Selectivity Curves Research Articles

Estimating spatio-temporal distribution of fish and gear selectivity functions from pooled scientific survey and commercial fishing data

Model-based prediction of fish distribution at fine resolutions in space and time has the potential to inform area-based and dynamic forms of management, such as permanent marine protected areas or real-time temporary closures. A major limitation to the spatial and temporal mapping resolution that is achievable is the amount of high quality, standardised data that can be utilized for fitting statistical models. To achieve an adequate spatio-temporal resolution from sparse data, one option is pooling information from several sources, such as scientific surveys and fisheries data. Because surveys and fisheries data usually use different sampling methods, pooling information from different sources requires cross-calibration of catch rates values across multiple gears. However, the individual gear efficiency and selectivity curves (the ratio between catch and availability at a given length) for all fishing gears and species are typically unknown. Using cod (Gadus morhua) in the northern North Sea as a case study, we developed a new formulation of spatio-temporal generalised additive models (GAM) of relative abundance of fish, combining catch data from multiple sources. Differences in gear efficiency and selectivity were internally calibrated within the model by the estimation of the local spatio-temporal variation in abundance. We show that pooling data sources enables the prediction of multi-annual and seasonal spatial variation in cod relative abundance-at-size, at spatio-temporal resolutions that are relevant for informing fishing strategies, e.g., reducing bycatch in real-time, or management objectives, e.g., real-time closed areas. We also show that GAM models fit to catch and effort data can reveal the relative efficiency and selectivity of different survey and commercial gears. The selectivity curve estimates that emerged as a by-product of our analysis are consistent with expert knowledge of the performance of the gears employed for cod. Our analytical approach can therefore serve two useful purposes: to estimate spatio-temporal variation in relative abundance of fish and to estimate relative gear efficiency and selectivity.

Cyclic Plasticity and Low Cycle Fatigue of an AISI 316L Stainless Steel: Experimental Evaluation of Material Parameters for Durability Design.

AISI 316L stainless steels are widely employed in applications where durability is crucial. For this reason, an accurate prediction of its behaviour is of paramount importance. In this work, the spotlight is on the cyclic response and low-cycle fatigue performance of this material, at room temperature. Particularly, the first aim of this work is to experimentally test this material and use the results as input to calibrate the parameters involved in a kinematic and isotropic nonlinear plasticity model (Chaboche and Voce). This procedure is conducted through a newly developed calibration procedure to minimise the parameter estimates errors. Experimental data are eventually used also to estimate the strain–life curve, namely the Manson–Coffin curve representing the 50% failure probability and, afterwards, the design strain–life curves (at 5% failure probability) obtained by four statistical methods (i.e., deterministic, “Equivalent Prediction Interval”, univariate tolerance interval, Owen’s tolerance interval for regression). Besides the characterisation of the AISI 316L stainless steel, the statistical methodology presented in this work appears to be an efficient tool for engineers dealing with durability problems as it allows one to select fatigue strength curves at various failure probabilities depending on the sought safety level.

Fishing gear selectivity of wire trap to limbat fish (Clarias nieuhofii) in swamp water Rimbo Ulu, Tebo Regency, Jambi Province

This study aims to analyze the level of selectivity of wire trap fishing gear against limbat fish (Clarias nieuhofii) in the swamp waters of Tebo Regency, Jambi Province. Data collection was carried out by catching trials using 3 units of wire traps with 30 replications, in June-August 2020. The research data were analyzed descriptively using the logistical selectivity model of the maximum likelihood method equation in the solver program from microsoft excel. The results showed that the wire traps were not selective for size but were selective for the limbat fish species (C.nieuhofii). The selectivity curve based on the logistical function shows that the probability of being caught by fish are at 22-48 mm body height, while the size of the fish that can escape has a maximum height of 34 mm or a length of 182 mm.

