. Total NOS1 protein content was reduced by 41% in patients compared to controls, whereas no significant changes were found in levels and localization of NOS2, NOS3, and nitrotyrosine. Further studies are warranted to determine whether NOS1 loss plays a role in the pathophysiology of CIM, possibly reducing the release of NO at the sarcolemma and affecting muscle fiber excitability. Muscle Nerve, 2007
Reaction products of parabanic acid and alkylene carbonates as components of polyurethane foams
Authors: Zarzyka‐Niemiec Iwona
Published: October 2007

Esteramidoimidotetraols are obtained by reacting 8‐ and 12‐molar excess of ethylene carbonate or propylene carbonate with parabanic acid. The parabanic acid ring undergoes opening, and linear polymeric products are formed. The products can conveniently be used as polyols for polyurethane foams. The results of a study on thermal stability and on compressive strength of foams prepared from these tetraols, measured before and after thermal treatment, are reported. Copyright © 2007 Society of Chemical Industry
Coconut water as a potential resource for cellulose acetate membrane preparation
Authors: Radiman Cynthia , Yuliani Galuh
Published: October 2007

BACKGROUND: Cellulose acetate membranes are frequently used for pressure‐driven membrane processes. The aim of this work was to prepare cellulose acetate membranes from nata‐de‐coco using coconut water as starting material. The use of this lignin‐free material will certainly minimize the use of chemicals usually needed in the traditional pulps and substitute for the use of wood, which helps prevent global warming and preserves nature as well.

RESULTS: Coconut water was fermented by Acetobacter xylinum for 6 days to produce nata‐de‐coco, which was then acetylated to produce cellulose diacetate with an acetyl content of 39.6%. Fourier transform infrared analysis showed characteristic peaks for the acetyl group at 1748 and 1236 cm−1. The resulting membranes made from the hydrolysis product showed a water flux of 210.5 L m−2 h−1 under an applied pressure of 2 kg cm−2 while the rejection coefficients of dextran T‐500 and T‐2000 solutions were 78 and 93.7%, respectively.

CONCLUSION: Coconut water has a potential to be used in the fabrication of membranes by converting it to nata‐de‐coco and then to cellulose diacetate which gives an added value to its original nature. It is also highly competitive compared to the traditional pulps, by which acetylation decreases the degree of crystallinity of nata‐de‐coco resulting in higher membrane permeability. Copyright © 2007 Society of Chemical Industry
Preparation and properties of styrene–ethylene–butylene–styrene block copolymer/clay nanocomposites: I. Effect of clay content and compatibilizer types
Authors: Chen Wen‐Chih , Lai Sun‐Mou , Chen Chun‐Ming
Published: October 2007

BACKGROUND: Polymer/clay (silicate) systems exhibit great promise for industrial applications due to their ability to display synergistically advanced properties with relatively small amounts of clay loads. The effects of various compatibilizers on styrene–ethylene–butylene–styrene block copolymer (SEBS)/clay nanocomposites with various amounts of clay using a melt mixing process are investigated.

RESULTS: SEBS/clay nanocomposites were prepared via melt mixing. Two types of maleated compatibilizers, styrene–ethylene–butylene–styrene block copolymer grafted maleic anhydride (SEBS‐g‐MA) and polypropylene grafted maleic anhydride (PP‐g‐MA), were incorporated to improve the dispersion of various amounts of commercial organoclay (denoted as 20A). Experimental samples were analyzed using X‐ray diffraction and transmission electron microscopy. Thermal stability was enhanced through the addition of clay with or without compatibilizers. The dynamic mechanical properties and rheological properties indicated enhanced interaction for the compatibilized nanocomposites. In particular, the PP‐g‐MA compatibilized system conferred higher tensile strength or Young's modulus than the SEBS‐g‐MA compatibilized system, although SEBS‐g‐MA seemed to further expand the interlayer spacing of the clay compared with PP‐g‐MA.

