Regular adjustment: theory and evidence

We ask why, in many circumstances and many environments, decision-makers choose to act on a time-regular basis (e.g. adjust every six weeks) or on a stateregular basis (e.g. set prices ending in a 9), even though such an approach appears suboptimal. The paper attributes regular behaviour to adjustment cost heterogeneity. We show that, given the cost heterogeneity, the likelihood of adopting regular policies depends on the shape of the benefit function: the flatter it is, the more likely, ceteris paribus, is regular adjustment. We provide sufficient conditions under which, when policymakers differ with respect to the shape of the benefit function (as in Konieczny and Skrzypacz, 2006), the frequency of adjustments across markets is negatively correlated with the incidence of regular adjustments. On the other hand, if policymakers differences are due to the level of adjustment costs (as in Dotsey, King and Wolman, 1999), then the correlation is positive. To test the model we apply it to optimal pricing policies. We use a large Austrian data set, which consists of the direct price information collected by the statistical office and covers 80% of the CPI over eight years. We run cross-sectional tests, regressing the proportion of attractive prices and, separately, the excess proportion of price changes at the beginning of a year and at the beginning of a quarter, on various conditional frequencies of adjustment, inflation and its variability, dummies for good types, and other relevant variables. We find that the lower is, in a given market, the conditional frequency of price changes, the higher is the incidence of time- and state-regular adjustment. JEL Classification: E31, L11, E52, D01attractive prices, menu costs, Optimal pricing

Toughening of BIS maleimide resins: Synthesis and characterization of maleimide terminated poly(arylene ether) oligomers and polymers

Amine functional poly(arylene ether) sulfones were previously reported. Herein, the chemistry was extended to amorphous poly(arylene ether) ketones because of their higher fracture toughness values, relative to the polysulfones. It was demonstrated that the amino functional oligomers undergo a self-crosslinking reaction at temperatures above about 220 C. This produces an insoluble, but ductile network that has excellent resistance. A ketamine structure hypothesis was proposed and verified using solid state magic angle NMR. In most cases, the water generated upon ketamine formation is too low to produce porosity and solid networks are obtained. The stability of the ketamine networks towards hydrolysis is excellent. The chemistry was further demonstrated to be able to crosslink preformed nonfunctional poly(arylene ether) ketones if a difunctional amine was utilized. This concept has the possibility of greatly improving the creep resistance of thermoplastics. Also, a new technique was developed for converting the amine functional oligomers cleanly into maleimide structures. This method involves reacting maleic anhydride with monomeric aminophenols in the presence of solvent mixtures

The reproductive cycle of the thorny skate (Amblyraid radiata) in the western Gulf of Maine

The thorny skate (Amblyraja radiata) is a large species of skate that is endemic to the waters of the western north Atlantic in the Gulf of Maine. Because the biomass of thorny skates has recently declined below threshold levels mandated by the Sustainable Fisheries Act, commercial harvests from this region are prohibited. We have undertaken a comprehensive study to gain insight into the life history of this skate. The present study describes and characterizes the reproductive cycle of female and male thorny skates, based on monthly samples taken off the coast of New Hampshire, from May 2001 to May 2003. Gonadosomatic index (GSI), shell gland weight, follicle size, and egg case formation, were assessed for 48 female skates. In general, these reproductive parameters remained relatively constant throughout most of the year. However, transient but significant increases in shell gland weight and GSI were observed during certain months. Within the cohort of specimens sampled monthly throughout the year, a subset of females always had large preovulatory follicles present in their ovaries. With the exception of June and September specimens, egg cases undergoing various stages of development were observed in the uteri of specimens captured during all other months of the year. For males (n=48), histological stages Ill through VI (SIII-SVI) of spermatogenesis, GSI, and hepatosomatic index (HSI) were examined. Although there appeared to be monthly fluctuations in spermatogenesis, GSI, and HSI, no significant differences were found. The production and maintenance of mature spermatocysts (SVI) within the testes was observed throughout the year. These findings collectively indicate that the thorny skate is reproductively active year round

The reproductive cycle of the thorny skate (Amblyraja radiata) in the western Gulf of Maine

