bluuebunny/crossref_metadata_2025 huggingface dataset:
Post-transcriptional regulation of gene expression by alternative 5′-untranslated regions in carcinogenesis
Authors: Smith Laura
Published: July 2008

Post-transcriptional regulation, via 5′-UTRs (5′-untranslated regions), plays an important role in the control of eukaryotic gene expression. Recent analyses of the mammalian transcriptome suggest that most of the genes express multiple alternative 5′-UTRs and inappropriate expression of these regions has been shown to contribute to the development of carcinogenesis. The present review will focus on the complex post-transcriptional regulation of ERβ (oestrogen receptor β) expression. In particular, results from our laboratory suggest that the expression of alternative 5′-UTRs plays a key role in determining the level of ERβ protein expression. We have also shown that these alternative ERβ 5′-UTRs have a tissue-specific distribution and are differentially expressed between various normal and tumour tissues. Our results also suggest that alternative 5′-UTRs can influence downstream splicing events, thereby perhaps affecting ERβ function. These results suggest that alternative 5′-UTRs may have an overall influence on ER activity and this may have important implications for our understanding of cancer biology and treatment.
Red light, green light: probing single molecules using alternating-laser excitation
Authors: Santoso Yusdi , Hwang Ling Chin , Le Reste Ludovic , Kapanidis Achillefs N.
Published: July 2008

Single-molecule fluorescence methods, particularly single-molecule FRET (fluorescence resonance energy transfer), have provided novel insights into the structure, interactions and dynamics of biological systems. ALEX (alternating-laser excitation) spectroscopy is a new method that extends single-molecule FRET by providing simultaneous information about structure and stoichiometry; this new information allows the detection of interactions in the absence of FRET and extends the dynamic range of distance measurements that are accessible through FRET. In the present article, we discuss combinations of ALEX with confocal microscopy for studying in-solution and in-gel molecules; we also discuss combining ALEX with TIRF (total internal reflection fluorescence) for studying surface-immobilized molecules. We also highlight applications of ALEX to the study of protein–nucleic acid interactions.
Time-resolved footprinting for the study of the structural dynamics of DNA–protein interactions
Authors: Sclavi Bianca
Published: July 2008

Transcription is often regulated at the level of initiation by the presence of transcription factors or nucleoid proteins or by changing concentrations of metabolites. These can influence the kinetic properties and/or structures of the intermediate RNA polymerase–DNA complexes in the pathway. Time-resolved footprinting techniques combine the high temporal resolution of a stopped-flow apparatus with the specific structural information obtained by the probing agent. Combined with a careful quantitative analysis of the evolution of the signals, this approach allows for the identification and kinetic and structural characterization of the intermediates in the pathway of DNA sequence recognition by a protein, such as a transcription factor or RNA polymerase. The combination of different probing agents is especially powerful in revealing different aspects of the conformational changes taking place at the protein–DNA interface. For example, hydroxyl radical footprinting, owing to their small size, provides a map of the solvent-accessible surface of the DNA backbone at a single nucleotide resolution; modification of the bases using potassium permanganate can reveal the accessibility of the bases when the double helix is distorted or melted; cross-linking experiments report on the formation of specific amino acid–DNA contacts, and DNase I footprinting results in a strong signal-to-noise ratio from DNA protection at the binding site and hypersensitivity at curved or kinked DNA sites. Recent developments in protein footprinting allow for the direct characterization of conformational changes of the proteins in the complex.
Translating Principles of Speech Science to Clinical Practice: Current and Future Trends in Craniofacial Disorders
Authors: Zajac David J.
Published: July 2008

The purpose of this opinion article is to review the impact of the principles and technology of speech science on clinical practice in the area of craniofacial disorders. Current practice relative to (a) speech aerodynamic assessment, (b) computer-assisted single-word speech intelligibility testing, and (c) behavioral management of hypernasal resonance are reviewed. Future directions and/or refinement of each area are also identified. It is suggested that both challenging and rewarding times are in store for clinical researchers in craniofacial disorders.
Inhibition of Arterial Thrombogenesis by Quinapril but Not Losartan
Authors: Bavry Anthony A. , Li Dayuan , Zander Dani S. , Phillips M. Ian , Mehta Jawahar L.
Published: July 2008

The cardioprotective effect of angiotensin converting enzyme (ACE) inhibitors and angio tensin type I (AT1) receptor blockers may relate to their antithrombotic effect. We determined the differential effects of the ACE inhibitor quinapril and the AT1 receptor blocker losartan on arterial thrombus formation in the rat. Sprague-Dawley rats were fed regular chow or chow mixed with low-dose quinapril (0.6 mg/kg/day), high-dose quinapril (1.2 mg/kg/day), or losartan (10 mg/kg/day) for 15 days. Abdominal aorta was exposed and wrapped with Whatman paper impregnated with 29% FeCl3 (ferric chloride). Time to occlusive thrombus formation and weight of the thrombus were recorded. Aortic superoxide anion generation, platelet aggregation, plasma angiotensin II levels, and morphology of the thrombus were also examined. Both losartan and quinapril caused similar reductions in arterial pressure. Losartan did not affect the time to thrombus formation, whereas quinapril (both low and high doses) delayed the time to thrombus formation ( P < .01 vs control). Weight of the thrombus was similar in all groups of rats. Platelet aggregation was inhibited by approximately 50% in both quinapril- and losartan-treated rats. The high-dose quinapril-treated rats showed markedly reduced vascular superoxide anion generation compared with the control rats ( P < .05). Plasma angiotensin II levels were unaffected by quinapril treatment but were elevated 7-fold in losartan-treated rats ( P < .001 vs. control rats). The thrombi in the control rats consisted of platelet aggregates, fibrin, and red blood cells. The intravascular platelet aggregates were much smaller in the quinapril-treated rats ( P < .05 vs. control), but were similar in control and losartan-treated rats. In conclusion, quinapril but not losartan prolongs time to arterial throm bus formation and results in smaller platelet aggregates in the thrombus. Both quinapril and losartan decrease platelet aggregation, but only quinapril decreases superoxide anion gen eration. This effect on superoxide anion generation as well as mechanisms other than AT 1 receptor blockade may underlie the salutary effect of quinapril on arterial thrombogenesis.
Oxidizability of Atherogenic Low-Density Lipoprotein Subspecies in Severe Familial Hypercholesterolemia: Impact of Long-Term Low-Density Lipoprotein Apheresis
Authors: Lepage Sylvie , Nigon Fabienne , Bonnefont-Rousselot Dominique , Assogba Ubald , Goulinet Sylvie , Chancharme Laurent , Delattre Jacques , Bruckert Eric , Chapman M. John
Published: July 2008

