Significant Differences In Mass Research Articles

Conformation-Selective Ultraviolet-Ultraviolet Hole Burning Spectra of Ubiquitin Ions in a Cryogenic Ion Trap.

Understanding the structural variations of conformational isomers in proteins is crucial for elucidating protein folding mechanisms. Here, we present a novel method for obtaining conformation-selective ultraviolet (UV)-UV hole burning (HB) spectra of ubiquitin ions ((Ubi+zH)+z, z = 7-10) produced via electrospray ionization. Our approach involves binding multiple N2 molecules to ubiquitin ions ((Ubi+zH)+z(N2)m, m = 1-55) within a cryogenic ion trap. Upon exposure to UV irradiation, efficient fragmentation of (Ubi+zH)+z(N2)m occurs, primarily yielding bare (Ubi+zH)+z ions as fragments. The significant mass difference between the parent and fragment ions facilitates the acquisition of UV-UV HB spectra, which reveal the presence of at least two distinct conformers. Molecular dynamics simulations suggest that these conformers correspond to A-state structures, differing only in the interactions of a tyrosine residue with neighboring residues. Our findings underscore UV-UV HB spectroscopy of protein ions as a powerful tool for exploring diverse protein isomers.

Yield Comparison of Sweet Potato Grown in Four Commercial Organic Soils

Aims: The experiment was conducted to observe the effects on comparative yields of sweet potato (Ipomea batatas ‘Beauregard’) grown in four different soilless media. Study Design: Mention the design of the study here. Place and Duration of Study: Pullen Farm at Murray State University, in Murray, Kentucky, USA., between May 2018 and August 2018. Methodology: 16 3.048m x .3046m troughs (four of each treatment) each containing five sweet potato plants were established. No treatments received supplemental fertilization. Descriptive statistics and quantitative analysis were performed on yield characteristics of the sweet potato crop (sweet-potato tuber and biomass yields). Results: While a significant difference in mass of above-ground biomass between the treatments could not be determined, growth parameters of the Organiloc treatments (A, B) were marginally greater than treatments C and D (Table 1). The fresh weight of treatments A (38.91 t ha-1) and B (42.75 t ha-1) were statistically greater than treatment C (21.23 t ha-1). Treatment B was also statistically greater that treatment D (23.92 t ha-1). The number of tubers in treatment A and B were not significantly different than treatment D, but were significantly greater than treatment C (Fig. 2). Conclusion: The results of this one cropping season study suggest that yields of sweet potatoes grown in these two biochar-based treatments (A + B), in which they were statistically greater than the Miracle Gro treatment (C), and Treatment B was statistically greater than the Magic Dirt treatment (D), may help to fulfill the increasing demand for locally-produced food and agricultural products while providing an efficient means of disposing of agricultural waste products and may promote sustainable crop production and food security.

1641-P: C-C Motif Chemokine Ligand 2 Promotes Myogenesis Recovery, Muscle Strength, and Muscle Performance In Vivo and Has Clinical Relevance for Muscle Performance in Human

Muscle mass decreases with aging, while the C-C motif chemokine ligand 2 (CCL2) increases with aging. In our previous study, CCL2 positively affects in vitro myogenesis. In this context, CCL2 can be considered a potential aging-promoting factor. To further confirm the relationship between muscle and CCL2, we sought to establish the role of CCL2 in vivo and in humans. It was divided into Dimethyl Sulfoxide (DMSO) control, dexamethasone (Dexa) intraperitoneal treatment group, and Dexa with the CCL2 treatment group. As a result, grip power and exercise endurance were reduced in the Dexa treatment group compared to the control group but recovered with the CCL2 treatment. In muscle mass, there was no significant difference in mass between groups. We examined the cross-sectional area distribution (CSA) with the tibialis anterior muscle. The Dexa treatment group was distributed between CSA 1000-3000 µm² and was left-shifted. However, the Dexa and CCL2 group was similar or slightly higher than the DMSO group; it was right-shifted and distributed in the 2000-5000 µm². In humans, the median value was 303.8 pg/ml in the no sarcopenia group and 321.7 pg/ml in the sarcopenia group. Subsequently, the CCL2 level was checked by dividing the groups into whether there was sarcopenia, low mass, low strength, or low speed. The CCL2 level was statistically significantly higher in the group showing low speed. In conclusion, CCL2 promotes myogenesis recovery, muscle strength, and muscle performance in vivo and has clinical relevance for muscle performance in humans. Disclosure E.Hong: None. E.Ha: None. J.Lee: None. Y.Choi: None. K.Lee: None. J.Won: None. M.Kwak: None. Funding Ministry of Education, Republic of Korea (2020R1I1A3073230)

