Effect Of Additional Terms Research Articles

STAT4 is a genetic risk factor for systemic sclerosis having additive effects with IRF5 on disease susceptibility and related pulmonary fibrosis

Systemic sclerosis (SSc) belongs to the group of connective tissue disorders (CTDs), among which are several disorders characterized by a type I interferon (IFN) signature. The recent identification of an association between IRF5 and SSc further highlights a key role for IFN. STAT4, which encodes STAT-4, contributes to IFN signaling, and its genetic variants were found to be associated with CTDs. The aim of this study was to determine whether the STAT4 rs7574865 single-nucleotide polymorphism is associated with SSc, and whether it interacts with IRF5. Both the STAT4 rs7574865 and IRF5 rs2004640 polymorphisms were genotyped in 1,855 individuals of French Caucasian origin comprising a discovery set of 440 patients with SSc and 485 control subjects and a replication set of 445 patients with SSc and an additional 485 control subjects. STAT4 rs7574865 was shown to be associated with SSc (P=0.001, odds ratio [OR] 1.29, 95% confidence interval [95% CI] 1.11-1.51). This association was not restricted to a particular phenotype. An additive effect of the STAT4 rs7574865 T allele and the IRF5 rs2004640 T allele was observed, resulting in a multiple increased 1.28-fold risk of SSc. The OR for SSc was 2.72 (95% CI 1.86-3.99) for combinations of genotypes with >or=3 risk alleles. An additive effect was also detected for fibrosing alveolitis: carriage of at least 3 risk alleles appeared to be an independent risk factor (P=2.2x10(-4), OR 1.97, 95% CI 1.28-3.04). Our results establish STAT4 rs7574865 as a new SSc genetic susceptibility factor. STAT4 and IRF5 act with additive effects in terms of susceptibility to both SSc and SSc-related fibrosing alveolitis.

Analysis of Stokes waves theory as a diffusion problem

This mathematical model concerns the theory of Stokes waves. These wave types belong to the class of ocean surface waves found in deep and intermediate waters. In this consideration, the fifth order expansion was obtained using Korteweg de Vries equation with diffusion term. This study suggests that the phase velocity grows with increase in wave steepness whilst the group velocity shows the opposite tendency .The effect of diffusion introduced through depth distribution is obvious as the solutions apparently depend strongly on the water depth in inverse form. Interestingly, this analysis strongly suggests that the peak for potential energy lies between second and third order solutions while that of kinetic energy attains the peak at second and then becomes fairly stable. High seismic response associated with sea-bed motion corresponding to second order solution strongly support the result. However, the effect of additional terms on the wave profile appears somewhat insignificant. The wave profile of first order to fifth order in this consideration remains unchanged as expected. Journal of the Nigerian Association of Mathematical Physics Vol. 10 2006: pp. 59-68

Coexpression of HER-2/neu and p53 in Breast Cancer Identifies a Subset with an Aggressive Biopathological Profile

Amplification/overexpression of HER-2/neu and inactivation of p53 may be reliable parameters for the prognostic assessment of breast carcinomas. Several studies have addressed the prognostic significance of simultaneous expression of these gene abnormalities with controversial results. In this study we analyzed the biopathological profile of 45 breast cancers with both HER-2/neu and p53 overexpression and compared their features with those of 45 randomly selected cases negative for these gene products. Tumors with HER-2/neu and p53 coexpression were found in younger patients, were more often multifocal and/or multicentric, were poorly differentiated in 55% of cases and lymph node-positive in 57%, showing a statistically significant difference compared to tumors with neither alteration (11% and 28%, respectively). Moreover, they were prevalently negative for estrogen (71% vs 22%) and progesterone receptors (78% vs 40%) and showed a higher proliferative activity. Our data demonstrate that the coexpression of p53 and HER-2/neu is an additive effect in terms of genetic instability reflected by both morphological and biological adverse features; patients with such coexpression should be assigned to specific therapeutic and follow-up protocols.