CONCLUSION: These unusual results suggest that the matrix properties and compatibilizer types are crucial factors in attaining the best mechanical property performance at a specific clay content. Copyright © 2007 Society of Chemical Industry
Optically active polyethers from chiral terminal epoxides with bulky group
Authors: Cao Jing , Yang Nian‐Fa , Wang Pang‐Deng , Yang Li‐Wen
Published: October 2007

BACKGROUND: Although the backbone of polyethers from epoxides is flexible and less rigid in solution, we try to determine whether chiral terminal epoxides could form single‐handed helical coiling in solution with the introduction of a bulky group at the 3‐carbon that may fix the helix sense through the large interaction between pendants.

RESULTS: Several chiral terminal epoxides with bulky groups at the 3‐carbon such as (S)‐4,4,4‐triphenyl‐1‐butene oxide ((S)‐TPBO), (S)‐4,4‐diphenyl‐1‐butene oxide, (S)‐4‐benzyl‐4,4‐diphenyl‐1‐butene oxide and (S)‐4,4‐diphenyl‐1‐nonene oxide were synthesized and polymerized. Except for poly[(S)‐TPBO], the polyepoxides could not retain a stable helical conformation in solution.

CONCLUSION: The conformation and length of polymers were directly related to the bulky substituent on the 3‐carbon of chiral epoxides, and if the bulkiness and rigidity of the substituent were appropriate, the helical conformation of the polyethers formed could be retained in solution. Optically active polyethers would be potential substitutes for optically active poly(triphenylmethyl methacrylate) due to their much greater hydrolytic resistance. Copyright © 2007 Society of Chemical Industry
Effects of thermal volume expansion on positive temperature coefficient effect for carbon black filled polymer composites
Authors: Shen L. , Lou Z. D. , Qian Y. J.
Published: October 2007

Polymeric positive temperature coefficient (PTC) materials have been prepared by incorporating carbon black (CB) into two different polymer matrices, crystalline high density polyethylene (HDPE) and amorphous polystyrene (PS). The effects of thermal volume expansion on the electrical properties of conductive polymer composites were studied. The volume fraction of conductive particles behaves like a switch from insulator to conductor in the polymeric PTC composite. Our mathematical model and experimental model have proved that the abrupt resistivity increase at PTC transition range and at the percolation curve close to the critical volume fraction for both polymeric PTC composites have the same conductive mechanism. The thermal expansion is one of the key factors responsible for the PTC effect and can be seen by comparing the PTC transition curves from model predictions and experiment. Furthermore, the model predicts PTC curves of CB/PS composite more successfully than it does for the CB/HDPE composite, and the reasons for this are also discussed. © 2007 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 45: 3078–3083, 2007
Removal of Color Caused by Various Chemical Compounds Using Electrical Discharges in a Foaming Column
Authors: Pawłat Joanna , Ihara Satoshi
Published: October 2007

Production of oxidants during the electrical discharge in a foaming environment is confirmed. The influence of electrical discharge on the removal of color caused by various organic compounds such as ethyl violet, humic acid, indigo blue, and methylene blue in the foaming apparatus has been investigated. Discoloration is observed visually and concentrations of pollutants have been measured, which include the influence of the type of gas, gas flow rate, and frequency on the removal rate.

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Summary of European directives for explosion safety
Authors: Versloot N.H.A. , Klein A.J.J. , De Maaijer M.
Published: October 2007

On July 1, 2003 a transitional period has ended and two European directives became fully active:

Directive 1999/92/EC

Directive 94/9/EC

These directives have an impact on companies with an explosion hazard (gas, vapor, mist, or dust explosions) and on manufacturers of equipment intended to be used in explosive atmospheres. The directives were incorporated into the national law of each member state of the European Union. These regulations are examples of achieving a common European market. In this article, the background of the European Directives will be discussed and the impact on the users. © 2007 American Institute of Chemical Engineers Process Saf Prog 2008
Plant volatile aldehydes as natural insecticides against stored‐product beetles
Authors: Hubert Jan , Münzbergová Zuzana , Santino Angelo
Published: October 2007

BACKGROUND: Infestation by stored‐product pests causes serious losses in food and feed commodities. Among possible strategies against these pests, which aim to reduce the use of synthetic insecticides, including fumigants, natural insecticides produced by plants represent one of the most promising approaches for their ecochemical control. Three six‐carbon and nine‐carbon aldehydes, natural plant volatiles produced by the plant lipoxygenase pathway, were tested for their insecticidal activity against five species of stored‐product beetles in feeding, fumigation and combined bioassays.

