Length-weight relationships of fish from sandy beaches

This study estimated the length–weight relationships of 16 fish species occurring close to the shores of sandy beaches along the lower Negro River basin, Brazilian Amazon. The specimens were captured for one day each month, in October to November 2016, early in the morning and early evening, using trawl net (20 m taken for standard length (SL – 0.1 cm precision) and total weight (TW – 0.01 g precision). The parameters a and b of the equation WT = a.LTb were estimated. The a values ranged from 0.0018 to 0.0226 and b values ranged from 2.5271 to 3.3244. This study also provides new data on of maximum lengths for six species, Amazonsprattus scintilla, Brycon pesu, Moenkhausia megalops, Pachyurus paucirastrus, Reganella depressa and Trachydoras microstomus, and new reports of the LWRs parameters of 15 fish species.

Preparation of tambacu protein concentrates using different methodologies

The aim of this study was to develop methodologies to obtain fish protein concentrates from tambacu filleting residues, characterize their physical-chemical composition and evaluate their sensory profile. Concentrates were prepared by one of three methodologies: cooking of the raw material and subsequent drying (FPC1); cooking, drying, lipid removal with ethanol at 70 °C and final drying (FPC2); and three washing steps of the raw material with ethanol at 70 °C and drying (FPC3). FPC2 had a lower final yield (15.5%) and chroma a* (1.77) and chroma b* values (14.12) but higher moisture (5.22%) and protein content (80.39%) and luminosity (74.97), in addition to having the weakest fish taste compared to FPC1 and FPC3. FPC1 had the strongest odour, darkest colour, and strongest fish taste compared to FPC2 and FPC3. Ash, pH values, and water activity were not different between the concentrates. It is concluded that the methodology where lipid removal steps are carried out after cooking and drying (FPC2) is more effective for the removal of lipids and deodorization of tambacu protein concentrate.

Spray chilling on carcass weight loss, and physicochemical and microbiological quality of beef cuts during storage

ABSTRACT: Different chilling treatments are used before meat storage. The effect of spray chilling (SC) on meat quality appears to vary. Here, we investigated the effects of SC on beef carcass weight loss and meat quality during subsequent storage. The 2-h SC program tested involved 180-s initial spraying, followed by 60-s spray cycles at 540-s intervals. Deboned chuck tender (IMPS 116B) beef cuts were vacuum-packaged and stored for up to 60 d. Purge and cooking losses, Warner-Bratzler shear force, meat colour [CIE L*, a*, b*], and microbiological quality were evaluated. SC reduced carcass weight loss (P<0.001) compared with conventional chilling. However, storage time affected the purge and cooking losses, and Warner-Bratzler shear force. CIE a* and b* values increased (P<0.05) after 30-d aging in both chilling treatments. Pronounced psychrotrophic growth was observed during storage after both treatments. In conclusion, SC can be used to reduce the economic losses associated with meat chilling, without affecting meat quality attributes.

Box Counting Fractal Dimension and Frequency Size Distributon of Earthquakes in the Central Himalaya Region

To establish the relations between b-value and fractal dimension (D0) for the earthquake distribution, we study the regional variations of those parameters in the central Himalaya region. The earthquake catalog of 989 events (Mc = 4.0) from 1994.01.31 to 2020.10.28 was analyzed in the study. The study region is divided into two sub-regions (I) Region A: 27.3°N -30.3°N and 80°E -84.8°E (western Nepal and vicinity) and (II) Region B: 26.4°N -28.6°N and 84.8°E -88.4°E (eastern Nepal and vicinity). The b-value observed is within the range between 0.92 to 1.02 for region A and 0.64 to 0.74 for region B showing the homogeneous nature of the variation. The seismic a-value for those regions ranges respectively between 5.385 to 6.007 and 4.565 to 5.218. The low b-values and low seismicity noted for region B may be related with less heterogeneity and high strength in the crust. The high seismicity with average b-values obtained for region A may be related with high heterogeneity and low strength in the crust. The fractal dimension ≥1.74 for region A and ≥ 1.82 for region B indicate that the earthquakes were distributed over two-dimensional embedding space. The observed correlation between D0 and b is negative for western Nepal and positive for eastern Nepal while the correlation between D0 and a/b value is just opposite for the respective regions. The findings identify both regions as high-stress regions. The results coming from the study agree with the results of the preceding works and reveal information about the local disparity of stress and change in tectonic complexity in the central Himalaya region.

