2,558 research outputs found
Production and Marketing Characteristics of U.S. Pork Producers – 2003
Livestock Production/Industries,
Nonperturbative corrections to B -> X_s l^+ l^- with phase space restrictions
We study nonperturbative corrections up to O(1/m_b^3) in the inclusive rare B
decay B -> X_s l^+ l^- by performing an operator product expansion. The values
of the matrix elements entering at this order are unknown and introduce
uncertainties into physical quantities. Imposing a phase space cut to eliminate
the resonances we find that the O(1/m_b^3) corrections introduce an
O(10%) uncertainty in the measured rate. We also find that the contributions
arising at O(1/m_b^3) are comparable to the ones arising at O(1/m_b^2) over the
entire region of phase space.Comment: 7 pages, 2 figures, revte
Orthogonal, metal-free surface modification by strain-promoted azide–alkyne and nitrile oxide–alkene/alkyne cycloadditions
In this article we present a fast and efficient methodology for biochemical surface patterning under extremely mild conditions. Micropatterned azide/benzaldoxime-surfaces were prepared by microcontact printing of a heterobifunctional cyclooctyne oxime linker on azide-terminated self-assembled monolayers (SAMs). Strain-promoted azide–alkyne cycloaddition (SPAAC) in combination with microcontact printing allows fast and effective surface patterning. The resulting bifunctional azide/oxime substrates could successfully be used for metal-free, orthogonal immobilization of various biomolecules by 1,3-dipolar cycloadditions at room temperature. Azide-decorated areas were modified by reaction with a cyclooctyne-conjugate using SPAAC, while benzaldoxime-decorated areas were activated by in situ oxidation to the reactive nitrile oxides and subsequent nitrile oxide cycloaddition with alkene- and alkyne-functionalized bioconjugates. In addition, orthogonal double immobilization was achieved by consecutive and independent SPAAC and nitrile oxide cycloadditions
Effect of glucosinolate profile modifications in Arabidopsis thaliana (L.) on the performance of different specialist Lepidoptera
Die Glucosinolate (GS) sind charakteristische sekundäre Pflanzeninhaltsstoffe, vorkommend in der Gruppe der Brassicaceae und anderen Familien der Ordnung Brassicales (Halkier & Gershenzon 2006). Bisher sind mehr als 120 verschiedene GS beschrieben, welche eine gemeinsame Grundstruktur mit variablem Seitenkettenrest kennzeichnet (Fahey et al. 2001). Je nach chemischer Natur der Seitenkette werden die GS in aliphatische, aromatische und Indolyl-GS unterteilt. Alle GS-enthaltenden Pflanzen besitzen zusätzlich räumlich getrennt von den GS hydrolysierende Enzyme, so genannte Myrosinasen. Erst nach Zellbeschädigung kommen die beiden Komponenten in Kontakt zueinander und weitere biologisch aktive Verbindungen wie z. B. Isothiocyanate und Nitrile werden freigesetzt (Rask et al. 2000). Das GS-Myrosinase-System ist ein effektives Abwehrsystem insbesondere gegenüber generalistischen Insekten, Pathogenen und Bakterien, allerdings dienen vielen spezialisierten Insekten diese Stoffe zur Wirtspflanzenfindung und -akzeptanz (Renwick 2002, Halkier & Gershenzon 2006). Die Modellpflanze Arabidopsis thaliana L. enthält als Vertreter der Brassicaceae GS als Fraßabwehrstoffe. In A. thaliana als auch in Brassica ist das aliphatische GS-Muster sehr variabel, wohingegen die Indolyl-GS weit verbreitet sind (Kliebenstein 2001, Li & Quiros 2002). Allerdings fehlen Studien zur Funktion dieser GS-Klassen innerhalb der Pflanzenresistenz gegenüber Phytophagenfraß. Deshalb wurden zwei A. thaliana -Mutanten mit verändertem aliphatischen bzw. Indolyl-GS-Profil im Vergleich zu Columbia WT auf die Wirtspflanzeneignung für drei verschieden spezialisierte Lepidoptera-Arten getestet.Plants have developed diverse, complex defense mechanisms for dealing with their enemies. Members of the Brassicaceae family use the glucosinolate(GS)-myrosinase system to deal with their enemies. According to their precursor amino acid the GS are classified in aliphatic, aromatic, and indolyl GS. Indolyl GS are widely distributed in Arabidopsis thaliana (L.) ecotypes and Brassica ssp., but the presence of aliphatic GS is highly variable. The impact of certain GS classes on plant resistance to insects is not yet discovered. Therefore, we studied the host-plant suitability of A. thaliana Columbia GS mutants to different Lepidopteran species compared to the wild-type. Two specialist species, Pieris rapae L. and Pieris brassicae L. and one generalist species Spodoptera exigua (Hübner) were selected for the feeding studies. As mutants we used mam3+ with reduced aliphatic GS levels compared to Columbia wild-type and cyp79B2-cyp79B3- which is characterized by the complete loss of indolyl GS. The weight gain of the generalist S. exigua within three days was significantly higher on mutant lines of mam3+ and cyp79B2-cyp79B3- than on Columbia wild-type. In contrast, the performance of the specialist species P. rapae and P. brassicae was not different on the genotypes. The reason for different host-plant suitability of mutants for the generalist and specialist insects is discussed
In Vivo Multimodal Imaging of Drusenoid Lesions in Rhesus Macaques.
