Changes in Maximal Strength and Home Run Performance in Ncaa Division I Baseball Players Across 3 Competitive Seasons: A Descriptive Study

The purpose of this longitudinal, descriptive study was to observe changes in maximal strength measured via isometric clean grip mid-thigh pull and home runs (total and home runs per game) across three years of training and three competitive seasons for four National Collegiate Athletic Association (NCAA) Division 1 baseball players. A one-way repeated measures analysis of variance (ANOVA) was performed, revealing significant univariate effects of time for peak force (PF) (p = 0.003) and peak force allometrically scaled (PFa) (p = 0.002). Increases in PF were noted from season 1 to season 2 (p = 0.031) and season 3 (p = 0.004), but season 2 was not significantly different than season 3 (p = 0.232). Additionally, increases in PFa were noted from season 1 to season 2 (p = 0.010) and season 3 (p \u3c 0.001), but season 2 was not significantly different than season 3 (p = 0.052). Home runs per game rose from the 2009 (0.32) to 2010 season (1.35) and dropped during the 2011 season (1.07). A unique aspect of the study involves 2010 being the season in which ball-bat coefficient of restitution (BBCOR) bats were introduced to the NCAA competition

Finishing the euchromatic sequence of the human genome

The sequence of the human genome encodes the genetic instructions for human physiology, as well as rich information about human evolution. In 2001, the International Human Genome Sequencing Consortium reported a draft sequence of the euchromatic portion of the human genome. Since then, the international collaboration has worked to convert this draft into a genome sequence with high accuracy and nearly complete coverage. Here, we report the result of this finishing process. The current genome sequence (Build 35) contains 2.85 billion nucleotides interrupted by only 341 gaps. It covers ∼99% of the euchromatic genome and is accurate to an error rate of ∼1 event per 100,000 bases. Many of the remaining euchromatic gaps are associated with segmental duplications and will require focused work with new methods. The near-complete sequence, the first for a vertebrate, greatly improves the precision of biological analyses of the human genome including studies of gene number, birth and death. Notably, the human enome seems to encode only 20,000-25,000 protein-coding genes. The genome sequence reported here should serve as a firm foundation for biomedical research in the decades ahead

Regional Paleoenvironments Recorded in Sedimentary Rocks of the Western Fan-Delta, Jezero Crater, Mars

International audienceThe Mars 2020 Perseverance rover science team recently completed an investigation of the fan-delta sedimentary sequence [1] and has begun exploration of the crater margin. High resolution chemical, mineralogical, and morphological observations collected with the rover instrument payload provide powerful constraints on rock origins, contextualizing the suite of high-value samples collected as part of the Mars Sample Return campaign

Regional Paleoenvironments Recorded in Sedimentary Rocks of the Western Fan-Delta, Jezero Crater, Mars

International audienceThe Mars 2020 Perseverance rover science team recently completed an investigation of the fan-delta sedimentary sequence [1] and has begun exploration of the crater margin. High resolution chemical, mineralogical, and morphological observations collected with the rover instrument payload provide powerful constraints on rock origins, contextualizing the suite of high-value samples collected as part of the Mars Sample Return campaign

Provenance and Diagenesis of Martian Sedimentary Rocks in the Jezero Crater Delta Front from Microscale Observations by the Mars 2020 PIXL Instrument

International audienceOn ~sol 370 of the Perseverance rover mission, the Mars 2020 Science Team completed its investigation of igneous units of the Jezero crater floor [1] and directed Perseverance to drive towards the topographic scarp that marks the interface between the crater floor and Jezero’s western delta. The “Delta Front Campaign” consisted of close-up investigation and sampling of lithologies located there.Here, we report on the major findings relevant to the provenance and diagenetic history of these lithologies deduced from measurements made by the Planetary Instrument for X-ray Lithochemistry (PIXL), a micro-focus X-ray fluorescence (XRF) microscope [2]. Data were collected from the Shenandoah formation at two stratigraphic sections: Cape Nukshak and Hawksbill Gap [3].Sediment provenance ranges from relatively homogeneous, altered olivine-dominated sources at the base of the section at Cape Nukshak in the Amalik member, to highly heterogeneous and altered (likely serpentinized) mafic to ultramafic sources at the top of the section at Hawksbill Gap in the Rockytop member. The presence of Fe-bearing carbonate at both locations indicates precipitation from anoxic, alkaline waters of moderate pH. The Yori Pass member (Cape Nukshak), and the Hogwallow Flats and Devils Tanyard members (Hawksbill Gap) contain abundant Fe-Mg sulfates and phyllosilicates, with compositions that indicate at least one period of deposition under anoxic, hypersaline conditions. The preservation of the Fe-Mg sulfate component of these rocks is remarkable, given its extreme solubility and susceptibility to oxidation. Fluids that precipitated later cross-cutting anhydrite apparently had little effect on rock bulk compositions. At present, it is uncertain whether observed evidence for oxidation, including ferric-sulfate, results from ~syn-depositional variability in atmospheric and aquatic redox state, or later diagenesis or weathering. A major finding of this investigation is that the Shenandoah formation contains compositionally and mineralogically diverse sedimentary rocks, which bodes well for sample return science, and indicates that paleo-environmental conditions were variable in space and/or time during delta deposition and diagenesis

Provenance and Diagenesis of Martian Sedimentary Rocks in the Jezero Crater Delta Front from Microscale Observations by the Mars 2020 PIXL Instrument

