Comparisons within and between years resulting in contrasting recruitment of Pacific hake (Merluccius productus) in the California Current System

2000 ◽  
Vol 57 (7) ◽  
pp. 1434-1447 ◽  
Author(s):  
Michael M Mullin ◽  
Erica Goetze ◽  
Stace E Beaulieu ◽  
Jacqueline M Lasker
Keyword(s):  
Overall Survival ◽  
Current System ◽  
Survival Rates ◽  
California Current ◽  
Ekman Transport ◽  
California Current System ◽  
Merluccius Productus ◽  
The Difference ◽  
Simple Ratio ◽  
Overall Survival Rates

In a search for correlates and possible causes of the difference in recruitment success of Pacific hake (Merluccius productus) of the 1981 and 1984 year-classes, we analyzed (by optical plankton counter) the distribution into sizes of preserved zooplankton samples from stations with and without larval hake in winter and spring of these two years. We also assessed the onshore/offshore distributions of larvae, potential for geostrophic and Ekman transport, and their overall survival rates. Cluster analyses of biovolume spectra led to the development of a simple ratio of "medium" to "small + large" zooplankton that statistically separated stations within a year where larval hake were likely to be found from those where they were unlikely to be found. This biovolume ratio was independent of temperature, and the same ratio statistically distinguished stations where larval hake tended to occur in spring 1998. However, we found no property or process that might explain why the 1984 year-class was spectacularly successful.

Mesoscale to Submesoscale Transition in the California Current System. Part II: Frontal Processes

2008 ◽  
Vol 38 (1) ◽  
pp. 44-64 ◽  
Author(s):  
X. Capet ◽  
J. C. McWilliams ◽  
M. J. Molemaker ◽  
A. F. Shchepetkin
Keyword(s):  
Potential Vorticity ◽  
Current System ◽  
California Current ◽  
Force Balance ◽  
Ekman Transport ◽  
Dynamical Process ◽  
Surface Dynamics ◽  
Near Surface ◽  
California Current System ◽  
Secondary Circulations

Abstract This is the second of three papers investigating the regime transition that occurs in numerical simulations for an idealized, equilibrium, subtropical, eastern boundary, upwelling current system similar to the California Current. The emergent upper-ocean submesoscale fronts are analyzed from phenomenological and dynamical perspectives, using a combination of composite averaging and separation of distinctive subregions of the flow. The initiating dynamical process for the transition is near-surface frontogenesis. The frontal behavior is similar to both observed meteorological surface fronts and solutions of the approximate dynamical model called surface dynamics (i.e., uniform interior potential vorticity q and diagnostic force balance) in the intensification of surface density gradients and secondary circulations in response to a mesoscale strain field. However, there are significant behavioral differences compared to the surface-dynamics model. Wind stress acts on fronts through nonlinear Ekman transport and creation and destruction of potential vorticity. The strain-induced frontogenesis is disrupted by vigorous submesoscale frontal instabilities that in turn lead to secondary frontogenesis events, submesoscale vortices, and excitation of even smaller-scale flows. Intermittent, submesoscale breakdown of geostrophic and gradient-wind force balance occurs during the intense frontogenesis and frontal-instability events.

scholarly journals Reconstruction of Diffusion Coefficients and Power Exponents from Single Lagrangian Trajectories

Fluids ◽  
2021 ◽  
Vol 6 (3) ◽  
pp. 111
Author(s):  
Leonid M. Ivanov ◽  
Collins A. Collins ◽  
Tetyana Margolina
Keyword(s):  
Black Sea ◽  
Diffusion Coefficients ◽  
Current System ◽  
Mean Square Displacement ◽  
California Current ◽  
The Black Sea ◽  
Mean Square ◽  
California Current System ◽  
The Mean ◽  
Non Gaussian

Using discrete wavelets, a novel technique is developed to estimate turbulent diffusion coefficients and power exponents from single Lagrangian particle trajectories. The technique differs from the classical approach (Davis (1991)’s technique) because averaging over a statistical ensemble of the mean square displacement (<X2>) is replaced by averaging along a single Lagrangian trajectory X(t) = {X(t), Y(t)}. Metzler et al. (2014) have demonstrated that for an ergodic (for example, normal diffusion) flow, the mean square displacement is <X2> = limT→∞τX2(T,s), where τX2 (T, s) = 1/(T − s) ∫0T−s(X(t+Δt) − X(t))2 dt, T and s are observational and lag times but for weak non-ergodic (such as super-diffusion and sub-diffusion) flows <X2> = limT→∞≪τX2(T,s)≫, where ≪…≫ is some additional averaging. Numerical calculations for surface drifters in the Black Sea and isobaric RAFOS floats deployed at mid depths in the California Current system demonstrated that the reconstructed diffusion coefficients were smaller than those calculated by Davis (1991)’s technique. This difference is caused by the choice of the Lagrangian mean. The technique proposed here is applied to the analysis of Lagrangian motions in the Black Sea (horizontal diffusion coefficients varied from 105 to 106 cm2/s) and for the sub-diffusion of two RAFOS floats in the California Current system where power exponents varied from 0.65 to 0.72. RAFOS float motions were found to be strongly non-ergodic and non-Gaussian.

