Production of optical phase space vortices with non-locally distributed mode converters

Optical vortices have been observed in a wide variety of optical systems. They can be observed directly in the wavefront of optical beams, or in the correlations between pairs of entangled photons. We present a novel optical vortex which appears in a non-local plane of the two-photon phase space, composed of a single degree of freedom of each photon of an entangled pair. The preparation of this vortex can be viewed as a "non-local" or distributed mode converter. We show how these novel optical vortices of arbitrary order can be prepared in the spatial degrees of freedom of entangled photons.Comment: To appear in upcoming special issue "Orbital Angular Momentum" of the Journal of Optic

Influence of the anisotropic behavior on equibiaxial paths

Marciniak and Nakajima tests are commonly used in building FLD's, since they allow covering all regions from uniaxial to almost equibiaxial strain paths. In this work, the deviation from equibiaxial strain paths is analyzed as function of the material anisotropic behavior. The numerical results show that material with r0 = r90 present equibiaxial stress and strain paths, while for the ones with r0 ≠ r90 the paths are neither equibiaxial in stress nor strain. Moreover, it is shown that despite the similarities between the two tests, they present different sensitivity to the control of the blank holder force and to the friction coefficient. Namely, the stress and strain paths in the Marciniak specimen center are more sensitive to the control of the blank holder force. On the other hand, the stress and strain paths in the Nakajima specimen center are more sensitive to the friction coefficient. The deviation from the equibiaxial strain path indicates that the stress ratio is also not necessarily 1.0, meaning that the stress triaxiality and the Lode parameter also present some deviation from the reference values for an equibiaxial stress state. This should be taken into account when analyzing forming limit results.The authors gratefully acknowledge the financial support of the projects POCI-01-0145-FEDER030592 (PTDC/EME-EME/30592/2017) and UIDB/00285/2020 financed by the Operational Program for Competitiveness and Internationalization, in its FEDER/FNR component, and the Portuguese Foundation of Science and Technology (FCT), in its State Budget component (OE)

El agua de coco(Cocus nucifera L) in natura integral y adicionada con citoquininas, como dilutor de semen caprino.

Este trabajo busca conocer el efecto de la adicion de citoquininas en el agua de coco utilizada como dilutor del semen caprino. Se evaluo in vitro el comportamiento de los espermatozoides colectados con vagina artificial de cuatro machos caprinos, diluidos en agua de coco in natura integral y adicionada con 5 o 100mg de zeatina, una citoquinina natural. Se aplico una prueba de termorresistencia, incubando los espermatozoides a 37 graus C entre 0 y 120 minutos. Se observo un considerable incremento de la motilidad individual progressiva y del porcentaje de los espermatozoides motiles a los 60 minutos, especialmente con la menor dilucion. Estos resultados deberan ser correlacionados con la fertilidad in vivo luego de la inseminacion artificial

Embryo transfer from seropositive goats for caprine arthritis-encephalitis virus (CAEV) with birth of seronegative kid.

Abstract: The aim of this study was to determine whether recipient goats would seroconvert following transfer of embryos collected from donor goats seropositive for CAEV and if kids produced would be clinically normal and seronegative for CAEV. Four does (Saanen and Alpine), seropositive for CAEV, were used as donors, receiving superovulation treatment consisting of progestagen, cloprostenol and FSH. During estrus the donors were mated with seropositive bucks. Seven days after estrus, embryo recovery was performed by surgery. The embryos were then frozen according to the protocol of the International Embryo Transfer Society (IETS). Twelve seronegative does were used as recipients and received an estrus synchronization treatment consisting of progestagen, cloprostenol and eCG. Embryo transfer was performed seven days after synchronized estrus using the semilaparoscopy technique. Pregnancy was verified in one of twelve recipients, that remained seronegative until six months after giving birth and the kid until six months of age. The preliminary success in producing CAEV negative kids and failure of seroconversion in previously seronegative recipients in this study suggests that embryo transfer technology may offer an alternative in the prevention of CAEV transmission in goat herds as well for the utilization of genetic patrimony of seropositive goats. [Transferência de embriões de cabras soropositivas para artrite-encefalite caprina a vírus (CAEV) com nascimento de cria soronegativa]. Resumo: O objetivo deste estudo foi verificar se cabras receptoras sofreriam soroconversão após a transferência de embriões colhidos de cabras soropositivas e se as crias nascidas seriam clinicamente normais e soronegativas para CAEV. Foram utilizadas quatro cabras (Saanen e Alpina), todas soropositivas para CAEV e que receberam um tratamento superovulatório que consistiu no uso de progestágeno, cloprostenol e FSH. Durante o estro, as doadoras foram cobertas por bodes soropositivos. Sete dias após o estro, a colheita de embriões foi realizada utilizando a técnica cirúrgica. Os embriões colhidos foram congelados de acordo com o protocolo da Sociedade Internacional de Transferência de Embriões (IETS). Doze cabras soronegativas foram utilizadas como receptoras e receberam um tratamento de sincronização do estro consistindo de progestágeno, cloprostenol e eCG. A transferência de embriões foi realizada sete dias após o estro sincronizado usando a técnica de semi-laparoscopia. A gestação foi confirmada em uma das doze receptoras, a qual permaneceu soronegativa até seis meses após o parto e sua cria até os seis meses de idade. O sucesso preliminar na produção de crias soronegativas para CAEV e a não soroconversão em receptoras soronegativas sugere que a tecnologia de transferência de embriões pode oferecer uma alternativa para a profilaxia da CAEV em rebanhos caprinos, bem como para o aproveitamento do patrimônio genético de animais soropositivos

The Promethean: Fall 2012

Fall 2012 edition of The Promethean. Contents: From the Director 2 Honors Study Abroad 4 Tips for Writing Your Senior Thesis 6 Collected Poetry 8 Freshman Experience Articles 9 Remembering Alex Kogut 10https://digitalcommons.brockport.edu/promethean/1007/thumbnail.jp

Experimental investigation of the dynamics of entanglement: Sudden death, complementarity, and continuous monitoring of the environment

We report on an experimental investigation of the dynamics of entanglement between a single qubit and its environment, as well as for pairs of qubits interacting independently with individual environments, using photons obtained from parametric down-conversion. The qubits are encoded in the polarizations of single photons, while the interaction with the environment is implemented by coupling the polarization of each photon with its momentum. A convenient Sagnac interferometer allows for the implementation of several decoherence channels and for the continuous monitoring of the environment. For an initially-entangled photon pair, one observes the vanishing of entanglement before coherence disappears. For a single qubit interacting with an environment, the dynamics of complementarity relations connecting single-qubit properties and its entanglement with the environment is experimentally determined. The evolution of a single qubit under continuous monitoring of the environment is investigated, demonstrating that a qubit may decay even when the environment is found in the unexcited state. This implies that entanglement can be increased by local continuous monitoring, which is equivalent to entanglement distillation. We also present a detailed analysis of the transfer of entanglement from the two-qubit system to the two corresponding environments, between which entanglement may suddenly appear, and show instances for which no entanglement is created between dephasing environments, nor between each of them and the corresponding qubit: the initial two-qubit entanglement gets transformed into legitimate multiqubit entanglement of the Greenberger-Horne-Zeilinger (GHZ) type.Comment: 15 pages, 14 figures; only .ps was working, now .pdf is also availabl

Inibidores de papaina e tripsina em frações proteicas de sementes de Libidibia ferrea (Mart. ex Tul.).

Verificar a inibição da papaína e da tripsina por frações protéicas de sementes de Libidibia ferreae seu perfil eletroforético