Small-scale Fishermen and Risk Preferences

Using an experimental approach, we investigate the risk preferences of artisanal fishermen in Tanzania waters of Lake Victoria. The experiment concerns pairwise comparisons of hypothetical fishing trips that vary in expected mean and spread of the net revenue. The results show that about 34% of the fishermen can be considered as risk neutral, 32% as risk averse, and 34% as risk seekers. Econometric analysis indicates that the likelihood of belonging to the risk-seeking group increases if motorboats are used, if fishing is the main source of household income, and if the fisherman is targeting Nile perch. Asset ownership and perhaps socioeconomic variables influence risk preferences.Risk aversion, artisanal fishermen, Tanzania, Lake Victoria, Nile perch, dagaa, Institutional and Behavioral Economics, Resource /Energy Economics and Policy, Q22,

Energies and wave functions for a soft-core Coulomb potential

For the family of model soft Coulomb potentials represented by V(r) = -\frac{Z}{(r^q+\beta^q)^{\frac{1}{q}}}, with the parameters Z>0, \beta>0, q \ge 1, it is shown analytically that the potentials and eigenvalues, E_{\nu\ell}, are monotonic in each parameter. The potential envelope method is applied to obtain approximate analytic estimates in terms of the known exact spectra for pure power potentials. For the case q =1, the Asymptotic Iteration Method is used to find exact analytic results for the eigenvalues E_{\nu\ell} and corresponding wave functions, expressed in terms of Z and \beta. A proof is presented establishing the general concavity of the scaled electron density near the nucleus resulting from the truncated potentials for all q. Based on an analysis of extensive numerical calculations, it is conjectured that the crossing between the pair of states [(\nu,\ell),(\nu',\ell')], is given by the condition \nu'\geq (\nu+1) and \ell' \geq (\ell+3). The significance of these results for the interaction of an intense laser field with an atom is pointed out. Differences in the observed level-crossing effects between the soft potentials and the hydrogen atom confined inside an impenetrable sphere are discussed.Comment: 13 pages, 5 figures, title change, minor revision

Differences in Complication Rates of Gluteoplasty Procedures That Utilize Autologous Fat Grafting, Implants, or Local Flaps.

BACKGROUND:Gluteoplasty (gluteal augmentation) procedures are increasing in popularity, but there is not a universally accepted technique to produce optimal outcomes while minimizing risk. In this systematic review, we perform a meta-analysis to evaluate rates of complication from autologous fat grafting, implants, and local flaps, which are the three most common gluteoplasty operations. METHODS:A search of the PubMed/MEDLINE database for articles including the terms "gluteoplasty" OR "gluteal augmentation" OR "buttock augmentation" OR "Brazilian butt lift" OR "gluteal autologous fat graft" OR "buttock autologous fat graft" OR "gluteal implant" OR "buttock implant" OR "gluteal flap" OR "buttock flap" generated 229 articles. This number was brought down to 134 after initial screening by title. Inclusion criteria then removed those not written in English, those without access to the full text, those without extractable data on complications, and duplicates, leaving 46 articles to examine. RESULTS:A total of 4362 patients who underwent gluteoplasty between 1992 and 2017 were found. The overall complication rate was 12.4%. Implants had the highest rate (31.4%), whereas fat grafting had the lowest (6.8%); flaps were intermediate (23.1%). A χ test yielded a statistically significant (P < 0.001) nonindependent relationship between combined complication rate and type of surgery. Individual complications, such as asymmetry, capsular contracture, fat embolism, hematoma, infection, necrosis, pain, seroma, wide scar formation, and wound dehiscence, were also analyzed. CONCLUSIONS:Fat grafting by plastic surgeons might be the best option for gluteoplasty with regard to complications. In certain cases, however, there may only exist one choice for an operation because of anatomical limitations, which predisposes patients to those associated complications

Frequency of Rare Allelic Variation in Candidate Genes among Individuals with Low and High Urinary Calcium Excretion

Our study investigated the association of rare allelic variants with extremes of 24-hour urinary calcium excretion because higher urinary calcium excretion is a dominant risk factor for calcium-based kidney stone formation. We resequenced 40 candidate genes potentially related to urinary calcium excretion in individuals from the Nurses' Health Studies I & II and the Health Professionals Follow-up Study. A total of 960 participants were selected based on availability of 24-hour urine collection data and level of urinary calcium excretion (low vs. high). We utilized DNA sample pooling, droplet-based target gene enrichment, multiplexing, and high-throughput sequencing. Approximately 64% of samples (n = 615) showed both successful target enrichment and sequencing data with >20-fold deep coverage. A total of 259 novel allelic variants were identified. None of the rare gene variants (allele frequencies <2%) were found with increased frequency in the low vs. high urinary calcium groups; most of these variants were only observed in single individuals. Unadjusted analysis of variants with allele frequencies ≥2% suggested an association of the Claudin14 SNP rs113831133 with lower urinary calcium excretion (6/520 versus 29/710 haplotypes, P value = 0.003). Our data, together with previous human and animal studies, suggest a possible role for Claudin14 in urinary calcium excretion. Genetic validation studies in larger sample sets will be necessary to confirm our findings for rs113831133. In the tested set of candidate genes, rare allelic variants do not appear to contribute significantly to differences in urinary calcium excretion between individuals

Coherent Fe-rich nano-scale perovskite oxide phase in epitaxial Sr2FeMoO6 films grown on cubic and scandate substrates

We report the growth of high-quality epitaxial Sr2FeMoO6 (SFMO) thin films on various unconventional oxide substrates, such as TbScO3, DyScO3, and Sr2Al0.3Ga0.7TaO6 (SAGT) as well as on the most commonly used one, SrTiO3 (STO), by pulsed laser deposition. The films were found to contain a foreign nano-scale phase coherently embedded inside the SFMO film matrix. Through energy dispersive X-ray spectroscopy and scanning transmission electron microscopy, we identified the foreign phase to be Sr2−xFe1+yMo1−yO6, an off-stoichiometric derivative of the SFMO compound with Fe rich content (y ≈ 0.6) and a fairly identical crystal structure to SFMO. The films on STO and SAGT exhibited very good magnetic properties with high Curie temperature values. All the samples have fairly good conducting behavior albeit the presence of a foreign phase. Despite the relatively large number of items of the foreign phase, there is no significant deterioration in the properties of the SFMO films. We discuss in detail how magneto-transport properties are affected by the foreign phase. INT

Self-consistent multi-mode lasing theory for complex or random lasing media

A semiclassical theory of single and multi-mode lasing is derived for open complex or random media using a self-consistent linear response formulation. Unlike standard approaches which use closed cavity solutions to describe the lasing modes, we introduce an appropriate discrete basis of functions which describe also the intensity and angular emission pattern outside the cavity. This constant flux (CF) basis is dictated by the Green function which arises when formulating the steady state Maxwell-Bloch equations as a self-consistent linear response problem. This basis is similar to the quasi-bound state basis which is familiar in resonator theory and it obeys biorthogonality relations with a set of dual functions. Within a single-pole approximation for the Green function the lasing modes are proportional to these CF states and their intensities and lasing frequencies are determined by a set of non-linear equations. When a near threshold approximation is made to these equations a generalized version of the Haken-Sauermann equations for multi-mode lasing is obtained, appropriate for open cavities. Illustrative results from these equations are given for single and few mode lasing states, for the case of dielectric cavity lasers. The standard near threshold approximation is found to be unreliable. Applications to wave-chaotic cavities and random lasers are discussed.Comment: 18 pages, 9 figure