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Diffractive Imaging of C60 Structural Deformations Induced by Intense Femtosecond Midinfrared Laser Fields
Get PDFTheoretical studies indicated that C60 exposed to linearly polarized intense infrared pulses undergoes periodic cage structural distortions with typical periods around 100 fs (1 fs=10−15 s). Here, we use the laser-driven self-imaging electron diffraction technique, previously developed for atoms and small molecules, to measure laser-induced deformation of C60 in an intense 3.6 μm laser field. A prolate molecular elongation along the laser polarization axis is determined to be (6.1±1.4)% via both angular- and energy-resolved measurements of electrons that are released, driven back, and diffracted from the molecule within the same laser field. The observed deformation is confirmed by density functional theory simulations of nuclear dynamics on time-dependent adiabatic states and indicates a nonadiabatic excitation of the hg(1) prolate-oblate mode. The results demonstrate the applicability of laser-driven electron diffraction methods for studying macromolecular structural dynamics in four dimensions with atomic time and spatial resolutions
Bond rearrangement during Coulomb explosion of water molecules
Get PDFBond rearrangement, namely the dissociation of water ions into H2++O(q−1)+ (q=1–4) following fast ion-impact ionization, unexpectedly occurs following multiple ionization of water in spite of the presumably fast “Coulomb explosion” of the transient molecular ion. Furthermore, the branching ratio of bond rearrangement is found to be nearly equal for each level of ionization, q. In addition, formation of H2+ is more than twice as likely to occur from the lighter water isotopologue H2O+ than D2+ from D2O+. These findings are consistent with the ground state dissociation mechanism in which a fast projection of the ground state nuclear wave function onto the vibrational continuum of the cation potential energy surface is sometimes followed by H2+ formation
Habitat configuration matters when evaluating habitat-area effects on host–parasitoid interactions
Get PDFCitation: With, K. A., & Pavuk, D. M. (2019). Habitat configuration matters when evaluating habitat-area effects on host–parasitoid interactions. Ecosphere, 10(2), e02604. https://doi.org/10.1002/ecs2.2604Higher trophic levels tend to be more sensitive to habitat fragmentation than lower trophic levels, which is why parasitism rates should decline in fragmented landscapes. Habitat loss and fragmentation (the subdivision of habitat) are typically interrelated processes, and thus, their effects are confounded in most studies. To address this, we quantified parasitism rates in pea aphids (Acyrthosiphon pisum) within an experimental model landscape system, in which we independently controlled the amount vs. the fragmentation of habitat (red clover, Trifolium pratense) within individual landscape plots (16 × 16 m). Aphid densities were generally unaffected by landscape pattern, except at the local scale for interior habitat cells within fragmented landscapes, which had significantly lower aphid densities than all other cell types. Aphid parasitism rates averaged about 40% and were significantly—albeit weakly—correlated with aphid density. Habitat amount had the greatest overall effect on parasitism rates, but fragmentation effects were evident in a shift in parasitism at intermediate habitat levels: Parasitism rates were higher in fragmented landscapes with 50% habitat. Edge effects alone did not explain this shift in parasitism rates. Parasitism rates were uniformly high within edge habitat and fragmented landscapes, and thus, the shift in parasitism at intermediate habitat levels was driven by increasing parasitism rates within interior cells and clumped landscapes at higher habitat amounts. Habitat configuration is thus important for evaluating habitat-area effects on species interactions, as habitat amount only affected parasitism rates within less-fragmented landscapes in this system
The Moral Dilemma to Antibiotic Overprescription
