Wide Variation In Composition Research Articles

Diversity of human salivary heparan sulfate.

The human oral cavity and upper airway serves as an early barrier and reservoir in the transmission of SARS-CoV-2. Saliva in this microenvironment may serve as a key host factor that can modulate susceptibility to infection and eventual infection of the lower respiratory tract. We sought to analyze the content and composition of heparan sulfate, a glycosaminoglycan identified as an important co-receptor for viral entry, and whether there is any correlation with SARS-CoV-2 infection. We enlisted 98 participants stratified by age, gender, race, and COVID-19 history. Notably, the concentration of heparan sulfate in saliva increased with age, and its composition showed a wide range of variability within each age group independently of age. Heparan sulfate concentration and composition did not differ significantly with gender, ethnicity or race. Compared to patients with no COVID-19 history, patients with previous infection had a similar salivary heparan sulfate concentration, but significant increases in overall sulfation were noted. Moreover, in a subset of participants, for which data was available pre- and post- infection, significant elevation in N-sulfoglucosamine in heparan sulfate was observed post- COVID-19. Examination of salivary bacterial 16S rRNA, showed a significant reduction in species predicted to possess heparan sulfate-modifying capacity among participants >60years old, which correlates with the increase in heparan sulfate content in older individuals. These findings demonstrate a surprisingly wide variation in heparan sulfate content and composition in saliva across the sampled population and confirm other findings showing variation in content and composition of glycosaminoglycans in blood and urine.

INFLAMMATORY RESPONSES TO POLYMICROBIAL INTRA-ABDOMINAL SEPSIS ARE HIGHLY VARIABLE BUT STRONGLY CORRELATED TO ENTEROBACTERIACEAE OUTGROWTH.

Sepsis is a common, heterogeneous, and frequently lethal condition of organ dysfunction and immune dysregulation due to infection. The causes of its heterogeneity, including the contribution of the pathogen, remain unknown. Using cecal slurry, a widely used murine model of intraperitoneal polymicrobial sepsis, as well as 16S ribosomal RNA sequencing and measurement of immune markers, we performed a series of translational analyses to determine whether microbial variation in cecal slurry composition (representing intra-abdominal pathogens) mediated variation in septic response. We found wide variation in cecal slurry community composition that changed markedly over the 24-h course of infection. This variation in cecal slurry bacteria led to large variation in physiologic and inflammatory responses. Severity of inflammatory response was positively correlated with intraperitoneal enrichment with Enterobacteriaceae. Likewise, in a human cohort of patients with intra-abdominal abscesses, Enterobacteriaceae was also associated with increased inflammatory markers. Taken together, these data demonstrate that intra-abdominal Enterobacteriaceae drives inflammation in sepsis both in animal models and human subjects. More broadly, our results demonstrate that pathogen identity is a major driver of the host response in polymicrobial sepsis and should not be overlooked as a major source of phenotypic heterogeneity.

The Essential Oil Compositions of Ambrosia acanthicarpa Hook., Artemisia ludoviciana Nutt., and Gutierrezia sarothrae (Pursh) Britton & Rusby (Asteraceae) from the Owyhee Mountains of Idaho.

As part of our interest in the volatile phytoconstituents of aromatic plants of the Great Basin, we have obtained essential oils of Ambrosia acanthicarpa (three samples), Artemisia ludoviciana (12 samples), and Gutierrezia sarothrae (six samples) from the Owyhee Mountains of southwestern Idaho. Gas chromatographic analyses (GC-MS, GC-FID, and chiral GC-MS) were carried out on each essential oil sample. The essential oils of A. acanthicarpa were dominated by monoterpene hydrocarbons, including α-pinene (36.7-45.1%), myrcene (21.6-25.5%), and β-phellandrene (4.9-7.0%). Monoterpene hydrocarbons also dominated the essential oils of G. sarothrae, with β-pinene (0.5-18.4%), α-phellandrene (2.2-11.8%), limonene (1.4-25.4%), and (Z)-β-ocimene (18.8-39.4%) as major components. The essential oils of A. ludoviciana showed wide variation in composition, but the relatively abundant compounds were camphor (0.1-61.9%, average 14.1%), 1,8-cineole (0.1-50.8%, average 11.1%), (E)-nerolidol (0.0-41.0%, average 6.8%), and artemisia ketone (0.0-46.1%, average 5.1%). This is the first report on the essential oil composition of A. acanthicarpa and the first report on the enantiomeric distribution in an Ambrosia species. The essential oil compositions of A. ludoviciana and G. sarothrae showed wide variation in composition in this study and compared with previous studies, likely due to subspecies variation.

