2,847 research outputs found
The mitogenic potential of heparin-binding epidermal growth factor in the human endometrium is mediated by the epidermal growth factor receptor and is modulated by tumor necrosis factor-alpha
No full textHeparin-binding epidermal growth factor (HB-EGF), a member of the epidermal growth factor (EGF) family, is implicated in a variety of biological processes, including reproduction. Previous studies describe increased levels of HB-EGF in the human endometrium during the midsecretory stage of the menstrual cycle, suggesting a function for HB-EGF in implantation of the human blastocyst. Here we have investigated the expression and function of the soluble and transmembrane forms of HB-EGF in the human endometrium. We show that the expression of the transmembrane form of HB-EGF in the human endometrium is modulated according to the stage of the menstrual cycle. We present data demonstrating that both the soluble and transmembrane forms of HB-EGF induce DNA synthesis in human endometrial stromal cells. Furthermore, TNFalpha has a cooperative effect on HB-EGF, EGF, TGFalpha, and betacellulin-induced DNA synthesis in stromal cells, suggesting roles for the EGF family and TNFalpha in regeneration and maturation of human endometrium. Induction of DNA synthesis by HB-EGF and its modulation by TNFalpha in endometrial stromal cells are mediated by the EGF receptor and not the HB-EGF receptor ErbB4. Our data suggest key functions for HB-EGF, TNFalpha, and the EGF receptor in endometrial maturation, via autocrine/paracrine and juxtacrine pathways, in preparation for embryo implantation
On the Security of Non-Linear HB (NLHB) Protocol Against Passive Attack
No full textAs a variant of the HB authentication protocol for RFID systems, which relies on the complexity of decoding linear codes against passive attacks, Madhavan et al. presented Non-Linear HB(NLHB) protocol. In contrast to HB, NLHB relies on the complexity of decoding a class of non-linear codes to render the passive attacks proposed against HB ineffective. Based on the fact that there has been no passive solution for the problem of decoding a random non-linear code, the authors have claimed that NLHB’s security margin is very close to its key size. In this paper, we show that passive attacks against HB protocol can still be applicable to NLHB and this protocol does not provide the desired security margin. In our attack, we first linearize the non-linear part of NLHB to obtain a HB equivalent for NLHB, and then exploit the passive attack techniques proposed for the HB to evaluate the security margin of NLHB. The results show that although NLHB’s security margin is relatively higher than HB against similar passive attack techniques, it has been overestimated and, in contrary to what is claimed, NLHB is vulnerable to passive attacks against HB, especially when the noise vector in the protocol has a low weight
Control of human endometrial stromal cell motility by PDGF-BB, HB-EGF and trophoblast-secreted factors
No full textHuman implantation involves extensive tissue remodeling at the fetal-maternal interface. It is becoming increasingly evident that not only trophoblast, but also decidualizing endometrial stromal cells are inherently motile and invasive, and likely contribute to the highly dynamic processes at the implantation site. The present study was undertaken to further characterize the mechanisms involved in the regulation of endometrial stromal cell motility and to identify trophoblast-derived factors that modulate migration. Among local growth factors known to be present at the time of implantation, heparin-binding epidermal growth factor-like growth factor (HB-EGF) triggered chemotaxis (directed locomotion), whereas platelet-derived growth factor (PDGF)-BB elicited both chemotaxis and chemokinesis (non-directed locomotion) of endometrial stromal cells. Supernatants of the trophoblast cell line AC-1M88 and of first trimester villous explant cultures stimulated chemotaxis but not chemokinesis. Proteome profiling for cytokines and angiogenesis factors revealed neither PDGF-BB nor HB-EGF in conditioned media from trophoblast cells or villous explants, while placental growth factor, vascular endothelial growth factor and PDGF-AA were identified as prominent secretory products. Among these, only PDGF-AA triggered endometrial stromal cell chemotaxis. Neutralization of PDGF-AA in trophoblast conditioned media, however, did not diminish chemoattractant activity, suggesting the presence of additional trophoblast-derived chemotactic factors. Pathway inhibitor studies revealed ERK1/2, PI3 kinase/Akt and p38 signaling as relevant for chemotactic motility, whereas chemokinesis depended primarily on PI3 kinase/Akt activation. Both chemotaxis and chemokinesis were stimulated upon inhibition of Rho-associated, coiled-coil containing protein kinase. The chemotactic response to trophoblast secretions was not blunted by inhibition of isolated signaling cascades, indicating activation of overlapping pathways in trophoblast-endometrial communication. In conclusion, trophoblast signals attract endometrial stromal cells, while PDGF-BB and HB-EGF, although not identified as trophoblast-derived, are local growth factors that may serve to fine-tune directed and non-directed migration at the implantation site
Legal regulation of prices in Tanzania : an examination of the Regulation of Prices Act 1973 as a tool of social change and development
No full textDrawing mainly from the Tazanian experience this study
attempts to review the principal issues in the legal regulation of
prices, by identifying both the general and specific importance
of law in this respect. The position I shall present is that
legal control is both necessary and desirable for the welfare
and social development of the people. The key issue is whether
the market-place will perform its function satisfactory: Will
it produce socially desirable results? If it will not, why will
it not? And will legal regulation help to do the job a little
better?
