New Keynesian Dynamics in a Low Interest Rate Environment

Recent research has found that the dynamics of the New Keynesian model are very different when the nominal interest rate is zero. Improvements in technology shocks and reductions in the labor tax rate lower economic activity and the size of the government purchase multiplier can be as large as four. We consider the empirical relevance of these dynamics using Japanese data. Japan is interesting because it experienced a protracted period of zero nominal interest rates. A prototypical New Keynesian model calibrated to Japan and solved using nonlinear methods exhibits orthodox dynamics with a government purchase multiplier that is less than one.Government purchases, zero nominal interest rates, monetary policy

Identification of synergistic interactions among microorganisms in biofilms by digital image analysis

Digital image analysis showed that reductions in biofilm plating efficiency were due to the loss of protection provided by two benzoate-degrading strains of Pseudomonas fluorescens. This loss in protection was due to the spatial separation of the protective organisms from benzoate-sensitive organisms during the dilution process. Communities were cultivated in flow cells irrigated with trypticase soy broth. When the effluent from these flow cells was plated on 0.15% benzoic acid, satellite colonies formed only in the vicinity of primary colonies. A digital image analysis procedure was developed to measure the size and spatial distribution of these satellites as a function of distance from the primary colony. The size of satellites served as a measure of growth, and the number per unit area served as a measure of survival. At the three dilutions tested, the size and concentration of satellite colonies varied inversely with distance from the primary colonies. When these measurements were plotted, the slopes were used to quantify the effect of bacterial association on the growth and survivability of the satellites. In the absence of the primary colonies, satellites grew in axenic culture only at low benzoate concentrations. Thus benzoate-degrading organisms are capable of creating a protective microenvironment for other members of biofilm communities

Extreme N-emitters at high-redshift: signatures of supermassive stars and globular cluster or black hole formation in action?

[Abridged] Using the JWST/NIRSpec observations from CEERS we found an extreme N-emitter, CEERS-1019 at z=8.6782 showing intense NIV and NIII emission. From the observed rest-UV and optical lines we conclude that it is compatible with photoionization from stars and we determine accurate abundances for C, N, O, and Ne, relative to H, finding a highly supersolar ratio log(N/O) = -0.18+/-0.11, and normal log(C/O) = -0.75+/-0.11 and log(Ne/O) = -0.63+/-0.07, for its low metallicity, 12+log(O/H)= 7.70+/-0.18. We also analyze other N-emitters from the literature. All show strongly enhanced N/O ratios and two of them normal C/O. Massive star ejecta from WR stars are needed to explain the galaxies with enhanced C/O (Lynx arc and Mrk 996). On the other hand, supermassive stars (>1000 Msun, SMS) in the ``conveyer-belt model'' put forward to explain globular clusters (GCs), predict a high N/O and small changes in C/O, compatible with CEERS-1019, the Sunburst cluster, SMACS2031, and GN-z11. Based on the chemical abundances, possible enrichment scenarios, compactness, and high ISM density, we suggest that CEERS-1019, SMACS2031, and the Sunburst cluster could contain proto-GCs. Finally, we propose that some N-emitters enriched by SMS could also have formed intermediate-mass black holes, and we suggest that this might be the case for GN-z11. Our observations and analysis reinforce the suggested link between some N-emitters and proto-GC formation, which is supported both by empirical evidence and quantitative models. Furthermore, the observations provide possible evidence for the presence of supermassive stars in the early Universe (z>8) and at z~2-3. Our analysis also suggests that the origin and nature of the N-emitters is diverse, including also objects like GN-z11 which possibly host an AGN.Comment: Submitted to A&A, 19 pages, 8 figures, 4 table

Effect of Lactobacillus plantarum Fermentation on the Surface and Functional Properties of Pea Protein-Enriched Flour