The thorny skate (Amblyraja radiata) is a large species of skate that is endemic to the waters of the western north Atlantic in the Gulf of Maine. Because the biomass of thorny skates has recently declined below threshold levels mandated by the Sustainable Fisheries Act, commercial harvests from this region are prohibited. We have undertaken a comprehensive study to gain insight into the life history of this skate. The present study describes and characterizes the reproductive cycle of female and male thorny skates, based on monthly samples taken off the coast of New Hampshire, from May 2001 to May 2003. Gonadosomatic index (GSI), shell gland weight, follicle size, and egg case formation, were assessed for 48 female skates. In general, these reproductive parameters remained relatively constant throughout most of the year. However, transient but significant increases in shell gland weight and GSI were obser ved during certain months. Within the cohort of specimens sampled monthly throughout the year, a subset of females always had large preovulatory follicles present in their ovaries. With the exception of June and September specimens, egg cases undergoing various stages of development were observed in the uteri of specimens captured during all other months of the year. For males (n=48), histological stages III through VI (SIII−SVI) of spermatogenesis, GSI, and hepatosomatic index (HSI) were examined. Although there appeared to be monthly fluctuations in spermatogenesis, GSI, and HSI, no significant differences were found. The production and maintenance of mature spermatocysts (SVI) within the testes was observed throughout the year. These findings collectively indicate that the thorny skate is reproductively active year round

Yield Curve Shapes and the Asymptotic Short Rate Distribution in Affine One-Factor Models

We consider a model for interest rates, where the short rate is given by a time-homogenous, one-dimensional affine process in the sense of Duffie, Filipovic and Schachermayer. We show that in such a model yield curves can only be normal, inverse or humped (i.e. endowed with a single local maximum). Each case can be characterized by simple conditions on the present short rate. We give conditions under which the short rate process will converge to a limit distribution and describe the limit distribution in terms of its cumulant generating function. We apply our results to the Vasicek model, the CIR model, a CIR model with added jumps and a model of Ornstein-Uhlenbeck type

Myocyte Enhancer Factor 2A (MEF2A) Defines Oxytocin-Induced Morphological Effects and Regulates Mitochondrial Function in Neurons

The neuropeptide oxytocin (OT) is a well-described modulator of socio-emotional traits, such as anxiety, stress, social behavior, and pair bonding. However, when dysregulated, it is associated with adverse psychiatric traits, such as various aspects of autism spectrum disorder (ASD). In this study, we identify the transcription factor myocyte enhancer factor 2A (MEF2A) as the common link between OT and cellular changes symptomatic for ASD, encompassing neuronal morphology, connectivity, and mitochondrial function. We provide evidence for MEF2A as the decisive factor defining the cellular response to OT: while OT induces neurite retraction in MEF2A expressing neurons, OT causes neurite outgrowth in absence of MEF2A. A CRISPR-Cas-mediated knockout of MEF2A and retransfection of an active version or permanently inactive mutant, respectively, validated our findings. We also identified the phosphatase calcineurin as the main upstream regulator of OT-induced MEF2A signaling. Further, MEF2A signaling dampens mitochondrial functioning in neurons, as MEF2A knockout cells show increased maximal cellular respiration, spare respiratory capacity, and total cellular ATP. In summary, we reveal a central role for OT-induced MEF2A activity as major regulator of cellular morphology as well as neuronal connectivity and mitochondrial functioning, with broad implications for a potential treatment of disorders based on morphological alterations or mitochondrial dysfunction

The Effects of Slow Deep Breathing on Measures of Microvascular and Autonomic Function in an Irritable Bowel Syndrome Population

Irritable Bowel Syndrome (IBS) is a functional disorder linked to disruptions in autonomic nervous system regulation, which could impair vascular homeostasis. Studies have shown that slow, deep breathing reduces muscle sympathetic nerve activity and arterial stiffness; however, its effects on autonomic regulation in adults with IBS have not been previously investigated. Moreover, the effects of breathing on microvascular endothelium function are unknown. PURPOSE: To investigate the effects of slow, deep breathing on measures of autonomic function and microvascular endothelial function in adults with IBS. METHODS: Adults (ages 18-65 years) with a formal diagnosis of IBS were enrolled and randomized to 4-week controlled breathing or time-control conditions. The experimental group followed a 20-minute slow, deep breathing video 4 to 6 days per week while the control group maintained their regular activity. To assess autonomic function, heart rate variability (HRV) and exercise heart rate recovery (HRR) were measured at baseline and week 4. The HRV test was accompanied by respiration rate measurements to ensure no significant deviations in respiration occurred between assessments as this could impact HRV. Exercise HRR was assessed 30, 60, and 120 seconds following a Balke treadmill VO2 max test. Laser Doppler flowmetry was assessed at baseline (33°C) and in response to local heating up to 43.5°C while blood pressure was measured throughout for the calculation of cutaneous vascular conductance (CVC). RESULTS: Of the 14 participants enrolled, 12 (n=6 for control and experimental groups) completed the study. At baseline, age (p = 0.47) and body mass index (p=0.14) were similar between groups. Respiration rate was similar between HRV assessments in both groups. In the experimental group, %CVC max significantly increased (p = 0.027) at week 4 while HRR was unchanged. A tendency toward a time by group interaction was observed for HRV low frequency to high frequency (LF/HF) ratio (p = 0.066) with slight reductions in the breathing group and increases in the control group. In the control group, %CVC max and HRR were unaltered, though HRR at 120 seconds tended to improve (p=0.08). CONCLUSIONS: Preliminary results from this ongoing study suggest that microvascular endothelial function can improve with 4 weeks of slow, deep breathing exercises in adults with IBS. These alterations in vascular function were unaccompanied by significant changes in autonomic function though trends were observed in HRV. Results show that slow, deep breathing is a viable alternative to physical exercise for improving microvascular function. Findings also suggest that this intervention could result in improved sympathovagal balance in adults with IBS and potentially other individuals with functional disorders