Impact of Cr3+ substitution on the nephelauxetic ratio and Racah parameter of Cr-Mn-Zn nanoferrites

For the first time, we present the ligand field splitting (10Dq) nephelauxetic ratio (β), Racah parameter (B) and stability of Cr3+ within Mn–Zn nanoferrite which synthesized using the citrate route. These parameters were determined via optical absorption spectra. The obtained bands in the significance range of optical absorption spectra are wide as well as asymmetric; therefore the deconvolution process becomes a necessary task. The values of 10Dq and B have been estimated from the produced bands. The values of 10Dq are observed to increase from 16366.61 to 16447.37 cm-1 whereas, B values are observed to decrease from 829.81 to 760.80 cm-1 with additional Cr3+ substitution. The increasing 10Dq and decreasing B values, evidence for bonds between Cr3+ ions with their environments became a further covalent (less ionic). Moreover, the values of β are observed to decrease for further Cr3+ substitution. This decrease of β produces less stability between Cr3+ and its ligand. Furthermore, Dq/B values declare that Cr3+ centers are in the low-field sites by a slight tendency towards the high-field sites with further Cr/Fe substitution process. Therefore, it was suggested that Cr3+ substituted Mn–Zn nanoferrites are excellent candidates for diverse optical applications such as a tunable laser.

Effects of episodic slow slip on seismicity and stress near a subduction-zone megathrust

Slow slip phenomena deep in subduction zones reveal cyclic processes downdip of locked megathrusts. Here we analyze seismicity within a subducting oceanic slab, spanning ~50 major deep slow slip with tremor episodes over 17 years. Changes in rate, b-values, and stress orientations of in-slab seismicity are temporally associated with the episodes. Furthermore, although stress orientations in the slab below these slow slips may rotate slightly, in-slab orientations 20–50 km updip from there rotate farther, suggesting that previously-unrecognized transient slow slip occurs on the plate interface updip. We infer that fluid pressure propagates from slab to interface, promoting episodes of slow slip, which break mineral seals, allowing the pressure to propagate tens of km further updip along the interface where it promotes transient slow slips. The proposed methodology, based primarily on in-slab seismicity, may help monitor plate boundary conditions and slow slip phenomena, which can signal the beginning stages of megathrust earthquakes.

Fluids sources in basement-hosted unconformity-uranium ore systems: tourmaline chemistry and boron isotopes from the Patterson Lake corridor deposits, Canada

The Patterson Lake corridor is a new uranium district located on the southwestern margin of the Athabasca Basin. Known resources extend almost one kilometer below the unconformity in graphite- and sulfide-bearing shear zones within highly altered metamorphic rocks. Despite different host rocks and greater depths below the unconformity, alteration assemblages (chlorite, illite, kaolinite, tourmaline and hematite), ore grades and textures are typical of unconformity-related deposits. This alteration includes at least three generations of Mg-rich tourmaline (magnesio-foitite). The boron isotopic composition of magnesio-foitite varies with generation: the earliest generation only observed in shallow samples from the Triple R deposit (Tur 1) contain the heaviest isotopic signature (δ11B ≈ +26 to +19 ‰), whereas subsequent generations (Tur 2, Tur 3) yield lighter and more homogeneous isotopic signatures (δ11B ≈ +17.5 to +19.9 ‰). These results are consistent with precipitation from low temperature, NaCl- and CaCl2-rich brine(s) derived from an isotopically heavy boron source (e.g. evaporated seawater) that interacted with tourmaline and silicates in the basement rocks and/or fluids derived from depth (with low δ11B values). The lower δ11B values in paragenetically later magnesio-foitite reflect greater contributions of basement-derived boron over time whereas minor compositional variations reflect local metal sources (e.g. Cr, V, Ti) and evolving fluid chemistry (decreasing Na and Ca, increasing Mg) over time. The δ11B and chemical variation in magnesio-foitite over time reinforce the strong interactions with basement rocks in these systems while supporting incursion of basinal brines well below the unconformity contact.Thematic collection: This article is part of the Uranium Fluid Pathways collection available at: https://www.lyellcollection.org/cc/uranium-fluid-pathwaysSupplementary material:https://doi.org/10.6084/m9.figshare.c.5727555