Manufacturing of mini-tablets. Focus and impact of the tooling systems

Mini-tablets are gaining importance for the pharmaceutical industry as several clinical studies and organizations emphasize the benefits for special patient groups such as paediatrics. Mini-tablets can be manufactured on tablet presses using special tooling systems. For industrial purposes often multi-tips are used, in order to achieve a high yield during production time. However, the effect of the used tooling system on quality attributes is not fully investigated yet. Therefore, 2 and 3 mm mini-tablets have been manufactured on a compaction simulator using single-tip, 7-tip and 19-tip punches and industrial relevant excipients. Mass variation and tensile strengths of the mini-tablets were evaluated as critical quality attributes. Additionally, the deformation behaviour and specific plastic energy (SPE) were analyzed. For evaluating the tableting performance tabletability and compactibility plots were created. With all used tooling systems significant differences in mass were observed for all excipients, despite of same filling procedure and filling heights. In-die Heckel plot revealed that the lowest yield pressures and in most cases the highest SPE were obtained using a single-tip. No major differences were found regarding tabletability but in most cases compactibility was improved using a 19-tip tooling. On the other hand, with a 19-tip the highest ejection forces were measured and targeted tensile strengths could not be achieved.

Seismic Fragility Functions for Non-Seismically Designed RC Structures Considering Pounding Effects

The proposed study develops fragility functions for non-seismically designed reinforced concrete structures considering different pounding configurations. The study addresses an existing research gap, since large-scale seismic risk assessment studies involving the seismic performance assessment of building portfolios usually do not involve fragility functions accounting for the possibility of pounding. The selected structures include configurations involving different separation distance values and exhibiting floor-to-floor pounding, floor-to-column pounding, pounding between structures with a significant height difference, and pounding between structures with a significant mass difference. The behaviour of these pounding configurations was analysed using incremental dynamic analysis and compared with that of the corresponding control cases (i.e., individual structures with no interaction with other structures). The results indicate the type of failure mechanism that contributes to the global collapse of the different configurations and the influence of the separation distance. Results highlight the main differences between the expected performance of different pounding configurations with respect to the occurrence of the failure mechanism that governs their collapse. Finally, results indicate that large-scale seismic risk assessment studies should consider fragility functions accounting for different pounding configurations when the possibility of pounding is not negligible, except in cases involving floor-to-floor pounding.

Effect of Ta5+ doping on the thermal physical properties of defective fluorite Y3NbO7 ceramics

AbstractThe effects of substituting the B cation in A3BO7 ceramics on their thermal physical properties were investigated by applying a large mass difference. Y3(Nb1‐xTax)O7 (x = 0, 0.1, 0.2, 0.3, 0.4, and 0.5) ceramics were synthesized, and their structural characteristics were determined. All the fabricated Y3(Nb1‐xTax)O7 ceramics showed defective fluorite structures and glass‐like low thermal conductivity (1.18−2.04 W/m∙K at 25°C) because of the highly distorted crystal structure and significant mass difference. Substitution with Ta5+ enhanced the sintering resistance, leading to superior thermal‐insulating performance via grain boundary scattering. Furthermore, the ceramics exhibited excellent coefficients of thermal expansion, implying the promising applicability of Y3(Nb1‐xTax)O7 as new thermal barrier materials. The effect of mass difference on the thermomechanical properties of the ceramics was examined, suggesting a simple strategy for engineering the chemical composition of new thermal barrier materials.