Nonhuman primates are the only mammals to possess a true macula similar to humans, and spontaneously develop drusenoid lesions which are hallmarks of age-related macular degeneration (AMD). Prior studies demonstrated similarities between human and nonhuman primate drusen based on clinical appearance and histopathology. Here, we employed fundus photography, spectral domain optical coherence tomography (SD-OCT), fundus autofluorescence (FAF), and infrared reflectance (IR) to characterize drusenoid lesions in aged rhesus macaques. Of 65 animals evaluated, we identified lesions in 20 animals (30.7%). Using the Age-Related Eye Disease Study 2 (AREDS2) grading system and multimodal imaging, we identified two distinct drusen phenotypes - 1) soft drusen that are larger and appear as hyperreflective deposits between the retinal pigment epithelium (RPE) and Bruchs membrane on SD-OCT, and 2) hard, punctate lesions that are smaller and undetectable on SD-OCT. Both exhibit variable FAF intensities and are poorly visualized on IR. Eyes with drusen exhibited a slightly thicker RPE compared with control eyes (+3.4 μm, P=0.012). Genetic polymorphisms associated with drusenoid lesions in rhesus monkeys in ARMS2 and HTRA1 were similar in frequency between the two phenotypes. These results refine our understanding of drusen development, and provide insight into the absence of advanced AMD in nonhuman primates
Thermal acclimation to 4 or 10°C imparts minimal benefit on swimming performance in Atlantic cod ( Gadus morhua L.)
Thermal acclimation is frequently cited as a means by which ectothermic animals improve their Darwinian fitness, i.e. the beneficial acclimation hypothesis. As the critical swimming speed (U crit) test is often used as a proxy measure of fitness, we acclimated Atlantic cod (Gadus morhua) to 4 and 10°C and then assessed their U crit swimming performance at their respective acclimation temperatures and during acute temperature reversal. Because phenotypic differences exist between different populations of cod, we undertook these experiments in two different populations, North Sea cod and North East Arctic cod. Acclimation to 4 or 10°C had a minimal effect on swimming performance or U crit, however test temperature did, with all groups having a 10-17% higher U crit at 10°C. The swimming efficiency was significantly lower in all groups at 4°C arguably due to the compression of the muscle fibre recruitment order. This also led to a reduction in the duration of "kick and glide” swimming at 4°C. No significant differences were seen between the two populations in any of the measured parameters, due possibly to the extended acclimation period. Our data indicate that acclimation imparts little benefit on U crit swimming test in Atlantic cod. Further efforts need to identify the functional consequences of the long-term thermal acclimation proces
Production and Marketing Characteristics of U.S. Pork Producers - 2003
This revision is dated July 2004.Bertold Brecht once said, “Because things are the way they are, things will not stay the way they are.” Because things in the U.S. pork industry never seem to “stay the way they are,” researchers at the University of Missouri and Iowa State University have documented and analyzed changes in the U.S. pork industry for three decades. Thirty years ago, a pork producer could get a fairly good perspective on changes in the industry by looking out the window on a drive to the county seat. Today, hogs have moved indoors. Fewer neighbors are raising hogs, and those that are may have specialized in different methods, have chosen to become very large, or have chosen to contract, thereby making what is happening in one region bear little resemblance to what is happening elsewhere. This report highlights the results of the most recent survey conducted as part of research by the University of Missouri and Iowa State University into the structure of the U.S. pork industry.The project was supported by National Pork Board, PIC Inc., Monsanto Choice Genetics, Land' O Lakes, PORK Magazine, University of Missouri, and Iowa State University
Radiosynthesis, in vitro and preliminary in vivo evaluation of the novel glutamine derived PET tracers [18F]fluorophenylglutamine and [18F]fluorobiphenylglutamine
