726 research outputs found
NOD.Cd1-/- mice have increased numbers of CD4+CD25+Foxp3+ T regulatory cells in the periphery
Recent studies indicate Natural Killer T (NKT) lymphocytes and Regulatory T (Treg) cells interact to regulate immune responses. NOD mice bearing a targeted deletion of the NKT cell restriction molecule, CD1d, lack NKT cells. To determine whether absence of NKT cells has an effect on Treg numbers, NOD/Lt and NOD.Cd1-/- mice were examined for differences in their Treg population. Flow cytometric analysis of 10-week old female mice of both strains revealed that NOD.Cd1-/- mice have a higher number of CD4+CD25+Foxp3+ T cells in both the spleen and liver. Further studies on differences in regulatory T cells between these strains at different ages and the effect of adoptive transfer of NKT cells on Treg cells would give us a better understanding about interactions of these two populations
Factors Influencing Nest Attendance and Time-activity Budgets of Peregrine Falcons in Interior Alaska
An essential prerequisite to examining the impacts of anthropogenic disturbance on avian nesting activities is understanding the intrinsic and extrinsic factors that influence the birds' allocation of time to breeding behaviors. We examined factors influencing nest attendance and time-activity budgets of peregrine falcons (Falco peregrinus anatum) breeding along the Tanana River in Alaska in 1995, 1996, and 1997. First, as is typical of most bird species with nidicolous young and biparental care, females attended the nest more than males and, as the nesting cycle progressed, female attendance decreased to levels similar to those of males. Second, nest area attendance followed a circadian rhythm; parents attended the nest area less during early morning and late evening, which are prime hunting periods, than during late morning. Finally, although females typically performed most of the incubating, the division of labor between males and females during incubation differed among pairs. Higher attendance in the nest area by females during incubation appeared to be associated with more young fledged among successful pairs.Une condition indispensable pour examiner les retombées de la perturbation anthropique sur la nidification aviaire est reproducteurs. On a étudié les facteurs qui ont influencé la présence au nid et les budgets temps-activités des faucons pèlerins (Falco peregrinus anatum) nichant le long de la rivière Tanana en Alaska en 1995, 1996 et 1997. Tout d'abord, comme on doit s'y attendre de la plupart des espèces aviaires dont les petits sont nidicoles et où les soins sont biparentaux, les femelles étaient présentes au nid plus que les mâles et, à mesure que le cycle de nidification avançait, la présence des femelles diminuait à des niveaux semblables à ceux de la présence des mâles. Deuxièmement, la présence aux environs du nid suivait un rythme circadien, les parents passant moins de temps près du nid au début de la matinée et en fin de soirée - temps forts de la chasse - qu'en fin de et femelles durant l'incubation différait selon les paires. Durant l'incubation, la présence plus affirmée des femelles dans la zone du nid semblait être associée à un nombre supérieur de petits qui prenaient leur envol chez les paires qui avaient réussi à se reproduire
Challenging Existing Perspectives of “Ideal” Characteristics of Teachers of English
Addressing their concern about status inequalities among teachers of English, in this viewpoint paper, the authors argue that characteristics related to association with an Inner Circle country, Caucasian appearance, middle and upper class socio-economic status and university education seem to be related to the image of the “ideal” teacher of English to Speakers of Other Languages (ESOL). This image, in turn, affects job prospects, salary and recognition by students and peers. By reflecting on their experiences in relation to how well they fit the “ideal”, the authors show that the construct is highly flawed and potentially destructive and divisive. To redress the inequities brought about by perceptions of the “ideal” language teacher, strategies pertaining to providing role models, raising awareness, providing tools and techniques for improving proficiency, and discussing status and identity issues are suggested for assigning competence to people who do not fit the idealized image. The article aims to offer a fairly new perspective from the unique experiences of three established language teachers, one from each of Kachru\u27s (1992) circles, and to also raise awareness about the need to accept greater diversity among language teaching professionals.
Keywords: teacher identity, teacher characteristics, teacher employment, NNESTs, non-native teachers of English, assigning competence, narrative enquir
Unexpected Features of Supersymmetry with Central Charges
It is shown that N=2 supersymmetric theories with central charges present
some hidden quartic symmetry. This enables us to construct representations of
the quartic structure induced by superalgebra representations.Comment: 14 pages, more details have been given, to appear in J. Phys.
Review of upper limb kinematics after cervical spinal cord injury: Implications for rehabilitation
IntroductionThe aim of this literature review is to provide a clear understanding of motor control and kinematic changes during open-chain upper limb (UL) movements after tetraplegia.MethodUsing data from MEDLINE between 1966 and August 2014, we investigated kinematic UL studies after tetraplegia.ResultsWe included fourteen control case and three series case studies with a total of 161 SCI participants and 126 healthy control participants. SCI participants efficiently perform a broad range of tasks with their UL This is achieved by effective scapulothoracic and glenohumeral compensation which provide a dynamic mechanical coupling between the shoulder and elbow joints thus palliating elbow extension despite triceps brachii paralysis. The mechanism is incomplete, however, since C5-C6 SCI individuals are forced to reduce overhead workspace to keep the elbow extended and to maintain the mechanical dynamic interaction between the shoulder and elbow. Furthermore, motion slowing is a clear kinematic characteristic, caused by:– decreased strength;– triceps brachii paralysis disrupting normal agonist-antagonist co-contraction;– accuracy requirements at movement endpoint;– grasping.Grasping requires a prolonged deceleration phase during transport to ensure hand placement with respect to the to-be-grasped object then wrist extension during grasping to elicit either whole hand or lateral grip. Contrary to the normal pattern, where grasping is prepared during the transport phase, SCI individuals transport the wrist in flexion leading to passive finger opening that did not attest a grip preparation particularly if object size is greater than maximal grip aperture. The pattern (wrist flexed then extended) indicates that reaching and grasping are performed consecutively suggesting that these two phases are independent. Elbow extension restoration causes increased elbow stiffness resulting in increased movement velocity, reduced need for glenohumeral compensation, and overall improved motor control.ConclusionRehabilitation and surgical restoration should take these kinematic characteristics into account to reinforce proximal and distal compensations allowing elbow extension and grasp using tenodesis and consequently favoring greater autonomy of individuals after SCI
Ternary algebras and groups
We construct explicitly groups associated to specific ternary algebras which
extend the Lie (super)algebras (called Lie algebras of order three). It turns
out that the natural variables which appear in this construction are variables
which generate the three-exterior algebra. An explicit matrix representation of
a group associated to a peculiar Lie algebra of order three is constructed
considering matrices with entry which belong to the three exterior algebra.Comment: 11 pages contribution to the 5th International Symposium on Quantum
Theory and Symmetries (QTS5
Design of the Spitzer Space Telescope Heritage Archive
It is predicted that Spitzer Space Telescope’s cryogen will run out in April 2009, and the final reprocessing for the cryogenic mission is scheduled to end in April 2011, at which time the Spitzer archive will be transferred to the NASA/IPAC Infrared Science Archive (IRSA) for long-term curation. The Spitzer Science Center (SSC) and IRSA are collaborating to design and deploy the Spitzer Heritage Archive (SHA), which will supersede the current Spitzer archive. It will initially contain the raw and final reprocessed cryogenic science products, and will eventually incorporate the final products from the Warm mission. The SHA will be accompanied by tools deemed necessary to extract the full science content of the archive and by comprehensive documentation
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