Use of the North American Standard Gill Net for Sampling the Invasive White Perch: Information from Three Kansas Reservoirs

AbstractThe invasive White Perch Morone americana occurs intermittently throughout Kansas and is ubiquitous in three Kansas reservoirs. However, a paucity of information on the effectiveness of sampling gears for providing accurate and precise estimates of size structure and relative abundance for White Perch precludes reasonable assessments of the effectiveness of control measures. The North American standard gill net has been used to sample White Perch in Kansas since 2010. Previous studies have provided selectivity curves for several species that are sampled with this gear to mitigate overall size bias, which is inherently present in gill‐net catches. However, White Perch populations have not been included in these initial studies. We fit selectivity models to catch data from three Kansas reservoirs to adjust the gill‐net catch data for contact selectivity. We used the most parsimonious selectivity curve to adjust the values for White Perch capture at length for 10 years of catch data. Most of the adjusted samples resulted in meaningful changes to the length distributions. To test for the effectiveness of the North American standard gill net for sampling White Perch populations, we measured the precision of the relative abundance estimates for White Perch and the frequency of obtaining 100 stock‐size fish with a standard sampling effort from 9 to 10 years of historical gill‐net samples. Our results suggest the North American standard gill net provides precise and robust estimates for the relative abundance of stock‐sized White Perch, but a correction factor that is derived from the selectivity curve might be needed to accurately estimate relative abundance for small individuals and to evaluate population size structure.

Clinical outcomes of selective fusion for the thoracolumbar-lumbar curve in patients with Lenke type 6C adolescent idiopathic scoliosis: a preliminary study.

Limited evidence is available in the literature regarding the fate of the unfused structural thoracic curve following selective thoracolumbar-lumbar curve fusion (SLF) in Lenke 6C adolescent idiopathic scoliosis (AIS) patients. Therefore, we compared the outcomes of SLF between Lenke 6C and 5C AIS patients. We retrospectively reviewed 31 patients Lenke 5C (n = 18) and Lenke 6C (n = 13) AIS patients who underwent SLF at a single institution. Multiple radiological parameters were measured using whole-spine radiographs taken before and after surgery and at the last follow-up visit. SRS-22 at the final follow-up was obtained for clinical assessment. A total of 31 patients with a mean age of 14.6 years at operation who were followed for a mean of 6.4 years were included in this study. The Cobb angle of the unfused thoracic curve was spontaneously corrected immediately following SLF and increased slightly but not significantly at the final follow-up in both groups (Lenke 5C: pre 33.0°, post 14.4°, final 19.4°, Lenke 6C: pre 46.1°, post 31.7°, final 34.2°). At every time point, the thoracic Cobb angle was significantly larger in the Lenke 6C. SRS-22 score at the final follow-up, including the self-image domain, did not differ between the two groups. In this study, SLF for Lenke 6C AIS achieved a significant spontaneous correction of the unfused thoracic curve and yielded a comparable SRS-22 result at the final follow-up to that of Lenke 5C. Our findings suggest that SLF is a viable treatment option for Lenke 6C AIS.

Selectivity estimates for Sepiella inermis (Van Hasselt, 1835) in 40 mmdiamond mesh codend trawl net

Cephalopods are mostly targeted by trawlers and Sepiella inermis (spineless cuttlefish), contributes about 2-4 percent oftotal cephalopod landings in India. Cephalopods accounted for 6.9 percent of total landings in Gujarat in 2018, with S.inermis accounting for approximately 1 %. The most common length of this species in the fishery is between 35 mm to 147mm. The length at first sexual maturity varies along the coast, and recent estimates for west coast of India for this species is48 and 55 mm for males and females, respectively.There are no estimates of trawl codend selectivity for this species and experiments were carried out using a 40 mmdiamond mesh codend using covered codend method. The selection parameters for S. inermis were derived using SELECTmethodology and the length at 50 % retention (L50)±(s.e.) was worked out as 36.2±1.2 mm and selection range as 19.9±2.1mm. The selection factor and the selection ratio for the codend were worked out as 0.9 and 0.55, respectively. The suggestedmesh size for the codend based on length at first sexual maturity (LFM) of females (55 mm) and males (48 mm) wereestimated as 60 and 53 mm (diamond mesh), respectively. This is the first estimate of trawl selection for this species andoperational parameters like towing speed, codend catch etc., that could influence selectivity were not considered and hencemore studies by incorporating these factors will help in further refining the parameters of the selection curve.

Predictive Factors for In-Hospital Preoperative Rupture in Hyperacute Type A Aortic Dissection.