RESULTS: The compounds (2E,6Z)‐nonadienal, (2E)‐nonenal and (2E)‐hexenal were incorporated into feeding discs in feeding bioassays or evaporated from filter paper in closed glass chambers in fumigation tests. Beetle sensitivity to aldehydes differed according to the different treatments. The highest activity was obtained by (2E)‐hexenal in fumigation tests, with the LC50 ranging from 4 to 26 mg L−1, while (2E, 6Z)‐nonadienal was the most effective in feeding tests, giving LD50s ranging from 0.44 to 2.76 mg g−1 when applied to feeding discs. Fumigation tests in the presence of wheat grains confirmed that (2E)‐hexenal was the most effective compound, with a calculated LC99 ranging from 33 to 166 mg L−1.

CONCLUSION: The results of both feeding and fumigation tests indicated that natural plant aldehydes are potential candidates to control stored‐product beetles. Copyright © 2007 Society of Chemical Industry
In vitro and in vivo antiplasmodial activity of ‘Saye’, an herbal Remedy used in Burkina Faso traditional medicine
Authors: Traoré M. , Diallo A. , Nikièma J. B. , Tinto H. , Dakuyo Z. P. , Ouédraogo J. B. , Guissou I. P. , Guiguemdé T. R.
Published: October 2007

‘Saye’, a traditional medicine used in Burkina Faso, which consists of extracts of Cochlospermum planchonii (rhizome), Cassia alata (leaf) and Phyllanthus amarus (whole plant), showed a significant effect against Plasmodium falciparum and Plasmodium berghei parasites grown in vivo (IC50 = 80.11 ± 3.40 µg/mL; ED50 = 112.78 ± 32.32 mg/kg). In vitro the activity was lower. Copyright © 2007 John Wiley & Sons, Ltd.
In vitro anti‐biofilm activity of macelignan isolated from Myristica fragrans Houtt. against oral primary colonizer bacteria
Authors: Yanti  , Rukayadi Yaya , Kim Kyu‐Hoi , Hwang Jae‐Kwan
Published: October 2007

In early dental plaque formation, oral primary colonizers such as Streptococcus mutans, Streptococcus sanguis and Actinomyces viscosus are initially attached to the pellicle‐coated tooth surface to form a biofilm. The study aimed to determine the efficacy of macelignan, isolated from nutmeg (Myristica fragrans Houtt.), in removing each single oral primary biofilm in vitro on a polystyrene 96‐well microtiter plate. Four biofilm growth phases (4, 12, 20 and 24 h) were evaluated in this study after treatment with macelignan at various concentrations (0.2, 2 and 10 µg/mL) and exposure times (5, 10 and 30 min). Anti‐biofilm activity of macelignan was measured as the percentage of the remaining biofilm absorbance after macelignan treatment in comparison with the untreated control. At 24 h of biofilm growth, S. mutans, A. viscosus and S. sanguis biofilms were reduced by up to 30%, 30% and 38%, respectively, after treatment with 10 µg/mL macelignan for 5 min. Increasing the treatment time to 30 min resulted in a reduction of more than 50% of each of the single primary biofilms. The results indicate that macelignan is a potent natural anti‐biofilm agent against oral primary colonizers. Copyright © 2007 John Wiley & Sons, Ltd.
Anti‐acne activity of Selaginella involvens extract and its non‐antibiotic antimicrobial potential on Propionibacterium acnes
Authors: Joo Seong Soo , Jang Su Kil , Kim Sung Geun , Choi Jae‐Seok , Hwang Kwang Woo , Lee Do Ik
Published: October 2007

