Is consumption growth consistent with intertemporal optimization? evidence from the consumer expenditure survey

In this paper we show that some of the predictions of models of consumer intertemporal optimization are in line with the patterns of nondurable expenditure observed in U.S. household-level data. We propose a flexible specification of preferences that allows multiple commodities and yields empirically tractable equations. We estimate preference parameters using the only U.S. micro data set with complete consumption information. We show that previous rejections can be explained by the simplifying assumptions made in previous studies. We also show that results obtained using good consumption or aggregate data can be misleading

ASSESSMENT OF FLESH TEXTURE IN PEACH (PRUNUS PERSICA L. BATSCH)

The Italian peach compartment is nowadays experiencing a period of crisis. The cause of this crisis can be traced to a chain of production and distribution which is too attentive to the satisfaction of the individual components of the chain (e.g. large fruit size for the growers, fruit firmness for the packers, fruit color, size and texture for retailers) and not sufficiently focused on overall fruit quality at the end of the chain, on the table of the final consumers. The development of new cultivars belonging to the Slow Melting phenotype, characterized by a firmer texture even at full ripening and by softening more slowly (so that they can be harvested at a riper stage), definitely could help the fruit sector. Until now, the recognition of this new flesh phenotype was entrusted only to operator experience, which is not very reliable and allows flesh phenotype recognition only after obtaining the fruit, therefore some years after planting. An early determination, as it could be achieved through molecular markers, would lead to an early selection of fruit phenotypes, thus saving time, money and space. The objective of this research is to find possible physical or chemical differences in different flesh phenotypes, in order to characterize flesh texture. Accordingly, at the same time the expression profiles of the different flesh textures, in order to better understand which genes and pathways are involved in flesh firmness, were investigated. To reach these goals, three different approaches were performed: i) the characterization by a non-destructive approach. Time Resolved Spectroscopy (TRS) was performed on peaches belonging to different flesh phenotypes (Melting, Non Melting, Slow Melting, and Stony Hard). This technique gives information about fruit absorption and scattering properties. Scattering measurements in particular provide information concerning fruit structural characteristics, which could give useful information about the peculiar characteristics of the flesh. The results showed that this technique is able to discriminate only three flesh phenotypes (Melting, Slow Melting and Stony hard) out of the four that were tested. ii) The characterization by a traditional approach. Peaches belonging to M, NM, SM, and SH phenotypes were analyzed for weight loss, soluble solid contents (SSC), titratable acidity (TA), firmness, and expressible juice. Among all, expressible juice may be the key factor discriminating between the different flesh phenotypes. In fact it discriminated between all the flesh phenotypes in samples at physiological ripening in two consecutive years (2011 and 2012). Further studies are needed to determine whether this trait can be used as phenotyping method to be applied in QTL analysis, to the end of finding molecular markers associated with this character. iii) The characterization by gene expression analysis. Through this method, different gene expression peach profiles belonging to M, NM, SM, and SH phenotypes were compared at 2 different stages of ripening (fruit veraison and commercial ripening), in order to better understand which genes and pathways are involved in flesh firmness. The expression profile analysis gave partially unexpected results. In one of the most important contrasts of the experiment, M vs. SM, no differentially expressed genes were found, either in fruit veraison or in commercial ripening. On the contrary, differences were found in M vs SH and SH vs NM at varaison and again in M vs SH at commercial ripening

Humps and bumps in lifetime consumption

In this paper we argue that once one departs from the simple classroom example, or `stripped down life-cycle model,' the empirical model for consumption growth can be made flexible enough to fit the main features of the data. More specifically, we show that allowing demographics to affect household preferences and relaxing the assumption of certainty equivalence can generate hump-shaped consumption profiles over age that are very similar to those observed in household-level data sources, without appealing to alternative explanations (such as liquidity constraints, myopia or mental accounting). The hump-shape is partly attributable to precautionary savings, and partly due to demographics; the tracking (whereby consumption jumps with income) is instead due to the permanent nature of the income shocks. We use US household-level data to estimate preference parameters and income profiles, and then simulate consumption profiles for different education groups. Our simulated profiles show that the key features observed in the data can be closely matched in simulation. We also show that neglecting uncertainty produces consumption profiles that are `too flat,' whereas neglecting demographics generates consumption profiles that peak `too late.