In an attempt to answer some of these questions,
first of all, outline the basic issues raised by the study in
the first Chapter. Then I examine the general case for price
controls - the theory about the controls, the motives and reasons
for their imposition and the manner in which they are effected
in different economic systems. This is done in Chapter Two. Relying
most on the available literature on the regulatory process, this
Chapter also looks at the relationship between law and economic
regulation and concludes that the effectiveness of law depends
on the existence of a conducive socio-economic environment. In
Chapter Three I describe the past record of price control laws
in Tanzania. I conclude that despite the failure in the past,
the controls still constitute an important policy instrument
in the transition to socialism. In Chapters Four and Five I describe
the manner in which the current regulations are implemented and
the problems encountered. I conclude that the operational performance
of the controls is constrained by internal and external influences on the economic and political life of the country. In the concluding
Chapter I assess the impact of the controls: Do the controls
work? Do people buy goods at the controlled prices? Why today
the controls are almost popularly accepted as worthwhile? I conclude
that while there may be no measurable economic gains derived
by consumers, the controls have a stabilising effect on the social
and political front. In the final section I argue that the
future success of the legislation depends on creating a correspondence
between the economic structures and the control system. What
makes the controls ineffective is not so much defects in the
law but the contradictions between the orientation of and functioning
of the economic system and the ideological commitment
On
No full textIn this paper, this author proved that always has
the integral solutions for Then we conjecture the equation always has the integral solutions
Evaluation of the efficacy of HB-surface assembled CSNC prototypes.
No full text<p>Immune response induced by the nanovaccine prototypes (CSNC− and CSNC+) and the positive control (HB-alum) administered intramuscularly following different vaccination protocols. (<b>A</b>) IgG anti-HB levels generated after prime-boost immunization (arrows, weeks 0–4) with both prototypes: CSNC− (blue –▴–); CSNC+ (green –•–) and HB-alum (black –·X·–) at the same dose (10 µg). Results are presented as mean ± SEM.*Alum or CSNC+ vs. CSNC− (p<0.05). ** CSNC+ vs. Alum and CSNC- (p<0.05). (<b>B</b>) IgG anti-HB (mIU/ml) levels elicited after a single dose (arrow) of CSNC+ (10 µg; green –•–) compared to alum-HB administered twice (10 µg, weeks 0 and 4) (black –·X·–). Results are presented as mean ± SEM.*(p<0.05).</p
Corrosion Protection in Chloride Environments of Nanosilica Containing Epoxy Powder Coatings with Defects
No full textThis paper describes the use of innovative, nanosilica containing epoxy powder coatings for the corrosion protection of steel. Two types of nanosilica particles (hydrophilic -HL- and hydrophobic -HB-) were mixed by ball milling with the powders (0.75 wt.%). The adequate homogeneity and embedding of nanoparticles were verified by transmission electron microscopy. The corrosion performance of the coatings as-received, and with HL and HB additions, were analyzed in 3.5 wt.% NaCl solutions. The mechanism and rate of delamination of defective coatings under drops simulating atmospheric conditions were analyzed by Scanning Kelvin Probe measurements for 30 d. The results show that the corrosion attack progresses through a cathodic delamination mechanism. Besides, fully-immersed samples, with and without defects, were monitored by electrochemical impedance spectroscopy. In defective coatings under these conditions, the occurrence of anodic undermining is proved. The results obtained reveal that the corrosion driven coating failure is delayed in the case of the epoxy coatings containing nanosilica. This delay is larger in the case of HB additions than HL additions in both atmospheric and immersion conditions. The corrosion mechanism observed is dependent upon exposure conditions. It is proposed that the nanoparticles delay water absorption, thus delaying corrosion attack. Accepted Author Manuscript(OLD) MSE-
SOME NEWMAN-TYPE THEOREMS FOR MAPS FROM RIEMANNIAN-MANIFOLDS INTO MANIFOLDS
No full textMathematics, AppliedMathematicsSCI(E)1ARTICLE53-5911
SOME BORSUK-ULAM-TYPE THEOREMS FOR MAPS FROM RIEMANNIAN-MANIFOLDS INTO MANIFOLDS
No full textMathematics, AppliedMathematicsSCI(E)1ARTICLE61-6711
Authoring Reading Lolita in Tehran in America: Diasporic Memoir and Rebirth of the Author
No full textAzar Nafisi’s Reading Lolita in Tehran is a diasporic memoir that simultaneouslychallenges Roland Barthes’ Death of the Author and benefits from the said vacant positionBarthes bid farewell. The vacated authorial seat, previously occupied by a majority of eastern andwestern male authors by tradition, is an invitation for diasporic female authors. Azar Nafisi andother Iranian female memoirists like Marina Nemat, Masih Alinejad, Shirin Ebadi, and othershave long had their voices, fantasies, and beings conventionally constrained by the banality oftheir day-to-day lives, not necessarily by the male figures in their lives, but under the strictpatriarchal watch that speculates every dim corner of their private lives. The exilic life in diasporais a condition of liminality that thrusts the individual into an in-between state of constantbecoming. In diaspora, the selective nature of memory, as an elusive and illusive faculty,contributes to the author’s process of identity-making. The homeless author cuts off her rootsfrom homeland, so that she may float on the tides with no solid destination; but the uncertainty,also, presents authorship as a liminal initiatiary step for the author to construct her identitywhere belonging seems to be a bygone tale. As such, Nafisi, the previous reader of Nabokov’sLolita in Tehran, occupies the vacated seat of the dead author as a diasporic author and pens herworldview from the position of an exile in form of a memoir, Reading Lolita in Tehran, amouthpiece for the hitherto silent reader
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