Female gamete preservation

The use of multiple agent chemotherapy and combined modality treatment of childhood and adolescent cancers has markedly increased survival rates. Thus, the majority of young cancer patients survive into adulthood and the potential long-term consequences of the therapies are of ongoing concern. Alkylating agents have proven to be the most toxic to the ovaries; however radiation is also extremely gonadotoxic. In addition, combination of these modalities will produce additive effects in terms of ovarian damage (follicle depletion). As a result, there are increasing numbers of young cancer survivors with impaired or absent gonadal function. Advances in the field of assisted reproductive technology (ART) provide hope that the reproductive impact of cancer therapy can be reduced. Those technologies that may be applicable prior to gonadotoxic therapy are pretreatment ovarian protection with oral contraceptives or gonadotropin releasing hormone agonist; ART using pretreatment cryopreservation of embryos or gametes; posttreatment ART with donor gametes or embryos; or adoption. However, ovarian protection is not of proven benefit and oocyte/ovary cryopreservation has had only limited success to date. Information regarding cancer treatment's possible effects on fertility and ways to potentially circumvent these should be part of routine counseling to allow the patient to make an informed decision.

DNA Priming E and NS1 Constructs–Homologous Proteins Boosting Immunization Strategy to Improve Immune Response Against Dengue in Mice

DNA priming-protein boosting is a strategy used to establish strong immunity to a specific pathogen by the use of two different antigens through sequential delivery systems. In this work, two recombinant plasmids were used, one encoding for the dengue virus E protein, which is know to induce neutralizing antibodies (pcDNA 3.1/E), and the other encoding for the Dengue virus nonstructural protein 1 (pcDNA 3.1/NS1), as a source of B- and T-cell epitopes possibly involved in protective immunity. We showed that immunization of BALB/c mice with three priming doses of both plasmids pcDNA 3.1/E and/or pcDNA 3.1/NS1 were able to induce antibody responses to E protein with a single plasmid; in contrast to the antibody response to NS1 protein we observed an additive effect in terms of antibody response. Moreover, using a prime-boost protocol in which both plasmid constructs were co-administrated followed by a boost of homologous GST-E and GST-NS1 recombinant proteins, we observed an increased antibody response to NS1 and to E protein compared to animals vaccinated with the proteins or with dengue constructs alone. If neutralizing antibodies play an important role in dengue infection, antibodies generated with this regimen was also significantly better than the administration of the mix of proteins alone. These results suggest that NS1 and E proteins together could be considered in a design of subunit recombinant vaccines.

In Vitro Effects of the Combination of Idarubicin (IDA) with Suberoylanilide Hydroxamic Acid (SAHA) or Valproic Acid (VPA) in Leukemia Cell Lines.

