Preliminary Results of Commercial Sea Scallop Survey in the Hudson Canyon South Closed Area June 2000

This report presents the preliminary results of the commercial survey of the Hudson Canyon Closed Area. The survey was conducted aboard the FN Alice Amanda from June 8-15, 2000. A systematic grid design was utilized with survey stations located approximately 5 nm apart (Figure 1). Survey stations were located both inside and outside the boundaries of the closed area. Additional stations were added along the western, northern and southern boundaries in an attempt to resolve the boundary effects on sea scallop abundance and size distribution. Survey tows were 10 minutes in duration at a speed of 4.5-5.0 kts. The sampling gear consisted of two standard 15 ft. New Bedford style sea scallop dredges with 8 inch twine tops, ring bags knit with 3.5 ·(88.9 mm) rings, and no tickler or rock chains. An inclinometer was attached to the frame of the starboard dredge to measure dredge angle and bottom contact time. The results of the initial data analysis are shown in Figures 2-8. Catch data are shown in Figures 2-4 with scallop catches separated into two categories of shell height: less than 90 mm (Figure 2) and greater than or equal to 90 mm shell height (Figure 3). A total scallop catch at each station is shown in Figure 4. Differences in sea scallop abundance and size structure were examined with respect to samples taken inside or outside of the closed area (Figure 5), strata calculated by dividing the closed area into equal North and South portions along the 39° 01.566\u27 latitude (Figure 6), and by depth regimes within the closed area (Figure 7). Catch data stratified by two factors: 1). North and South 2). inside and outside the closed area are shown in Table 1. The initial biomass estimate is shown in Table 2. The following assumptions were used in calculating biomass: 1. Stratification of the closed area into two roughly equal portions. 2. Utilizing a systematic grid design, number of stations was proportional to area of strata. 3. Tows that fell on closed area boundary were included in the calculation. 4. All scallops harvested were included 5. The coefficients of the shell height-meat weight relationship a=-12.1628 b=3.2539. 6. A nominal tow length of 1 nm. Each tow covered 0.00494 nm2 7. A dredge efficiency of 40% 8. Harvest represents a removal of 25% of the standing stock The next iterations of biomass estimates will follow accordingly: 1. The number of scallops from 80-100 mm will be corrected for the selectivity of the 3.5 ring dredge. This means that the total number of scallops at each 5 mm interval from 80-100 mm will increase. Consequently, their contribution will also increase the biomass estimate. We will still use the nominal tow length of l nm and a 40% dredge efficiency. 2. The biomass estimate in l will be calculated to account for growth and natural mortality (0.1) to project the standing stock in 2001. 3. The biomass estimate in l and 2 will be calculated to account for actual tow length and changes in dredge efficiency based on the 1999 depletion experiments in the Hudson Canyon Closed Area on 100+ mm scallop

Results of Commercial Sea Scallop Survey in the Virginia Beach Closed Area September 2000

This report presents the results of the commercial survey of the Virginia Beach Closed Area. The survey was conducted aboard the commercial sea scallop vessel F IV Alice Amanda from Hampton VA. Sampling began September 19, 2000 and was completed September 22, 2000

Results of Commercial Sea Scallop Survey in the Hudson Canyon South Closed Area

This report presents the results of the commercial survey of the Hudson Canyon Closed Area. The survey was conducted aboard the FN Alice Amanda from June 8-15, 2000. A systematic grid design was utilized with survey stations located approximately 5 nm apart (Figure l ). Survey stations were located both inside and outside the boundaries of the closed area. Additional stations were added along the western, northern ru1d southern boundaries in an attempt to resolve the boundary effects on sea scallop abundance and size distribution. Survey tows were l O minutes in duration at a speed of 4.5-5.0 kts. The sampling gear consisted of two standard 15 ft. New Bedford style sea scallop dredges with 8 inch twine tops. ring bags knit with 3.5\u27\u27 (88.9 mm) rings, and no tickler or rock chains. An inclinometer was attached to the frame of the starboard dredge to measure dredge angle and bottom contact time. The results of the initial data analysis are shovm in Figures 2-8. Catch data are shown in Figures 2-4 with scallop catches separated into two categories of shell height: less than 90 mm (Figure 2) and greater than or equal to 90 mm shell height (Figure 3). A total scallop catch at each station is shown in Figure 4. Differences in sea scallop abundance and size structure were examined with respect to samples taken inside or outside of the closed area (Figure 5), strata calculated by dividing the closed area into equal North and South portions along the 39° 01.566\u27 latitude (Figure 6), and by depth regimes within the closed area (Figure 7). Catch data stratified by two factors: 1 ). North and South 2). inside and outside the closed area are shown in Table l. The initial biomass estimate is shown in Table 2. The following assumptions were used in calculating biomass: l. Stratification of the closed area into two roughly equal portions. 2. Utilizing a systematic grid design, number of stations was proportional to area of strata. 3. Tows that fell on closed area boundary were included in the calculation. 4. All scallops harvested were included 5. The coefficients of the shell height-meat weight relationship a=-12.1628 b=3.2539. 6. A nominal tow length of 1 nm. Each tow covered 0.00494 nm2 • 7. A dredge efficiency of 40% 8. Harvest represents a removal of 25% of the standing stoc