INTRODUCTION: Glucose has been deemed the driving force of tumor growth for decades. However, research has shown that several tumors metabolically shift towards glutaminolysis. The development of radiolabeled glutamine derivatives could be a useful molecular imaging tool for visualizing these tumors. We elaborated on the glutamine-derived PET tracers by developing two novel probes, namely [(18)F]fluorophenylglutamine and [(18)F]fluorobiphenylglutamine MATERIALS AND METHODS: Both tracers were labelled with fluorine-18 using our recently reported ruthenium-based direct aromatic fluorination method. Their affinity was evaluated with a [(3)H]glutamine inhibition experiment in a human PC-3 and a rat F98 cell line. The imaging potential of [(18)F]fluorophenylglutamine and [(18)F]fluorobiphenylglutamine was tested using a mouse PC-3 and a rat F98 tumor model. RESULTS: The radiosynthesis of both tracers was successful with overall non-decay corrected yields of 18.46 ± 4.18 % (n=10) ([(18)F]fluorophenylglutamine) and 8.05 ± 3.25 % (n=5) ([(18)F]fluorobiphenylglutamine). In vitro inhibition experiments showed a moderate and low affinity of fluorophenylglutamine and fluorobiphenylglutamine, respectively, towards the human ASCT-2 transporter. Both compounds had a low affinity towards the rat ASCT-2 transporter. These results were endorsed by the in vivo experiments with low uptake of both tracers in the F98 rat xenograft, low uptake of [(18)F]FBPG in the mice PC-3 xenograft and a moderate uptake of [(18)F]FPG in the PC-3 tumors. CONCLUSION: We investigated the imaging potential of two novel PET radiotracers [(18)F]FPG and [(18)F]FBPG. [(18)F]FPG is the first example of a glutamine radiotracer derivatized with a phenyl group which enables the exploration of further derivatization of the phenyl group to increase the affinity and imaging qualities. We hypothesize that increasing the affinity of [(18)F]FPG by optimizing the substituents of the arene ring can result in a high-quality glutamine-based PET radiotracer. ADVANCES IN KNOWLEDGE AND IMPLICATIONS FOR PATIENT CARE: We hereby report novel glutamine-based PET-tracers. These tracers are tagged on the arene group with fluorine-18, hereby preventing in vivo defluorination, which can occur with alkyl labelled tracers (e.g. (2S,4R)4-[(18)F]fluoroglutamine). [(18)F]FPG shows clear tumor uptake in vivo, has no in vivo defluorination and has a straightforward production. We believe this tracer is a good starting point for the development of a high-quality tracer which is useful for the clinical visualization of the glutamine transport
Förvirring – en framgångsrik metod att kontrollera inomhuslevande mottfjärilar
Förvirring – en framgångsrik metod att kontrollera inomhuslevande mottfjärilar, Vad vi kan finna i maten:
Tre mycket vanliga mottfjärilar, kvarnmott (Ephestia kuehniella), mandelmott (Ephestia cautella) och indiskt mjölmott (Plodia interpunctella) angriper matprodukter över hela världen och orsakar stor skada i fabriker, lagerlokaler och i hem. Fram till väldigt nyligen bekämpades angrepp med kemiska bekämpningsmedel, t.ex. med metylbromid. En ökande insikt om mänsklig hälsovådlighet och insekters ökade resistens mot insekticider ledde till ett förbud mot användning av dessa kemikalier. Alternativa metoder krävs nu för att minska skadeinsekters angrepp. En alternativ metod är att använda feromoner.
Feromoner och möjligheten att använda dem i kontrollsyfte: Innan parning avger honan hos alla de tre nämnda arterna en specifik doft (feromon) som attraherar hanar. De tre arternas feromon består av två till fyra olika ämnen som gör doften artspecifik (tillhör endast en art). Dessa närbesläktade mottfjärilar har emellertid samma huvudkomponent i sina feromoner ((Z,E)-9,12-tetradecadienylactetat) och denna ensam fungerar relativt väl för samtliga arter. ”Förvirring” är en metod som numera vinner mer och mer mark hos odlare över hela världen. Den övergripande hypotesen är att genom att sprida ut ett moln av det artspecifika doftämnet hindra hanen att hitta doftspåret till honan. Därigenom hindras parning och populationen minskar eller dör ut. Förvirringsmetoden används oftare utomhus i odlingar men dess effekt inomhus har inte hittills blivit undersökt. Vi redovisar här försök på hur förvirring har minskat antalet mottfjärilar i olika typer av lokaler, i kvarnar (kvarnmott), i husdjursfoderlager (Indiskt mjölmott) och i en chokladfabrik (mandelmott) och som tyder på att förvirring är en mycket lovande alternativ metod mot skadeangrepp av mottfjärilar.
Förvirring i kvarnar och chokladfabriker: Tre kvarnar har behandlats med förvirring där populationsstorleken har mätts genom att räkna antalet fångade hanar i feromonfällor. Fällfångster minskade drastiskt i alla lokaler och jämförelser mellan år visar att metoden fungerar bättre under en längre tid (cirka 20 månader). Feromonkoncentrationen mättes med en bärbar elektroantennograf (EAG) som visade att feromonhalten ökade direkt efter uppsättandet av feromonavgivarna och att feromonet var jämnt fördelat över hela lokalerna. Färre mott kunde observeras i lokalerna och antalet kundreklamationer minskade under de år försöken pågick. I chokladfabriken kunde vi även fånga mandelmott i vattenfällor som ett oberoende mått på populationsstorleken. Fångster i dessa fällor visade en signifi kant nedgång av populationen av mandelmott. Av dessa förvirringsförsök kan vi sammanfatta att denna metod har stor möjlighet att, på ett miljövänligt sätt, kunna minska populationer av dessa tre inomhuslevande mottfjärilar
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