The nucleosome is the basic structure of chromatin. Changes in the biochemical composition of nucleosome-associated histone tails are associated with specific gene activation states, and are the target of several antineoplastic agents such as histone deacetylase inhibitors (HDI). Nucleosomes are constrained into loops that are flanked by domains known as matrix-attached regions (MARs). MARs contain DNA topoisomerase II (Topo II) consensus sequences. Topo II is responsible for regulating and maintaining DNA topology and is the target of several antineoplastic agents such as the anthracycline IDA, an effect mediated by the induction of double strand DNA breaks (DSB). We hypothesized that the combination of a Topo II inhibitor and a HDI will have synergistic antileukemia activity. VPA and SAHA are two HDIs currently studied in several clinical trials with known antileukemia activity and tolerable toxicity. To test our hypothesis and to develop future clinical studies, we have analyzed the effect of the combination of IDA, a potent Topo II inhibitor, with VPA or SAHA. We treated the leukemic cells lines MOLT4 and HL60 with increasing doses of IDA (0.5-20nM), SAHA (0.3-3μM) or VPA (0.25-3mM) daily for 3 days. First, using trypan blue viability assays, we identified the IC10 of IDA to be 0.5nM for MOLT4 and 1.5nM for HL60. Doses in excess of 2μM of SAHA or 3mM of VPA resulted in more than 90% decrease in cell viability in both cell lines. Subsequently, SAHA at doses of 0.075-1μM and VPA at 1-3mM were used for the combination experiments with IDA at its specific cell line IC10. At low doses of SAHA (0.075-0.45 μM) and VPA (0.25-1 mM) the combination was shown to have synergistic antileukemia activity by the Fractional Product Method of Webb. These results were confirmed using Annexin V assays. Of importance, growth inhibition was independent of the sequence used. To analyze the effects of this combination on DSB generation, we analyzed using immonocytochemistry and western blot, the induction of γH2AX, a histone variant that has been identified as an early event after the DSBs. SAHA alone induced a modest increase in γH2AX compared to baseline, whereas IDA alone had a significant effect that was not potentiated by the addition of SAHA. Histone H3 and H4 acetylation increased in a dose-dependent manner (2.4–15 fold) with both SAHA and VPA, starting at 0.3μM of SAHA and 0.25mM of VPA. The addition of IDA had no significant effect on histone acetylation. Because of previous data indicating that HDIs may down-regulate the expression of Topo II-alpha, the target of IDA, we have studied using real-time PCR its levels prior and during exposure to the different combinations. SAHA or VPA had no effect on Topo II-alpha mRNA levels whereas IDA induced 2.0–3.5 fold its expression in a dose-independent manner, an effect no altered by the addition of SAHA or VPA. Expression of p21CIP1, that is silenced in both cell lines, was restored by single agent VPA, SAHA or IDA. The combination of these drugs resulted in an additive effect in terms of p21CIP1 induction. Despite this phenomenon, no changes in cell cycle status were observed in these cells. In summary, the combination of IDA and SAHA or VPA has potent in vitro antileukemia effect, and should be studied in clinical trials.

Interactions of chemostimuli at the single cell level: studies in a model system.

The responses of afferent chemosensory fibres of the carotid body to individual chemostimuli have long been established. However, the mechanisms underlying the multiplicative interactions of these stimuli (i.e. how the combined effects of hypoxia and hypercapnia exert a greater effect on afferent nerve discharge than the sum of their individual effects) have not been elucidated. Using the membrane hypothesis for carotid body chemoreception, in which chemostimuli inhibit type I cell K+ channels, leading to depolarization, voltage-gated Ca2+ entry and hence the triggering of exocytosis, this article considers data acquired in isolated type I carotid body cells and model chemoreceptor (PC12) cells to attempt to explain stimulus interactions. Whilst stimulus interactions are not clearly evident at the level of K+ channel inhibition or rises of [Ca2+]i, they are apparent at the level of transmitter release. Thus, it is clear that individual chemoreceptor cells can sense multiple stimuli, and that interactions of these stimuli can produce greater than additive effects in terms of transmitter release.

The effect of immunoglobulin immunadsorptions on delayed xenograft rejection of human CD55 transgenic pig kidneys in baboons.

Delayed xenograft rejection (DXR) remains a major obstacle in discordant xenotransplantation. As strategies of complement inhibition and xenogeneic natural antibody (Ab) removal have been shown to give prolonged xenograft survival, we endeavored to determine whether combining these two strategies would lead to an additive effect in terms of graft survival. The study was initiated with two groups, A and B, where group A received normal kidneys and group B received hCD55 transgenic kidneys. Both groups underwent pre-transplant (day-1) total immunoglobulin (Ig) immunoadsorption (IA) and received an immunosuppression of cyclophosphamide, cyclosporine A, mycophenolate mofetil and corticosteroids. Two subsequent groups (C and D) receiving hCD55 transgenic pig kidneys were then performed with an 'optimized' immunosuppression (Cyclophosphamide starting 1 day earlier) but only group D recipients were immunoadsorbed. Biopsies taken during the post-transplantation period were analyzed for Ab deposition, compliment activation and cellular infiltration. No hyperacute rejection was observed. In the initial immunoadsorbed groups A and B, all baboons underwent DXR, which started surprisingly early (day 5 in most cases. In the subsequent two groups, the immunoadsorbed group D baboons also underwent DXR, again as early as day 5. In contrast, group C baboons did not show any signs of DXR on their day 6 biopsy or at their time of death. Analysis of graft biopsies from the kidneys undergoing rejection or with stable function showed strong deposition of anti-Gal IgM in all cases whereas strong complement C5b-9 deposits were only observed in biopsies at rejection. Cellular infiltration consisted mostly of monocytes/macrophages, was more pronounced in biopsies taken at rejection and was associated with a pro-inflammatory environment involving interleukins 1alpha, 6 and 8. Our findings suggest non-specific Ig (anti-Gal and non-Gal Ig of all isotypes) IA or even incomplete IA in immunosuppressed baboon recipients of transgenic pig kidneys is detrimental to graft survival by being associated with an Ab and compliment driven rejection. We speculate that the IA were insufficient in terms of Ig depletion or frequency inducing an Ab rebound or that this total Ig depletion also removed components facilitating graft survival.