Effects of age on quality of slaughterhouse by-products in Black Bengal goat

This study was conducted with a view to investigate the yield percentage as well as nutritional composition of slaughterhouse by-products from Black Bengal goats of Bangladesh depending on different age groups. The experiment was conducted in different markets and slaughterhouses of Mymensingh district. Data and samples were collected from 50 (fifty) goats of different ages. Treatment group were executed according to the age, namely T0= 0 permanent incisor teeth (under 1 year), T1= 2 permanent incisor teeth (1 to 1.5 year), T2= 4 permanent incisor teeth (2 years), T3= 6 permanent incisor teeth (2 to 2.5 years), T4= 8 permanent incisor teeth (more than 2.5 years). Live weight, warm carcass weight, dressing percentage, percentage and nutritional composition of different slaughterhouse by-products were measured to identify the variation among the age group. The results showed a wide variation of yield percentage and nutritional composition of edible by-products for different ages of Black Bengal goats. A significant variation (P>0.01) of dressing percentage was found with the increase of age. Dressing percentage was 45.87 ± 3.23 in T0 group and 55.94 ± 2.08 in T4 group. Live weight and warm carcass weight were also increased significantly with the increase of age. No significant variation was found in the weight and percentage of different inedible by-products like skin, eye, teeth and hoof as well as edible by-products like liver, brain, kidney, lungs, heart, tongue, intestine with the increase of age. Higher percentage of dry matter and ether extract was found in the liver and heart. Crude protein was almost similar for liver, heart, kidney, lung but pH level was high at kidney. Findings of this investigation of basic properties of edible and inedible by-products of Black Bengal goat will be helpful in livestock researches. Bangladesh Journal of Animal Science 52 (3): 61-68.

Native Gold and Unique Gold–Brannerite Nuggets from the Placer of the Kamenny Stream, Ozerninsky Ore Cluster (Western Transbakalia, Russia) and Possible Sources

We carried out a comprehensive study of native gold (morphology, composition, intergrowths, and microinclusions) from alluvial deposits of the Kamenny stream (Ozerninsky ore cluster, Western Transbaikalia, Russia). The study showed that there were four types of native gold, which differed significantly in their characteristics and probably had different primary sources from which placers were formed: gold–quartz, oxidized gold–sulfide, gold–silver, and zones of listvenites with copper–gold and gold–brannerite (Elkon-type). Particular attention was paid to the study of unique, both in size and in composition, gold–brannerite nuggets of the Kamenny stream. It was established that the gold in the gold–brannerite nuggets (GBNs) had wide variations in chemical composition and mineral features. According to them, there were five different fineness types of native gold: 750–800‰; 850–880‰; 880–920‰; 930–960‰; and 980–1000‰. The data obtained indicated a multistage, possibly polygenic, and probably polychronous formation of GBN gold–uranium mineralization. The first stage was the formation of early quartz–nasturanium–gold–W–rutile–magnetite association (Middle–Late Paleozoic age). The second was the crystallization of brannerite and the replacement of an earlier pitchblende with brannerite (Late Triassic (T3)–Early Jurassic (J1) age). The third was the formation of the hematite–barite–rutile–gold association as a result of deformation–hydrothermal processes, which was associated with the appearance of zones of alteration in brannerite in contact with native gold with 8–15 wt.% Ag. The fourth was hypergene or the low-temperature hydrothermal alteration of minerals of early stages with the development of iron hydroxides (goethite) with impurities of manganese, tellurium, arsenic, phosphorus, and other elements. The carbon isotopic composition of an organic substance indicates the involvement of a biogenic carbon source. In the OOC area, there were signs that the composition of the GBNs and the quartz–chlorite–K–feldspar-containing rocks corresponded to Elkon-type deposits.

Machine learning prediction of corrosion rate of steel in carbonated cementitious mortars

Corrosion rate (i.e., corrosion current density), a crucial kinetic parameter for predicting and modeling service-life performance of reinforced concrete structures, can be estimated using empirical and physics-based models. However, existing corrosion rate predictive models have limited applicability and lowered accuracy to complex scenarios when the material composition and corrosion conditions are substantially varied. In this work, machine learning approach is explored to predict the corrosion rate of steel based on a comprehensive experimental dataset. To consider the wide variation of binder composition and corrosion environment in marine concrete, the experiment involves a broad range of mixture design parameters and relative humidity levels. The result shows that electrical resistivity is the most relevant factor to corrosion rate, and its relationship with corrosion rate is highly dependent on the chloride-to-hydroxide concentration ratio ([Cl−]/[OH−]). Of the various machine learning algorithms tested, support vector regression demonstrates the highest predictability for corrosion rate. Using the feature selection method, electrical resistivity, pore solution composition ([Cl−]/[OH−]), cement proportion, and corrosion potential are identified as the major related features for corrosion rate prediction of steel in carbonated cementitious mortars. The results demonstrate that machine learning is a promising tool for predicting the corrosion rate of steel embedded in cementitious mortars.