Differences in the Buccal Bone Marrow Distance of ≤0.8 mm in the Mandible of Patients Undergoing Sagittal Split Ramus Osteotomy among the Different Skeletal Patterns: A Retrospective Study

This study investigated the relationship between the thickness of the ramus and skeletal patterns using cone-beam computed tomography (CBCT) for sagittal split ramus osteotomy. Ninety participants were categorized into three skeletal patterns (Class I, Class II, and Class III). The first vertical slice (slice 0) was observed in the intact mandibular canal, and then moved forward to 40 mm (slice 21) with a 2 mm interval. The thickness of buccal bone marrow (B value) was measured. A B value of ≤0.8 mm was considered to be the major risk factor causing the occurrence of postoperative lower lip paresthesia. There were 461 sides with a B value of ≤0.8 mm. There was a significant difference in the skeletal patterns [Class III (198 sides: 15.7%) > Class I (159 sides: 12.6%) > Class II (104 sides: 8.3%)]. Class II participants had significantly larger B values (2.14 to 3.76 mm) and a lower occurrence rate (≤0.8 mm) than those of Class III participants (1.5 to 3 mm) in front of the mandibular foramen (from 6 mm to 20 mm). Class III participants had significantly shorter buccal bone marrow distance and a higher occurrence rate of B values (≤0.8 mm) than Class II.

Exploring the possibilities of some selected flour blends for the development of bakery products: Comparison with some physicochemical and functional properties of wheat flour

This study explored the possibilities of some selected flour blends vis-a-vis the physicochemical and functional properties of wheat flour. Ten flour blends from potato starch, cassava, maize and soybean flours and wheat flour were made and evaluated for physicochemical, functional and anti-nutritional properties. The range of proximate values were for moisture (3.76%–6.67%), protein (4.33–8.96%), ash (1.35–1.96%), fat (3.37–4.88%), fibre (1.22–1.89%) and carbohydrate (78.35–84.94%), whereas wheat flour had moisture (9.45%), protein (11.31%), ash (2.54%), fat (3.78%), fibre (1.31%) and carbohydrate (73.90%). Cyanogenic glucoside, saponion and tannin contents increased with increase substitution of cassava and soybean flours. Pasting temperatures of flour blends ranged from 69.03°C to 78.83°C, while wheat flour had 78.05°C. Peak, hot paste, breakdown, setback and cold paste viscosities were 1514–2822, 1036–1597, 487–1225, 580–884 and 1616–2461 cp in flour blends compared to 2361, 1360, 1001, 1079 and 2439 cp of wheat flour. Substitutions with soy flour decreased the peak, hot paste, breakdown and cold paste viscosities but increased the pasting temperatures. L*, a* and b* values ranged from 78.56 to 87.65, −0.34 to 0.71 and 10. 95 to 13.50 in flour blends while the wheat flour varied significantly at 2361.00, 1360.00 and 1001.00. The nutritional and pasting properties of some of flour blends were closely related to wheat flour and may be used for bakery requirements.