Prediction of hearing recovery in sudden deafness treated with intratympanic steroids

The present study aims to obtain a probability model allowing the prediction of the auditory recovery in patients affected by sudden sensorineural hearing loss treated exclusively with intratympanic steroids. A monocentric retrospective chart review of three-hundred eighty-one patients has been performed. A Probit model was used to investigate the correlation between the success of the treatment (marked or total recovery according to Furuashi's criteria), and the delay between the onset of disease and the beginning of therapy. The age of the patients and the audiometric curve shapes were included in the analysis. Results show that delay is negatively correlated with the variable success. Considering the entire sample, each day of delay decreases by 3% the probability of success. The prediction model shows that for every day that passes from the onset of the disease the probability of success declines in absence of the medical treatment, hence we conclude that early treatment is strongly recommended

Nonlinear current-voltage characteristics due to quantum tunneling of phase slips in superconducting Nb nanowire networks

We report on the transport properties of an array of N about 30 interconnected Nb nanowires, grown by sputtering on robust porous Si substrates. The analyzed system exhibits a broad resistive transition in zero magnetic field, H, and highly nonlinear V(I) characteristics as a function of H which can be both consistently described by quantum tunneling of phase slips.Comment: accepted for publication on Appl. Phys. Let

The impact of cash transfers to poor women in Colombia on BMI and obesity: Prospective cohort study

INTRODUCTION: Prevalence of obesity is rising in Latin America, is increasingly affecting socially disadvantaged groups, particularly women. Conditional cash transfers are recently established welfare interventions in the region. One, Familias en Accion, transfers ~20% of average monthly income to women in Colombia’s poorest families. Previous work has found that families buy more food as a result. We tested the hypothesis that participation in Familias would be associated with increasing body mass index (BMI) in participating women METHODS: Women from participating areas and control areas (matched on environmental and socioeconomic criteria) were surveyed in 2002 and 2006. Pregnant, breast-feeding or women aged<18 or with BMI<18.5kg/m(2) were excluded. The sample comprises 835 women from control and 1238 from treatment areas. Because some treatment areas started Familias shortly before baseline data collection, a dummy variable was created that identified exposure independent of time-point or area. Follow-up was 61.5%. BMI was measured by trained personnel using standardized techniques. Overweight was defined as BMI>25kg/m(2) and obesity as >30kg/m(2). The effect of Familias was estimated using linear regression (or logistic regression for dichotomous outcomes) in a double-difference technique, controlling for several individual, household and area characteristics, including parity and baseline BMI, using robust standard-errors clustered at area-level in an intention-to-treat analysis. RESULTS: At baseline, women’s mean age was 33.3 years and mean BMI 25.3kg/m(2); 12.3% women were obese. After adjustment, exposure to Familias was significantly associated with increased BMI (β=0.25, 95% CI 0.03, 0.47; p=0.03). Age (β=0.09; 95%CI 0.06, 0.13; p<0.001) and household wealth (β=0.78; 95%CI 0.41, 1.15; p<0.001) were also positively associated with BMI. Familias was also associated with increased odds of obesity (O.R.=1.27 95%CI 1.03, 1.57; p=0.03), as was age (O.R.=1.04; 95%CI 1.02, 1.06; p=0.001). CONCLUSION: Conditional cash transfers to poor women in Colombia are independently associated with increasing BMI and obesity risk. Although conditional cash transfers are generally regarded as popular and successful schemes, parallel interventions at individual, household and community level are needed to avoid unanticipated adverse outcomes

Complex Langevin simulations and the QCD phase diagram: Recent developments

In this review we present the current state-of-the-art on complex Langevin simulations and their implications for the QCD phase diagram. After a short summary of the complex Langevin method, we present and discuss recent developments. Here we focus on the explicit computation of boundary terms, which provide an observable that can be used to check one of the criteria of correctness explicitly. We also present the method of Dynamic Stabilization and elaborate on recent results for fully dynamical QCD.Comment: 7 pages, 1 figure, 4 tables, to appear in EPJ

An experimental study on micro-milling of a medical grade Co-Cr-Mo alloy produced by selective laser melting

Cobalt-chromium-molybdenum (Co-Cr-Mo) alloys are very promising materials, in particular, in the biomedical field where their unique properties of biocompatibility and wear resistance can be exploited for surgery applications, prostheses, and many other medical devices. While Additive Manufacturing is a key technology in this field, micro-milling can be used for the creation of micro-scale details on the printed parts, not obtainable with Additive Manufacturing techniques. In particular, there is a lack of scientific research in the field of the fundamental material removal mechanisms involving micro-milling of Co-Cr-Mo alloys. Therefore, this paper presents a micro-milling characterization of Co-Cr-Mo samples produced by Additive Manufacturing with the Selective Laser Melting (SLM) technique. In particular, microchannels with different depths were made in order to evaluate the material behavior, including the chip formation mechanism, in micro-milling. In addition, the resulting surface roughness (Ra and Sa) and hardness were analyzed. Finally, the cutting forces were acquired and analyzed in order to ascertain the minimum uncut chip thickness for the material. The results of the characterization studies can be used as a basis for the identification of a machining window for micro-milling of biomedical grade cobalt-chromium-molybdenum (Co-Cr-Mo) alloys