Optimization of Spark Plasma Sintering Technology by Taguchi Method in the Production of a Wide Range of Materials: Review.

This paper reviews the production of sinters using the spark plasma sintering method. SPS (spark plasma sintering) technology has been used for several decades, mainly in laboratories, to consolidate a huge number of both new and traditional materials. However, it is now more often introduced into practical industrial use, with equipment as early as the fifth generation capable of producing larger-size components at competitive costs. Although the mechanism of sintering with the use of this method is not yet understood, the effectiveness of the SPS process for the rapid and efficient consolidation of a wide range of materials with novel micro-structures remains indisputable. With a relatively wide variation in chemical composition, the structure allows the selection of appropriate consolidation parameters for these materials. The influence on the values of apparent density and mechanical properties depends on the parameters of the spark plasma sintering process. In order to achieve a density close to the theoretical density of sinters, optimization of the sintering parameters, i.e., sintering temperature, heating rate, sintering time, pressing pressure and protective atmosphere, should be carried out. In this paper, the optimization of spark plasma sintering of Si3N4-Al2O3-ZrO2 composite was carried out using the Taguchi method. The effects of four sintering factors, namely heating rate, sintering time, sintering temperature and sintering pressure, on the final density were investigated. Optimal sintering conditions were proposed and a confirmation experiment was conducted. The optimal combination of sintering conditions for spark plasma sintering (SPS) of Si3N4-Al2O3-ZrO2 composite for high apparent density was determined as A3-B3-C3-D2. Based on ANOVA analysis, it was found that the apparent density of sintering was significantly influenced by sintering temperature, followed by pressing pressure, sintering time and heating rate. Validation of the developed mathematical model predicting the apparent density of sinters showed close agreement between the predicted response results and experimental results.

A 13-year experience with biologic and biosynthetic absorbable mesh reinforced laparoscopic paraesophageal hernia repair.

Mesh reinforced cruroplasty during laparoscopic paraesophageal hernia repair remains controversial due to wide variation in surgical technique and mesh composition. This study aims to review outcomes and rates of recurrence following laparoscopic paraesophageal hernia repair (LPEHR) with mesh reinforced cruroplasty utilizing absorbable mesh at a single institution. A retrospective review of all patients who underwent LPEHR with mesh was performed. Medical records were reviewed for patient reported, radiographic or endoscopic evidence of recurrence, defined as > 2cm of vertical intrathoracic stomach. If no studies were available for review, patients were considered to have no recurrence. Outcomes and mesh-related complications were also reviewed. Between 10/2008 and 9/2021, 473 patients underwent LPEHR with absorbable mesh; 1.3% type 2 hernias, 86.0% type 3 hernias, 12.7% type 4 hernias. Three types of mesh were used: initially biologic mesh (n = 83), then heavyweight synthetic bioabsorbable mesh (n = 261), and finally lightweight synthetic bioabsorbable mesh (n = 111). There were no significant differences in age, ASA, BMI, gender, smoking status, chronic steroid use, preoperative acid suppression, hernia type, or recurrent hernia between groups. There were no significant differences in 30-day postoperative outcomes. Reflux Symptom Index, GERD-HRQL, and Dysphagia Scores at 1- and 2-year postoperative timepoints were not significantly different. The overall recurrence rate was 16.7%, with no significant differences in recurrence rates between biologic, heavyweight or lightweight biosynthetic absorbable mesh through 2 years after surgery. A shorter median time to recurrence (10months, p = 0.016) was seen in the lightweight group. LPEHR with absorbable mesh reinforced cruroplasty is feasible and safe, with equivalent patient-reported outcomes, including dysphagia, up to 2-years postop regardless of mesh choice. No significant differences in recurrence rates between biologic, heavyweight, or lightweight synthetic bioabsorbable mesh were seen up to 2 years after LPEHR.

Evaporation dominates the loss of plateau lake in Southwest China using water isotope balance assessment

The water balance budget in remote plateau lakes provides a fundamental information on the local climate-hydrological pattern. However, integrated investigation on the waters entering the lake, especially groundwater, was limited. To assess the current climate stress on Yunnan-Guizhou Plateau lakes, we collected rivers, groundwater, lake, and precipitation with varying isotopic compositions in the Chenghai Lake basin over four separate campaigns during a hydrological year. The wide and enriched variation of isotope composition in rivers, groundwater, and lake indicate that they have undergone distinct evaporations, which further reveal the recharging and mixing processes. Based on the similar isotopic signals between rivers and precipitation, rivers can serve as proxies for precipitation. Groundwater was primarily replenished by high mountain precipitation duo to the stable isotopic values in aquifers. Even through mass water in lake was able to smooth out some variability, the considerable isotopic variation of lake during the four collections suggested the influence of meteorological conditions. According to the assessment of isotope balance model, lake evaporation accounts for almost 65 % of the total inflow for one year, which partially explains the climate stress on the lake level. As the most sensitive variables, changes in relative humidity (h) and isotope composition of atmospheric moisture (δA) resulted in remarkable variations in E/I ratios and the constructed water isotope framework. These results shed light on the capacity of evaporation relative to lake input and provide interpretations on local paleoclimate and predicted-climate construction.