International audienceOn ~sol 370 of the Perseverance rover mission, the Mars 2020 Science Team completed its investigation of igneous units of the Jezero crater floor [1] and directed Perseverance to drive towards the topographic scarp that marks the interface between the crater floor and Jezero’s western delta. The “Delta Front Campaign” consisted of close-up investigation and sampling of lithologies located there.Here, we report on the major findings relevant to the provenance and diagenetic history of these lithologies deduced from measurements made by the Planetary Instrument for X-ray Lithochemistry (PIXL), a micro-focus X-ray fluorescence (XRF) microscope [2]. Data were collected from the Shenandoah formation at two stratigraphic sections: Cape Nukshak and Hawksbill Gap [3].Sediment provenance ranges from relatively homogeneous, altered olivine-dominated sources at the base of the section at Cape Nukshak in the Amalik member, to highly heterogeneous and altered (likely serpentinized) mafic to ultramafic sources at the top of the section at Hawksbill Gap in the Rockytop member. The presence of Fe-bearing carbonate at both locations indicates precipitation from anoxic, alkaline waters of moderate pH. The Yori Pass member (Cape Nukshak), and the Hogwallow Flats and Devils Tanyard members (Hawksbill Gap) contain abundant Fe-Mg sulfates and phyllosilicates, with compositions that indicate at least one period of deposition under anoxic, hypersaline conditions. The preservation of the Fe-Mg sulfate component of these rocks is remarkable, given its extreme solubility and susceptibility to oxidation. Fluids that precipitated later cross-cutting anhydrite apparently had little effect on rock bulk compositions. At present, it is uncertain whether observed evidence for oxidation, including ferric-sulfate, results from ~syn-depositional variability in atmospheric and aquatic redox state, or later diagenesis or weathering. A major finding of this investigation is that the Shenandoah formation contains compositionally and mineralogically diverse sedimentary rocks, which bodes well for sample return science, and indicates that paleo-environmental conditions were variable in space and/or time during delta deposition and diagenesis

Provenance and Diagenesis of Martian Sedimentary Rocks in the Jezero Crater Delta Front from Microscale Observations by the Mars 2020 PIXL Instrument

International audienceOn ~sol 370 of the Perseverance rover mission, the Mars 2020 Science Team completed its investigation of igneous units of the Jezero crater floor [1] and directed Perseverance to drive towards the topographic scarp that marks the interface between the crater floor and Jezero’s western delta. The “Delta Front Campaign” consisted of close-up investigation and sampling of lithologies located there.Here, we report on the major findings relevant to the provenance and diagenetic history of these lithologies deduced from measurements made by the Planetary Instrument for X-ray Lithochemistry (PIXL), a micro-focus X-ray fluorescence (XRF) microscope [2]. Data were collected from the Shenandoah formation at two stratigraphic sections: Cape Nukshak and Hawksbill Gap [3].Sediment provenance ranges from relatively homogeneous, altered olivine-dominated sources at the base of the section at Cape Nukshak in the Amalik member, to highly heterogeneous and altered (likely serpentinized) mafic to ultramafic sources at the top of the section at Hawksbill Gap in the Rockytop member. The presence of Fe-bearing carbonate at both locations indicates precipitation from anoxic, alkaline waters of moderate pH. The Yori Pass member (Cape Nukshak), and the Hogwallow Flats and Devils Tanyard members (Hawksbill Gap) contain abundant Fe-Mg sulfates and phyllosilicates, with compositions that indicate at least one period of deposition under anoxic, hypersaline conditions. The preservation of the Fe-Mg sulfate component of these rocks is remarkable, given its extreme solubility and susceptibility to oxidation. Fluids that precipitated later cross-cutting anhydrite apparently had little effect on rock bulk compositions. At present, it is uncertain whether observed evidence for oxidation, including ferric-sulfate, results from ~syn-depositional variability in atmospheric and aquatic redox state, or later diagenesis or weathering. A major finding of this investigation is that the Shenandoah formation contains compositionally and mineralogically diverse sedimentary rocks, which bodes well for sample return science, and indicates that paleo-environmental conditions were variable in space and/or time during delta deposition and diagenesis

Alteration history of Séítah formation rocks inferred by PIXL x-ray fluorescence, x-ray diffraction, and multispectral imaging on Mars.

Collocated crystal sizes and mineral identities are critical for interpreting textural relationships in rocks and testing geological hypotheses, but it has been previously impossible to unambiguously constrain these properties using in situ instruments on Mars rovers. Here, we demonstrate that diffracted and fluoresced x-rays detected by the PIXL instrument (an x-ray fluorescence microscope on the Perseverance rover) provide information about the presence or absence of coherent crystalline domains in various minerals. X-ray analysis and multispectral imaging of rocks from the Séítah formation on the floor of Jezero crater shows that they were emplaced as coarsely crystalline igneous phases. Olivine grains were then partially dissolved and filled by finely crystalline or amorphous secondary silicate, carbonate, sulfate, and chloride/oxychlorine minerals. These results support the hypothesis that Séítah formation rocks represent olivine cumulates altered by fluids far from chemical equilibrium at low water-rock ratios

An olivine cumulate outcrop on the floor of Jezero crater, Mars

The geological units on the floor of Jezero crater, Mars, are part of a wider regional stratigraphy of olivine-rich rocks, which extends well beyond the crater. We investigated the petrology of olivine and carbonate-bearing rocks of the Séítah formation in the floor of Jezero. Using multispectral images and x-ray fluorescence data, acquired by the Perseverance rover, we performed a petrographic analysis of the Bastide and Brac outcrops within this unit. We found that these outcrops are composed of igneous rock, moderately altered by aqueous fluid. The igneous rocks are mainly made of coarse-grained olivine, similar to some martian meteorites. We interpret them as an olivine cumulate, formed by settling and enrichment of olivine through multistage cooling of a thick magma body.</p