Relationships of epidermal morphology and breeding behaviors in pebble nest-building minnows (Pisces: Cyprinidae)

Abstrad The objective of this study was to determine if epidermal morphology corresponds with reproductive behavior in cyprinid fishes. Representative species of nest-building fishes (Nocomds leptocephalus, Semotilus atromeculatus, exoglossum maxillingua) and non nest-building fishes (Campostoma anomaulm and Clinostomus funduloides) were studied. Light and scanning electron microscopy were used to examine epidermal morphology and keratin distribution of skins from the snout, cheek, mandible, anterior dorso-lateral trunk, and caudal peduncle of breeding males of nest-building species and were compared to those in non nest-building cyprinid species. Previous frame-by-frame analysis of video tapes of reproductive activities of each species and literature accounts were used to identify and describe breeding behaviors. The location and structure of keratinized regions in the epidermis of these cyprinid fishes is specifies-specific. The distribution of keratin and the form in which it occurs correlates with four primary aspects of reproduction: substrate modification (nest-building or pit digging), spawning, agnostic behaviors (combat and/or aggressive displays), and ornamentation (species and sex identification)

Determination of Uncertainties for Analytically Derived Material Properties to Be Used in Monte Carlo Based Orion Heatshield Sizing

Ablative materials are often used for spacecraft heatshields to protect underlying structures from the extreme environments associated with atmospheric reentry. NASA's Orion EM-1 capsule has been designed to use a molded Avcoat material system. In order to determine the required heatshield thickness, a Monte Carlo approach to the sizing process was proposed. To perform the Monte Carlo simulation, statistical uncertainties on all material property input parameters were required. Obtaining these values for measured properties is straightforward, however input parameters that are derived analytically have historically used uncertainties based on engineering judgment. A MATLAB program was created to use laboratory generated thermogravimetric analysis (TGA) data to calculate uncertainties on the Arrhenius parameters for molded Avcoat. Uncertainties associated with the normalized ablation rate and pyrolysis gas enthalpy were also generated using a wrapper script and the ACE code. These uncertainties could then be tied directly to measured values of individual elemental constituents. The resulting uncertainty values will allow for a probabilistic sizing approach on molded Avcoat with a higher level of confidence in the input parameters

Groundwater depletion and sustainability of irrigation in the US High Plains and Central Valley

Aquifer overexploitation could significantly impact crop production in the United States because 60% of irrigation relies on groundwater. Groundwater depletion in the irrigated High Plains and California Central Valley accounts for ∼50% of groundwater depletion in the United States since 1900. A newly developed High Plains recharge map shows that high recharge in the northern High Plains results in sustainable pumpage, whereas lower recharge in the central and southern High Plains has resulted in focused depletion of 330 km3 of fossil groundwater, mostly recharged during the past 13,000 y. Depletion is highly localized with about a third of depletion occurring in 4% of the High Plains land area. Extrapolation of the current depletion rate suggests that 35% of the southern High Plains will be unable to support irrigation within the next 30 y. Reducing irrigation withdrawals could extend the lifespan of the aquifer but would not result in sustainable management of this fossil groundwater. The Central Valley is a more dynamic, engineered system, with north/south diversions of surface water since the 1950s contributing to ∼7× higher recharge. However, these diversions are regulated because of impacts on endangered species. A newly developed Central Valley Hydrologic Model shows that groundwater depletion since the 1960s, totaling 80 km3, occurs mostly in the south (Tulare Basin) and primarily during droughts. Increasing water storage through artificial recharge of excess surface water in aquifers by up to 3 km3 shows promise for coping with droughts and improving sustainability of groundwater resources in the Central Valley

Altitude of the Potentiometric Surface in the Mississippi River Valley Alluvial Aquifer, Spring 2018

