6,904 research outputs found
Whale-watching and Herring Fishing: Joint or Independent Production?
The effects of "localized depletion" of a pelagic fishery (herring) on a non-extractive marine activity (tourism) are investigated. Proponents of the localized depletion theory claim that intense fishing effort can lead to areas that are unsuitable for predators like tuna, groundfish, and whales. This leads to poor outcomes for the fishing and whale-watching industries. However, there has been no consensus in the scientific community about the existence of this phenomenon. Localized depletion would be consistent with an economic theory of joint production, in which nearshore herring stocks are an input in production of both herring and whale-watching trips. A unique dataset of daily whale-watching outcomes is combined with fishing effort and oceanographic data. This dataset is used to test the hypothesis that intensive fishing effort increases the search time of whale-watching companies. Our results suggest that while fishing has a statistically significant impact on sightings, this magnitude of this effect is fairly small. Sightings seem to be determined mostly by large scale oceanographic processes. These results should be of interest to policymakers in determining future fishing regulations.whales, fishing, panel data, search, Ecosystem Based Management, Resource /Energy Economics and Policy, Q57, Q26, Q22,
Consolidation as a Regulatory Compliance Strategy: Small Drinking Water Systems and the Safe Drinking Water Act
Despite extensive research and policy initiatives to increase the technical, financial, and managerial capacity of small drinking water systems, there has been little research focusing on understanding how consolidation can increase the overall capacity of the drinking water industry. Consolidation of water systems may be a mechanism that increases regulatory compliance by removing poorly performing systems from the industry and replacing inefficient management and/or capital. The US drinking water system is highly fragmented, with over 50,000 Community Water Systems (CWSs), of which the vast majority are classified as "small" by the US Environmental Protection Agency (EPA). A discrete choice model is employed to determine the characteristics shared by small water systems that are acquired. On average, these acquired firms are small, have frequent drinking water violations, are privately-owned, and purchase their water from another system. These results suggest that consolidation may have an important role to play in increasing overall industry compliance with the Safe Drinking Water Act (SDWA).Community Water System, Drinking Water, Merger, Consolidation, Resource /Energy Economics and Policy, Q25, Q53,
Low-energy Effective Theory for One-dimensional Lattice Bosons near Integer Filling
A low-energy effective theory for interacting bosons on a one-dimensional
lattice at and near integer fillings is proposed. It is found that two sets of
bosonic phase fields are necessary in order to explain the complete phase
diagram. Using the present effective theory, the nature of the quantum phase
transitions among various phases can be identified. Moreover, the general
condition for the appearance of the recently proposed Pfaffian-like state can
be realized from our effective action.Comment: 6 pages, 2 figures, 1 tabl
Kinetic stabilization of Fe film on (4 by 2)-GaAs(100)
We grow Fe film on (4 by 2)-GaAs(100) at low temperature, (~ 130 K) and study
their chemical structure by photoelectron spectroscopy using synchrotron
radiation. We observe the effective suppression of As segregation and
remarkable reduction of alloy formation near the interface between Fe and
substrate. Hence, this should be a way to grow virtually pristine Fe film on
GaAs(100). Further, the Fe film is found stable against As segregation even
after warmed up to room temperature. There only forms very thin, ~ 8 angstrom
thick interface alloy. It is speculated that the interface alloy forms via
surface diffusion mediated by interface defects formed during the low
temperature growth of the Fe film. Further out-diffusion of both Ga and As are
suppressed because it should then proceed via inefficient bulk diffusion.Comment: 4 figure
Heterogeneous amplification of ERBB2 in primary lesions is responsible for the discordant ERBB2 status of primary and metastatic lesions in gastric carcinoma