Chemical Characterization of Three Artemisia tridentata Essential Oils and Multivariate Analyses: A Preliminary Investigation

Background/Objective: Big sagebrush ( Artemisia tridentata Nutt., Asteraceae) is a conspicuous shrub growing in arid and semi-arid regions of intermountain western North America, from eastern Washington and Oregon, through Nevada, Idaho, and Utah, into northern Arizona and New Mexico, and east as far as the western Dakotas, and Colorado. At least three subspecies of A. tridentata have been recognized, including A. tridentata subsp. tridentata Nutt. (basin big sagebrush), A. tridentata subsp. wyomingensis Beetle & A.L.Young (Wyoming big sagebrush), and A. tridentata subsp. vaseyana (Rydb.) Beetle (mountain big sagebrush). Although big sagebrush is an important food source and cover for several animal species, the volatile phytochemistry has shown wide variation in composition. The purpose of this work was to compare and contrast the essential oil compositions of the three subspecies of A. tridentata growing in southwestern Idaho. Methods/Results: Several samples of A. tridentata subsp. wyomingensis and A. tridentata subsp. vaseyana were collected, the essential oils obtained by hydrodistillation using a Likens-Nickerson apparatus in yields of 2.33%-4.45% and 0.90%-1.73%, respectively, and the essential oils analyzed by gas chromatographic techniques. Although A. tridentata shows wide variation in essential oil compositions, multivariate analysis (hierarchical cluster analysis and principal component analysis) indicated A. tridentata subsp. tridentata to be characterized by high concentrations of yomogi alcohol (5.8%-30.8%) and camphor (5.2%-20.1%), while camphor was the defining component in A. tridentata subsp. wyomingensis (10.0%-30.1%) and subsp. vaseyana (16.1%-40.2%). One sample of A. tridentata subsp. vaseyana was dominated by α-thujone (76.1%), however. Conclusion: There is much variation in essential oil compositions of A. tridentata, both within subspecies and between geographical locations; much additional investigation is necessary to more fully characterize the volatile phytochemistry of this plant.

Understanding the Role of Urology Practice Organization and Racial Composition in Prostate Cancer Treatment Disparities.

Black men have a higher risk of prostate cancer diagnosis and mortality but are less likely to receive definitive treatment. The impact of structural aspects on treatment is unknown but may lead to actionable insights to mitigate disparities. We sought to examine the associations between urology practice organization and racial composition and treatment patterns for Medicare beneficiaries with incident prostate cancer. Using a 20% sample of national Medicare data, we identified beneficiaries diagnosed with prostate cancer between January 2010 and December 2015 and followed them through 2016. We linked urologists to their practices with tax identification numbers. We then linked patients to practices on the basis of their primary urologist. We grouped practices into quartiles on the basis of their proportion of Black patients. We used multilevel mixed-effects models to identify treatment associations. We identified 54,443 patients with incident prostate cancer associated with 4,194 practices. Most patients were White (87%), and 9% were Black. We found wide variation in racial practice composition and practice segregation. Patients in practices with the highest proportion of Black patients had the lowest socioeconomic status (43.1%), highest comorbidity (9.9% with comorbidity score ≥ 3), and earlier age at prostate cancer diagnosis (33.5% age 66-69 years; P < .01). Black patients had lower odds of definitive therapy (adjusted odds ratio, 0.87; 95% CI, 0.81 to 0.93) and underwent less treatment than White patients in every practice context. Black patients in practices with higher proportions of Black patients had higher treatment rates than Black patients in practices with lower proportions. Black patients had lower predicted probability of treatment (66%) than White patients (69%; P < .05). Despite Medicare coverage, we found less definitive treatment among Black beneficiaries consistent with ongoing prostate cancer treatment disparities. Our findings are reflective of the adverse effects of practice segregation and structural racism, highlighting the need for multilevel interventions.