The Mississippi River Valley alluvial (MRVA) aquifer is an important surficial aquifer in the Mississippi Alluvial Plain (MAP) area. The aquifer is generally considered to be an unconfined aquifer (fig. 1; Clark and others, 2011), and withdrawals are primarily used for irrigation (Maupin and Barber, 2005). These groundwater withdrawals have resulted in substantial areas of water-level decline in parts of the aquifer. Concerns about water-level declines and the sustainability of the MRVA aquifer have prompted the U.S. Geological Survey (USGS), as part of the USGS Water Availability and Use Science Program and with assistance from other Federal, State, and local agencies, to undertake a regional water-availability study to assess the characteristics of the MRVA aquifer, including the potentiometric-surface altitude of the MRVA aquifer for spring 2018, and to provide information to water managers to inform their decisions about resource allocations and aquifer sustainability. The purpose of this report was to present a potentiometric-surface map for the MRVA aquifer using manually measured groundwater-altitude data and daily mean or maximum groundwater-altitude data from wells measured generally in spring 2018, which is after water levels have substantially recovered from pumping in the previous irrigation season and before pumping begins for the next irrigation season, and using the altitude of the top of the water surface in rivers in the area, hereinafter referred to as “surface-water altitude,” generally on April 10, 2018, from streamgages in the area. The term “potentiometric surface” is used in this report because it is applicable for maps of the groundwater-altitude surface in unconfined, semiconfined, and confined aquifers (Lohman, 1972). In this report, the maps of the MRVA aquifer’s groundwater surface are termed potentiometric-surface maps as opposed to water-table maps because, although the MRVA aquifer generally exhibits characteristics of unconfined conditions, where surface-water features may or may not be hydraulically connected, it also exhibits characteristics of confined or semiconfined conditions in some areas at least during part of the year. The location of these areas, where the aquifer is confined or semiconfined, is not well understood or defined (Arthur, 1994; Kleiss and others, 2000). Datasets used attache

Altitude of the Potentiometric Surface in the Mississippi River Valley Alluvial Aquifer, Spring 2018

The Mississippi River Valley alluvial (MRVA) aquifer is an important surficial aquifer in the Mississippi Alluvial Plain (MAP) area. The aquifer is generally considered to be an unconfined aquifer (fig. 1; Clark and others, 2011), and withdrawals are primarily used for irrigation (Maupin and Barber, 2005). These groundwater withdrawals have resulted in substantial areas of water-level decline in parts of the aquifer. Concerns about water-level declines and the sustainability of the MRVA aquifer have prompted the U.S. Geological Survey (USGS), as part of the USGS Water Availability and Use Science Program and with assistance from other Federal, State, and local agencies, to undertake a regional water-availability study to assess the characteristics of the MRVA aquifer, including the potentiometric-surface altitude of the MRVA aquifer for spring 2018, and to provide information to water managers to inform their decisions about resource allocations and aquifer sustainability. The purpose of this report was to present a potentiometric-surface map for the MRVA aquifer using manually measured groundwater-altitude data and daily mean or maximum groundwater-altitude data from wells measured generally in spring 2018, which is after water levels have substantially recovered from pumping in the previous irrigation season and before pumping begins for the next irrigation season, and using the altitude of the top of the water surface in rivers in the area, hereinafter referred to as “surface-water altitude,” generally on April 10, 2018, from streamgages in the area. The term “potentiometric surface” is used in this report because it is applicable for maps of the groundwater-altitude surface in unconfined, semiconfined, and confined aquifers (Lohman, 1972). In this report, the maps of the MRVA aquifer’s groundwater surface are termed potentiometric-surface maps as opposed to water-table maps because, although the MRVA aquifer generally exhibits characteristics of unconfined conditions, where surface-water features may or may not be hydraulically connected, it also exhibits characteristics of confined or semiconfined conditions in some areas at least during part of the year. The location of these areas, where the aquifer is confined or semiconfined, is not well understood or defined (Arthur, 1994; Kleiss and others, 2000). Datasets used attache