Ergodic sampling of the topological charge using the density of states

In lattice calculations, the approach to the continuum limit is hindered by the severe freezing of the topological charge, which prevents ergodic sampling in configuration space. In order to significantly reduce the autocorrelation time of the topological charge, we develop a density of states approach with a smooth constraint and use it to study SU(3) pure Yang Mills gauge theory near the continuum limit. Our algorithm relies on simulated tempering across a range of couplings, which guarantees the decorrelation of the topological charge and ergodic sampling of topological sectors. Particular emphasis is placed on testing the accuracy, efficiency and scaling properties of the method. In their most conservative interpretation, our results provide firm evidence of a sizeable reduction of the exponent z related to the growth of the autocorrelation time as a function of the inverse lattice spacing

Measurement errors in body size of sea scallops (Placopecten magellanicus) and their effect on stock assessment models

Body-size measurement errors are usually ignored in stock assessments, but may be important when body-size data (e.g., from visual sur veys) are imprecise. We used experiments and models to quantify measurement errors and their effects on assessment models for sea scallops (Placopecten magellanicus). Errors in size data obscured modes from strong year classes and increased frequency and size of the largest and smallest sizes, potentially biasing growth, mortality, and biomass estimates. Modeling techniques for errors in age data proved useful for errors in size data. In terms of a goodness of model fit to the assessment data, it was more important to accommodate variance than bias. Models that accommodated size errors fitted size data substantially better. We recommend experimental quantification of errors along with a modeling approach that accommodates measurement errors because a direct algebraic approach was not robust and because error parameters were diff icult to estimate in our assessment model. The importance of measurement errors depends on many factors and should be evaluated on a case by case basis

Compact anisotropic spheres with prescribed energy density

New exact interior solutions to the Einstein field equations for anisotropic spheres are found. We utilise a procedure that necessitates a choice for the energy density and the radial pressure. This class contains the constant density model of Maharaj and Maartens (Gen. Rel. Grav., Vol 21, 899-905, 1989) and the variable density model of Gokhroo and Mehra (Gen. Rel. Grav., Vol 26, 75-84, 1994) as special cases. These anisotropic spheres match smoothly to the Schwarzschild exterior and gravitational potentials are well behaved in the interior. A graphical analysis of the matter variables is performed which points to a physically reasonable matter distribution.Comment: 22 pages, 3 figures, to appear in Gen. Rel. Gra

Nodular Thyroid Disease in the Era of Precision Medicine

Management of thyroid nodules in the era of precision medicine is continuously changing. Neck ultrasound plays a pivotal role in the diagnosis and several ultrasound stratification systems have been proposed in order to predict malignancy and help clinicians in therapeutic and follow-up decision. Ultrasound elastosonography is another powerful diagnostic technique and can be an added value to stratify the risk of malignancy of thyroid nodules. Moreover, the development of new techniques in the era of "Deep Learning," has led to a creation of machine-learning algorithms based on ultrasound examinations that showed similar accuracy to that obtained by expert radiologists. Despite new technologies in thyroid imaging, diagnostic surgery in 50-70% of patients with indeterminate cytology is still performed. Molecular tests can increase accuracy in diagnosis when performed on "indeterminate" nodules. However, the more updated tools that can be used to this purpose in order to "rule out" (Afirma GSC) or "rule in" (Thyroseq v3) malignancy, have a main limitation: the high costs. In the last years various image-guided procedures have been proposed as alternative and less invasive approaches to surgery for symptomatic thyroid nodules. These minimally invasive techniques (laser and radio-frequency ablation, high intensity focused ultrasound and percutaneous microwave ablation) results in nodule shrinkage and improvement of local symptoms, with a lower risk of complications and minor costs compared to surgery. Finally, ultrasound-guided ablation therapy was introduced with promising results as a feasible treatment for low-risk papillary thyroid microcarcinoma or cervical lymph node metastases

Efficient computations of continuous action densities of states for lattice models

Abstract The Logarithmic Linear Relaxation (LLR) algorithm is an efficient method for computing densities of states for systems with a continuous spectrum. A key feature of this method is exponential error reduction, which allows us to evaluate the density of states of a system over hundreds of thousands of orders of magnitude with a fixed level of relative accuracy. As a consequence of exponential error reduction, the LLR method provides a robust alternative to traditional Monte Carlo calculations in cases in which states suppressed by the Boltzmann weight play nevertheless a relevant role, e.g., as transition regions between dominant configuration sets. After reviewing the algorithm, we will show an application in U(1) Lattice Gauge Theory that has enabled us to obtain the most accurate estimate of the critical coupling with modest computational resources, defeating exponential tunneling times between metastable vacua. As a further showcase, we will then present an application of the LLR method to the decorrelation of the topological charge in SU(3) Lattice Gauge Theory near the continuum limit. Finally, we will review in general applications of the LLR algorithm to systems affected by a strong sign problem and discuss the case of the Bose gas at finite chemical potential.</jats:p