Background: Oxidative modification of low-density lipoprotein (LDL) plays a key role in the pathophysiology of atherosclerosis. LDL-apheresis, which involves direct removal of plasma LDL from circulating blood, is an efficient treatment of homozygous familial hypercholes terolemia (FH).

Methods: We evaluated impact of long-term LDL apheresis treatment on the atherogenicity of the major LDL subclasses (light, LDL1, and LDL2, density [d] 1.018-1.030 g/mL; inter mediate, LDL3, d 1.030-1.040 g/mL, and dense LDL, LDL4 and LDL5, d 1.040-1.065 g/mL) separated by density gradient ultracentrifugation in severe FH patients. Therefore, we compared the oxidative resistance as well as the chemical and physical properties of each LDL subpopulation in the FH group with those in the corresponding LDL subfractions from normocholesterolemic control subjects.

Results: Both intermediate and dense LDL subfractions were significantly more resistant to copper-mediated oxidation in FH patients treated regularly by LDL-apheresis than their counterpart controls. The lag phases for LDL3, LDL4, and LDL5: 63.9 ± 1 1.6, 55.8 ± 1.2, and 47.2 ± 6.5 min. in FH patients were significantly longer than those of the corresponding subfractions in normocholesterolemic controls (P < .01 for LDL3 and LDL5, P < .005 for LDL4). This protective effect was reflected in the delayed formation of biologically active lipid oxidation products such as oxysterols, lipid hydroperoxides, dienes, and dienals in the intermediate and dense LDL subfractions of FH patients. These findings may result from lower "seed" contents of lipid hydroperoxide (LOOH) detected as dienes in plasma LDL from apheresis-treated FH patients; indeed, baseline LOOH/diene contents in all 5 LDL subclasses from FH patients were significantly lower than those of the corresponding subclasses in normolipidemic subjects (P < .0005). On the other hand, the enhanced oxidative resistance of both intermediate (LDL3) and dense (LDL4 and LDL5) LDL subpopulations in FH patients could not be accounted for by any consistent modification in chemical composition or in lipophilic antioxidant content, although minor differences were observed between patients and controls in unsaturated fatty acid profile. In contrast, sphingomyelin content was enriched in FH LDL subclasses, potentially resulting in reduced penetration of the hydrophilic surface layer of LDL by oxygen radicals.

Conclusion: We conclude that low concentrations of preformed lipid hydroperoxides and dienes, together with surface sphingomyelin enrichment, can account for the enhanced oxi dative resistance of intermediate (LDL3) and atherogenic dense LDL (LDL4, LDL5) induced by long-term LDL apheresis in severe FH patients.
Efficacy of Pretreatment With the Angiotensin II Type 1 Receptor Blocker UP269-6 and Losartan in the Dog: Effect on Hemodynamics and Ischemia-Reperfusion
Authors: O'Brien Darryl W. , Xu Yi , Menon Vijayan , Jugdutt Bodh I.
Published: July 2008

Background: Whether pretreatment with the novel oral angiotensin II (AngII) type 1 receptor (AT,R) antagonist UP269-6 (UP) can produce more effective AT,R blockade than losartan (LN) for cardioprotection during ischemia-reperfusion (IR) in the dog has not been deter mined.

Methods and Materials: We compared the effect of UP (n = 5) and LN (n = 5) on serial in vivo hemodynamics, AngII pressor responses, and left ventricular (LV) volumes and function (echocardiograms) during escalation to optimal oral dosage over 7 days (day 0 to day 6), and acute IR (15 minutes ischemia, 30 minutes reperfusion) and ex vivo AT,R protein (Western immunoblots) with additional sham (n = 5) and IR (n = 5) controls on day 6. Compared with LN, UP produced greater vasodepression and decrease in diastolic volume during dose escalation and greater inhibition of the AngII pressor response over the range of escalating concentrations (0.05, 0.10, 0.25, and 0.50 μg/kg) on day 6. Acute IR after UP pretreatment resulted in less increase in LV filling pressure and LV diastolic and systolic volumes and greater ejection fraction, although UP and LN had similar effects on AT,R protein.

Conclusion: Pretreatment with UP269-6 over 7 days produces more effective pharmacologi cal AT,R blockade and cardioprotection after acute IR than LN in the dog.
Characterization of Cardioprotection Mediated by AT2 Receptor Antagonism After Ischemia-Reperfusion in Isolated Working Rat Hearts
Authors: Ford William R. , Clanachan Alexander S. , Jugdutt Bodh I.
Published: July 2008

Background: Whether cardioprotection induced by the angiotensin II (AngII) type 2 receptor (AT2R) antagonist PD123,319 (PD) after ischemia-reperfusion (IR) is influenced by the concentration of PD, presence of AngII, timing of exposure, or inhibition of proton produc tion from glucose metabolism is not known.