Early full enteral feeding for preterm or low birth weight infants

BACKGROUND: The introduction and advancement of enteral feeds for preterm or low birth weight infants is often delayed because of concerns that early full enteral feeding will not be well tolerated or may increase the risk of necrotising enterocolitis. Early full enteral feeding, however, might increase nutrient intake and growth rates; accelerate intestinal physiological, metabolic, and microbiomic postnatal transition; and reduce the risk of complications associated with intravascular devices for fluid administration. OBJECTIVES: To determine how early full enteral feeding, compared with delayed or progressive introduction of enteral feeds, affects growth and adverse events such as necrotising enterocolitis, in preterm or low birth weight infants. SEARCH METHODS: We used the standard search strategy of Cochrane Neonatal to search Cochrane Central Register of Controlled Trials; MEDLINE Ovid, Embase Ovid, Maternity & Infant Care Database Ovid, the Cumulative Index to Nursing and Allied Health Literature, and clinical trials databases, conference proceedings, and the reference lists of retrieved articles for randomised controlled trials and quasi-randomised trials to October 2020. SELECTION CRITERIA: Randomised controlled trials that compared early full enteral feeding with delayed or progressive introduction of enteral feeds in preterm or low birth weight infants. DATA COLLECTION AND ANALYSIS: We used the standard methods of Cochrane Neonatal. Two review authors separately assessed trial eligibility, evaluated trial quality, extracted data, and synthesised effect estimates using risk ratios (RR), risk differences, and mean differences (MD) with 95% confidence intervals (CI). We used the GRADE approach to assess the certainty of evidence. MAIN RESULTS: We included six trials. All were undertaken in the 2010s in neonatal care facilities in India. In total, 526 infants participated. Most were very preterm infants of birth weight between 1000 g and 1500 g. Trials were of good methodological quality, but a potential source of bias was that parents, clinicians, and investigators were not masked. The trials compared early full feeding (60 mL/kg to 80 mL/kg on day one after birth) with minimal enteral feeding (typically 20 mL/kg on day one) supplemented with intravenous fluids. Feed volumes were advanced daily as tolerated by 20 mL/kg to 30 mL/kg body weight to a target steady-state volume of 150 mL/kg to 180 mL/kg/day. All participating infants were fed preferentially with maternal expressed breast milk, with two trials supplementing insufficient volumes with donor breast milk and four supplementing with preterm formula. Few data were available to assess growth parameters. One trial (64 participants) reported a slower rate of weight gain (median difference -3.0 g/kg/day), and another (180 participants) reported a faster rate of weight gain in the early full enteral feeding group (MD 1.2 g/kg/day). We did not meta-analyse these data (very low-certainty evidence). None of the trials reported rate of head circumference growth. One trial reported that the mean z-score for weight at hospital discharge was higher in the early full enteral feeding group (MD 0.24, 95% CI 0.06 to 0.42; low-certainty evidence). Meta-analyses showed no evidence of an effect on necrotising enterocolitis (RR 0.98, 95% CI 0.38 to 2.54; 6 trials, 522 participants; I² = 51%; very low-certainty evidence). AUTHORS' CONCLUSIONS: Trials provided insufficient data to determine with any certainty how early full enteral feeding, compared with delayed or progressive introduction of enteral feeds, affects growth in preterm or low birth weight infants. We are uncertain whether early full enteral feeding affects the risk of necrotising enterocolitis because of the risk of bias in the trials (due to lack of masking), inconsistency, and imprecision

Topological Electronic Structure Evolution with Symmetry Breaking Spin Reorientation in (Fe1−x_{1-x}Cox_{x})Sn

Topological materials hosting kagome lattices have drawn considerable attention due to the interplay between topology, magnetism, and electronic correlations. The (Fe$_{1-x}$Co$_x$)Sn system not only hosts a kagome lattice but has a tunable symmetry breaking magnetic moment with temperature and doping. In this study, angle resolved photoemission spectroscopy and first principles calculations are used to investigate the interplay between the topological electronic structure and varying magnetic moment from the planar to axial antiferromagnetic phases. A theoretically predicted gap at the Dirac point is revealed in the low temperature axial phase but no gap opening is observed across a temperature dependent magnetic phase transition. However, topological surface bands are observed to shift in energy as the surface magnetic moment is reduced or becomes disordered over time during experimental measurements. The shifting surface bands may preclude the determination of a temperature dependent bulk gap but highlights the intricate connections between magnetism and topology with a surface/bulk dichotomy that can affect material properties and their interrogation.Comment: 11 pages, 4 figure