Acne is a typical condition of adolescence and is caused by multi‐factorial events including hormonal, microbiological and immunological mechanisms. Although there has been much debate about the direct involvement of bacteria, Propionibacterium acnes is now believed to contribute to the inflammatory stages of the condition, and thus initiate the inflamed lesion. The present study examined the anti‐acne properties of the Selaginella involvens extract (SIE) in cell models. Primarily, SIE was not found to be cytotoxic under 50 µg/mL, and revealed the inhibitory effect on both nitric oxide (NO) production and iNOS/IL‐1β expression as well as the NO scavenging effect. The IL‐1α and IL‐8 cytokines, triggering the inflammatory acne response, were also inhibited in keratinocytes when stimulated with viable P. acnes. Furthermore, SIE was found to have an antioxidant effect in a dose‐dependent manner in the hydroxyl radical‐mediated oxidation test. Finally, it was found that SIE has non‐antibiotic antimicrobial activity at a dose greater than 100 µg/mL on P. acnes. In conclusion, SIE may be a safe non‐antibiotic anti‐acne source in the therapeutic application of the treatment of acne development by reducing the chance of non‐specific initiation and augmentation phase of the inflammatory response. Copyright © 2007 John Wiley & Sons, Ltd.
Minimally Invasive Robotic Association 2nd International Congress
Authors: Taylor G. W.
Published: October 2007

Background

The Minimally Invasive Robotic Association (MIRA) is an international organization that aims to provide a cross‐specialty forum in which minimal access surgeons can share their experience of the new and emerging discipline of robotic surgery. This is an overview of the 2nd International Congress.

Methods

There was heavy emphasis on short presentations that allowed maximum opportunity for delegates to participate, share experience and exchange ideas.

Results

Over 90 presentations were enjoyed by delegates over the 3 day event, each stimulating lively discussion from the audience. Experience of robotic urological, general, gynaecological, paediatric, cardiac and thoracic surgery was presented. There were also several presentations of new technology in the field.

Conclusions

Robotic surgery is being taken up by a diverse range of surgeons across the world. Early success in urological surgery is beginning to be mirrored in other surgical specialties. Robotic procedures are evolving to include new benefits and new technologies are beginning to emerge which will further expand the role and capabilities of robotic surgery. Copyright © 2007 John Wiley & Sons, Ltd.
A probabilistic counting lemma for complete graphs
Authors: Gerke Stefanie , Marciniszyn Martin , Steger Angelika
Published: October 2007

We prove the existence of many complete graphs in almost all sufficiently dense partitions obtained by an application of Szemerdi's regularity lemma. More precisely, we consider the number of complete graphs Kℓ on ℓ vertices in ℓ‐partite graphs where each partition class consists of n vertices and there is an ϵ‐regular graph on m edges between any two partition classes. We show that for all β > 0, at most a βm‐fraction of all such graphs contain a little less than the expected number of copies of Kℓ provided ϵ is sufficiently small, m ≫ n2−1/(ℓ−1), and n is sufficiently large. This result is a counting version of a restricted version of a conjecture (Kohayakawa, Łuczak, and Rödl, Combinatorica 17 (1997), 173–213), and it is well known that this result implies several results for random graphs. © 2007 Wiley Periodicals, Inc. Random Struct. Alg., 2007
Milk production and reproductive performance of Sahiwal cattle in semi‐arid Kenya
Authors: Ilatsia ED , Muasya TK , Muhuyi WB , Kahi AK
Published: October 2007

The aim of this study was to evaluate milk production and reproductive performance of Sahiwal cattle in semi‐arid Kenya. Milk production traits considered were lactation milk yield, lactation length and test‐day milk yield, while reproductive traits included age at first calving, calving interval and number of services per conception. Various fixed effects affected performance of milk production and reproductive traits to varying significance levels. The mean estimates for milk production traits were 1368 kg, 282 days and 4.9 kg for lactation milk yield, lactation length and test‐day milk yield, respectively. For reproductive traits, mean estimates were 468 days, 2.2 and 1345 days for calving interval, number of services per conception and age at first calving, respectively. There was a decline in lactation milk yield and lactation length, and an increase in calving interval and age at first calving over the years. Satisfactory management and appropriate genetic improvement strategies would result in improved performance. Implications of the results for genetic improvement of the breed in Kenya are discussed. Copyright © 2007 John Wiley & Sons, Ltd
Small‐scale species richness and its spatial variation in an alpine meadow on the Qinghai‐Tibet Plateau
Authors: Chen Jun , Yamamura Yasuo , Hori Yoshimichi , Shiyomi Masae , Yasuda Taisuke , Zhou Hua‐kun , Li Ying‐nian , Tang Yan‐hong
Published: October 2007

