1,967 research outputs found
A Preliminary Study of Trunk Kinematics during Walking in Normal Subjects
The purpose of this study was to systematically describe the three-dimensional trunk kinematics in normal subjects, to establish a baseline for comparison to future research in gait analysis and aid in the identification of pathological gait. Seventeen volunteers between the ages of twenty and fifty, who met criteria for normal subjects, participated in this study. Trunk kinematic data were collected using an optoelectronic technique. An ensemble average of trunk kinematic data in each of the cardinal planes was plotted in degrees of motion versus percentage of gait cycle. A distinct pattern of trunk kinematics during gait was found in this study. Trunk motion relative to the pelvis was of greater magnitude than motion relative to the lab in the frontal and transverse planes. Inter-subject variability ranged from 37% to 644%, with the greatest amount of variability occurring in measurements of trunk movement relative to the lab in all three planes. Stride to stride variability within subjects ranged from 28% to 182%, with the greatest amount of intra-subject variability in trunk movements relative to the pelvis
Transient activation of mucosal effector immune responses by resident intestinal bacteria in normal hosts is regulated by interleukin-10 signalling
Interleukin-10 (IL-10) is a key regulator of mucosal homeostasis. In the current study we investigated the early events after monoassociating germ-free (GF) wild type (WT) mice with an E. coli strain that we isolated previously from the cecal contents of a normal mouse housed under specific pathogen free (SPF) conditions. Our results show that IFN-γ secreted by mesenteric lymph node (MLN) cells from both IL-10 deficient mice and WT mice, stimulated ex vivo with E. coli lysate, was dramatically higher at day 4 after monoassociation compared to IFN-γ secreted by cells from GF mice without E. coli colonization. Production of IFN-γ rapidly and progressively declined after colonization of WT but not IL-10 deficient mice. E. coli lysate-stimulated WT MLN cells also produced IL-10 that peaked at day 4 and subsequently declined, but not as precipitously as IFN-γ. WT cells that express CD4, CD8, and NKp46 produced IFN-γ; WT CD4-positive cells and B cells produced IL-10. Recombinant IL-10 added to E. coli-stimulated MLN cell cultures inhibited IFN-γ secretion in a dose-dependent fashion. MLN cells from WT mice treated in vivo with neutralizing anti-IL-10 receptor antibody produced more IFN-γ compared with MLN cells from isotype control antibody-treated mice. These findings show that a resident E. coli that induces chronic colitis in monoassociated IL-10 deficient mice rapidly but transiently activates the effector immune system in normal hosts, in parallel with induction of protective IL-10 produced by B cells and CD4(+) cells that subsequently suppresses this response to mediate mucosal homeostasis. This article is protected by copyright. All rights reserved
Robustness trade-offs and host–microbial symbiosis in the immune system
The immune system provides organisms with robustness against pathogen threats, yet it also often adversely affects the organism as in autoimmune diseases. Recently, the molecular interactions involved in the immune system have been uncovered. At the same time, the role of the bacterial flora and its interactions with the host immune system have been identified. In this article, we try to reconcile these findings to draw a consistent picture of the host defense system. Specifically, we first argue that the network of molecular interactions involved in immune functions has a bow-tie architecture that entails inherent trade-offs among robustness, fragility, resource limitation, and performance. Second, we discuss the possibility that commensal bacteria and the host immune system constitute an integrated defense system. This symbiotic association has evolved to optimize its robustness against pathogen attacks and nutrient perturbations by harboring a broad range of microorganisms. Owing to the inherent propensity of a host immune system toward hyperactivity, maintenance of bacterial flora homeostasis might be particularly important in the development of preventive strategies against immune disorders such as autoimmune diseases
Time Budget in Two Desert Gerbils: is the Diet Important?