Methods and Results: We examined these factors in isolated working rat hearts subjected to IR injury, no treatment (control), or treatment with N6-cyclohexyl adenosine (CHA, 0.5 μmol/L), an adenosine A1receptor agonist that induces cardioprotection by decreasing pro tons ("positive" control). Compared with control, 1 μmol/L PD present throughout IR im proved recovery of left ventricular work (73 ± 5 vs. 40 ± 8%) to the level with CHA (82 ± 5%), but 0.1 μmol/L PD did not (58 ± 6 vs. 40 ± 8%). AngII (1 nmol/L) did not effect postischemic recovery associated with 1 μmol/L PD (73 ± 7%) but improved that associated with 0.1 μmol/L PD (86 ± 3%). PD (1 μmol/L), present solely during reperfusion, enhanced postischemic left ventricular recovery to 72 ± 5%. Also, PD (1 μmol/L) did not affect glycolytic rates or proton production in nonischemic or IR hearts.

Conclusion: PD-induced cardioprotection is 1) PD concentration-dependent, 2) AngII- sensitive, 3) mediated during reperfusion, and 4) independent of proton production, suggest ing that reduction in IR injury and indirect AT1R stimulation might be involved.
The Actions of Ibutilide and Class Ic Drugs on the Slow Sodium Channel: New Insights Regarding Individual Pharmacologic Effects Elucidated Through Combination Therapies
Authors: Reiffel James A. , Blitzer Mark
Published: July 2008

Background: Ibutilide (I) has been reported to block Ik and to delay inactivation of the slow Na+ current (S-Na). There is debate about the clinical importance of the latter. Class Ic drugs block the fast Na+ channel, but their effect on S-Na is uncertain. If Ic treatment before infusion lessened the QT increase with I, this result would suggest both an Ic effect on S-Na and significant S-Na actions of I.

Methods: We infused I, 2 mg over 30 minutes, to 6 patients pretreated with propafenone (n = 5) or flecainide (n = 1) (group 1) and compared their increase with the QT increase seen with I alone in a combined group of 85 patients from our lab and the multicenter I database (group 2).

Results: The QTc increased in group 2, 65 ms, from 413 to 478 ms. This effect was attenuated by 47% in group 1 patients to 34 ms (P < .01). There appeared to be a dose-response relationship between Ic dose and its effects on QTc prolongation. The lowest dose of propafe none had minimal effect on the increase in QTc with I (72 ms), while higher doses of propafenone and high doses of flecainide attenuated the increase to 13 to 39 ms. Nonetheless, ibutilide efficacy was not changed, possibly suggesting differing importance of K+ channel and slow sodium-channel effects in atrial versus ventricular tissues, and having implications for means to reduce some antiarrhythmic drug proarrhythmia without reducing efficacy.

Conclusions: (1) Pretreatment with Ic agents can reduce the increase in QTc seen with I; (2) I's effect in humans appears to be at least partly mediated through the delay of S-Na inactivation; and (3) Ic agents probably inhibit S-Na.
Hyaluronidase Can Be Used to Reduce Interstitial Edema in the Presence of Heparin
Authors: Johnsson Cecilia , Hällgren Roger , Tufveson Gunnar
Published: July 2008

Background: Treatment with the hyaluronan-degrading enzyme, hyaluronidase, reduces re jection-induced interstitial edema of transplanted organs. Hyaluronidase has also been dem onstrated to reduce tissue necrosis after experimentally induced myocardial infarction, but its clinical use has been limited by an observed interaction between heparin and hyaluronan. In the present work, we investigated whether it is also possible to retain the effect of the enzyme in heparinized animals.

Methods: Day 5 after heterotopic heart transplantation, recipient rats received a 2-hour intravenous infusion of hyaluronidase, either of ovine or of bovine origin. Concomitantly, the animals received intravenous heparin, either as 2 bolus doses or as a constant infusion.

Results: Both hyaluronidase preparations effective reduced the hyaluronan content as well as the water content of the rejecting cardiac grafts. The concomitant use of heparin did not hamper the positive results, neither when heparin was administered intermittently nor when it was given continuously.

Conclusions: Our results in the transplantation model clearly demonstrate that hyaluronidase can be successfully used in heparinized individuals, provided that sufficient doses of the enzyme are given.
Modeling of InGaN/Si tandem solar cells
Authors: Hsu L. , Walukiewicz W.
Published: July 2008

We investigate theoretically the characteristics of monolithic InGaN/Si two-junction series-connected solar cells using the air mass 1.5 global irradiance spectrum. The addition of an InGaN junction is found to produce significant increases in the energy conversion efficiency of the solar cell over that of one-junction Si cells. Even when Si is not of high quality, such two-junction cells could achieve efficiencies high enough to be practically feasible. We also show that further, though smaller, improvements of the efficiency can be achieved by adding another junction to form an InGaN/InGaN/Si three-junction cell.
Spin-polarized electron transport in fractal semiconductor multilayers with two ferromagnetic contacts
Authors: Liu De , Kong Xiao-Jun
Published: July 2008

We investigate theoretically the transmission properties of electrons tunneling through fractal semiconductor multilayers (FSMs) sandwiched between two ferromagnets (Fs) in the presence of a spin-orbit interaction. Calculations are carried out with and without presumed randomly distributed uncertainties in the semiconductor layer thicknesses. Within the Landauer framework of ballistic transport and using transfer matrix methods, the transmission coefficients of the F/FSM/F heterostructures are numerically calculated and compared with that of periodic semiconductor multilayers (PSMs) again with ferromagnetic contacts. The results indicate that the transmission spectrum of the F/FSM/F heterostructures has partially self-similar properties as well as stability against the effects of random variations in layer thicknesses. Furthermore, compared to the F/PSM/F heterostructures, the transmission spectrum of the F/FSM/F heterostructures exhibits sharp localized transmission peaks and a more marked quantum size effect. Interestingly, for the case with random layer-thickness fluctuations, the transmissions for spin-up and spin-down electrons can be separated when the magnetizations of the left and right ferromagnetic layers are antiparallel. This is quite different from the case without random layer-thickness fluctuations.
Energy transfer of highly vibrationally excited 2-methylnaphthalene: Methylation effects
Authors: Hsu Hsu Chen , Liu Chen-Lin , Hsu Yuan Chin , Ni Chi-Kung
Published: July 2008