Aims: To determine the extent of HER2 homogeneity/heterogeneity in primary versus metastatic gastric carcinoma ( GC). Materials and results: The human epidermal growth factor receptor 2 ( HER2) status in primary and metastatic lesions was evaluated by immunohistochemistry ( IHC) and fluorescence in-situ hybridization ( FISH). Four separate cohorts consisting of primary GC alone or primary GC paired with metastatic lesions were examined. In the FISH analysis of 325 primary GCs, eight cases ( 2.5%) showed amplification with a heterogeneous pattern, whereas 27 cases ( 8.3%) showed amplification with a homogeneous pattern, and in this cohort the discordant: concordant FISH ratio based on examination of three different areas in each primary lesion was 0.30: 1. FISH testing using 250 paired primary and metastatic lesions revealed seven cases (2.8%) with discordant amplification. In metastatic disease positive conversion occurred in six cases (2.4%), whereas negative conversion happened in one case (0.4%). The discordant: concordant ratio of primary versus secondary lesions was 0.23: 1. When the seven discordant cases were re-evaluated using whole sections of primary GCs, six showed a heterogeneous pattern of amplification. Conclusions: These findings suggest that the discordant HER2 amplification observed in metastatic lesions is explained substantially by heterogeneity within primary tumours
Accuracy of Neck Circumference in Classifying Overweight and Obese US Children
Objective. To evaluate classification accuracy of NC and compare it with body mass index (BMI) in identifying overweight/obese US children. Methods. Data were collected from 92 children (boys: 61) aged 7 to 13 over a 2-year period. NC, BMI, and percent of body fat (BF%) were measured in each child and their corresponding cut-off values were applied to classify the children as being overweight/obese. Classification accuracy of NC and BMI was systematically investigated for boys and girls in relation to true overweight/obesity categorization as assessed with a criterion measure of BF% (i.e., Bod Pod). Results. For boys, Cohen’s k (0.25), sensitivity (38.1%), and specificity (85.0%) of NC were smaller in comparison with Cohen’s k (0.57), sensitivity (57.1%), and specificity (95.0%) of BMI in relation to BF% categorization. For girls, Cohen’s k (0.45), sensitivity (50.0%), and specificity (91.3%) of NC were smaller in comparison with Cohen’s k (0.52), sensitivity (50.0%), and specificity (95.7%) of BMI. Conclusion. NC measurement was not better than BMI in classifying childhood overweight/obesity and, for boys, NC was inferior to BMI. Pediatricians and/or pediatric researchers should be cautious or wary about incorporating NC measurements in their pediatric care and/or research
Numerical Test of Disk Trial Wave function for Half-Filled Landau Level
The analyticity of the lowest Landau level wave functions and the relation
between filling factor and the total angular momentum severely limits the
possible forms of trial wave functions of a disk of electrons subject to a
strong perpendicular magnetic field. For N, the number of electrons, up to 12
we have tested these disk trial wave functions for the half filled Landau level
using Monte Carlo and exact diagonalization methods. The agreement between the
results for the occupation numbers and ground state energies obtained from
these two methods is excellent. We have also compared the profile of the
occupation number near the edge with that obtained from a field-theoretical
method. The results give qualitatively identical edge profiles. Experimental
consequences are briefly discussed.Comment: To be published in Phys. Rev. B. 9 pages, 6 figure
Anti-Food allergic activity of sulfated polysaccharide from Gracilaria lemaneiformisis dependent in immunosuppression and inhibition of p38 MAPK
Polysaccharides from Gracilaria lemaneiformis in particular possess various bioactive functions, but their antiallergic activity remains incompletely defined. Sulfated polysaccharide from Gracilaria lemaneiformis (GLSP) was obtained by water extraction and ethanol precipitation followed by column chromatography. BALB/c mice, RBL-2H3, and KU812 cells were used for verifying the anti food allergic activity of GLSP. According to the results of mice experiment, GLSP was able to alleviate allergy symptoms, to reduce TM-specific IgE and IgG1, to suppress Th2 cell polarization, and to promote the function of regulatory T (Treg) cells. In addition, GLSP had the ability to inhibit the function of RBL-2H3 cells. Furthermore, GLSP inhibited the activation of KU812 via suppression of p38 mitogen-activated protein kinase (MAPK). In conclusion, immunosuppression as well as the reduction in the level of p38 MAPK may contribute to GLSP’s putative activity against food allergy. GLSP may be used as a functional food component for allergic patients
Gene Therapy for Head and Neck Squamous Cell Carcinoma Using KITENIN (KAI1 COOH-Terminal Interacting Tetraspanin)-Antisense Therapy
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