NUMBER OF FINE PARTICLES’ AND THEIR MASS CONCENTRATION: COMPARISON OF EMISSION OF NEW PRINTING TECHNOLOGY VERSUS TRADITIONAL LASER TECHNOLOGY

For many years the printers have been essential part of our offices and exposures from various printing technologies have been widely researched. The main objective of this study was to compare emitted number and mass of fine particles from laser printers and new Micro Piezo technology ink jet printers during the printing process and one hour afterwards as these emissions have potential for negative health effects.Air samples were taken with the particle size spectrometer for real-time ELPI+, Dekati (air flow rate 10 l/min). Measurements were taken ~0.5 m from the printers: one hour before the test, during printing and one hour afterwards. Similar class blackwhite (b/w) and colour printer of each technology were tested. Each printer performed a 10-page and a 100-page test according to ECMA 328-1 Standard [1].During laser printer tests from 8324 to 19943 pt/cm3 fine particles were determined on printing phase from b/w and colour printers. Ink jet (Micro Piezo) printers produced less: from 3239 to 5247 pt/cm3. One hour after the printing phase for both types of laser printers’ there were 54722 to 152351 pt/cm3 particles in air and 4270 to 9579 pt/cm3 particles for ink jet printers. Detected particle mass differences was insignificant: in range of 0.002 to 0.012 mg/m³ for laser printers and 0.002 to 0.019 mg/m³ for ink jet printers. Micro Piezo technology printers emitted mass particles were with bigger median size μm.The highest number of particles was observed one hour after the printing for both tested printer technologies. Laser printers’ emitted 2.5 to 3.8 times more particles in printing phase and 12.8 to 15.9 times more after printing phase. Particle mass in mg/m³ was detected in the size range 6nm - 2.5 μm with no significant mass differences.

Effect of cation substitution on thermophysical properties of fluorite A3BO7 ceramics

The effects of substituting A and B cations in A3BO7 compounds on their thermophysical properties were studied by imposing a significant mass difference on the substituents. Specifically, (Yb1−xYx)3(Nb1−yTay)O7 (YYNT) ceramics were synthesized, and their structural characteristics were investigated. All the YYNT ceramics had defective fluorite structures and exhibited glass-like low thermal conductivity (1.19 W/m K at 25 °C), which was derived from the highly distorted crystal structure and cation substitution. In addition, their excellent thermophysical properties, such as compatible thermal expansion, high elastic modulus, and hardness, make them promising candidates for new thermal barrier materials.

Dynamically induced magnetism in KTaO3

Dynamical multiferroicity features entangled dynamic orders: fluctuating electric dipoles induce magnetization. Hence, the material with paraelectric fluctuations can develop magnetic signatures if dynamically driven. We identify the paraelectric KTaO3 (KTO) as a prime candidate for the observation of the dynamical multiferroicity. We show that when a KTO sample is exposed to a circularly polarized laser pulse, the dynamically induced ionic magnetic moments are of the order of 5% of the nuclear magneton per unit cell. We determine the phonon spectrum using ab initio methods, and we identify T1u as relevant phonon modes that couple to the external field and induce magnetic polarization. We also predict a corresponding electron effect for the dynamically induced magnetic moment, which is enhanced by several orders of magnitude due to the significant mass difference between electron and ionic nucleus.Received 12 March 2021Revised 9 April 2021Accepted 14 April 2021DOI:https://doi.org/10.1103/PhysRevResearch.3.L022011Published by the American Physical Society under the terms of the Creative Commons Attribution 4.0 International license. Further distribution of this work must maintain attribution to the author(s) and the published article's title, journal citation, and DOI.Published by the American Physical SocietyPhysics Subject Headings (PhySH)Research AreasLaser applicationsMagnetization dynamicsPhononsPhysical SystemsMultiferroicsParaelectricsPerovskitesPropertiesMagnetic momentPolarizationTechniquesDensity functional theoryTerahertz spectroscopyCondensed Matter, Materials & Applied Physics