Lateral variations in the Hosen 8‐2 vein in the Hishikari deposit, Japan: Implications for high Au‐grade zone

AbstractLateral sampling of each blasting interval (~ 2.6 m) along a 79 m strike length was conducted for the Hosen 8‐2 vein on the −5 ML (mining level, meters relative to sea level) of the Main ore zone in the Hishikari epithermal Au deposit, Kagoshima, Japan. The horizontal variation of mineral textures, bulk chemical compositions, and fluid inclusion temperatures and apparent salinity of ore fluids were determined. The major gangue minerals of the quartz veins studied include quartz and adularia with minor amounts of calcite and smectite. The major ore minerals include electrum, galena, and sphalerite with minor pyrite, petzite, and hessite. Electrum commonly occurs in a discrete band with microcrystalline quartz, granular adularia, and smectite. The electrum‐bearing band is followed by tabular adularia, and finally by granular or comb quartz. Mineral textures that indicate high degrees of supersaturation with respect to amorphous silica (presently quartz with microcrystalline/mosaic and feathery textures) and adularia (with tabular, rhombic, and granular textures) were common throughout the vein strike. Bulk chemical analyses indicate that Au grade is positively correlated with Ag, Bi, Pb, and Te contents. A bonanza zone with Au grades up to 10,800 ppm occurs in the central part of the Hosen 8‐2 vein on the −5 ML, and is associated with high adularia content, calculated as adularia / (quartz + adularia). The wide lateral variation in the geochemical composition contrasts with the consistent association of electrum with microcrystalline quartz, granular adularia, and smectite throughout the Hosen 8‐2 vein on the −5 ML. Fluid inclusion microthermometry of primary and pseudosecondary inclusions in quartz and adularia yielded histogram modes of homogenization temperature between 160 and 240°C; the most frequent mode is 200–210°C, with most data within ±10°C from this value. The maximum ice‐melting temperature of most samples excluding late comb quartz is −1.5°C, which is equivalent to an apparent salinity of 2.6 wt% NaCl eq. The wide variation in ice‐melting temperatures and apparent salinities (up to 5.2 wt% NaCl eq.) may be due to dissolved CO2 in the fluids, while the sharp decrease in apparent salinity with temperature decrease indicates CO2 loss due to fluid boiling during vein formation. The intimate association of electrum with microcrystalline quartz that recrystallized from amorphous silica indicate sharp boiling and vapor loss as the primary mechanism of Au deposition in the Hosen 8‐2 vein.

The state of gold in phases of the Cu-Fe-S system: In situ X-ray absorption spectroscopy study

Chalcopyrite and bornite are the main Au-bearing minerals at Cu porphyry deposits, volcanogenic massive sulfide (VMS) deposits, Cu-Ni deposits of the mafic magmatic complexes, and ores of submarine sulfide edifices. Bornite and intermediate solid solutions with wide compositional variations (bnss and iss – high-temperature chalcopyrite, correspondingly), which can scavenge economic concentrations of Au, appear in the Cu-Fe-S system at ore-forming conditions. However, the state of Au in bnss and iss is yet unknown. To solve this conundrum, we synthesized samples with net chemical composition of bnss and iss, studied them by in situ X–ray absorption spectroscopy (XAS), and used the experimental data to explain the Au distribution among natural ore-forming minerals. The sulfide samples were obtained at 495–700 °C in Au-saturated system by means of salt flux method. The bnss contained ∼1.2–1.6 log units more Au than iss: up to 18 wt.% Au in bnss vs 0.4 wt.% Au in iss at 700 °C. An increase of temperature resulted in the sharp increase of Au concentration in both phases, ∼1 log unit per 100 °C at f(S2) close to S(l) saturation. Analysis of Au L3-edge spectra recorded at 25–675 °C revealed that at 25 °C Au exists mainly in the metallic state. At t > 500 °C the spectral features of Au° disappear, and “chemically bound” Au predominates. The Au form of occurrence in the iss field is interpreted as Au-bearing clusters with a stromeyerite-like (CuAgS) structure. Digenite Cu2–xS and bnss contain Au in a mixture of stromeyerite-like and petrovskaite-like (Au0.8Ag1.2S) clusters. The chemical composition of both forms is close to CuAuS, where the nearest Au neighbors are two S atoms at RAu-S = 2.34–2.36 Å. Results of the present study allow to determine the state of Au and its concentration in the main Cu-bearing minerals of sulfide ores as a function of the T-f(S2)-compositional parameters. Due to the sharp increase of the CuAuS clusters stability with increasing temperature, in high-temperature ores formed at t > 350 °C Au enriches Cu-bearing minerals in comparison with Cu-free or Cu-deficient ones. As a result, in these ores native gold, being a product of decomposition of the Au-bearing clusters, is associated with Cu-rich minerals – chalcopyrite, bornite, digenite, chalcocite.