This study aims to figure out risk factors of in-hospital preoperative rupture of hyperacute type A aortic dissection (haTAAD) patients and build a prediction and risk stratification model. From January 2011 to December 2019, 830 patients diagnosed as haTAAD from Nanjing Drum Tower Hospital were enrolled. Among them, 799 patients received prompt surgery and 31 suffered aortic rupture before operation. The association between in-hospital preoperative rupture and perioperative parameters were examined. Best subset selection was used for feature selection and ROC curve was used to identify the model. Age, winter season, back pain, preoperative hypotension, albumin and globulin ratio, high serum phosphorus level are risk factors for in-hospital preoperative rupture of haTAAD. On the basis of six variables with AUC 0.828, a nomogram was established. According to the robustness test, actual in-hospital preoperative ruptures were fitted well. The in-hospital rupture prediction model was developed using logistic regression analysis. High serum phosphorus level is one of the strongest predictors. This nomogram may be useful when evaluating the risk of aortic dissection in-hospital rupture in future trials.

Mesh selectivity of neuston nets for microplastics

Two neuston nets, mesh opening 1.00 mm and 0.333 mm, were towed in parallel. The 0.333 mm net collected more microplastics of longest length ≤2.00 mm than the 1.00 mm net. Mesh selection curve of the 1.00 mm mesh net for microplastics was estimated with the SELECT analysis by comparison of size distributions of microplastics collected by the two nets. Selection curve of the 0.333 mm mesh net, often used as a standard mesh size for microplastic net sampling, was also estimated on the assumption of geometrical similarity between microplastic size and mesh opening for a given retention probability. Approximately 60% amount of microplastics (0.4–1.0 mm) in net sampling with the 0.333 mm net passed through the mesh and was thus unaccounted for. The 0.333 mm net can retain at most 1.5% of microplastics ≤0.4 mm entering the net, and rarely retained microplastics ≤0.3 mm.

A validated Folin-Ciocalteu method for total phenolics quantification of condensed tannin-rich açaí (Euterpe oleracea Mart.) seeds extract

The widely used methodology to quantify polyphenols-the Folin-Ciocalteu (FC) method-cannot be applied indiscriminately since different matrices may impair the assay's accuracy. Thus, this study aimed to adapt the FC method for the açaí seed extract, a tannin-rich extract with potential applications for various therapies. Firstly, a pre-method standardization was established to determine parameters such as reading wavelength (765nm), reaction time (30min), and the reference substance (pyrogallol). In the validation step, the adapted method responded linearly to the analyte (R2 = 0.9910), ensuring its selectivity (linearity and selectivity curves statistically parallel) and accuracy (99.18-101.43%). Furthermore, the method proved to be precise (RSD ≤ 2.63%) at the two levels assessed (repeatability and intermediate precision) and robust (RSD ≤ 4.45%) concerning variation on the Na2CO3 concentration and the reaction time. The limits of detection and quantification were also calculated (9.9µg/mL and 33.1µg/mL, respectively). An additional step for tannins quantification based on its reported selective precipitation by complexing agents was also evaluated; however, unspecific precipitation was observed, reducing the results' accuracy. Our work successfully adapted and validated a method for total phenolics quantification of açaí seed extract, resulting in 38g of pyrogallol equivalent/100g of extract.

АНАЛИЗ ОБЪЕМА СБРОСА ЗАГРЯЗНЕННЫХ СТОЧНЫХ ВОД ПО БАССЕЙНАМ РЕК И МОРЕЙ РФ

The study was conducted on the basis of official data of the State Statistics Service of the Russian Federation for 1993 - 2020. A number of dynamics of the volume of discharge of polluted wastewater in the basins of individual rivers and seas of the Russian Federation are analyzed. Integral and selective distribution curves are constructed. To build a prediction model, a factor field was constructed, and the quality of the re-sulting model was checked according to individual criteria. A regression equation was compiled, which was used to make a short-term forecast for 2021-2022. A set of measures necessary to reduce the indicator on the volume of discharge of contaminated wastewater is indicated.

Gillnet selectivity for swimming crab Portunus trituberculatus in the East China Sea

To explore the gillnet selectivity for swimming crab Portunus trituberculatus, six mesh sizes (100, 110, 120, 130, 140 and 150 mm) were tested to determine the optimal mesh size for swimming crab. The experiments were conducted in the traditional area for fishing crab in the East China Sea from 25 to 29 July 2018. Four kinds of selectivity curves were used for fitting, and the maximum likelihood method was used to estimate the model parameters. In this experiment, 436 swimming crabs were caught with six different mesh sizes. The carapace length range was 46.2–83.7 mm, and all crabs were caught by entanglement (i.e. body or limb). When the mesh size was larger than 100 mm, the proportion of juvenile crab (carapace length < 60 mm) was less than 20% of the total catch. A linear relationship was observed between the carapace width and height and the carapace length of the crab. Gillnet selectivity for swimming crab was well described by the normal model based on the smallest Akaike information criterion value. The optimal lengths calculated by the normal model were 49.8, 54.8, 59.8, 64.8, 69.8 and 74.8 mm for the six mesh sizes, respectively.

