926 resultados para IT order list
Resumo:
A change in synaptic strength arising from the activation of two neuronal pathways at approximately the same time is a form of associative plasticity and may underlie classical conditioning. Previously, a cellular analog of a classical conditioning protocol has been demonstrated to produce short-term associative plasticity at the connections between sensory and motor neurons in Aplysia. A similar training protocol produced long-term (24 hour) enhancement of excitatory postsynaptic potentials (EPSPs). EPSPs produced by sensory neurons in which activity was paired with a reinforcing stimulus were significantly larger than unpaired controls 24 hours after training. To examined whether the associative plasticity observed at these synapses may be involved in higher-order forms of classical conditioning, a neural analog of contingency was developed. In addition, computer simulations were used to analyze whether the associative plasticity observed in Aplysia could, in theory, account for second-order conditioning and blocking. ^
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Histone gene expression is replication-independent during oogenesis and early embryogenesis in amphibians; however, it becomes replication-dependent during later embryogenesis and remains replication-dependent through adulthood. In order to understand the mechanism for this switch in transcriptional regulation of histone gene expression during amphibian development, linker-scanning mutations were made in a Xenopus laevis H2B histone gene promoter by oligonucleotide site-directed mutagenesis and assayed by microinjection into oocytes and embryos. The Xenopus H2B gene has a relatively simple promoter containing several transcriptional regulatory elements, including TFIID, CCAAT, and ATF motifs, required for maximal transcription in both oocytes and embryos. Factors binding to the CCAAT and ATF motifs are present in oocytes and embryos and increase slightly in abundance during early development. A sequence (CTTTACAT) in the frog H2B promoter resembling the conserved octamer motif (ATTTGCAT), the target for cell-cycle regulation of a human H2B gene, is additionally required for maximal H2B transcription in frog embryos. Oocytes and embryos contain multiple octamer-binding proteins that are expressed in a sequential manner during early development. Sequences encoding three novel octamer-binding proteins were isolated from Xenopus cDNA libraries by virtue of their similarity with the DNA binding (POU) domain of the ubiquitously expressed transcription factor Oct-1. The protein encoded by one of these genes, termed Oct-60, was localized mainly in the cytoplasm of oocytes and was also present in early embryos until the gastrula stage of development. Proteins encoded by the other two genes, Oct-25 and Oct-91, were present in embryos after the mid-blastula stage of development and decreased by early neurula stage. The activity of the Xenopus H2B octamer motif in embryos is not specifically associated with increased binding by Oct-1 or the appearance of novel octamer-binding proteins but requires the presence of an intact CCAAT motif. We found that synergistic interactions among promoter elements are important for full H2B promoter activity. The results suggest that transcription of the Xenopus H2B gene is replication-dependent when it is activated at the mid-blastula stage of development and that replication-dependent H2B transcription is mediated by Oct-1. ^
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The c-mos proto-oncogene, which is expressed at relatively high levels in male and female germ cells, plays a key role in oocyte meiotic maturation. The c-mos gene product in oocytes (p39$\sp{\rm c-mos}$) is necessary and sufficient to initiate meiosis. p39$\sp{\rm c-mos}$ is also an essential component of the cytostatic factor, which is responsible for arresting vertebrate oocytes at the second meiotic metaphase by stabilizing the maturation promoting factor (MPF). MPF is a universal regulator of both meiosis and mitosis. Much less is understood about c-mos expression and function in somatic cells. In addition to gonadal tissues, c-Mos has been detected in some somatic tissues and non-germ cell lines including NIH 3T3 cells as a protein termed p43$\sp{\rm c-mos}$. Since c-mos RNA transcripts were not previously detected in this cell line by Northern blot or S1 protection analyses, a search was made for c-mos RNA in NIH 3T3 cells. c-mos transcripts were detected using the highly sensitive RNA-PCR method and RNase protection assays. Furthermore, cell cycle analyses indicated that expression of c-mos RNA is tightly controlled in a cell cycle dependent manner with highest levels of transcripts (approximately 5 copies/cell) during the G2 phase.