Get PDFKirmser Undergraduate Research Award - Individual Freshman category, grand prizeAmelia HicksWhen creating our final project for Moral Philosophy we were tasked with investigating a moral issue. My ethical concept centered around the morality of antibiotic prescription. In particular I reviewed three main moral concepts in the topic being 1. Should our current use of antibiotics be restricted our of consideration for future generations? 2. Who is the physician's main moral duty towards a) future of public health b) current patient demands 3. How much responsibility falls on the patient to refute antibiotic treatment? Within searching to answer these questions I including many philosophical concepts such as the use of a prisoner's dilemma in order to better understand the topic
The effects of medium chain fatty acids as alternatives to zinc oxide or carbadox in nursery pig performance
Get PDFThere is an increased consumer pressure to limit the use of feed based antibiotic in nursery pig diets. A total of 360 weanling pigs (DNA 200×400; 5.4 ± 0.07 kg) were used in a 35-d growth experiment with 6 treatments to evaluate MCFA as an alternative to ZnO or carbadox to examine the outcome of their ADG, BW, ADFI, and G:F. A completely randomized design was conducted using 10 replicates pens per treatment with 6 pigs per pen. The treatments were 1) control; 2) 3,000 ppm ZnO in Phase 1 and 1,500 ppm ZnO in Phase 2; 3) 50 g/ton carbadox; 4) 1% blend of C6:C8:C10; 5) 1% Feed Energy R2 (Feed Energy Corp, Des Moines, IA); 6) 1% FORMI GML (ADDCON, Bitterfeld-Wolfen, Germany). The data was analyzed using the GLIMMIX procedure of SAS (SAS Inst., Cary, NC) with pens being the Experiential Unit. The treatment diets had two phases, Phase 1 d 0 to 7, Phase 2 d 8 to 19, with a common diet fed from d 20 to 35. From d 0 to 19, pens fed ZnO or carbadox had greater (P<0.05) ADG than pens fed control or R2. The overall treatment shows there was no significant change in the G:F (P=0.320). The results of this experiment suggest that feeding ZnO and carbadox will have ahigher ADG (P=0.012) and ADFI (P=0.001) in weanling pigs. FORMI GML had a similar growth performance, however additional research is needed to confirm if certain MCFA could replace feed-based antibiotics in commercial swine production
Effects of medium chain fatty acids and their ability to replace ZnO in weanling pig diets
Get PDFThe objective of this study was to test the effects of medium chain fatty acids compared to standard ZnO or carbadox in diets for weanling pigs. A total of 360 weanling pigs of 21 days of age were used in a 35-day growth study. Pigs were weaned on day 0 of the experiment in a completely randomized design with a total of 6 dietary treatments being used. The diets are as follows: 1) control; 2) 3,000 ppm ZnO in Phase 1 and 1,500 ppm in Phase 2; 3) 50 g/ton carbadox; 4) 1% blend of C6:C8:C10; 5) 1% Feed Energy 2 (Feed Energy Corp, Des Moines, IA); 6) 1% FORMI (ADDCON, Bitterfeld-Wolfen, Germany). Phases 1 and 2 of the diets were fed from initial weaning to day 19, and a common phase 3 diet was fed from day 20 to 35. During the treatment period, pigs fed ZnO or carbadox had greater (P0.05) ADG results as the carbadox treatment. During phase 3, pigs initially fed ZnO had higher (P<0.05) ADG than those fed R2, with the other treatments performing intermediately between the two treatments. There was little impact of G:F (P=0.078) during treatment phases. In conclusion, pigs on the ZnO or carbadox diets performed better than pigs on the MCFA diets when maximizing growth performance. Alternatives such as FORMI resulted in similar growth performance, but more research is needed on MCFA’s in order to replace ZnO or other similar antibiotics in pork production
Evaluating alternatives to zinc oxide and antibiotics in nursery pig diets
Get PDFProducers aspire to reduce the use of antibiotics and ZnO in swine diets to limit antimicrobial resistance and negative environment impact. This 35-d study was conducted using 360 weanling pigs (DNA 200×400; 5.4±0.07 kg BW) to evaluate the effects of substituting medium chain fatty acids (MCFA) for carbadox and ZnO. Pens were allotted in a completely randomized design with 6 pigs/pen and 10 pens/treatment. The treatment diets: 1) control; 2) 3,000 ppm ZnO in Phase 1 and 1,500 ppm ZnO in Phase 2; 3) 50 g/ton carbadox; 4) 1% C6:C8:C10; 5) 1% Feed Energy R2 (Feed Energy Corp., Des Moines, IA); 6) 1% FORMI GML (ADDCON, Bitterfeld-Wolfen, Germany). Treatment diets were fed for 19 d, with a common diet fed from d 19 to 35 (Phase 3). In Phase 1 (d 0 to 7) ADG and ADFI had a significant difference (P0.05) ADG as those fed carbadox. During the common period, pigs fed ZnO continued to have greater (P<0.05) ADG than those fed R2, with other treatments being intermediate. There was no overall impact on G:F (P = 0.320). The results of this study suggest that although the MCFA did not improve weanling pig growth over ZnO and Carbadox, 1% FORMI GML may be a promising alternative. Thus, additional research regarding MCFA is warranted to effectively replace ZnO or antibiotics in pork production