History of surgery lecture.

I read with great interest and enjoyment Dr Starzl’s excellent Charles Drake History of Surgery Lecture. I wish to endorse strongly, on the basis of our experimental work with tolerogenesis in the baboon (Papio ursinus) kidney transplant model, the two principles of tolerogenic immunosuppression he derived from historical observations, namely pretreatment and the importance of limiting posttransplant immunosuppression. In many hundreds of experiments we demonstrated consistently the ability of a modified regimen of pretransplant total lymphoid irradiation (TLI) to induce durable (greater than 10 years survival with normal graft function) and donor-specific transplantation tolerance in baboon kidney and liver transplantation, without the use of any posttransplant immunosuppressive treatment. The most effective TLI protocol obtained consisted of a total dose of 800 cGy given in 80or 100-cGy fractions twice a week to a wide field. Tolerance occurred in one-third to one-half of many groups studied. In efforts to increase the tolerant fraction obtained we studied the effect of adding posttransplant immunosuppressive drug therapy to the pretransplant TLI regimen. With even limited 2-week courses of cyclosporine A, prednisone, or antilymphocyte globulin, there was either no additive effect in terms of tolerance production, or, in the case of cyclosporine A, a counterproductive effect. Even more dramatic was the effect of adding only two fractions of 100 cGy each in the second and third weeks after transplantation. Graft survival was drastically shortened and tolerance induction was abrogated. We interpreted these findings as indicating that an active mechanism or mechanisms, capable of inhibition by immunosuppressive measures, were involved the process of tolerance induction. We were able to demonstrate a marked increase in activated T cells and of usually nonspecific suppressor cells in the circulation of these tolerant baboons soon after transplantation. These findings also probably explain why we did not achieve the same results in terms of full tolerance production with pretransplant TLI in 73 kidney transplantation patients. For ethical reasons, as a result of the unpredictability of tolerance production in individual baboons, all our patients received fairly conventional doses of posttransplant immunosuppressive drugs.

Additive effects of enalapril and losartan in (mREN-2)27 transgenic rats.

Blockade of angiotensin II AT1 receptors combined with angiotensin I-converting enzyme inhibition might amplify the potency of the renin-angiotensin system blockade. We studied whether chronic and simultaneous administration of enalapril and losartan would result in additive or synergistic effects in the (mREN-2)27 transgenic rat (TGR), the investigated targets being blood pressure, cardiac hypertrophy, renin-angiotensin system blockade achieved, and plasma active renin concentration. In addition, the origin (renal or extrarenal, rat or mouse) of the induced renin release was determined. Adult TGRs were treated orally and daily for 5 to 7 weeks with 1 mg/kg (E1) or 3 mg/kg (E3) enalapril or 1 mg/kg (L1) or 3 mg/kg (L3) losartan, or their combinations (E1L1 and E3L3). At the end of the treatment period, enalapril and losartan exerted dose-dependent and, when combined, additive effects in terms of blood pressure fall and cardiac hypertrophy limitation, and synergistic effects in terms of plasma active renin stimulation and blockade of exogenous angiotensin I pressor effects, with E3L3>E3>L3, E1L1>E1> or =L1, and E1L1=E3>L3). This indicates that in the TGR, (1) the greater the renin-angiotensin system blockade achieved, the greater are the reduction in blood pressure, the limitation of cardiac hypertrophy, and the reactive rise in plasma renin concentration elicited, and (2) the enalapril-losartan combinations are more potent at achieving these goals than any of their constituents individually. In contrast, there was no interaction between the two drugs regarding aldosteronuria reduction. Measurement of plasma renin concentration and renal renin at pH 6.5 and 8.5, ie, the optimal pH values for rat and mouse renin activities, respectively, indicates that in TGRs the counterregulatory process for renin release elicited by enalapril, losartan, or their combination involves primarily rat renin of renal origin, a finding supported further by the observed increase in the rat renal renin hybridization index.