^ In order to determine the physiological significance of c-mos RNA expression in somatic cells, antisense mos was placed under the control of an inducible promoter and introduced into either NIH 3T3 cells or C2 cells. It was found that a basal level of expression of antisense mos resulted in interference with mitotic progression and growth arrest. Several nuclear abnormalities were observed, especially the appearance of binucleated and multinucleated cells as well as the extrusion of microvesicles containing cellular material. These results indicate that antisense mos expression results in a block in cytokinesis. In summary, these results establish that c-mos expression is not restricted to germ cells, but instead indicate that c-mos RNA expression occurs during the G2 stage of the cell cycle. Furthermore, these studies demonstrate that the c-mos proto-oncogene plays an important role in cell cycle progression. As in meiosis, c-mos may have a similar but not identical function in regulating cell cycle events in somatic cells, particularly in controlling mitotic progression via activation/stabilization of MPF. ^
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Neuromodulation is essential to many functions of the nervous system. In the simple gastropod mollusk Aplysia californica, neuromodulation of the circuits for the defensive withdrawal reflexes has been associated with several forms of learning. In the present work, the neurotransmitters and neural circuitry which contribute to the modulation of the tail-siphon withdrawal reflex were examined.^ A recently-identified neuropeptide transmitter, buccalin A was found to modulate the biophysical properties of the sensory neurons that mediate the reflex. The actions of buccalin A on the sensory neurons were compared with those of the well-characterized modulatory transmitter serotonin, and convergence and divergence in the actions of these two transmitters were evaluated. Buccalin A dramatically increased the excitability of sensory neurons and occluded further enhancement of excitability by serotonin. Buccalin A produced no significant change in spike duration, and it did not block serotonin-induced spike broadening. Voltage-clamp analysis revealed the currents that may be involved in the effects on spike duration and excitability. Buccalin A decreased an outward current similar to the S-K$\sp+$ current (I$\sb{\rm K,S}$). Buccalin A appeared to occlude further modulation of I$\sb{\rm K,S}$ by serotonin, but did not block serotonin-induced modulation of the voltage-dependent delayed rectifier K$\sp+$ current (I$\sb{\rm K,V}$). These results suggest that buccalin A converges on some, but not all, of the same subcellular modulatory pathways as serotonin.^ In order to begin to understand neuromodulation in a more physiological context for the tail-siphon withdrawal reflex, the modulatory circuitry for the tail-withdrawal circuit was examined. Mechanoafferent neurons in the J cluster of the cerebral ganglion were identified as elements of a modulatory circuit for the reflex. Excitatory and inhibitory connections were observed between the J cells and the pleural sensory neurons, the tail motor neurons, and several classes of interneurons for the tail-siphon withdrawal circuit. The J cells produced both fast and slow PSPs in these neurons. Of particular interest was the ability of the J cells to produce slow EPSPs in the pleural sensory neurons. These slow EPSPs were associated with an increase in the excitability of the sensory neurons. The J cells appear to mediate both sensory and modulatory inputs to the circuit for the tail-siphon withdrawal reflex from the anterior part of the animal. ^
Resumo:
In vitro, RecA protein catalyses the exchange of single strands of DNA between different DNA molecules with sequence complementarity. In order to gain insight into this complex reaction and the roles of ATP binding and hydrolysis, two different approaches have been taken. The first is to use short single-stranded deoxyoligonucleotides as the ssDNA in strand exchange. These were used to determine the signal for hydrolysis and the structure of the RecA-DNA complex that hydrolyses ATP. I present a defined kinetic analysis of the nucleotide triphosphatase activity of RecA protein using short oligonucleotides as ssDNA cofactor. I compare the effects of both homopolymers and mixed base composition oligomers on the ATPase activity of RecA protein. I examine the steady state kinetic parameters of the ATPase reaction using these oligonucleotides as ssDNA cofactor, and show that although RecA can both bind to, and utilise, oligonucleotides 7 to 20 residues in length to support the repressor cleavage activity of RecA, these oligonucleotides are unable to efficiently stimulate the ATPase activity of RecA protein. I show that the K$\sb{\rm m}\sp{\rm ATP}$, the Hill coefficient for ATP binding, the extent of reaction, and k$\sb{\rm cat}$ are all a function of ssDNA chain length and that secondary structure may also play a role in determining the effects of a particular chain length on the ATPase activity of RecA protein.