Controls on development and diversity of Early Archean stromatolites

The ≈3,450-million-year-old Strelley Pool Formation in Western Australia contains a reef-like assembly of laminated sedimentary accretion structures (stromatolites) that have macroscale characteristics suggestive of biological influence. However, direct microscale evidence of biology—namely, organic microbial remains or biosedimentary fabrics—has to date eluded discovery in the extensively-recrystallized rocks. Recently-identified outcrops with relatively good textural preservation record microscale evidence of primary sedimentary processes, including some that indicate probable microbial mat formation. Furthermore, we find relict fabrics and organic layers that covary with stromatolite morphology, linking morphologic diversity to changes in sedimentation, seafloor mineral precipitation, and inferred microbial mat development. Thus, the most direct and compelling signatures of life in the Strelley Pool Formation are those observed at the microscopic scale. By examining spatiotemporal changes in microscale characteristics it is possible not only to recognize the presence of probable microbial mats during stromatolite development, but also to infer aspects of the biological inputs to stromatolite morphogenesis. The persistence of an inferred biological signal through changing environmental circumstances and stromatolite types indicates that benthic microbial populations adapted to shifting environmental conditions in early oceans

Thermally induced gluten modification observed with rheology and spectroscopies

The protein vital gluten is mainly used for food while interest for non-food applications, like biodegradable materials, increases. In general, the structure and functionality of proteins is highly dependent on thermal treatments during production or modification. This study presents conformational changes and corresponding rheological effects of vital wheat gluten depending on temperature. Dry samples analyzed by X-ray photoelectron spectroscopy (XPS), Fourier-transform infrared spectroscopy (FTIR) and thermalgravimetric analysis coupled with mass spectrometry (TGA-MS) show surface compositions and conformational changes from 25 to 250 °C. Above 170 °C, XPS reveals a decreased N content at the surface while FTIR band characteristics for β-sheets prove structural changes. At 250 °C, protein denaturation accompanied by a significant mass loss due to dehydration and decarbonylation reactions is observed. Oscillatory measurements of optimally hydrated vital gluten describing network properties of the material show two structural changes along a temperature ramp from 25 to 90 °C: at 56–64 °C, the temperature necessary to trigger structural changes increases with the ratio of gliadin to total protein mass, determined by reversed-phase high performance liquid chromatography (RP-HPLC). At a temperature of 79–81 °C, complete protein denaturation occurs. FTIR confirms the denaturation process by showing band shifts with both temperature steps

Report of the Terrestrial Bodies Science Working Group. Volume 5: Mars

Present knowledge of the global properties and surface characteraretics of Mars and the composition and dynamics of its atmosphere are reviewed. The objectives of proposed missions, the exploration strategy, and supporting research and technology required are delineated

Physical characteristics of soybean cultivated under the conditions of integrated agrosystems.

Abstract: Integrated crop-livestock-forest (ICLF) systems involve intercropping of various crops to achieve beneficial and synergistic outcomes, enhancing both economic viability and environmental sustainability. Considering the complexity of integrated agrosystems and the economic importance of soybean production in Brazil, we aimed to investigate the effects of two ICLF systems on the physical characteristics and quality of soybeans produced. The treatments comprised plots (two ha) with either single-row (ICLFS) or triple-row (ICLFT), tree configurations intercropped with soybean (maize and forage grass), and control plots (one ha), whose crops were cultivated under full sunlight (CFS). Soybeans were harvested from plants located at 3, 6, 10 and 15 m from tree bands in the north and south faces of the ICLF systems and at random positions in the CFS plots. The moisture content, electrical conductivity of the exudate solution, hue angle and chroma index of grains harvested from ICLFS and ICLFT were similar to those of CFS-grown soybeans. However, the mass of 1000 grains and the bulk density values of ICLF-grown soybeans were significantly higher (P ≤ 0.05) than those of grains harvested from CFS plots. We conclude that the quality of soybean seeds was not negatively affected by the conditions prevailing in the ICLF systems. Moreover, it appears that the forest component contributed positively to the ecosystem by providing a favorable microclimate for the development of soybean grains

Advantages of doubly polished thin sections for the study of microfossils in volcanic rock

Doubly polished thin sections, originally prepared for fluid inclusion studies, present great advantages in the study of microfossils in volcanic rocks. Better visibility and light conditions, variation in thickness of the thin sections and the possibility to combine fluid inclusion studies with microfossil studies lead to a wide range of advantages over ordinary thin sections. This includes the study of morphology, internal microstructures, colonies, association with the substrate that microfossils are attached to and geological and environmental context in which the microfossil once lived. When meeting the criteria of microfossil recognition the advantages of doubly polished thin sections are substantial and can be crucial in distinguishing between biogenic microfossils and abiotically formed abiomorphs

An interleukin-1 polymorphism additionally intensified by atopy as prognostic factor for aseptic non-mechanical complications in metal knee and hip arthroplasty