scholarly journals Association of chemotherapy with survival in stage II colon cancer patients who received radical surgery: a retrospective cohort study

BMC Cancer ◽  
2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Zhihao Lv ◽  
Yuqi Liang ◽  
Huaxi Liu ◽  
Delong Mo
Keyword(s):  
Colon Cancer ◽  
Overall Survival ◽  
Cancer Patients ◽  
Prediction Models ◽  
Radical Surgery ◽  
Survival Rates ◽  
Stage Ii ◽  
Survival Prediction ◽  
Stage Ii Colon Cancer ◽  
Overall Survival Rates

Abstract Background It remains controversial whether patients with Stage II colon cancer would benefit from chemotherapy after radical surgery. This study aims to assess the real effectiveness of chemotherapy in patients with stage II colon cancer undergoing radical surgery and to construct survival prediction models to predict the survival benefits of chemotherapy. Methods Data for stage II colon cancer patients with radical surgery were retrieved from the Surveillance, Epidemiology, and End Results (SEER) database. Propensity score matching (1:1) was performed according to receive or not receive chemotherapy. Competitive risk regression models were used to assess colon cancer cause-specific death (CSD) and non-colon cancer cause-specific death (NCSD). Survival prediction nomograms were constructed to predict overall survival (OS) and colon cancer cause-specific survival (CSS). The predictive abilities of the constructed models were evaluated by the concordance indexes (C-indexes) and calibration curves. Results A total of 25,110 patients were identified, 21.7% received chemotherapy, and 78.3% were without chemotherapy. A total of 10,916 patients were extracted after propensity score matching. The estimated 3-year overall survival rates of chemotherapy were 0.7% higher than non- chemotherapy. The estimated 5-year and 10-year overall survival rates of non-chemotherapy were 1.3 and 2.1% higher than chemotherapy, respectively. Survival prediction models showed good discrimination (the C-indexes between 0.582 and 0.757) and excellent calibration. Conclusions Chemotherapy improves the short-term (43 months) survival benefit of stage II colon cancer patients who received radical surgery. Survival prediction models can be used to predict OS and CSS of patients receiving chemotherapy as well as OS and CSS of patients not receiving chemotherapy and to make individualized treatment recommendations for stage II colon cancer patients who received radical surgery.

scholarly journals Long Noncoding RNA Lnc-TLN2-4:1 Suppresses Gastric Cancer Metastasis and Is Associated with Patient Survival

2020 ◽  
Vol 2020 ◽  
pp. 1-8
Author(s):  
Yuyun Wu ◽  
Ningbo Hao ◽  
Suming Wang ◽  
Xin Yang ◽  
Yufeng Xiao ◽  
...  
Keyword(s):  
Gastric Cancer ◽  
Overall Survival ◽  
Noncoding Rna ◽  
Tumor Metastasis ◽  
Cancer Metastasis ◽  
Survival Rates ◽  
Migration And Invasion ◽  
Poor Overall Survival ◽  
Low Expression ◽  
Overall Survival Rates

Gastric cancer (GC) is one of the most common malignancies worldwide, and the tumor metastasis leads to poor outcomes of GC patients. Long noncoding RNAs (lncRNAs) have emerged as new regulatory molecules that play a crucial role in tumor metastasis. However, the biological function and underlying mechanism of numerous lncRNAs in GC metastasis remain largely unclear. Here, we report a novel lncRNA, lnc-TLN2-4:1, whose expression is decreased in GC tissue versus matched normal tissue, and its low expression is involved in the lymph node and distant metastases of GC, as well as poor overall survival rates of GC patients. We further found that lnc-TLN2-4:1 inhibits the ability of GC cells to migrate and invade but does not influence GC cell proliferation and confirmed that lnc-TLN2-4:1 is mainly located in the cytoplasm of GC cells. We then found that lnc-TLN2-4:1 increases the mRNA and protein expression of TLN2 in GC cells and there is a positive correlation between the expression of lnc-TLN2-4:1 and TLN2 mRNA in GC tissue. Collectively, we identified a novel lncRNA, lnc-TLN2-4:1, in GC, where lnc-TLN2-4:1 represses cell migration and invasion. The low expression of lnc-TLN2-4:1 is associated with poor overall survival rates of GC patients. These suggest that lnc-TLN2-4:1 may be a tumor suppressor during GC metastasis.

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