Subwavelength spatial solitons

We analyze the effects of additional terms in the nonlinear Schrödinger equation for spatial solitons, directly derived from the Maxwell's equations with the Kerr nonlinearity, on the shapes of bright and dark solitons with a fixed polarization. Combining analytical and numerical methods, we find that the additional terms always render the solitons broader. The most essential result is a fundamental limitation on the width of the subwavelength soliton: The ratio of the FWHM of the bright soliton to the wavelength cannot be smaller than 1/2, and the same ratio for the FWHM of the dark soliton cannot be smaller than 1/4.

Expression characteristics of pokeweed antiviral proteins (PAPs): Two distinct types of proteins

Pokeweed antiviral proteins (PAPs) become novel therapeutic agents in relation to application in human viral diseases and cancer, as well as potent tools in plant system for defending viral infection. We have studied the expression characteristics of PAPs in pokeweed plants by western blot analysis. PAP-I was constitutively expressed in leaves, stems and roots of the pokeweed plant, while PAP-II was not expressed in roots. The expression of PAP-II began in May and then gradually increased with development of the plants. The PAP-II expression was induced and/or stimulated not only by biotic stresses, such as insect pests and viral infection, but also by abiotic stresses, like drought. Interestingly, low-light intensity was found to be more effective than high-light in the expression of both PAP-I and PAP-II. Our results suggest that PAP-II appears to have an additive effect in terms of protection of the plant against pathogens during summer-time when the plant actively grows and is attacked by various pathogens.

Additive effects common to radiation grafting and wood plastic composite formation

A range of additives has been developed for enhancing grafting yields in a variety of systems initiated by ionizing radiation. Cellulose has been adopted as the predominant naturally occurring model backbone polymer in these studies because of its structural relationship to wood which is the reference substrate for the work reported in the related second part of this paper concerning composites. Some experiments have been performed with the other major naturally occurring polymer, wool. For comparison purposes with synthetic materials, some studies have also been performed with polypropylene as trunk polymer. Styrene has been used as a predominant monomer in grafting with some experiments utilizing the acrylates like methyl methacrylate. The role of solvent in grafting has been evaluated. UV has been used as initiator to replace ionizing radiation for certain experiments. The additives used were mineral acids, lithium salts, multifunctional acrylates and their methacrylate analogues, urea, oligomer acrylates, silane, fluorinated alkyl esters and thermal free radical initiators. A mechanism to explain the additive effect in terms of reagent partitioning has been proposed. The most efficient of the additives in grafting have been applied to the radiation synthesis of wood-polymer composites using two different types of wood, namely simul from Bangladesh and Pinus radiata from Australia with two different monomers with and without solvent, namely butyl methacrylate and methyl methacrylate. The effect of the additives on the physical properties, such as polymer loading and tensile strength, of the wood composites were determined. The partition concept developed for grafting has been used to explain the reactivity of the additives in wood plastic formation. The polymerization of monomers in wood plastic systems is shown to be related to simple homopolymerization of monomers in solution, a reaction which is also shown to be capable of interpretation in terms of partition phenomena.