Effect of source heterogeneity, melt extraction and crystal separation on the composition of a suite of ferroan (A-type) granites from parts of the Chotanagpur Granite Gneissic Complex (CGGC), India

Ferroan granitoids constitute a considerable proportion of the upper continental crust formed during the Proterozoic eon and their origin is usually linked to high-temperature processes (fractionation or anatexis) occurring at shallow crustal depths. However, the relative role of mantle melts vs. crustal rocks as the source of these granitoids has been largely debated. In the Chotanagpur Granite Gneissic Complex (CGGC), located in the East Indian shield, a suite of Mesoproterozoic (ca. 1450–1350 Ma) ferroan granites has intruded the Paleoproterozoic (ca. 1700–1630 Ma) arc granites and currently occurs either as migmatitic gneisses or as biotite gneisses in different parts of the terrane . Previous studies postulated that these Mesoproterozoic extensional granites were sourced from older crustal rocks with limited mantle input. In the current study, the geochemistry of the biotite gneisses is combined with that of the migmatitic gneisses and coeval ferroan granites from northern and western parts of the CGGC to comprehend the wide spatial and compositional variation observed. With the help of phase equilibrium modelling, the current study quantifies the role of the heterogeneity of the crustal source and path-dependent melting in shaping the composition of the ferroan granites. The study demonstrates that the composition of the modelled melt derived from the older (late Paleoproterozoic) granites under low-pressure high-temperature conditions (750-1000 °C; 4–8 kbar) closely resembles the compositions observed in the younger (Mesoproterozoic) ferroan granites. Compositional variation of the melt is further accentuated by high-temperature progressive melting and extraction of melt in small batches during anatexis . Phase equilibrium studies further delineate the significant role of crystal fractionation in shaping the chemical variations observed in the studied granites. • Mesoproterozoic ferroan granites of CGGC formed via anatexis of older arc granites. • Source heterogeneity produces variable composition of the granites. • Melt extraction in small batches produces chemical variation in ferroan granites. • Post-emplacement crystal separation accentuates the compositional variations.

Alkaline rocks of the Bobaomby volcanic field point to a petrogenetic link between Comoros and northern Madagascar lithosphere

The Bobaomby volcanic field (10–11 Ma) is the northernmost volcanic area of Madagascar, and is a monogenetic volcanic field comprising outcrops of lava flows, dykes, scoria cones, tuff rings and plugs, widely scattered over an area of roughly 500 km2. The volcanic rocks range in composition from nephelinite, basanite and tephrite, through tephritic phonolite, to F- and Cl-rich peralkaline phonolite (MgO from 13 to 0.01 wt%), and the serial affinity varies from sodic to potassic. A few mica-amphibole-rich lamprophyric dykes have tephritic composition and ultrapotassic affinity. The mafic lavas host intrusive xenoliths with evident cumulate features (wehrlites, composite olivine gabbros s.l., amphibole clinopyroxenites and “kaersutitites”), as well as various types of mantle-derived xenoliths and xenocrysts in the most primitive rocks. The very wide compositional variations of the observed phases (olivine, clinopyroxene, amphibole, oxides, feldspars, feldspathoids, apatite, titanite, aenigmatite and other accessories) in lavas, dykes and cognate xenoliths are fully consistent with the variable degree of differentiation of the host lavas/dykes, and pointing out to limited open-system or polybaric crystallization. The mafic lavas have marked enrichment in incompatible elements and light rare-earth element (LREE) (e.g., Lan/Ybn = 19–27), whereas concave REE patterns are found in the peralkaline phonolites, as a result of removal of accessory titanite starting from tephritic phonolite magmas. The gabbroic/ultramafic xenoliths are interpreted as crustal cumulates of basanitic and tephritic magmas. Several liquid lines of descent in the basanites and tephrites are evident from the trace-element distribution, and from the differing geochemistry of the evolved rocks. The isotopic compositions reach extreme values (e.g., 206Pb/204Pb = 20.065 in the ultrapotassic lamprophyre) when compared to the rest of the Cenozoic/Recent Madagascan volcanic rocks, but similar to those of the Comoros archipelago, suggesting analogies of mantle sources and enrichment processes in the lithosphere of this volcanic archipelago. The origin of the Bobaomby mafic rocks is compatible from a derivation from low degree partial melting of an incompatible element-enriched peridotite source (possibly located in the lowermost lithospheric mantle) rich in volatile-rich phases (pargasite, locally also phlogopite and possibly carbonates), matching the sources of other Cenozoic volcanic areas throughout Madagascar, and perhaps Comoros.

Foliage of Tropical Trees and Shrubs and Their Secondary Metabolites Modify In Vitro Ruminal Fermentation, Methane and Gas Production without a Tight Correlation with the Microbiota.