Hook selectivity and catch efficiency in two sport fishing sectors in the Strait of Istanbul, Turkey: Classic handline fishing and Light Rock Fishing (LRF)

In this study, the efficiency of two fishing methods (a) traditional handline commonly used in the Strait of Istanbul and (b) light rock fishing (LRF), which is beginning to spread in recent years, were investigated by monthly sampling between September 2014 and September 2015. One classic handline fishing tackle and one LRF fishing tackle were used in the test fishing exercise. In addition, the effects of the hook sizes (numbers 6, 8 and 10) used in the handline fishery on the size selectivity for horse mackerels were also studied. Catches using both types of fishing gear were mainly composed of Trachurus mediterraneus (89.60%), Scorpeana porcus (5.12%), Sardina pilchardus (1.98%), Atherina boyeri (0.99%), Liza aurata (0.66%), Scorpaena scrofa (0.50%), Pomatomus saltatrix (0.33%), Sprattus sprattus (0.33%) and a few other species. The frequency distributions of horse mackerel caught using handlines and LRF were slightly different and ranged between 6.1–19.0 cm and 9.0–16.0 cm, respectively. Of all the handlines, LRF yielded the highest catch per unit effort (CPUE), 1.295 kg/10 hooks/hour. The log normal model selectivity curve gave the best fit for the T. mediterraneus by using the SELECT method. The modal lengths of horse mackerel caught by handline hook sizes no.10 and no. 8 hook were calculated as 13.4 cm and 17.7 cm, respectively. In addition, the spread values were determined with 3.58 and 4.74, respectively.

Selective One-Dimensional 13C-13C Spin-Diffusion Solid-State Nuclear Magnetic Resonance Methods to Probe Spatial Arrangements in Biopolymers Including Plant Cell Walls, Peptides, and Spider Silk.

Two-dimensional (2D) and 3D through-space 13C-13C homonuclear spin-diffusion techniques are powerful solid-state nuclear magnetic resonance (NMR) tools for extracting structural information from 13C-enriched biomolecules, but necessarily long acquisition times restrict their applications. In this work, we explore the broad utility and underutilized power of a chemical shift-selective one-dimensional (1D) version of a 2D 13C-13C spin-diffusion solid-state NMR technique. The method, which is called 1D dipolar-assisted rotational resonance (DARR) difference, is applied to a variety of biomaterials including lignocellulosic plant cell walls, microcrystalline peptide fMLF, and black widow dragline spider silk. 1D 13C-13C spin-diffusion methods described here apply in select cases in which the 1D 13C solid-state NMR spectrum displays chemical shift-resolved moieties. This is analogous to the selective 1D nuclear Overhauser effect spectroscopy (NOESY) experiment utilized in liquid-state NMR as a faster (1D instead of 2D) and often less ambiguous (direct sampling of the time domain data, coupled with increased signal averaging) alternative to 2D NOESY. Selective 1D 13C-13C spin-diffusion methods are more time-efficient than their 2D counterparts such as proton-driven spin diffusion (PDSD) and dipolar-assisted rotational resonance. The additional time gained enables measurements of 13C-13C spin-diffusion buildup curves and extraction of spin-diffusion time constants TSD, yielding detailed structural information. Specifically, selective 1D DARR difference buildup curves applied to 13C-enriched hybrid poplar woody stems confirm strong spatial interaction between lignin and acetylated xylan polymers within poplar plant secondary cell walls, and an interpolymer distance of ∼0.45-0.5 nm was estimated. Additionally, Tyr/Gly long-range correlations were observed on isotopically enriched black widow spider dragline silks.