The methylation effects in the energy transfer between Kr atoms and highly vibrationally excited 2-methylnaphthalene in the triplet state were investigated using crossed-beam/time-sliced velocity-map ion imaging at a translational collision energy of ∼520cm−1. Comparison of the energy transfer between naphthalene and 2-methylnaphthalene shows that the difference in total collisional cross section and the difference in energy transfer probability density functions are small. The ratio of the total cross sections is σ(naphthalene): σ(methylnaphthalene)=1.08±0.05:1. The energy transfer probability density function shows that naphthalene has a little larger probability at small T→V∕R energy transfer, ΔEu<300cm−1, and 2-methylnaphthalene has a little larger probability at large V→T energy transfer, −800cm−1<ΔEd<−100cm−1. However, these differences are close to our experimental uncertainty. No significant difference in the probability of very large energy transfer, such as supercollisions defined arbitrarily as ΔEd<−1500cm−1, was observed. The possible methylation effects due to the subsequent successive collisions were discussed.
Laser induced popcornlike conformational transition of nanodiamond as a nanoknife
Authors: Chang Chia-Ching , Chen Pei-Hsin , Chu Hsueh-Liang , Lee Tzu-Cheng , Chou Ching-Chung , Chao Jui-I , Su Chien-Ying , Chen Jyh Shin , Tsai Jin-Sheng , Tsai Chuan-Mei , Ho Yen-Peng , Sun Kien Wen , Cheng Chia-Liang , Chen Fu-Rong
Published: July 2008

Nanodiamond (ND) is surrounded by layers of graphite on its surface. This unique structure feature creates unusual fluorescence spectra, which can be used as an indicator to monitor its surface modification. Meanwhile, the impurity, nitroso (CNO) inside the ND can be photolyzed by two-photon absorption, releasing NO to facilitate the formation of a sp3 diamond structure in the core of ND and transforming it into a sp2 graphite structure. Such a conformational transition enlarges the size of ND from 8to90nm, resulting in a popcornlike structure. This transition reaction may be useful as nanoknives in biomedical application.
Controlled electron injection into the wake wave using plasma density inhomogeneity
Authors: Brantov A. V. , Esirkepov T. Zh. , Kando M. , Kotaki H. , Bychenkov V. Yu. , Bulanov S. V.
Published: July 2008

The electron injection, for the laser wake field accelerator, controlled through the plasma density inhomogeneity is studied on a basis of analytical estimates and two- and three-dimensional particle-in-cell simulations. The injection scheme requires a concordance of the density scale length and laser intensity. It is shown that at a sloping inhomogeneity of plasma the wave breaking produces stronger singularity of the electron density than at a density discontinuity, but develops slower. With the help of simulations for a moderate laser intensity, we demonstrate the optimal plasma density gradient, where the electron injection into the wake wave forms the electron beam with low divergence, small energy spread and high energy.
Influence of fine roughness of insulator surface on threshold voltage stability of organic field-effect transistors
Authors: Suemori Kouji , Uemura Sei , Yoshida Manabu , Hoshino Satoshi , Takada Noriyuki , Kodzasa Takehito , Kamata Toshihide
Published: July 2008

We have investigated the influence of the surface roughness of an insulator on the threshold voltage shift caused by gate bias stressing in organic field-effect transistors (OFETs). Our investigation was conducted for OFETs with SiO2 insulators. We observed that the threshold voltage shift is extremely sensitive to changes in the fine roughness of the SiO2 surface; the shift increased with the roughness. The large shift in OFETs with rough SiO2 insulators can be attributed to lattice distortion in pentacene layers deposited on rough SiO2 surfaces.
The influence of Reynolds number on a plane jet
Authors: Deo Ravinesh C. , Mi Jianchun , Nathan Graham J.
Published: July 2008

The present study systematically investigates through experiments the influence of Reynolds number on a plane jet issuing from a radially contoured, rectangular slot nozzle of large aspect ratio. Detailed velocity measurements were performed for a jet exit Reynolds number spanning the range 1500≤Reh≤16 500, where Reh≡Ubh/υ with Ub as the momentum-averaged exit mean velocity, h as the slot height, and υ as the kinematic viscosity. Additional centerline measurements were also performed for jets from two different nozzles in the same facility to achieve Reh=57 500. All measurements were conducted using single hot-wire anemometry to an axial distance (x) of x≤160h. These measurements revealed a significant dependence of the exit and the downstream flows on Reh despite all exit velocity profiles closely approximating a “top-hat” shape. The effect of Reh on both the mean and turbulent fields is substantial for Reh<10 000 but becomes weaker with increasing Reh. The length of the jet’s potential core, initial primary-vortex shedding frequency, and far-field rates of decay and spread all depend on Reh. The local Reynolds number, Rey0.5≡2Ucy0.5/υ, where Uc and y0.5 are the local centerline velocity and half-width, respectively, are found to scale as Rey0.5∼x1/2. It is also shown that, for Reh≥1500, self-preserving relations of both the turbulence dissipation rate (ε) and smallest scale (η), i.e., ε∼Reh3(x/h)−5/2 and η∼Reh−3/4(x/h)5/8, become valid for x/h≥20.
Noninvasive nuclear magnetic resonance profiling of painting layers
Authors: Presciutti Federica , Perlo Juan , Casanova Federico , Glöggler Stefan , Miliani Costanza , Blümich Bernhard , Brunetti Brunetto Giovanni , Sgamellotti Antonio
Published: July 2008