Star Formation Timescales of the Halo Populations from Asteroseismology and Chemical Abundances*

Abstract We combine asteroseismology, optical high-resolution spectroscopy, and kinematic analysis for 26 halo red giant branch stars in the Kepler field in the range of −2.5 < [Fe/H] < −0.6. After applying theoretically motivated corrections to the seismic scaling relations, we obtain an average mass of 0.97 ± 0.03 M ⊙ for our sample of halo stars. Although this maps into an age of ∼7 Gyr, significantly younger than independent age estimates of the Milky Way stellar halo, we considered this apparently young age to be due to the overestimation of stellar mass in the scaling relations. There is no significant mass dispersion among lower red giant branch stars (log g > 2), which constrains the relative age dispersion to <18%, corresponding to <2 Gyr. The precise chemical abundances allow us to separate the stars with [Fe/H] > −1.7 into two [Mg/Fe] groups. While the [α/Fe] and [Eu/Mg] ratios are different between the two subsamples, [s/Eu], where s stands for Ba, La, Ce, and Nd, does not show a significant difference. These abundance ratios suggest that the chemical evolution of the low-Mg population is contributed by Type Ia supernovae, but not by low- to intermediate-mass asymptotic giant branch stars, providing a constraint on its star formation timescale as 100 Myr < τ < 300 Myr. We also do not detect any significant mass difference between the two [Mg/Fe] groups, thus suggesting that their formation epochs are not separated by more than 1.5 Gyr.

Trends in player body mass at men’s and women’s Rugby World Cups: a plateau in body mass and differences in emerging rugby nations

ObjectivesThis study assessed the mass of international rugby players in the men’s and women’s Rugby World Cups between 1991 and 2019. The objective was to quantify changes in mass of...

Assessment of Growth, Lipid Metabolism and Gene Expression Responses in Senegalese Sole Larvae Fed With Low Dietary Phospholipid Levels.

Phospholipids (PL) are essential molecules for larval growth and development. In this study, growth, lipid metabolism and gene expression responses associated with different dietary PL levels in pelagic sole larvae were evaluated. In a first trial, the long-term effects on growth and survival of two experimental microdiets (MD) containing high (High-PL) or low (Low-PL) PL levels were tested and compared to a diet based on live prey (rotifers). The MD were supplied from 3 to 10 days post-hatch (dph) and Artemia from day 8 to 29 dph. High-PL fed larvae had higher dry mass (1.2-fold) than Low-PL fed larvae at 8 dph and both MD were smaller (2.9-fold) than larvae fed live preys. However, a compensatory growth (33% between 8 and 20 dph) occurred when MD were substituted by Artemia and by the end of the trial no significant differences in mass or survival occurred between the dietary treatments. In a second trial, growth, lipid metabolism and gene expression profiles of larvae fed with MD up to 8 dph were analyzed. Growth data confirmed that mass of larvae fed with High-PL was higher (1.3-fold) than the those fed Low-PL and they had lower levels of triacylglycerol (2.8-fold), cholesterol (1.2-fold) and cetoleic acid (1.7-fold). Histological analysis indicated an excess of lipid vacuoles in larvae fed with Low-PL and the expression analysis revealed a coordinated response to enhance lipid mobilization since the expression of genes involved in PL intermediate synthesis, PL remodeling as well as eight apolipoprotein was up-regulated. The down-regulation of apolipoprotein apob2 in larvae fed with Low-PL indicated a specific regulation by PL levels. The present work provides insight into the responses associated with dietary PL in early fish larvae, which will be of use for future studies aimed as designing effective larval sole diets.