We investigated how the high small‐scale species richness of an alpine meadow on the Qinghai‐Tibet Plateau, China, is maintained. This area is characterized by strong wind and severe cold during long winters. In winter, most livestock is grazed on dead leaves in small pastures near farmers’ residences, whereas in the short summer, livestock is grazed in mountainous areas far from farmers’ residences. The number of plant species and the aboveground biomass were surveyed for three adjacent pastures differing in grazing management: a late‐winter grazing pasture grazed moderately from 1 February to 30 April, an early‐winter grazing pasture grazed lightly from 20 September to late October, and a whole‐year grazing pasture grazed intensively throughout the entire year. In each pasture, we harvested the aboveground biomass from 80 or 100 quadrats of 0.01 m2 along a transect and classified the contents by species. We observed 15.5–19.7 species per 0.01 m2, which is high richness per 0.01 m2 on a worldwide scale. The species richness in the two winter grazing pastures was higher than that in the whole‐year grazing pasture. The spatial variation in species richness and species composition in the two winter grazing pastures in which species richness was high was greater than that in the whole‐year grazing pasture in which species richness was lower. Most of the leaves that are preserved on the winter grazing pastures during summer are blown away by strong winds during winter, and the remaining leaves are completely exhausted in winter by livestock grazing. A pasture with a high richess is accompanied by a high spatial variation in species richness and species composition. There is a high possibility that the characteristic of spatial variation is also caused by traditional grazing practices in this area.
Selective Seasonal Fatty Acid Accumulation and Mobilization in the Wild Raccoon Dog (Nyctereutes procyonoides)
Authors: Mustonen Anne‐Mari , Asikainen Juha , Aho Jari , Nieminen Petteri
Published: October 2007

Previous studies on laboratory rodents, rabbits and humans have demonstrated that fatty acid (FA) mobilization from white adipose tissue (WAT) is selective and its efficiency is related to FA structure. Selective FA mobilization was also documented in a carnivore, the farmed raccoon dog (Nyctereutes procyonoides), fasted for 8 weeks. The present study explored whether similar selectivity of FA mobilization was manifested in wild mammals experiencing seasonal food scarcity and abundance. Fractional mobilization from and incorporation into WAT of a wide spectrum of FA were studied by gas–liquid chromatography from the subcutaneous WAT of free‐ranging raccoon dogs with the same individuals sampled in consecutive seasons. The wintertime FA mobilization was selective and mostly confirmed the patterns of FA release in captivity. Mobilization correlated inversely with the FA chain length but increased with unsaturation and when the first double bond was located closer to the methyl end. 18–20C n‐3 polyunsaturated FA (PUFA) and 14–17C monounsaturated FA (MUFA) were preferentially mobilized while 19–24C saturated FA and MUFA were preserved during wintering. The summertime FA incorporation correlated inversely with the chain length and increased with unsaturation and in MUFA and PUFA with double bonds closer to the methyl end. The principles of selective FA mobilization were valid in wild mammals. FA incorporation was also selective and reversed the wintertime losses of the preferably mobilized FA.
Robustness analysis identifies the plausible model of the Bcl‐2 apoptotic switch
Authors: Chen Chun , Cui Jun , Zhang Wei , Shen Pingping
Published: October 2007

In this paper two competing models of the B‐cell lymphoma 2 (Bcl‐2) apoptotic switch were contrasted by mathematical modeling and robustness analysis. Since switch‐like behaviors are required for models that attempt to explain the all‐or‐none decisions of apoptosis, ultrasensitivity was employed as a criterion for comparison. Our results successfully exhibit that the direct activation model operates more reliably to achieve a robust switch in cellular conditions. Moreover, by investigating the robustness of other important features of the Bcl‐2 apoptotic switch (including low Bax basal activation, inhibitory role of anti‐apoptotic proteins and insensitivity to small perturbations) the direct activation model was further supported. In all, we identified the direct activation model as a more plausible explanation for the Bcl‐2 apoptotic switch.