^ The second approach is to utilise one of the many mutants of RecA to gain insight into this complex reaction. The mutant selected was RecA1332. Surprisingly, in vitro, this mutant possesses a DNA-dependent ATPase activity. The K$\sb{\rm m}\sp{\rm ATP}$, Hill coefficient for ATP binding, and K$\sb{\rm m}\sp{\rm DNA}$ are similar to that of wild type. k$\sb{\rm cat}$ for the ATPase activity is reduced 3 to 12-fold, however. RecA1332 is unable to use deoxyoligonucleotides as DNA cofactors in the ATPase reaction, and demonstrates an increased sensitivity to inhibition by monovalent ions. It is able to perform strand exchange with ATP and ATP$\lbrack\gamma\rbrack$S but not with UTP, whereas the wild type protein is able to use all three nucleotide triphosphates. RecA1332 appears to be slowed in its ability to form intermediates and to convert these intermediates to products. (Abstract shortened by UMI.) ^
{\it In vivo\/} induction of DNA changes in cervicovaginal epithelium by perinatal estrogen exposure
Resumo:
Epidemiological studies have associated estrogens with human neoplasm such as the endometrium, cervix, vagina, breast, and liver. Perinatal exposure to natural (17$\beta$-estradiol (17$\beta$-E$\sb2)\rbrack$ and synthetic (diethylstilbestrol (DES)) estrogens induces neoplastic changes in humans and rodents. Previous studies demonstrated that neonatal 17$\beta$-E$\sb2$ treatment increased the nuclear DNA content of mouse cervicovaginal epithelium that preceded histologically evident neoplasia. In order to determine whether this effect was specific to 17$\beta$-E$\sb2,$ associated with chromosomal changes, and relevant to the human, female BALB/c mice were treated neonatally with either 17$\alpha$-estradiol (17$\alpha$-E$\sb2)$ and 5$\beta$-dihydrotestosterone ($5\beta$-DHT), both inactive steroids in adult reproductive tissue, or 17$\beta$-E$\sb2.$ Ten-day-old mice received pellet implants of 17$\beta$-E$\sb2,$ 17$\alpha$-E$\sb2,$ $5\beta$-DHT, or cholesterol. Seventy-day-old cervicovaginal tracts were examined histologically and flow cytometrically. 17$\beta$-E$\sb2$-treated animals were evaluated by fluorescent in situ hybridization (FISH) using a probe specific for chromosome 1. Trisomy of chromosomes 1, 7, 11, and 17 was evaluated by FISH in cervicovaginal material from 19 DES-exposed and 19 control patients.^ $17\beta$-E$\sb2, 17\alpha$-E$\sb2$, and $5\beta$-DHT-induced dramatic developmental and histological changes in the cervicovaginal tract, including hypospadia, hyperplasia, and persistent cornification. The changes induced by 17$\alpha$-E$\sb2$ were equivalent to 17$\beta$-E$\sb2.$ Neonatal 17$\alpha$-E$\sb2$-induced adenosquamous cervicovaginal tumors at 24 months. 17$\alpha$-E$\sb2$ and $5\beta$-DHT significantly increased the nuclear DNA content over control animals, but at significantly lower levels than 17$\beta$-E$\sb2.$ DNA ploidy changes were highest (80%) in animals treated neonatally and secondarily with 17$\beta$-E$\sb2.$ Secondary 17$\alpha$-E$\sb2$ and $5\beta$-DHT administration, unlike 17$\beta$-E$\sb2,$ didn't significantly increase DNA content. Chromosome 1 trisomy incidence was 66% in neonatal 17$\beta$-E$\sb2$-treated animals. Trisomy was evident in 4 DES-exposed patients: one patient with trisomy of chromosomes 1, 7, and 11; one patient with chromosome 7 trisomy; and two patients with chromosome 1 trisomy. These data demonstrated the biological effects of 17$\alpha$-E$\sb2$ and $5\beta$-DHT were age-dependent, 17$\alpha$-E$\sb2$ was equivalent to 17$\beta$-E$\sb2$ and tumorigenic when administered neonatally, and histological changes were not steroid specific. Chromosomal changes were associated with increased nuclear DNA content and chromosomal changes may be an early event in the development of tumors in human DES-exposed tissues. ^
Resumo:
Cell differentiation are associated with activation of cell lineage-specific genes. The $LpS{\it 1}\beta$ gene of Lytechinus pictus is activated at the late cleavage stage. $LpS{\it 1}\beta$ transcripts accumulate exclusively in aboral ectoderm lineages. Previous studies demonstrated two G-string DNA-elements, proximal and distal G-strings, which bind to an ectoderm-enriched nuclear factor. In order to define the cis-elements which control positive expression of the $LpS{\it 1}\beta$ gene, the regulatory region from $-$108 to +17 bp of the $LpS{\it 1}\beta$ gene promoter was characterized. The ectoderm G-string factor binds to a G/C-rich region larger than the G-string itself and the binding of the G-string factor requires sequences immediately downstream from the G-string. These downstream sequences are essential for full promoter activity. In addition, only 108 bp of $LpS{\it 1}\beta\ 5\sp\prime$ flanking DNA drives $LpS{\it 1}\beta$ gene expression in aboral ectoderm/mesenchyme cells. Therefore, for positive control of $LpS{\it 1}\beta$ gene expression, two regions of 5$\sp\prime$ flanking DNA are required: region I from base pairs $-$762 to $-$511, and region II, which includes the G/C-rich element, from base pairs $-$108 to $-$61. A mesenchyme cell repressor element is located within region I.