Simple SummaryRuminants produce methane, a potent greenhouse gas, as a byproduct of microbial activity during ruminal fermentation. To lessen greenhouse gases emissions, it is necessary to evaluate methane-reducing feeding alternatives for ruminants, such as the use of tropical trees and shrubs. The secondary metabolites produced by these plants have been shown to reduce ruminal methane emissions. Here, we evaluated the effect of the foliage of eleven tropical trees and shrubs edible for cattle in ruminal fermentation, methane production and microbiota in an in vitro assay. The content of condensed tannins and saponins in the foliage was variable between the species of plants. We observed a reduction in methane production and changes in microbial populations depending on the species of tree or shrub. Additionally, condensed tannins reduced methane production. The inclusion of the foliage of tropical trees and shrubs in the diet of ruminants may be a step towards diminishing greenhouses gases emissions, and therefore reducing the contribution to global warming from cattle production.Ruminants, mainly cattle, contribute to greenhouse gases (GHG) emissions as methane (CH4) is produced by ruminal fermentation. Hence, various anti-methanogenic feed strategies have been studied, including the use of plants with secondary metabolites. This study evaluated in vitro ruminal fermentation metrics, microbial composition by digital droplet PCR (ddPCR) and the CH4 production of the foliage of several tropical trees and shrubs: Leucaena leucocephala, Moringa oleifera, Albizia lebbeck, Enterolobium cyclocarpum, Piscidia piscipula, Brosimum alicastrum, Lysiloma latisiliquum, Guazuma ulmifolia, Cnidoscolus aconitifolius, Gliricidia sepium and Bursera simaruba, using Cynodon plectostachyus grass as control. The results showed a wide variation in the chemical composition of the foliage, as well as in the ruminal microbiota. The crude protein (CP) content ranged from 11 to 25%, whereas the content of condensed tannins (CT) and saponins (S) was from 0.02 to 7%, and 3.2 to 6.6%, respectively. The greatest dry matter degradability (DMD) after 72 h was 69% and the least 35%, the latter coinciding with the least gas production (GP). A negative correlation was found between the CT and CH4 production, also between protozoa and fungi with the SGMT group of archaea. We concluded that the foliage of some tropical trees and shrubs has a high nutritional value and the potential to decrease CH4 production due to its CT content.

Germplasm variability-assisted near infrared reflectance spectroscopy chemometrics to develop multi-trait robust prediction models in rice.

Rice is a major staple food across the world in which wide variations in nutrient composition are reported. Rice improvement programs need germplasm accessions with extreme values for any nutritional trait. Near infrared reflectance spectroscopy (NIRS) uses electromagnetic radiations in the NIR region to rapidly measure the biochemical composition of food and agricultural products. NIRS prediction models provide a rapid assessment tool but their applicability is limited by the sample diversity, used for developing them. NIRS spectral variability was used to select a diverse sample set of 180 accessions, and reference data were generated using association of analytical chemists and standard methods. Different spectral pre-processing (up to fourth-order derivatization), scatter corrections (SNV-DT, MSC), and regression methods (partial least square, modified partial least square, and principle component regression) were employed for each trait. Best-fit models for total protein, starch, amylose, dietary fiber, and oil content were selected based on high RSQ, RPD with low SEP(C) in external validation. All the prediction models had ratio of prediction to deviation (RPD) > 2 amongst which the best models were obtained for dietary fiber and protein with R2 = 0.945 and 0.917, SEP(C) = 0.069 and 0.329, and RPD = 3.62 and 3.46. A paired sample t-test at a 95% confidence interval was performed to ensure that the difference in predicted and laboratory values was non-significant.

Age and Petrogenesis of Ultramafic Lamprophyres of the Arbarastakh Alkaline-Carbonatite Complex, Aldan-Stanovoy Shield, South of Siberian Craton (Russia): Evidence for Ultramafic Lamprophyre-Carbonatite Link

Abstract In this study, we discuss mineral chemistry data, melt inclusion study results, and report Ar–Ar phlogopite age for the aillikite dikes of the Arbarastakh alkaline-carbonatite complex on the Aldan-Stanovoy shield, Russia. Aillikite was crystallized at 631 ± 8.5 Ma, coeval with the intrusion age of the Arbarastakh rocks. The Arbarastakh complex was formed during the late Neoproterozoic epoch of rare earth element-Nb ore-bearing alkaline-carbonatite magmatic activity that was widespread on the southwestern and southern margins of the Siberian craton, related to rifting processes during the breakup of the supercontinent Rodinia. The aillikites show mineralogical characteristics of primitive magmas such as highly forsteritic olivine, Mg-ilmenite, and Cr-rich spinel. The variance in olivine zonation, morphologies, and chemical element distribution indicate that olivine in the aillikites is represented by several genetic types: xenogenic olivines (Fe-poor cores) from the sheared peridotite, olivine antecrysts (Fe-rich cores) related to mantle metasomatism by preceding proto-aillikite melt, and olivine phenocrysts formed during crystallization of aillikite melt. The latter shows decreasing Ni and Cr due to fractional crystallization of olivine, ilmenite, and chromite, along with increasing Mn and Ca concentrations that are consistent with enrichment of these elements in the residual melt. The olivine phenocrysts chemistry shows variations that are characteristic of the presence of phlogopite and carbonate in the mantle source (low 100*Ca/Fe (0.4–1.2) and 100*Mn/Fe (1–2), moderate 100*Ni/Mg (1.4–0.4)). Spinel shows a wide compositional variation with two compositional zoning trends, one of which follows the titanomagnetite trend, while the other follows the qandilite-rich magnesio-ulvöspinel-magnetite one. The latter trend indicates an increase in fO2 and attendant Fe oxidation to Fe3+ during crystallization. Ilmenite composition evolution (from Mg-rich to Mn-rich) also reflects the carbonate-rich nature of aillikite melt. We identify primary melt inclusions hosted in phlogopite and secondary melt inclusions in olivine; both melt inclusions types have daughter minerals dominated by dolomite, calcite, Na-Ca carbonates, phosphates, and phlogopite, consistent with the carbonate-rich nature of aillikite melt. The calculated temperatures reflect the early stage of aillikite crystallization, with values ranging from 1169 to 1296°C and fO2 values (olivine-spinel pair) varying from +0.40 to +1.03 ΔFMQ and from ΔNNO −0.9 to ΔNNO −2.0 (perovskite oxygen barometer); in contrast, the homogenization temperature of the secondary melt inclusions in olivine (700–720°C) characterizes late-stage aillikite melt evolution. The carbonate-rich nature of the Arbarastakh aillikite and its similar age to the carbonatites are consistent with a genetic relationship between them.