Istražen je utjecaj fermentacije s pomoću Lactobacillus plantarum na funkcionalna i fizikalno-kemijska svojstva brašna graška obogaćenog proteinima. Tijekom fermentacije povećavao se stupanj hidrolize do maksimuma od 13,5 % nakon 11 h. Prije mjerenja površinske hidrofobnosti i naboja te ispitivanja funkcionalnih svojstava podešena je pH-vrijednost fermentiranog brašna na pH=4 ili 7. Pri pH=4 površinski naboj, mjeren pomoću zeta potencijala, povećao se s +14 na +27 mV nakon 1 h fermentacije, a zatim smanjio na +10 mV nakon 11 h, dok se pri pH=7 naboj postepeno povećavao s -37 na -27 mV tijekom fermentacije. Površinska hidrofobnost znatno se smanjila tijekom fermentacije pri pH=4, dok se pri pH=7 neznatno smanjila. Kapacitet pijenjenja bio je najveći u emulziji brašna fermentiranog tijekom 5 h pri pH=4, dok je stabilnost pjene bila niska pri obje pH-vrijednosti u svim uzorcima. Emulgirajuća svojstva naglo su se smanjila nakon 5 h fermentacije pri pH=4, a stabilnost emulzija poboljšala se nakon 5 h fermentacije pri pH=7, u usporedbi s kontrolom. Sposobnost vezivanja ulja povećala se s 1,8 g/g pri 0 h na 3,5 g/g nakon 11 h fermentacije, a vode smanjila nakon 5 h, te zatim povećala nakon 9 h fermentacije. Rezultati pokazuju da se fermentacijom brašna graška obogaćenog proteinima mogu mijenjati njegova svojstva te na taj način proizvesti novi funkcionalni sastojci.The effect of Lactobacillus plantarum fermentation on the functional and physicochemical properties of pea protein-enriched flour (PPF) was investigated. Over the course of the fermentation the extent of hydrolysis increased continuously until reaching a maximum degree of hydrolysis of 13.5 % after 11 h. The resulting fermented flour was then adjusted to either pH=4 or 7 prior to measuring the surface and functional attributes as a function of fermentation time. At pH=4 surface charge, as measured by zeta potential, initially increased from +14 to +27 mV after 1 h of fermentation, and then decreased to +10 mV after 11 h; whereas at pH=7 the charge gradually increased from –37 to –27 mV over the entire fermentation time. Surface hydrophobicity significantly increased at pH=4 as a function of fermentation time, whereas at pH=7 fermentation induced only a slight decrease in PPF surface hydrophobicity. Foam capacity was highest at pH=4 using PPF fermented for 5 h whereas foam stability was low at both pH values for all samples. Emulsifying activity sharply decreased after 5 h of fermentation at pH=4. Emulsion stability improved at pH=7 after 5 h of fermentation as compared to the control. Oil-holding capacity improved from 1.8 g/g at time 0 to 3.5 g/g by the end of 11 h of fermentation, whereas water hydration capacity decreased after 5 h, then increased after 9 h of fermentation. These results indicate that the fermentation of PPF can modify its properties, which can lead towards its utilization as a functional food ingredient

Genital Tract Sequestration of SIV following Acute Infection

We characterized the evolution of simian immunodeficiency virus (SIV) in the male genital tract by examining blood- and semen-associated virus from experimentally and sham vaccinated rhesus monkeys during primary infection. At the time of peak virus replication, SIV sequences were intermixed between the blood and semen supporting a scenario of high-level virus "spillover" into the male genital tract. However, at the time of virus set point, compartmentalization was apparent in 4 of 7 evaluated monkeys, likely as a consequence of restricted virus gene flow between anatomic compartments after the resolution of primary viremia. These findings suggest that SIV replication in the male genital tract evolves to compartmentalization after peak viremia resolves

HIV Types, Groups, Subtypes and Recombinant Forms: Errors in Replication, Selection Pressure and Quasispecies