^ DNA-binding proteins play key roles in determination of cell differentiation. The zinc finger domain is a DNA-binding domain present in many transcription factors. Based on homologies in zinc fingers, a zinc finger-encoding gene, SpKrox-1, was cloned from S. purpuratus. The putative SpKrox-1 protein has all structural characteristics of a transcription factor: four zinc fingers for DNA binding; acidic domain for transactivation; basic domain for nuclear targeting; and leucine zipper for dimerization. SpKrox-1 RNA transcripts showed a transient expression pattern which correlates largely with early embryonic development. The spatial expression of SpKrox-1 mRNA was distributed throughout the gastrula and larva ectodermal wall. However, SpKrox-1 was not expressed in pigment cells. The SpKrox-1 gene is thus a marker of a subset of SMCs or ectoderm cells. The structural features, and the transient temporal and restricted spatial expression patterns suggest that SpKrox-1 plays a role in a specific developmental event. ^
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A fundamental problem in developmental biology concerns the mechanisms involved in the establishment of the embryonic axis. We are studying Xenopus nuclear factor 7 (xnf7) which we believe to be involved in dorsal-ventral patterning in Xenopus laevis. Xnf7 is a maternal gene product that is retained in the cytoplasm during early embryogenesis until the mid-blastula transition (MBT) when it reenters the nuclei. It is a member of a novel zinc finger proteins, the B-box family, consisting mainly of transcription factors and protooncogenes.^ The xnf7 gene is reexpressed during embryogenesis at the gastrula-neurula stage of development, with its zygotic expression limited to the central nervous system (CNS). In this study we showed that there are two different cDNAs coding for xnf7, xnf7-O and xnf7-B. They differ by 39 amino acid changes scattered throughout the cDNA. The expression of both forms of xnf7 is limited primarily to the central nervous system (CNS) and dorsal axial structures during later stages of embryogenesis.^ In order to study the spatial and temporal regulation of the gene, we screened a Xenopus genomic library using part of xnf7 cDNA as a probe. A genomic clone corresponding to the xnf7-O type was isolated, its 5$\sp\prime$ putative regulatory region sequenced, and its transcriptional initiation site mapped. The putative promoter region contained binding sites for Sp1, E2F, USF, a Pu box and AP1. CAT/xnf7 fusion genes were constructed containing various 5$\sp\prime$ deleted regions of the xnf7 promoter linked to a CAT (Chloramphenicol Acetyl Transferase) reporter vector. These constructs were injected into Xenopus oocytes and embryos to study the regions of the xnf7 promoter responsible for basal, temporal and spatial regulation of the gene. The activity of the fusion genes was measured by the conversion of chloramphenicol to its acetylated forms, and the spatial distribution of the transcripts by whole mount in situ hybridization. We showed that the elements involved in basal regulation of xnf7 lie within 121 basepairs upstream of the transcriptional inititiation site. A DNase I footprint analysis performed using oocyte extract showed that a E2F and 2 Sp1 sites were protected. During development, the fusion genes were expressed following the MBT, in accordance with the timing of the endogenous xnf7 gene. Spatially, the expression of the fusion gene containing 421 basepairs of the promoter was localized to the dorsal region of the embryo in a pattern that was almost identical to that detected with the endogenous transcripts. Therefore, the elements involved in spatial and temporal regulation of the xnf7 gene during development were contained within 421 basepairs upstream of the transcriptional initiation site. Future work will further define the elements involved in the spatial and temporal regulation and the trans-factors that interact with them. ^
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Ultraviolet B (UVB) radiation, in addition to being carcinogenic, is also immunosuppressive. Immunologically, UVB induces suppression locally, at the site of irradiation, or systemically, by inducing the production of a variety of immunosuppressive cytokines. Systemic effects include suppression of delayed-type hypersensitivity (DTH) responses to a variety of antigens (e.g. haptens, proteins, bacterial antigens, or alloantigens). One of the principal mediators of UV-induced immune suppression is the T helper-2 (Th2) cytokine interleukin-10 (IL-10); this suggests that UV irradiation induces suppression by shifting the immune response from a Th1 (cellular) to a Th2 (humoral) response. These "opposing" T helper responses are usually mutually exclusive, and polarized Th1 or Th2 responses may lead to either protection from infection or increased susceptibility to disease, depending on the infectious agent and the route of infection.