Increasing duration of feeding high dietary lysine and energy before farrowing on colostrum quality and yield in mixed parity sows
No full textA total of 472 mixed parity sows were used from d 106 of gestation until weaning to determine the effects of Lys and energy intake the last 7 d before farrowing on colostrum production, composition, and immunoglobulin G concentrations. On d 106 of gestation, sows were weighed, blocked by parity and weight, and allotted to dietary treatments. Treatments were based on corn-soybean meal diets fed to provide 1) 12.5 g SID Lys and 6.5 Mcal/d ME from d 107 to 112 of gestation, then 28 g SID Lys and 9.4 Mcal/d ME from until farrowing; 2) 12.5 g SID Lys and 6.5 Mcal/d ME from d 107 to 112 of gestation, then 40 g SID Lys and 13.3 Mcal/d ME from until farrowing; 3) 40 g SID Lys and 13.3 Mcal/d ME from d 107 of gestation until farrowing. After birth of the first piglet, a 50 mL colostrum sample was collected. Colostrum samples were analyzed for fat, protein, total solids, lactose, and IgG concentrations. Individual piglets were weighed at birth and 24 h to determine colostrum intake and yield. Data was analyzed for treatment within parity and treatment main effects. There was a treatment within parity difference observed where sows on treatment 3 had decreased (P < 0.05) fat and total solids concentrations compared to treatment 1 sows, with no evidence for difference within gilts. IgG concentrations were increased (P < 0.05) in females fed treatment 2 compared to treatment 1, regardless of parity. Total protein and lactose concentrations as well as colostrum intake and yield were similar across treatments, regardless of parity. In conclusion, feeding high Lys and energy for 8 d before farrowing decreased fat and solid concentrations in colostrum in sows, but did not impact other colostrum nutrients or colostrum production
Effects of corn dried distillers grains with solubles or corn gluten feed on Boer-type growing goat diets
Get PDFThere is lack of research on varying ingredients effect on goat growth performance. However, the number of goats in the U.S. has increased in the past 15 years from 1.3 to 2.6 million head (NASS, 2002 and 2017). This study aimed to help close that gap in knowledge by determining how replacing soybean meal (SBM) with corn gluten feed (CGF) or corn dried distillers grains with solubles (DDGS) would affect growth performance in Boer type goats. Seventy-five Boer type goats (29.6+ 0.2 kg, approximately 70 d of age) were used. Goats were assigned 1 of 5 treatments. Goats and treatments were randomly assigned to pen, with 3 goats per pen, and pen as the experimental unit. Treatments were isocaloric and isonitrogenous but varied in protein source: 1) SBM; 2) 100% DDGS/0% CGF; 3) 66% DDGS/33% CGF; 4) 33% DDGS/66% CGF; 5) 0% DDGS/100% CGF. Goats, and feeders, were weighed weekly during the 35 d experiment. The GLIMMIX procedure of SAS was used to analyze the data, the accepted alpha was 0.05. No treatment differences were detected for final BW, ADG, G:F, or ADFI (P>0.05). By including corn products, DDGS or CGF, feed costs were lowered by approximately $0.04/kg of feed. Goats fed diets with DDGS and/ or CGF had lower (P=0.0008) feed cost/ goat than goats on the SBM diets. There was, however, no evidence (P>0.05) that the diets affected the feed cost/ kg of gain. In conclusion, the experiment supports that corn DDGS or CGF may be used as an economic replacement for SBM in Boer-type growing diets
Leading by example: A three-wave sequential mixed method food safety study
Get PDF(Best Paper Award/ 253 submissions) According to the most recent government data, approximately 61% of foodborne illness outbreaks were attributed to lack of personal hygiene and improper food handling by employees in the foodservice industry. Foodservice employees fail to adhere to safe food preparation practices, may directly introduce pathogens that can cause illness and death. Few qualitative studies have examined the barriers of effective managerial practices that influence employee’s food safety behaviors. Therefore, the purpose of the study is to explore employees’ perspectives about managerial practices that influence their food safety behaviors