HIV-1 is a chimpanzee virus which was transmitted to humans by several zoonotic events resulting in infection with HIV-1 groups M P, and in parallel transmission events from sooty mangabey monkey viruses leading to infections with HIV-2 groups A H. Both viruses have circulated in the human population for about 80 years. In the infected patient, HIV mutates, and by elimination of some of the viruses by the action of the immune system individual quasispecies are formed. Along with the selection of the fittest viruses, mutation and recombination after superinfection with HIV from different groups or subtypes have resulted in the diversity of their patterns of geographic distribution. Despite the high variability observed, some essential parts of the HIV genome are highly conserved. Viral diversity is further facilitated in some parts of the HIV genome by drug selection pressure and may also be enhanced by different genetic factors, including HLA in patients from different regions of the world. Viral and human genetic factors influence pathogenesis. Viral genetic factors are proteins such as Tat, Vif and Rev. Human genetic factors associated with a better clinical outcome are proteins such as APOBEC, langerin, tetherin and chemokine receptor 5 (CCR5) and HLA B27, B57, DRB1{*}1303, KIR and PARD3B. Copyright (C) 2012 S. Karger AG, Base

Effect of Fermentation on the Protein Digestibility and Levels of Non-Nutritive Compounds of Pea Protein Concentrate

Radi utvrđivanja utjecaja fermentacije na kakvoću proteina u koncentratu proteina graška ispitani su sljedeći parametri: udjel ukupnih fenola i tanina, aktivnost inhibitora proteaze, sastav aminokiselina i probavljivost proteina in vitro nakon 11 sati fermentacije s pomoću bakterije Lactobacillus plantarum. Maseni se udjel fenola u koncentratu proteina graška, izražen kao ekvivalent katehina, povećao na bazi suhe tvari s 2,5 pri 0 h na 4,9 mg/g nakon 11 sati fermentacije. Udjel tanina se povećao s 0,14 pri 0 h na maksimalnih 0,96 mg/g koncentrata nakon 5 h fermentacije, a zatim se smanjio na 0,79 mg/g nakon 11 h fermentacije. Nakon 9 h fermentacije smanjila se aktivnost inhibitora tripsina, međutim, pri svim ostalim vremenima fermentacije dobivene su vrijednosti slične onima pri 0 h. Aktivnost se inhibitora kimotripsina smanjila s 3,7 na 1,1 jedinicu inhibicije kimotripsina po mg nakon 11 sati fermentacije. Probavljivost je proteina dosegla maksimalnu vrijednost od 87,4 % nakon 5 sati fermentacije, međutim vrijednost aminokiselina koje sadržavaju sumpor smanjila se s 0,84 pri 0 h na 0,66 nakon 11 h fermentacije. Smanjenjem udjela sumpora promijenila se vrijednost aminokiselina korigirana probavljivošću proteina in vitro s 67,0 pri 0 h na 54,6 % nakon 11 h fermentacije. Dobiveni podaci potvrđuju da je, iako je fermentacija valjana metoda za smanjenje udjela nekih nenutritivnih sastojaka u koncentratu proteina graška, potrebno odabrati odgovarajuće bakterije koje nemaju izraženu sposobnost razgradnje aminokiselina što sadržavaju sumpor.In order to determine the impact of fermentation on protein quality, pea protein concentrate (PPC) was fermented with Lactobacillus plantarum for 11 h and total phenol and tannin contents, protease inhibitor activity, amino acid composition and in vitro protein digestibility were analyzed. Phenol levels, expressed as catechin equivalents (CE), increased on dry mass basis from 2.5 at 0 h to 4.9 mg CE per 1 g of PPC at 11 h. Tannin content rose from 0.14 at 0 h to a maximum of 0.96 mg CE per 1 g of PPC after 5 h, and thereafter declined to 0.79 mg/g after 11 h. After 9 h of fermentation trypsin inhibitor activity decreased, however, at all other fermentation times similar levels to the PPC at time 0 h were produced. Chymotrypsin inhibitor activity decreased from 3.7 to 1.1 chymotrypsin inhibitory units (CIU) per mg following 11 h of fermentation. Protein digestibility reached a maximum (87.4 %) after 5 h of fermentation, however, the sulfur amino acid score was reduced from 0.84 at 0 h to 0.66 at 11 h. This reduction in sulfur content altered the in vitro protein digestibility-corrected amino acid score from 67.0 % at 0 h to 54.6 % at 11 h. These data suggest that while fermentation is a viable method of reducing certain non-nutritive compounds in pea protein concentrate, selection of an alternative bacterium which metabolises sulfur amino acids to a lesser extent than L. plantarum should be considered