Background: In contrast to infection or mechanical issues joint replacement failure following inflammatory adverse reactions is poorly understood. Objective: To assess the association of IL-1β polymorphisms and history of allergy with aseptic non-mechanical complications following arthroplasty. Methods: In 102 patients with aseptic non-mechanically caused symptomatic knee or hip arthroplasty (SA) and 93 patients with asymptomatic arthroplasty (AA) questionnaire-based history, patch test with at least standard series, lymphocyte transformation test (LTT) with nickel, cobalt and chromium and interleukin-1 polymorphism analysis were done. Three polymorphisms of the IL1B gene [IL-1b -3954 (rs1143634), IL-1b -511 (rs16944) and IL-1b -31 (rs1143627)] and one polymorphism of the IL1RN gene [IL1RN intron 2, variable number of tandem repeats, VNTR (rs2234663)] were assessed by PCR and gel electrophoresis. Results: We found no significant difference in smoking history and atopy but 25% versus 10% of self-reported metal allergy in SA versus AA; the patch test (respective, LTT) for metal sensitivity was more often positive in SA patients. The allele 498 bp of the IL1RN polymorphism occurred significantly more often in the SA group (37% versus 11%; p < 0.0001). Upon additional presence of atopy, the difference was even greater (60% vs 10%) (p < 0.000001). There was no association of IL-1 polymorphisms with metal allergy. Conclusion: The IL1RN VNTR allele 498 bp was strongly associated with SA. In patients with a history of atopy, presence of the IL1RN VNTR allele 498 bp led to a four-fold higher SA prevalence compared to patients without this allele

Origin of Life

The evolution of life has been a big enigma despite rapid advancements in the fields of biochemistry, astrobiology, and astrophysics in recent years. The answer to this puzzle has been as mind-boggling as the riddle relating to evolution of Universe itself. Despite the fact that panspermia has gained considerable support as a viable explanation for origin of life on the Earth and elsewhere in the Universe, the issue remains far from a tangible solution. This paper examines the various prevailing hypotheses regarding origin of life like abiogenesis, RNA World, Iron-sulphur World, and panspermia; and concludes that delivery of life-bearing organic molecules by the comets in the early epoch of the Earth alone possibly was not responsible for kick-starting the process of evolution of life on our planet.Comment: 32 pages, 8 figures,invited review article, minor additio

Épocas de dessecação influenciam na qualidade de grãos e do óleo de soja.

Resumo: A dessecação de lavouras de soja tem sido utilizada, em algumas situações, para acelerar a senescência das plantas e o processo de secagem natural dos grãos, possibilitando escalonar e condicionar a cultura à colheita mecanizada com menor índice de perdas. Por desconhecimento ou na imi nência de períodos climáticos instáveis que impossibilitem a colheita, alguns produtores realizam a dessecação em estádios anteriores ao recomendado. Dessa forma, avaliou-se a influência da aplicação de dessecante em dife rentes estádios de maturação dos grãos de soja na qualidade dos grãos e do óleo. Duas cultivares (BRS 7980 e M8372 IPRO) foram avaliadas quanto à dessecação em cinco estádios fenológicos (R5.5, R6, R7.1 R7.3, R8.1), utilizando-se o dessecante Diquat, na safra 2018/2019. Após a colheita, os grãos foram secos, limpos e classificados. Em seguida, avaliados quanto às propriedades físicas e fisiológicas. A antecipação da dessecação reduziu a massa de mil grãos, aumentou a massa específica aparente e diminuiu a quantidade de óleo nos grãos. A aplicação do herbicida dessecante no está dio recomendado reduziu a deterioração dos grãos no campo. | Abstract: The desiccation of soybean crops has been used to accelerate plant senescence and the natural drying process of grains, allowing for the scaling and conditioning of the crop for mechanical harvesting with lower loss rates. Due to ignorance or the imminent threat of unstable weather periods that may make harvesting impossible, some producers carry out desiccation at earlier stages than recommended. In this way, the influence of desiccant application at different stages of soybean grain maturity on grain and oil quality was evaluated. Two cultivars (BRS 7980 and M8372 IPRO) were evaluated for desiccation at five phenological stages (R5.5, R6, R7.1, R7.3, R8.1) using the desiccant Diquat in the 2018/2019 season. After harvesting, the grains were dried, cleaned, and classified. Subsequently, they were evaluated for physical and physiological properties. The early desiccation reduced the mass of one thousand grains, increased the apparent specific mass, and decreased the amount of oil in the grains. The application of the desiccant herbicide at the recommended stage reduced grain deterioration in the field

Evolución de la proteólisis durante la maduración de quesos Danbo elaborados con distintos cultivos iniciadores

La determinación de nitrógeno soluble a pH 4,6 (NNC), nitrógeno soluble en ácido tricloroacético (12 %) (NTCA) y nitrógeno soluble en ácido fosfotúngstico (5 %) (NPTA) se utiliza como índice de maduración de quesos, ya que proporciona información adecuada de la extensión global de la proteólisis. La formación de péptidos y aminoácidos durante la maduración del queso contribuye directamente al desarrollo del sabor y textura del queso, de allí la importancia de conocer si el uso de distintos cultivos iniciadores genera diferencias en el desarrollo de la proteólisis. En este trabajo se estudiaron los cambios proteolíticos durante la maduración de quesos Danbo elaborados con cultivos iniciadores que difieren en la proporción de sus microorganismos componentes: Lote A con: 60 % Streptococcus thermophilus subsp. thermophilus – 40 % (Lactococcus lactis subsp. lactis + Lactococcus lactis subsp. cremoris) y Lote B con: 50 % Streptococcus thermophilus subsp. thermophilus – 50 % (Lactococcus lactis subsp. lactis y Lactococcus lactis subsp. cremoris). Se analizaron quesos con 0, 15, 30 y 45 días de maduración y se determinó contenido de humedad, pH, contenido de nitrógeno en queso y contenido de nitrógeno de las distintas fracciones nitrogenadas. El lote elaborado con un mayor porcentaje de cultivo mesófilo (Lactococcus lactis subsp. lactis y Lactococcus lactis subsp. cremoris), lote B, fue el que presentó mayor proteólisis primaria y mayor formación de oligopéptidos y aminoácidos libres