In this work we demonstrate the potential of single-sided nuclear magnetic resonance (NMR) sensors to access deeper layers of paintings noninvasively by means of high-resolution depth profiles spanning several millimeters. The performance of the sensor in resolving painting structures was tested on models for which excellent agreement with microscopy techniques was obtained. The depth profiling NMR technique was used in situ to investigate old master paintings. The observation of differences in NMR relaxation times of tempera binders from these paintings and from artificially aged panels raises the possibility to differentiate between original and recently restored areas.
Decreased Dicer expression elicits DNA damage and up-regulation of MICA and MICB
Authors: Tang Kai-Fu , Ren Hong , Cao Jia , Zeng Gui-Li , Xie Jing , Chen Min , Wang Lu , He Cai-Xia
Published: July 2008

RNA interference (RNAi) acts constitutively to silence the innate immune response, and innate immunity genes are misregulated in Dicer-deficient Caenorhabditis elegans. Here, we show that inhibition of Dicer expression by RNAi in human cells up-regulates major histocompatibility complex class I–related molecules A and B (MICA and MICB). MICA and MICB are innate immune system ligands for the NKG2D receptor expressed by natural killer cells and activated CD8(+)T cells. We reveal that knockdown of Dicer elicits DNA damage. Up-regulation of MICA and MICB by Dicer knockdown is prevented by pharmacologic or genetic inhibition of DNA damage pathway components, including ataxia telangiectasia mutated (ATM) kinase, ATM- and Rad3-related kinase, or checkpoint kinase 1. Therefore we conclude that up-regulation of MICA and MICB is the result of DNA damage response activation caused by Dicer knockdown. Our results suggest that RNAi is indirectly linked to the human innate immune system via the DNA damage pathway.
Membrane heterogeneities in the formation of B cell receptor–Lyn kinase microclusters and the immune synapse
Authors: Sohn Hae Won , Tolar Pavel , Pierce Susan K.
Published: July 2008

Antigen binding to the B cell receptors (BCRs) induces BCR clustering, phosphorylation of BCRs by the Src family kinase Lyn, initiation of signaling, and formation of an immune synapse. We investigated B cells as they first encountered antigen on a membrane using live cell high resolution total internal reflection fluorescence microscopy in conjunction with fluorescence resonance energy transfer. Newly formed BCR microclusters perturb the local membrane microenvironment, leading to association with a lipid raft probe. This early event is BCR intrinsic and independent of BCR signaling. Association of BCR microclusters with membrane-tethered Lyn depends on Lyn activity and persists as microclusters accumulate and form an immune synapse. Membrane perturbation and BCR–Lyn association correlate both temporally and spatially with the transition of microclustered BCRs from a “closed” to an “open” active signaling conformation. Visualization and analysis of the earliest events in BCR signaling highlight the importance of the membrane microenvironment for formation of BCR–Lyn complexes and the B cell immune synapse.
A Hodge decomposition interpretation for the coefficients of the chromatic polynomial
Authors: Hanlon Phil
Published: July 2008

Let

G
G

be a simple graph with

n
n

nodes. The coloring complex of

G
G

, as defined by Steingrimsson, has

r
r

-faces consisting of all ordered set partitions,

(

B
1

,
…
,

B

r
+
2

)

(B_1, \ldots ,B_{r+2})

in which at least one

B
i

B_i

contains an edge of

G
G

. Jonsson proved that the homology

H

∗

(
G
)

H_{*}(G)

of the coloring complex is concentrated in the top degree. In addition, Jonsson showed that the dimension of the top homology is one less than the number of acyclic orientations of

G
G

.

In this paper, we show that the Eulerian idempotents give a decomposition of the top homology of

G
G

into

n
−
1

n-1

components

H

n
−
3

(
j
)

(
G
)

H_{n-3}^{(j)}(G)

. We go on to prove that the dimensions of the Hodge pieces of the homology are equal to the absolute values of the coefficients of the chromatic polynomial of

G
G

. Specifically, if we write
<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" alttext="chi Subscript upper G Baseline left-parenthesis lamda right-parenthesis equals left-parenthesis sigma-summation Underscript j equals 1 Overscript n minus 1 Endscripts c Subscript j Baseline left-parenthesis negative 1 right-parenthesis Superscript n minus j Baseline lamda Superscript j Baseline right-parenthesis plus lamda Superscript n">

χ
G

(
λ
)
=
(

∑

j
=
1

n
−
1

c
j

(
−
1

)

n
−
j

λ
j

)
+

λ
n

\chi _G(\lambda ) = (\sum _{j=1}^{n-1} c_j (-1)^{n-j} \lambda ^j) + \lambda ^n

, then

d
i
m
(

H

n
−
3

(
j
)

(
G
)
)
=

c
j

dim(H_{n-3}^{(j)}(G)) = c_j

.
An open mapping theorem for Young measures
Authors: Tateishi Hiroshi
Published: July 2008

Ditor and Eifler consider the open mapping theorem for the probability spaces. Here we attempt to generalize the theorem to the spaces of Young measures.
Extreme points of lattice intervals in the Minkowski-Rådström-Hörmander lattice
Authors: Grzybowski Jerzy , Urbański Ryszard
Published: July 2008

In this paper we characterize extreme points of any symmetric interval in the Minkowski–Rådström–Hörmander lattice

X
~

\widetilde {X}

over any Hausdorff topological vector space

X
X

(Theorem 1). Then we prove that the unit ball in the Minkowski–Rådström–Hörmander lattice

X
~

\widetilde {X}

over any normed space

X
X

, dim

X
≥
2
,

X\geq 2,

has exactly two extreme points (Theorem 2).
The first return time properties of an irrational rotation
Authors: Kim Dong Han , Park Kyewon
Published: July 2008