Structure evolution and mechanical properties of hard tantalum diboride films

Tantalum diboride (TaB2) belonging to the ultrahigh temperature ceramics family is proving to be a promising material for hard protective films, thanks to its high thermal stability and excellent mechanical properties. However, growth of TaB2 ± x films prepared using physical vapor deposition techniques is strongly affected by Ar neutrals reflected from a stoichiometric TaB2 target due to a significant mass difference of heavy Ta and light B atoms leading to substantial changes in the final chemical composition and structure of films. In this work, TaB2 ± x films are experimentally prepared using high target utilization sputtering. Stopping and range of ions in matter simulations are used to investigate the behavior of Ar neutrals during deposition processes. A wide range of analytical methods is used to completely characterize the chemical composition, structure, and mechanical properties of TaB2 ± x films, and the explanation of the obtained results is supported by density functional theory calculations. TaB2 ± x films grow in a broad compositional range from TaB1.36 to TaB3.84 depending on the kinetic energy of Ar neutrals. The structure of overstoichiometric TaB2 + x films consists of 0001 preferentially oriented α-TaB2 nanocolumns surrounded by a boron-tissue phase. In the case of highly understoichiometric TaB2 − x films, the boron-tissue phase disappears and the structure consisting of 0001 and 101¯1 oriented α-TaB2 nanocolumns is formed. All TaB2 ± x films exhibit excellent mechanical properties with high hardness, ranging from 27 to 43 GPa and relatively low values of Young's modulus in the range of 304–488 GPa.

The physiology of saltwater acclimation in large juvenile Atlantic salmon Salmo salar.

The present study investigated the effects of transferring freshwater (FW) acclimated S. salar (678 g) that had been maintained under a constant photoperiod and thermal regime, into FW (salinity 0) and salt water (SW; salinity 35) on growth and physiological responses over a 28 day period. There were no mortalities observed throughout the study and no significant differences in mass or fork length between FW and SW groups after 28 days. Compared with fish transferred to FW, plasma osmolality and plasma chloride levels increased significantly in fish in SW by day 1. In the SW group, plasma chloride and osmolality had decreased significantly at day 14 when compared with day 1. Na+ -K+ -ATPase activity was significantly higher in SW compared with the FW group from day 7 and thereafter, but continued to increase until day 22. No differences in plasma cortisol and thyroxine were observed between FW and SW groups throughout the study. Plasma glucose significantly increased from day 1 to day 2 in SW but not in the FW group and levels were significantly reduced in SW compared with the FW group at day 28. Plasma cholesterol and triglyceride levels were significantly higher in FW at day 22 and day 14 to day 22, respectively, when compared with the SW group. In the SW group, plasma cholesterol and triglyceride levels did not change significantly throughout the study. The findings of this study suggest that large S. salar retained in FW maintain a high level of SW tolerance in the absence of photoperiod and thermal regimes necessary for smoltification, as demonstrated by 100% survival, unaffected growth performance, increased Na+ -K+ -ATPase activity and a capacity to regulate plasma chloride and osmolality for 28 days in the SW group.

Ontogeny of skeletal and cardiac muscle mitochondria oxygen fluxes in two breeds of chicken

From its earliest days of domestication, the domestic chicken (Gallus gallus domesticus) has been selectively bred for specific traits. Decades of genetic selection have resulted in significant dissimilarities in metabolism and growth between breeds, in particular fast-growing broilers and highly productive layers. A chicken develops the capacity to elevate metabolism in response to decreases in ambient temperature upon hatching, including well-developed methods of regulating thermogenesis. However, a differential timing between incipient endothermic capacities of broiler and layer strains exists. Although both broiler and layer chicks show the hallmark rapid attainment of endothermic capacity of precocial birds, endothermic capacity of broilers matures faster than that of layers. Here we characterized changes in morphology and mitochondria physiology during the developmental transition as the animals become endothermic. Changes in body mass occurred at a faster rate in broilers, with hatching embryos showing significant increases over embryonic body mass, while layers did not exhibit significant differences in mass until after hatch. Heart and liver both exhibited rapid growth upon hatching that occurred with little change in body mass in both breeds. Skeletal and cardiac mitochondrial respiration capacity in broilers increased from the embryonic stage through hatching. Oxidative phosphorylation was more tightly coupled to ATP production in broilers than layer muscles during external pipping. By selecting for faster growth and higher meat yield, the physiological transition from ectothermy to endothermy was also affected: differences in whole-animal, tissue, and organelle responses are evident in these two divergent breeds of chicken.