Assessing the Relative Selectivity of Multiple Sampling Gears for Managed Reef Fishes in the Eastern Gulf of Mexico

AbstractFishery‐independent data are important for the effective management of reef fishes in the eastern Gulf of Mexico. Proper characterization of selectivity, or the effectiveness of each type of sampling gear in capturing a species or a size‐class, is essential to ensure that assessment models treat various sources of data appropriately. In this study, we analyzed fishery‐independent data that was collected using stereo‐baited remote underwater video (S‐BRUV) arrays, chevron traps (TRAP), and two types of hooked gear (repetitive timed‐drop [RTD] and vertical longline [VLL]) to assess gear‐related differences of species composition and size selectivity of managed reef fishes in the eastern Gulf of Mexico. Significant differences were detected in the assemblage structures of reef fishes in relation to region, gear type, and depth. Overall, eight managed species were identified as contributing to the top 70% of the assemblage structure for each gear type. Stereo‐baited remote underwater video had the highest abundances for most of the species and the highest number of species captured, while VLL had the lowest. Two economically and ecologically important species (Red GrouperEpinephelus morioand Red SnapperLutjanus campechanus) were common to all four gear types, and the size selectivity of these two species generally overlapped. However, significant differences among gear types were detected. Unimodal selection curves for hooked gears indicated that size of Red Snapper and Red Grouper increased as hook size increased. These data provide insight on species and size selectivity of multiple gears, which will contribute to future survey design and aid in the management of reef‐fish populations.

Non-Gaussian Copula Simulation for Estimation of Recoverable Reserve in an Indian Copper Deposit

The present study developed a geostatistical simulation technique based on non-Gaussian copula for recoverable reserve estimation considering support effect of a well-known open-pit mine of a copper deposit in India. The focus was to examine the efficacy of copula-based simulation model in recoverable reserve estimation. It was assessed by comparing three selectivity curves like grade–ore tonnage, grade–metal tonnage and ore–metal tonnage of reserve constructed using the copula-based simulation, disjunctive kriging and multi-Gaussian kriging with respect to the production data of blasting. The results informed that the copula-based simulation technique provided better accuracy than the nonlinear geostatistical techniques of disjunctive kriging and multi-Gaussian kriging. The root mean square error and standard error analysis indicated that the copula-based simulation model provided more accurate estimates compared with disjunctive kriging and multi-Gaussian kriging. All the three techniques yielded biased estimates, but the least bias was attributed to the copula-based simulation technique.

SELETIVIDADE DA REDE DE ESPERA UTILIZADA NA CAPTURA DA SARDINHA-BANDEIRA, Opisthonema oglinum (LESUEUR, 1818)

O presente trabalho teve como objetivo determinar a seletividade das redes de espera utilizadas na captura da sardinha-bandeira, Opisthonema oglinum, na Praia da Caponga, município de Cascavel, Ceará, Brasil. Os dados de comprimento total (em cm) foram obtidos de dois grupos, cada um com 780 indivíduos, capturados por redes de espera com malhas de 5 cm e 6 cm entre nós opostos, no período de agosto a outubro de 2014. Esses dados foram descritos em histogramas de frequência de comprimento, sendo mais representativasas classes de 21,6 cm (24,23%) para a malha de 5 cm e de 25,7 cm (23,08%) para a de 6 cm. O comprimento médio de seleção foi de 23,7 cm para a malha de 5 cm e de 28,5 cm para a de 6 cm. A amplitude de seleção foi de 23,7 ± 7,9 cm e de 28,5 ± 7,9 cm para as malhas de 5 cm e 6 cm, respectivamente. As equações das curvas de seleção das redes de espera para os dois tamanhos de malha foram obtidas, e a probabilidade de capturar indivíduos com comprimento inferior ao mínimo, estabelecido pela Instrução Normativa no 53,de 22/11/2005, em 15 cm, foi muito baixa e correspondeu a 1,32% e 0,03% para as malhas de 5 cm e de 6 cm, respectivamente.

Improving the size-selectivity of trammel net for Pomadasys stridens and Gerres oyena in Suez Bay, the Gulf of Suez, Red Sea

Size selectivity of the trammel net for Pomadasys stridens and Gerres oyena in Suez Bay, Gulf of Suez, Red sea, was estimated by comparing three mesh sizes 34, 37 and 40 mm for the inner layer of the trammel net. The SELECT model was used to estimate the selectivity curve. Length frequency data were fitted by five models: normal scale, gamma distribution model, normal location, lognormal distributions model, and bi-normal model. The results revealed that the best fit model of selectivity curve of the trammel nets data for Gerres oyena was obtained by the and bi-normal model, whilst the Log-normal model gave the best fit for Pomadasys stridens. The length-weight relationship equations were estimated to be W = 0.027 × L2.735 with r2 = 0.97 for Pomadasys stridens and W = 0.050 × L2.470, r2 = 0.93 for Gerres oyena. The study concluded that the mesh size of the trammel nets used in Suez Bay fishery should not be less than 40 mm especially for Pomadasys stridens and Gerres oyena to protect their stocks from overfishing.