If an ergodic system has positive entropy, then the Shannon-McMillan-Breiman theorem provides a relationship between the entropy and the size of an atom of the iterated partition. The system also has Ornstein-Weiss’ first return time property, which offers a method of computing the entropy via an orbit. We consider irrational rotations which are the simplest model of zero entropy. We prove that almost every irrational rotation has the analogous properties if properly normalized. However there are some irrational rotations that exhibit different behavior.
A note on scaling asymptotics for Bohr-Sommerfeld Lagrangian submanifolds
Authors: Paoletti Roberto
Published: July 2008

This paper deals with the asymptotic expansions describing the quantum states associated to Bohr Sommerfeld Lagrangian submanifolds of a compact Kähler manifold, in the context of geometric quantization. More precisely, it provides an improvement on a result of the work of Debernardi and the author (2006), describing a natural factorization of the expansion and providing certain remainder estimates.
Cramped subgroups and generalized Harish-Chandra modules
Authors: Webster Ben
Published: July 2008

Let

G
G

be a reductive complex Lie group with Lie algebra

g

\mathfrak g

. We call a subgroup

H
⊂
G

H\subset G

cramped if there is an integer

b
(
G
,
H
)

b(G,H)

such that each finite-dimensional representation of

G
G

has a non-trivial invariant subspace of dimension less than

b
(
G
,
H
)

b(G,H)

. We show that a subgroup is cramped if and only if the moment map

T
∗

(
K

/

L
)
→

k

∗

T^*(K/L)\to \mathfrak k^*

is surjective, where

K
K

and

L
L

are compact forms of

G
G

and

H
H

. We will use this in conjunction with sufficient conditions for crampedness given by Willenbring and Zuckerman (2004) to prove a geometric proposition on the intersections between adjoint orbits and Killing orthogonals to subgroups.

We will also discuss applications of the techniques of symplectic geometry to the generalized Harish-Chandra modules introduced by Penkov and Zuckerman (2004), of which our results on crampedness are special cases.
Lyapunov exponent estimates of a class of higher-order stochastic Anderson models
Authors: Tang Dan , Bo Lijun
Published: July 2008

In this article, we propose a class of high-order stochastic partial differential equations (SPDEs) for spatial dimensions

d
≤
5

d\leq 5

which might be called high-order stochastic Anderson models. This class of the equations is perturbed by a space-time white noise when

d
≤
3

d\leq 3

and by a space-correlated Gaussian noise when

d
=
4
,
5

d=4,5

. The objectives of this article are to get some estimates on the Lyapunov exponent of the solutions and to study the convergence rates of the chaos expansions of the solutions for the models.
Existence of quasi-arcs
Authors: Mackay John
Published: July 2008

We show that doubling, linearly connected metric spaces are quasi-arc connected. This gives a new and short proof of a theorem of Tukia.
On a desingularization of the moduli space of noncommutative tori
Authors: Nikolaev Igor
Published: July 2008

It is shown that the moduli space of the noncommutative tori

A

θ

{\mathbb A}_{\theta }

admits a natural desingularization by the group

E
x
t
 
(

A

θ

,

A

θ

)

Ext~ ({\mathbb A}_{\theta },{\mathbb A}_{\theta })

. Namely, we prove that the moduli space of pairs

(

A

θ

,
E
x
t
 
(

A

θ

,

A

θ

)
)

({\mathbb A}_{\theta }, Ext~ ({\mathbb A}_{\theta },{\mathbb A}_{\theta }))

is homeomorphic to a punctured two-dimensional sphere. The proof is based on a correspondence (a covariant functor) between the complex and noncommutative tori.
Characterizing indecomposable plane continua from their complements
Authors: Curry Clinton , Mayer John , Tymchatyn E.
Published: July 2008

We show that a plane continuum

X
X

is indecomposable iff

X
X

has a sequence

(

U
n

)

n
=
1

∞

(U_n)_{n=1}^\infty

of not necessarily distinct complementary domains satisfying the double-pass condition: for any sequence

(

A
n

)

n
=
1

∞

(A_n)_{n=1}^\infty

of open arcs, with

A
n

⊂

U
n

A_n \subset U_n

and

A
n

¯

∖

A
n

⊂
∂

U
n

\overline {A_n}\setminus A_n \subset \partial U_n

, there is a sequence of shadows

(

S
n

)

n
=
1

∞

(S_n)_{n=1}^\infty

, where each

S
n

S_n

is a shadow of

A
n

A_n

, such that

lim

S
n

=
X

\lim S_n=X

. Such an open arc divides

U
n

U_n

into disjoint subdomains

V

n
,
1

V_{n,1}

and

V

n
,
2

V_{n,2}

, and a shadow (of

A
n

A_n

) is one of the sets

∂

V

n
,
i

∩
∂
U

\partial V_{n,i}\cap \partial U

.
On a theorem of Brauer and Wielandt
Authors: Harada Koichiro
Published: July 2008

A classical theorem of Brauer and Wielandt which states the result under the assumption

G
=
[
G
,
G
]

G=[G,G]

is extended to all finite groups.
Specification property and distributional chaos almost everywhere
Authors: Oprocha Piotr , Štefánková Marta
Published: July 2008

Our main result shows that a continuous map

f
f

acting on a compact metric space

(
X
,
ρ
)

(X,\rho )

with a weaker form of specification property and with a pair of distal points is distributionally chaotic in a very strong sense. Strictly speaking, there is a distributionally scrambled set

S
S

dense in

X
X

which is the union of disjoint sets homeomorphic to Cantor sets so that, for any two distinct points

u
,
v
∈
S

u,v\in S

, the upper distribution function is identically 1 and the lower distribution function is zero at some

ε
>
0

\varepsilon >0

. As a consequence, we describe a class of maps with a scrambled set of full Lebesgue measure in the case when