^ This study examines the effects of UVB irradiation on cellular and humoral responses to Borrelia burgdorferi (Bb), the causative agent of Lyme disease (LD) in both immunization and infectious disease models; in addition, it examines the role of T cells in protection from and pathology of Bb infection. Particular emphasis is placed on the Bb-specific antibody responses following irradiation since UVB effects on humoral immunity are not fully understood. Mice were irradiated with a single dose of UV and then immunized (in complete Freund's adjuvant) or infected with Bb (intradermally at the base of the tail) in order to examine both DTH and antibody responses in both systems. UVB suppressed the Th1-associated antibodies IgG2a and IgG2b in both systems, as well as the DTH response to Bb in a dose dependent manner. Injection of anti-IL-10 antibody into UV-irradiated mice within 24 h after UV exposure restored the DTH response, as well as the Th1 antibody (IgG2a and IgG2b) response. In addition, injecting recombinant IL-10 mimicked some of the effects of UV radiation.^ Bb-specific Th1 T cell lines (BAT2.1-2.3) were generated to examine the role of T cells in Lyme borreliosis. All lines were CD4$\sp+,$ $\alpha\beta\sp+$ and proliferated specifically in response to Bb. The BAT2 cell lines not only conferred a DTH response to naive C3H recipients, but reduced the number of organisms recovered from the blood and tissues of mice infected with Bb. Furthermore, BAT2 cell lines protected mice from Bb-induced periarthritis. ^
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Under normal physiological conditions, cells of the hematopoietic system produce Interleukin-1$\beta$(IL-1$\beta)$ only when a stimulus is present. Leukemic cells, however, can constitutively produce this cytokine without an exogenous source of activation. In addition, IL-1$\beta$ can operate as an autocrine and/or paracrine growth factor for leukemic blasts. In order to study the cellular basis for this aberrant production, we analyzed two leukemic cell lines (B1 and W1) which express high levels of IL-1$\beta$ and use IL-1$\beta$ as an autocrine growth factor. Initial studies demonstrated: (1) lack of rearrangement and/or amplification in the IL-1$\beta$ gene and its promoter; and (2) intact responsiveness to regulators such as cycloheximide and dexamethasone, implying that the molecular defect was upstream. Analysis of the Ras inducible transcription factors by gel shift assay demonstrated constitutive transcription factor binding in the IL-1$\beta$ promoter. Furthermore, RAS mutations were found at codon 12 in the K-RAS and N-RAS genes in the B1 and W1 cells, respectively. To deduce the effects of activated Ras on IL-1$\beta$ expression, two classes of farnesyltransferase inhibitors and an adenoviral vector expressing antisense targeted to K-RAS were utilized. The farnesyltransferase inhibitors perillyl alcohol and B581 were able to reduce IL-1$\beta$ levels by 80% and 50% in the B1 cells, respectively. In W1 cells, IL-1$\beta$ was reduced by 60% with 1mM perillyl alcohol. Antisense RNA targeted to K-RAS confirmed the results demonstrating a 50% reduction in IL-1$\beta$ expression in the B1 cells. In addition, decreased binding at the crucial NF-IL6/CREB binding site correlated with decreased IL-1$\beta$ production and cellular proliferation implying that this site was a downstream effector of Ras signaling. Our data suggest that mutated RAS genes may be responsible for autocrine IL-1$\beta$ production in some leukemias by stimulating signal transduction pathways that activate the IL-1$\beta$ promoter. ^
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Genes of the basic helix-loop-helix transcription factor family have been implicated in many different developmental processes from neurogenesis to myogenesis. The recently cloned bHLH transcription factor, paraxis, has been found to be expressed in the paraxial mesoderm of the mouse suggesting a role for paraxis in the development of this mesodermal subtype which gives rise to the axial muscle, skeleton, and dermis of the embryo. In order to perform in vivo gain of function assays and obtain a better understanding of the possible roles of paraxis in mesodermal and somitic development, we have successfully identified homologues of paraxis in the frog, Xenopus laevis, where the process of mesodermal induction and development is best understood. The two homologues, Xparaxis-a and Xparaxis-b, are conserved with respect to their murine homologue in structure and expression within the embryo. Xparaxis genes are expressed immediately after gastrulation in the paraxial mesoderm of Xenopus embryos and are down regulated in the myotome of the mature somite