Induction and promotion of γ-glutamyltranspeptidase-positive foci in the liver of female rats treated with ethinyl estradiol, clomiphene, tamoxifen and their associations

The objective of the present study was to determine whether a short exposure (6 weeks) to high doses of ethinyl estradiol (EE) could not only promote but also initiate hepatocarcinogenesis, and whether two antiestrogens, clomiphene (C) and tamoxifen (T), could influence EE activity. 2-Acetylaminofluorene (AAF), which has been shown to produce rat liver hyperplastic lesions characterized by the presence of estrogen receptors, was used either as a promoter to test for initiating activity, or as an initiator to test for promoting activity. Putative preneoplastic lesions were identified by means of a positive gamma-glutamyltranspeptidase (GGT) reaction. The results revealed that when administered alone in female Sprague-Dawley rats, not only E, but also C and T were clearly active in both initiating and promoting the development of GGT-positive foci. Moreover, in rats of the same strain treated with EE + C or EE + T a significant increase in the incidence of GGT foci demonstrated the occurrence of an additive effect in terms of both initiating and promoting activity. Fischer 344 rats were more susceptible than Sprague-Dawley rats to promotion by EE, C and T, but any substantial evidence of an additive effect was absent when the two anti-estrogens were administered in association with the estrogen.

Structure-activity relationship of amiloride analogs as blockers of epithelial Na channels: II. Side-chain modifications

The overall on- and off-rate constants for blockage of epithelial Na channels by amiloride analogs were estimated by noise analysis of the stationary Na current traversing frog skin epithelium. The (2-position) side chain structure of amiloride was varied in order to obtain structure/rate constant relationships. Hydrophobic chain elongations (benzamil and related compounds of high blocking potency) increase the stability of the blocking complex (lowered off-rate), explained by attachment of the added phenyl moiety to a hydrophobic area near the site of side chain interaction with the channel protein. Some other chain modifications show that the on-rate, which is smaller than a diffusion-limited rate, varies with side chain structure. In several cases this effect is not attributable to steric hindrance on encounter, and implies that the side chain interacts briefly with the channel protein (encounter complex) before the main blocking position of the molecule is attained. The encounter complex must be labile since the overall rate constants of blockage are not concentration-dependent. In two cases, changes at the 2-position side chain and at other ring ligands, with known effects on the blocking rate constants, could be combined in one analog. The rate constants of blocking by the resulting compounds indicate that the structural changes have additive effects in terms of activation energies. Along with other observations (voltage dependence of the rate constants and competition with the transported Na ion), these results suggest a blocking process of at least two steps. It appears that initially the 2-position side chain invades the outward-facing channel entrance, establishing a labile complex. Then the molecule is either released completely (no block) or the 6-ligand of the pyrazine ring gains access to its receptor counterpart, thus establishing the blocking complex, the lifetime of which is strongly determined by the electronegativity of the 6-ligand.

Interaction of retinoids and tamoxifen on the inhibition of human mammary carcinoma cell proliferation.

The growth of chemically induced mammary tumors is inhibited by both hormone manipulation as well as by retinoids. Numerous mammary carcinoma cell lines are also inhibited by retinoids. Co-treatment of estrogen receptor (ER)-positive breast cancer cells resulted in an additive effect in terms of inhibition of cellular proliferation. The addition of varying concentrations of retinoic acid (RA) to varying concentrations of tamoxifen (TMX) resulted in an additive effect on the inhibition of proliferation of the ER-positive human carcinoma cell lines (MCF-7). Co-treatment of MCF-7 cells over time with RA and TMX resulted in enhanced inhibition of growth. A similar phenomenon was observed when other synthetic retinoids were combined with TMX. This enhanced inhibition by the combination of retinoids and TMX was also observed with other ER-positive cell lines (ZR-75, T47-D), while no effect was noted on the ER-negative cell lines (MDA-MB-231, Hs578T).