Surface and trapping energies as predictors for the photocatalytic degradation of aromatic organic pollutants

In this study, anatase samples enclosed by the majority of three different crystal facets {0 0 1}, {1 0 0}, and {1 0 1} were successfully synthesized. These materials were further studied toward photocatalytic degradation of phenol and toluene as model organic pollutants in water and gas phases. The obtained results were analyzed concerning their surface structure, reaction type, and surface development. Moreover, the regression model was created to find the correlation between the possible predictors and the photodegradation rate constants (k). From the studied factors, the trapping energy of charge carriers at the surface was found to be the most significant one, exponentially affecting the observed k. This resulted in the overall per-surface activity between the samples being in the order {1 0 1} > {1 0 0} > {0 0 1}. Further introduction of the surface energy (Esurf) to the regression model and the number of possible trapping centers per number of pollutant’s molecules (ntrap·n–1) improved the model accuracy, simultaneously showing the dependence on the reaction type. In the case of phenol photocatalytic degradation, the best accuracy was observed for the model including Esurf ·(ntrap·n–1)1/2 relation, while for the toluene degradation, it included Esurf2 and the S·n–1 ratio, where S is the simple surface area. Concerning different surface features which influence photocatalytic performance and are commonly discussed in the literature, the results presented in this study suggest that trapping is of particular importance.publishe

Differential Contribution of Hypothalamic MAPK Activity to Anxiety-Like Behaviour in Virgin and Lactating Rats

The c-Raf – MEK1/2 – ERK1/2 mitogen-activated protein kinase (MAPK) intracellular signalling cascade in neurons plays important roles in the control of a variety of behaviours, including social behaviours and anxiety. These roles partially overlap with those described for oxytocin (OXT), and it has been shown that OXT activates the MAPK pathway in the hypothalamus (of male), and hippocampus (of female) rats. Here, by combining behavioural (light/dark box) and biochemical analyses (western blotting), we tested two hypotheses: (i) that OXT is anxiolytic within the hypothalamus of females, and (ii) that this effect, as well as that of lactation-associated anxiolysis, depends on the recruitment of the MAPK pathway. We found that, when injected bilaterally into the hypothalamic paraventricular nucleus (PVN), OXT decreased anxiety-like behaviour in virgins, and that this effect depended on phosphorylation of MEK1/2. MAPK pathway activation in lactation was evident by high phosphorylated (p) MEK1/2 levels, and nuclear translocation of ERK1. The high pMEK1/2 levels were necessary for the anxiolytic phenotype typically observed during lactation. Interestingly, exogenous OXT in lactating rats reduced pMEK1/2 levels without a concomitant effect on anxiety, indicating that OXT receptor activation can lead to recruitment of additional intracellular pathways to modulate MEK activity. Still other pathways could include MEK, but without subsequent activation of ERK, as we did not observe any increase in OXT-induced ERK phosphorylation. Together the results demonstrate that the MAPK pathway, especially MEK1/2, is critically involved in the regulation of anxiety-like behaviour in female rats

A Catalog of Spectroscopically Confirmed White Dwarfs from the Sloan Digital Sky Survey Data Release 4

We present a catalog of 9316 spectroscopically confirmed white dwarfs from the Sloan Digital Sky Survey Data Release 4. We have selected the stars through photometric cuts and spectroscopic modeling, backed up by a set of visual inspections. Roughly 6000 of the stars are new discoveries, roughly doubling the number of spectroscopically confirmed white dwarfs. We analyze the stars by performing temperature and surface gravity fits to grids of pure hydrogen and helium atmospheres. Among the rare outliers are a set of presumed helium-core DA white dwarfs with estimated masses below 0.3 Msun, including two candidates that may be the lowest masses yet found. We also present a list of 928 hot subdwarfs.Comment: Accepted by the Astrophysical Journal Supplements, 25 pages, 24 figures, LaTeX. The electronic catalog, as well as diagnostic figures and links to the spectra, is available at http://das.sdss.org/wdcat/dr4