Estimating mortality for the assessment of a small-scale fishery: Lane snapper (Lutjanus synagris) in Honduras

Gillnets are very common in small-scale fisheries. However, data obtained using gillnets are biased because of their size selectivity, making accurate estimation of mortality difficult. This study applied various methods to estimate total, natural, and fishing mortality, using data for Lane Snapper (Lutjanus synagris) collected in Tela, Honduras. Total mortality was estimated using a catch-curve analysis with and without accounting for size-selectivity using fitted selectivity curves, the Chapman and Robson method, and Heincke’s method. Gillnet selectivity of Lane Snapper was best characterized by a skewed normal selectivity curve. The catch-curve method in the absence of correction for gear selectivity produced greater total mortality estimates than the Chapman and Robson and Heincke’s methods, with substantial variation among the three methods. Natural mortality estimates were consistent among five methods: Lorenzen, Peterson and Wroblewski, Sekharan, “FishLife” R package and Pauly’s method. Consequently, variation among fishing mortality estimates was primarily the result of variation in estimates of total mortality. Our results suggest that accounting for gear selectivity is critically important when assessing and managing small-scale fisheries.

Biomarkers for the Discrimination of Acute Kawasaki Disease From Infections in Childhood.

Background: Kawasaki disease (KD) is a vasculitis of early childhood mimicking several infectious diseases. Differentiation between KD and infectious diseases is essential as KD's most important complication—the development of coronary artery aneurysms (CAA)—can be largely avoided by timely treatment with intravenous immunoglobulins (IVIG). Currently, KD diagnosis is only based on clinical criteria. The aim of this study was to evaluate whether routine C-reactive protein (CRP) and additional inflammatory parameters myeloid-related protein 8/14 (MRP8/14 or S100A8/9) and human neutrophil-derived elastase (HNE) could distinguish KD from infectious diseases.Methods and Results: The cross-sectional study included KD patients and children with proven infections as well as febrile controls. Patients were recruited between July 2006 and December 2018 in Europe and USA. MRP8/14, CRP, and HNE were assessed for their discriminatory ability by multiple logistic regression analysis with backward selection and receiver operator characteristic (ROC) curves. In the discovery cohort, the combination of MRP8/14+CRP discriminated KD patients (n = 48) from patients with infection (n = 105), with area under the ROC curve (AUC) of 0.88. The HNE values did not improve discrimination. The first validation cohort confirmed the predictive value of MRP8/14+CRP to discriminate acute KD patients (n = 26) from those with infections (n = 150), with an AUC of 0.78. The second validation cohort of acute KD patients (n = 25) and febrile controls (n = 50) showed an AUC of 0.72, which improved to 0.84 when HNE was included.Conclusion: When used in combination, the plasma markers MRP8/14, CRP, and HNE may assist in the discrimination of KD from both proven and suspected infection.

New technology to improve the recovery of fine particles in froth flotation based on using hydrophobized glass bubbles

A new technology has been developed to improve the selective recovery of fine particles in the froth flotation process. The technology is based on using hydrophobized glass bubbles (HGB) as a carrier material for hydrophobic fine particles, which promotes selective particle agglomeration. A proof of concept was carried out using fine graphite particles (13 µm) in order to validate the technology. The results showed that HGB can collect fine, hydrophobic particles, forming particle aggregates of larger size. Batch flotation kinetics tests were also conducted to quantify the effect of using HGB in the flotation metallurgical performance of a finely ground copper ore (d80 = 12 µm). The results indicated that HGB addition increased the flotation kinetics rate constant by 1.4 times and the maximum attainable recovery from 64% up to 90% (considering a first-order kinetics model). The grade-recovery and selectivity curves are shifted positively using HGB. In conclusion, the use of HGB technology in the froth flotation process presents a significantly improved metallurgical performance and process selectivity, becoming an alternative to face the challenge of recovering fine particles.