Growth and evolution of long-lived, large volcanic clusters in the Central Andes: The Chachani Volcano Cluster, southern Peru

In the Central Andes, large (> 500 km2) and long-lived (1–5 Ma) volcanic clusters (LVCs) are less explored and their eruptive history and magmatic regimes less understood than smaller, short-lived (<0.5 Ma), individual stratocones. The Chachani-large volcanic cluster (C-LVC) sizeable volume (c. 290 km3) consists of twelve edifices forming the 1.06–0.64 Ma group of stratovolcanoes and the 0.46–0.05 Ma group of domes coulees and block-lava flow fields. Both groups overlie pre-Chachani lavas and tuffs 1.02–1.27 Ma, and together they have buried large nested craters or a caldera associated with the c. 1.62–1.66 Ma Arequipa Airport ignimbrite. The C-LVC evolved from: (i) homogeneous compositions of the pre-Chachani and Chachani basal eruptive units to (ii) relatively wide compositional variations (53–67 wt% SiO2) between mafic andesite and dacite at moderate eruptive rates (0.27–0.41 km3/ka) for the ‘Old Edifice’ group, and finally to (iii) narrower (57–64 wt% SiO2) andesitic compositions coinciding with extrusive activity at 2.5 times lower eruptive rates (0.12–0.15 km3/ka) for the ‘Young Edifice’ group. The large compositional variations in the Old Edifice group are related to strongly contrasting resident and recharge magma compositions of hybridized lavas. In contrast, the narrow compositional range and lower eruption rate during the second half of the C-LVC eruptive history represent a trend towards more homogeneous, andesitic magma composition with time. Mineral texture and compositional studies provide evidence for disequilibrium and magma mixing in the C-LVC shallow (5–20 km depth range) magma reservoirs. These temporal changes in magma composition document that the transcrustal magma systems of the C-LVC evolved and matured with time by a combination of processes: fractional crystallization, crustal contamination and magma mixing/mingling with variable rates of mafic recharge. This resulted in a shift in time to a steady state, monotonous (andesite) regime as a result of coupling between compositional parameters and thermal conditions, density constraints, and the viscosity/crystallinity of erupted magmas.

The Five-Factor Model of Indigenous Studies: A Quantitative Content Analysis of Postsecondary Indigenous Studies Websites in Canada, the United States, Australia, and New Zealand

Indigenous Studies (IS) is a multidisciplinary academic discipline chartered to offer more than just an education about Indigenous peoples. Indigenous Studies is a fought-for space on campus to properly represent the perspectives, processes, and communities of Indigenous peoples, for the benefit of Indigenous communities, organizations, and interests. Unfortunately, the extent to which IS fulfills its mission is ambiguous due to the wide variation in IS program composition, the broad scope of the discipline’s topical foci, and the lack of parameters or core ingredients that distinguish it from other disciplines. In this article, we describe the process and results of a content analysis of IS websites in the United States, Canada, Australia, and New Zealand. The goal of this study was to identify the major features of IS internationally and to show how IS programs vary in their embodiment of those major features. After an extensive coding process, we ran an exploratory factor analysis on the quantitative codings to derive a five-factor model of IS. Accordingly, IS included (1) Indigenous methodologies, (2) Indigenous community member involvement, (3) Indigenous Ways of Knowing and Doing, (4) Indigenous languages, and (5) Indigenous student community. How much these factors were emphasized depended on the country, institution type, and level of degree offered, controlling for website complexity and aesthetics. Our findings show that there is common ground across IS programs internationally, according to their websites, but that some countries (e.g., Canada), institution types (e.g., tribal colleges), and degree programs (e.g., undergraduate) reflect these factors more than others.