with continued expression in the undifferentiated dermatome. Overexpression of Xparaxis-b in Xenopus embryos caused defects in the organization and morphology of the somites. This effect was not dependent on DNA binding of Xparaxis but is likely due to its dimerization with other bHLH factors. Co-injections with XE12 did not diminish the effects indicating that the defects were not the result of limiting amounts of XE12. We also demonstrated that Xparaxis does not cause obvious defects in the cell adhesions and movements required for proper mesoderm patterning during gastrulation. The paraxis proteins also lacked the ability to activate transcription as GAL4 fusion proteins in a GAL4 reporter assay, indicating that the genes may function more as modulators of the activity of dimerization partners than as positively acting cell determination factors. In agreement with this, Xparaxis is regulated in response to other pathways of bHLH gene action, in that XE12 can activate Xparaxis-b, in vivo. In addition we show regulation of Xparaxis in response to mMyoD induced myogenesis pathways, again suggesting Xparaxis plays an important role in the patterning and organization of the paraxial mesoderm. ^
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Background Recent research has indicated a considerable contribution of placebo effects to the outcome of acupuncture treatments: especially patients’ expectations seem to have an influence [1, 2]. In this context it is important to better understand the patient-practitioner relationship. The aim of this study was to investigate why patients in Switzerland choose acupuncture or qigong, and what they expect from the treatment and the practitioners [3]. Method A qualitative survey with open questions was performed among 38 patients newly enrolled for treatment in 7 different practices for Traditional Chinese Medicine ((TCM); 6 practices for acupuncture, 1 for qigong). Questions aimed to identify reasons for choosing TCM, knowledge about its range of indications, and patients’ expectations towards method and therapist. Answers were categorised and analysed by frequency. Results The most common reasons for choosing TCM were recommendation by acquaintances, the idea of trying a new treatment and the perception of TCM as being a gentle method. The majority of respondents had poor knowledge about the range of conditions to be treated with TCM: pain of the musculoskeletal system, headaches and chronic problems were considered as main indications. Surprisingly, gynaecological or gastro-intestinal diseases were not mentioned by the respondents. Practitioners were expected to have professional competence, provide information, empathy and understanding. Discussion The most striking result of this survey was the fact that patients knew very little about TCM and its indications. Thus, more precise information about TCM and other complementary methods should be offered to the general public, which would help patients to decide whether to consider TCM for the treatment of their disease. And, on the other hand, for the therapists it is important to better understand and respond to patients’ expectations in order to achieve better treatment results. The results of this qualitative survey were briefly discussed with the participating practitioners, who found them remarkable and support further quantitative studies. We plan to further investigate this topic. Literature 1 Pariente J et al., Neuroimage 2005;25:1161-67 2 Karst M et al., Forsch Komplementmed 2010;17:21-7 3 Klein SD., Dt Ztschr f Akup. 2009;52:18-23
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Recently, it was shown that insertions of hadronic vacuum polarization at O(α4) generate non-negligible effects in the calculation of the anomalous magnetic moment of the muon. This result raises the question if other hadronic diagrams at this order might become relevant for the next round of g−2 measurements as well. In this note we show that a potentially enhanced such contribution, hadronic light-by-light scattering in combination with electron vacuum polarization, is already sufficiently suppressed.
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We study the strength of the electroweak phase transition in models with two light Higgs doublets and a light SU(3)c triplet by means of lattice simulations in a dimensionally reduced effective theory. In the parameter region considered the transition on the lattice is significantly stronger than indicated by a 2-loop perturbative analysis. Within some ultraviolet uncertainties, the finding applies to MSSM with a Higgs mass mh ≈ 126 GeV and shows that the parameter region useful for electroweak baryogenesis is enlarged. In particular (even though only dedicated analyses can quantify the issue), the tension between LHC constraints after the 7 TeV and 8 TeV runs and frameworks where the electroweak phase transition is driven by light stops, seems to be relaxed.