Influence of Nematode Parasitism, Body Size, Temperature, and Diel Period on the Flight Capacity of Sirex noctilio F. (Hymenoptera: Siricidae)

Sirex noctilio F. (Hymenoptera: Siricidae) is a woodwasp of pine trees that has recently invaded and established in North American forests. Although S. noctilio has had a limited impact in North America to date, there is some concern that it could have a significant impact on pine plantations, especially in the southeastern U.S.A. Moreover, there are few data on the flight capacity of male S. noctilio. We found no association between parasitism by D. siricidicola and whether or not S. noctilio initiated flight on the flight mill. Male wasps that were parasitized by nematodes were heavier than non-parasitized males, but there was no significant difference in mass between parasitized and non-parasitized females. We also examined the flight capacity of male and female S. noctilio in relation to nematode parasitism, body mass, temperature (for only males), and diel period. Body mass, temperature, and diel period affected flight in S. noctilio such that wasps were generally observed to fly faster, farther, and more frequently if they were heavier, flying at warmer temperatures, and flying during the photoperiod. The fact that nematode-parasitized male wasps were found to fly farther than the non-parasitized males is consistent with the hypothesis that nematode parasitism does not negatively affect the flight capacity of S. noctilio.

Effects of a Broad‐Spectrum Antibiotic on the Siberian Hamster (Phodopus sungorus ) Gut Microbiome

The gut microbiome is a diverse, host unique, and symbiotic bacterial environment. Host antibiotic treatment can adversely affect the diversity of the bacterial population and the symbiotic relationship with the host. Although therapeutically beneficial, antibiotics can change the structure, function, and evolution of host microbial communities in the gut, affecting nutrient availability and predisposing infection in the gut by non‐communal species (Archie & Theis, 2011). Previous studies have shown the effects of antibiotics on the host's gut microbiome in many model species, including mice and rats (reviewed in Clarke, O'Mahony, Dinan, & Cryan, 2014), yet, in non‐model species, such as the Siberian hamster, the role of the microbiome and the effects that antibiotics have on gut microbial communities have yet to be fully explored. Studying non‐model species is particularly valuable because it enables us to make meaningful comparisons between various organisms and to understand the strategies they use to cope with environmental pressures. In order to study the various effects of antibiotics on the microbiome and ultimately the consequences it has on behavior in our species, we first had to determine if and how antibiotic treatment affects the gut microbiome of both male and female Siberian hamsters. In order to assess this question, male (n=12) and female (n=12) hamsters were either administered sterilized water or a broad‐spectrum antibiotic (0.3 μl of enrofloxacin (Baytril) 10% oral solution per gram of body mass) via sterile pipette orally once daily for seven days (Romick‐Rosendale et al., 2009). Body mass was monitored, and fecal samples were taken throughout the seven days before treatment (D1–7), the seven days during treatment (D8–14), and the seven days following the treatment period (D15–21). Microbiome analysis was completed to determine the effects of this broad‐spectrum antibiotic on the gut microbiome. At the end of the experiment, all animals were euthanized and organs were harvested and weighed. To determine the bacteria makeup of the gut microbiome, DNA was extracted and purified from the fecal material, and the V4 region of the 16S rRNA gene was amplified using the Illumina MiSeq platform to identify the bacteria present in each sample. Antibiotic treatment decreased the diversity of the microbial communities, and by the end of the recovery period (D21), the host gut microbiome was able to regain much of its microbial diversity. There were no significant differences in body mass, and additionally, the liver, spleen, and reproductive organs showed no significant difference in mass at the end of the study. The results of this work help us to advance our understanding of the gut microbiome's function in host communities, and they will allow us to further investigate the role that the microbiome plays in the gut‐brain axis in non‐model species.