X
X

is the

k
k

-dimensional cube

I

k

I^{k}

. If

X
=
I

X=I

, then we can even construct scrambled sets whose complements have zero Hausdorff dimension.
Cloning and molecular characterization of outer membrane protein A (ompA) gene from Mycobacterium bovis
Authors: Singh J.P.N. , Verma Rishendra
Published: July 2008

The ompA gene, 981 bp in size and identified in the Mycobacterium bovis genome, was cloned and sequenced. Predicted amino acid sequences showed a protein of molecular weight 33.5 kDa with an isoelectric point of 7.28 and an OmpA conserved domain at the carboxy terminal with signal sequence at the N‐terminal. Homology search showed complete homology with the Mycobacterium tuberculosis ompA gene with varying degree of homology with omp genes of other bacteria, so it was predicted that it may act like porin. The ompA gene of M. bovis was expressed in the pProEX HTb expression vector. Recombinant protein OmpA, was purified by using a nickel affinity column. The expressed recombinant OmpA (32 kDa) was confirmed by western blot with Ni‐NTA horseradish peroxidase (HRP) conjugate and with specific antiserum raised in rabbits. The effect of low pH (pH 6.0, 5.5 and 5) on the transcription of the ompA gene in M. bovis using real‐time PCR showed that there was an increase in transcription of ompA in M. bovis cultured at low pH (maximum at pH 5.5).
Activated Stat3 expression in gestational trophoblastic disease: correlation with clinicopathological parameters and apoptotic indices
Authors: Chan H Y , Siu M K Y , Zhang H J , Wong E S Y , Ngan H Y S , Chan K Y K , Cheung A N Y
Published: July 2008

Aims:  To assess the expression profile of the activated form of signal transducer and activator of transcription (Stat)3 in gestational trophoblastic disease (GTD) and correlate the findings with clinicopathological parameters.

Methods and results:  By immunohistochemistry, both cytoplasmic and nuclear expression of p‐Stat3‐Ser727 was demonstrated in 88 trophoblastic tissues, including placentas and GTD. Nuclear immunoreactivity of p‐Stat3‐Ser727 was significantly higher in hydatidiform mole (HM) (P < 0.001) and choriocarcinoma (P = 0.009) when compared with normal placentas. Placental site trophoblastic tumours (PSTT) and epithelioid trophoblastic tumours (ETT) also demonstrated higher nuclear p‐Stat3‐Ser727 expression than their normal trophoblast counterparts. Higher p‐Stat3‐Ser727 expression was confirmed in choriocarcinoma cell lines, JEG‐3 and JAR, than in a normal trophoblast cell line, with both nuclear and cytoplasmic fractions demonstrated by immunoblotting. Spontaneously regressed HM showed significantly increased nuclear and cytoplasmic p‐Stat3‐Ser727 immunoreactivity over those that developed gestational trophoblastic neoplasia (GTN) (P = 0.013, P = 0.039). There was a significant positive and inverse correlation between nuclear p‐Stat3‐Ser727 immunoreactivity and apoptotic indices [terminal deoxynucleotidyl transferase (TdT)‐mediated deoxyuridine triphosphate (dUTP) nick end labelling and M30 CytoDeath antibody] (P = 0.001, P < 0.001, Spearman’s ρ test) and Bcl‐2 expression (P = 0.034), respectively.

Conclusions:  p‐Stat3‐Ser727 plays a role in the pathogenesis of GTD, probably through the regulation of apoptosis. p‐Stat3‐Ser727 immunoreactivity is a potential marker in predicting GTN in HM.
TNF/IL‐1/NIK/NF‐κB transduction pathway: a comparative study in normal and pathological human prostate (benign hyperplasia and carcinoma)
Authors: Nuñez C , Cansino J R , Bethencourt F , Pérez‐Utrilla M , Fraile B , Martínez‐Onsurbe P , Olmedilla G , Paniagua R , Royuela M
Published: July 2008

Aims:  Tumour necrosis factor (TNF)‐α induces death or cell proliferation by activation of nuclear factor (NF)‐κB, also activated by interleukin (IL)‐1α. The aim was to investigate upstream and downstream components of NIK transduction pathway in normal (NP), benign prostatic hyperplasia (BPH), prostatic intraepithelial neoplasia (PIN) and prostatic carcinoma (PC).

Methods and results:  Immunohistochemistry and Western blotting were performed. In NP, the cytoplasm of epithelial cells was intensely immunoreactive to IL‐1 receptor‐associated kinase (IRAK), TNF receptor‐associated factor (TRAF)‐6, NF‐κB inducing kinase (NIK), Iκκα/β, IκBα and p‐IκB; weakly to NF‐κB‐p50; and negative to NF‐κB‐p65. BPH samples were intensely immunoreactive to IRAK, TRAF‐6, NIK, Iκκα/β, IκBα, p‐IκB; weakly to NF‐κB‐p50 and NF‐κB‐p65. Whereas low‐grade PIN showed intermediate results between NP and BPH, results in high‐grade PIN were similar to those found in PC (low Gleason). In PC, immunoreactivity was intense for IRAK, TRAF‐6, NIK, Iκκα/β (increasing with Gleason), IκBα, p‐IκB (decreasing with Gleason); weak for NF‐κB‐p50 and NF‐κB‐p65 (decreasing with Gleason). Nuclear NF‐κB was observed in PC.