Empirically determined limits on absolute boson numbers for well deformed nuclei

In the context of the consistent Q formalism of the interacting boson approximation, which contains only one essential parameter, denoted chi, it is possible to investigate the limits of allowable boson numbers N for well deformed nuclei. This is done by examining the agreement with experiment of certain E2 branching ratios as a function of N. The results show that, in general, the best agreement is obtained for Nroughly-equalN/sub IBA/, where N/sub IBA/ is the usual interacting boson approximation value defined as the sum of half the number of valence protons and neutrons; moreover, significant discrepancies with experiment are obtained if N<((3/4))N/sub IBA/. The effect of additional terms in the interacting boson approximation Hamiltonian is also investigated.

On the Mechanism of Electrodeposition in the Dimercaptothiadiazole/Copper Pyrophosphate System

Cyclic voltammetric stripping results are presented which show that a dynamic equilibrium exists in the dimercaptothiadiazole (DMTD)/copper pyrophosphate system involving a species which accelerates the copper deposition rate, a decelerating species, Cu+2 ions, and other bath constituents. The experimental data are well explained by assuming that the accelerator is the copper‐complexed DMTD monomer species, whereas deceleration is produced by the DMTD dimer. A model is presented which explains the additive effects in terms of a critical balance between the nucleation of new growth centers by the accelerating additive species and copper ammine complexes, and the limitations on growth imposed by the decelerating additive species which functions by blocking growth sites. Based on this model, which is supported by a‐c impedance data and morphological studies, the important deposit properties can be understood and predicted.

Spin-fluctuation theory of strong coupling corrections to the free energy in superfluid 3He

Previous spin-fluctuation theories yielding the strong coupling corrections ..delta..beta-bar/sub i/ to the five coefficients of the fourth-order invariants in the free energy functional are extended. First, the superfluid part of the susceptibility is calculated up to order ..delta../sup 4/for all momenta and frequencies and the contribution arising from p-wave fluctuations of the order parameter is included. Then the frequency sums yielding the ..delta..beta-bar/sub i/ are calculated by taking into account the full momentum and frequency dependence of the superfluid susceptibility and the spin fluctuation propagator. The results for the ..delta..beta-bar/sub i/ are plotted vs. a cutoff q/sub c/ on the momentum integration for spin-fluctuation parameters IequivalentN(0)I=0.75 and I=0.95. The cutoff takes into account in a rough way the effect of additional terms in the free energy functional which were neglected in previous theories. These additional terms are due to the implicit dependence of the superfluid susceptibility on the spin-fluctuation parameter I via the gap parameter ..delta... The gap equation providing the relation between ..delta.. and I is derived in the weak coupling approximation. The cutoffs obtained by fitting the experimental values of the three combinations of ..delta..beta-bar/sub i/(arising from the measured specific heat discontinuities on the melting curve) are comparablemore » to the cutoff obtained from the spin-fluctuation contribution to the weak coupling free energy (q/sub c/=0.3(2k/sub F/) for I=0.75). The corrections due to the momentum and frequency dependence of the superfluid susceptibility and the spinfluctuation propagator are large and point in the direction of better agreement with experiment: The ratio R/sub 1/ =..delta..beta-bar/sub 5//(..delta..beta-bar/sub 2/+..delta..beta-bar/sub 4/) decreases from 2 to about 1.2. It is concluded that spin-fluctuation theory in its present form cannot account quantitatively for the measured specific heat discontinuities on the melting curve.« less

Effecr of light and temperature on the endocrine system of the golden hamster Mesocricetus auratus waterhouse)

1. 1. Exposure of male hamster to short photoperiods or low temperatures for 2, 4 and 6 weeks inhibits normal increases in body weight, atrophy of the gonads characterized by increased cholesterol concentration, and by histological and histochemical appearance, and an increase in brown fat weight. 2. 2. Study of the pituitary basophils suggested abnormalities of morphology and function while massive build-up of neurosecretory material (Herring bodies) of the hypothalamus and stalk gave evidence of reduced release of this material or perhaps increased synthesis. 3. 3. The combination of short photoperiods and low temperature resulted in additive effects in terms of degree of change and rapidity of development. 4. 4. Consideration of these data in conjunction with the literature on the hamster indicates that this anima is normally a continous breeder under laboratory conditions, but a seasonal under field conditions.