Thermal Response of Activated Charcoal Modified Investment Casting Moulds

Direct microwave dewaxing of investment casting moulds is possible at the expense of time and poor heat distribution. Modifying the back-up stucco of investment casting moulds may enhance microwave absorption; however, it may affect its thermal properties. In this study, the effects of adding activated charcoal in the back-up stucco of the investment casting mould were investigated. Samples prepared without and with 25% activated charcoal were tested for differential scanning calorimetry (DSC) and Thermogravimetric analysis (TGA). It was observed that the specific heat capacity is higher in the samples added with activated charcoal. The DSC curves exhibit a smooth trend with no indication of exothermic or endothermic peaks in both samples. The glass transition temperature was also increased from 515.29°C to 582.24°C after modifying the contents. However, the TGA results show no significant difference in mass lost between the two samples that are about 2%. The DSC and TGA curves for both samples show similar patterns indicating that there is very close similarity in their thermal behaviour. Due to that, it can be concluded that the addition of activated charcoal in the back-up stucco does not induce an unusual reaction or thermal behaviour in the moulds.

Juvenile invasive red-eared slider turtles negatively impact the growth of native turtles: Implications for global freshwater turtle populations

Invasive species are a significant cause of biodiversity declines on a global scale with novel species interactions often causing ecological damage through predation or competition. Red-eared slider turtles (Trachemys scripta elegans) have been introduced to wetlands throughout the world and have negatively impacted native species, particularly other species of turtles. In our controlled feeding experiments in mesocosms juvenile red-eared slider turtles negatively impacted the growth of juvenile red-bellied turtles (Pseudemys rubriventris), an IUCN near threatened species and a Pennsylvania threatened species, through exploitative competition for limited food. In mixed species experimental treatments, in which food resources were abundant, juvenile red-bellied turtles grew significantly faster and ate more food than juvenile red-eared slider turtles. In mixed species experimental treatments, in which food resources were limited, red-eared slider turtles ingested more food, gained mass faster, and maintained body condition while red-bellied turtles lost body condition. There were significant differences in growth rates seen between resource availability regimes. In treatments in which resources were abundant there were no significant differences between turtles housed in mixed species or single species groups. In limited resource treatments red-bellied turtle body condition was significantly different between single and mixed species groups while there were significant differences in mass and body condition for red-eared slider turtles. Our results suggest that one mechanism by which red-eared slider turtles detrimentally impact ecologically similar species is through competition for limited food resources. We hypothesize that growth of red-eared slider turtle populations will lead to population declines of native turtle species throughout their introduced ranges because they use limited food resources more efficiently for their growth and development than native species.

Influence of Implant Drill Materials on Wear, Deformation, and Roughness After Repeated Drilling and Sterilization

The aim of this study was to evaluate deformation, roughness, and mass loss of stainless steel, diamond-like carbon (DLC)-coated and zirconia drills after multiple osteotomies with sterilization procedures. Drilling procedures were performed using stainless steel (G1), DLC-coated (G2), and zirconia (G3) drills. All groups were divided in subgroups 1, 2, 3, 4, and 5, corresponded to drills used 0, 10, 20, 30, and 40 times, respectively. No significant differences in mass and roughness were detected among all groups and subgroups. In SEM images, all groups revealed signs of wear while coating delamination was detected in G2. Drills from G1 displayed more irregular surface, whereas cutting edges were more regular in G3. Zirconia drills presented more regular surfaces whereas stainless steel drills revealed more severe signs of wear. Further studies must be performed to evaluate the putative influence of these findings in heat generation.