Conclusions:  NF‐κB enhances cell proliferation, but also ATF‐2 or Elk‐1. Since IL‐1 and TNF‐α are related to inflammation and their immunoexpression increases in PC, inhibition of these cytokines might be a possible target for PC treatment, because they decrease the activity of all transduction pathway members that activate transcription factors such as NF‐κB, Elk‐1 or ATF‐2.
Entropy concentration and the empirical coding game
Authors: Grünwald Peter
Published: July 2008

We give a characterization of maximum entropy/minimum relative entropy inference by providing two ‘strong entropy concentration’ theorems. These theorems unify and generalize Jaynes’‘concentration phenomenon’ and Van Campenhout and Cover's ‘conditional limit theorem’. The theorems characterize exactly in what sense a prior distribution Q conditioned on a given constraint and the distribution  minimizing D(P ‖ Q) over all P satisfying the constraint are ‘close’ to each other. We then apply our theorems to establish the relationship between entropy concentration and a game‐theoretic characterization of maximum entropy inference of Topsøe and others.
The sampling properties of conditional independence graphs forI(1) structural VAR models
Authors: Wilson Granville Tunnicliffe , Reale Marco
Published: July 2008

Abstract. Structural vector autoregressions allow dependence among contemporaneous variables. If such models have a recursive structure, the relationships among the variables can be represented by directed acyclic graphs. The identification of these relationships for stationary series may be enabled by the examination of the conditional independence graph constructed from sample partial autocorrelations of the observed series. In this article, we extend this approach to the case when the series follows anI(1) vector autoregression. For such a model, estimated regression coefficients may have non‐standard asymptotic distributions and in small samples this affects the distribution of sample partial autocorrelations. We show that, nevertheless, in large samples, exactly the same inference procedures may be applied as in the stationary case.
THE LEAD INGOTS OF CAPO PASSERO: ROMAN GLOBAL MEDITERRANEAN TRADE
Authors: TISSEYRE PHILIPPE , TUSA SEBASTIANO , CAIRNS WARREN R.L. , BOTTACIN FOSCARINA SELVAGGIO , BARBANTE CARLO , CIRIMINNA ROSARIA , PAGLIARO MARIO
Published: July 2008

Summary.  Epigraphic and isotopic analysis of the lead ingots recovered from a shipwreck off Capo Passero (in Sicily) in mid‐2006 suggests that the ingots were produced in Spain, in the Cartagena region. The shipwreck is estimated to have occurred around 38 BC, at the beginning of the Hispanic era. This provides further evidence that the Romans were trading lead throughout the Mediterranean Sea.
Identification and characterization of a novel intraepithelial lymphoid tissue in the gills of Atlantic salmon
Authors: Haugarvoll Erlend , Bjerkås Inge , Nowak Barbara F. , Hordvik Ivar , Koppang Erling O.
Published: July 2008

In addition to being the respiratory organ in fish, the gills form a barrier against the external milieu. Innate and adaptive immune system components have been detected in the gills, but lymphoid cell accumulations similar to that seen in the mammalian mucosa have not been described. The present investigations revealed cell accumulations on the caudal edge of interbranchial septum at the base of the gill filaments in the Atlantic salmon. Cytokeratin immunohistochemical staining and identification of a basal membrane and desmosome cell junctions by electron microscopy showed that the cell accumulation was located intraepithelially. Major histocompatibility complex (MHC) class II+ cells were detected by immunohistochemistry, and laser capture micro‐dissection and subsequent RT‐PCR analysis revealed expression of T‐cell receptor transcripts in the investigated tissue, suggesting the presence of T cells. The intraepithelial tissue reported here may be a suitable location for immune surveillance of gill infections, as well as a target site for new vaccine approaches and investigations of epithelial immunity. This is the first description of a lymphocyte cell aggregation within a teleostian gill epithelium network, illustrating a phylogenetically early form of leukocyte accumulations in a respiratory organ.
Between Convergence and Divergence: Reformatting Language Purism in the Montreal Tamil Diasporas
Authors: Das Sonia Neela
Published: July 2008

This article examines how ideologies of language purism are reformatted by creating interdiscursive links across spatial and temporal scales. I trace convergences and divergences between South Asian and Québécois sociohistorical regimes of language purism as they pertain to the contemporary experiences of Montreal's Tamil diasporas. Indian Tamils and Sri Lankan Tamils in Montreal emphasize their status differences by claiming that the former speak a modern “vernacular” Tamil and the latter speak an ancient “literary” Tamil. The segregation and purification of these social groups and languages depend upon the intergenerational reproduction of scalar boundaries between linguistic forms, interlocutors, and decentered contexts. [Tamils, Quebec, diaspora, linguistic purism, spatiotemporal scales]
“At the Time She Was a Man”: The Temporal Dimension of Identity Construction
Authors: Conley Robin
Published: July 2008

This article examines the temporal elements of identity construction, drawing parallels between the construction of ethnographic, legal, and personal identities. The article presents a case of transsexual identity, analyzing how people reference a transsexual in order to illuminate the temporal complexity of gendered identity construction and identity in general. The study consists of a micro‐analysis of scientists and lawyers talking about transsexuals in and around a legal trial, and offers a model of identity that allows for disjuncture and incongruence over time. It argues that ethnographic and legal accounts of identity rely on a negotiation between coherence and discontinuity.
Sexual Citizenship: Articulating Citizenship, Identity, and the Pursuit of the Good Life in Urban Brazil
Authors: Castle Tomi
Published: July 2008

In this article, I examine a citizenship course held by a lesbian rights organization in Campinas, Brazil, and argue that claims for citizenship may go well beyond claims for civil rights and legal recognition and, instead, revolve around full, participatory inclusion in public life. I further argue that social actors who demand full citizenship may at the same time place demands on themselves to become what constitutes, in their view, “ideal citizens,” thereby neutralizing, at least in theory, the possibility of exclusion. In probing the understandings of the ideal lesbian citizen that surfaced during the course, including those that connect full citizenship with notions of the “good life,” I suggest both that these women are simultaneously capitulating to hegemonic cultural conceptions of propriety, and rewriting those conceptions by refusing the role of marginalized “other” in Brazilian society.[citizenship, identity, sexuality, activism, Brazil]