We studied time budgets and dietary intake in two desert gerbillids, Psammomys obesus, a diurnal herbivore, and Meriones crassus, a nocturnal granivore feeding three different types of diet (millet seeds together with leaves of Atriplex halimus for M. crassus, fresh leaves of A. halimus or fresh stems of Anabasis syriaca for P. obesus). M. crassus spent the lowest proportion of its time budget for feeding compared to P. obesus. Number of feeding sessions in M. crassus was approximately the same but each separate feeding session was almost three times shorter than those in P. obesus. No difference in temporal pattern of feeding was found between P. obesus fed different plants, in spite of sharp differences in chemical composition of food. P. obesus fed A. halimus was active significantly less time than M. crassus, whereas P. obesus fed A. syriaca stayed active the same time as M. crassus. Dry matter intake of P. obesus fed A. halimus was much higher than that of M. crassus and dry matter intake of P. obesus fed A. syriaca was lower than even that in M. crassus
Isospin splitting of the nucleon mean field
The isospin splitting of the nucleon mean field is derived from the Brueckner
theory extended to asymmetric nuclear matter. The Argonne V18 has been adopted
as bare interaction in combination with a microscopic three body force. The
isospin splitting of the effective mass is determined from the
Brueckner-Hartree-Fock self-energy: It is linear acording to the Lane ansatz
and such that for neutron-rich matter. The symmetry potential
is also determined and a comparison is made with the predictions of the
Dirac-Brueckner approach and the phenomenological interactions. The theoretical
predictions are also compared with the empirical parametrizations of neutron
and proton optical-model potentials based on the experimental nucleon-nucleus
scattering and the phenomenological ones adopted in transport-model simulations
of heavy-ion collisions. The direct contribution of the rearrangement term due
to three-body forces to the single particle potential and symmetry potential is
discussed.Comment: 8 pages, 10 figure
Identification and Cross-Directional Control of Coating Processes: Theory and Experiments
Of special industrial interest is the cross-directional control of continuous coating processes, where the cross-direction refers to the direction perpendicular to the substrate movement. The objective of the controller is to maintain a uniform coating under unmeasured process disturbances based on assumptions relevant to coating processes found in industry. A model for control design is developed. This model is used to derive a model predictive controller with the objective of maintaining flat profiles of coating across the substrate by varying the liquid flows along the cross direction. Actuator constraints, measurement noise, and model uncertainty are investigated to determine which of these limit the achivable closed loop performance. From a knowledge of the effect of these limitations on performance we determine how the plant could be modified to improve the coating uniformity. The theory developed throughout the paper is rigorously verified though experiments on an industrial pilot plant
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First Report of NRG Oncology/Radiation Therapy Oncology Group 0622: A Phase 2 Trial of Samarium-153 Followed by Salvage Prostatic Fossa Irradiation in High-Risk Clinically Nonmetastatic Prostate Cancer After Radical Prostatectomy.
PURPOSE: To investigate the utility of 153Sm lexidronam (Quadramet) in the setting of men with prostate cancer status post radical prostatectomy who develop biochemical failure with no clinical evidence of osseous metastases.
PATIENTS AND METHODS: Trial NRG Oncology RTOG 0622 is a single-arm phase 2 trial that enrolled men with pT2-T4, N0-1, M0 prostate cancer status post radical prostatectomy, who meet at least 1 of these biochemical failure criteria: (1) prostate-specific antigen (PSA) \u3e 1.0 ng/mL; (2) PSA \u3e 0.2 ng/mL if Gleason score 9 to 10; or (3) PSA \u3e 0.2 ng/mL if N1. Patients received 153Sm (2.0 mCi/kg intravenously × 1) followed by salvage external beam radiation therapy (EBRT) to the prostatic fossa (64.8-70.2 Gy in 1.8-Gy daily fractions). No androgen deprivation therapy was allowed. The primary objective was PSA response within 12 weeks of receiving 153Sm. The secondary objectives were to: (1) assess the completion rate for the regimen of 153Sm and EBRT; (2) evaluate the hematologic toxicity and other adverse events (AEs) at 12 and 24 weeks; and (3) determine the freedom from progression rate at 2 years.
RESULTS: A total of 60 enrolled eligible patients were included in this analysis. Median follow-up was 3.97 years. A PSA response was achieved in 7 of 52 evaluable patients (13.5%), compared with the 25% hypothesized. The 2-year freedom from progression rate was 25.5% (95% confidence interval 14.4%-36.7%), and the biochemical failure rate was 64.4% (95% CI 50.5%-75.2%). Samarium-153 was well tolerated, with 16 (of 60) grade 3 to 4 hematologic AEs and no grade 5 hematologic AEs. Radiation therapy was also well tolerated, with no grade 3 to 5 acute radiation therapy-related AEs and 1 grade 3 to 4 and no grade 5 late radiation therapy-related AEs.
CONCLUSIONS: Trial NRG Oncology RTOG 0622 did not meet its primary endpoint of PSA response, although the regimen of 153Sm and salvage EBRT was well tolerated. Although the toxicity profile supports study of 153Sm in high-risk disease, it may not be beneficial in men receiving EBRT
T cell-mediated oral tolerance is intact in germ-free mice
Commensal enteric bacteria stimulate innate immune cells and increase numbers of lamina propria and mesenteric lymph node (MLN) T and B lymphocytes. However, the influence of luminal bacteria on acquired immune function is not understood fully. We investigated the effects of intestinal bacterial colonization on T cell tolerogenic responses to oral antigen compared to systemic immunization. Lymphocytes specific for ovalbumin–T cell receptor (OVA–TCR Tg+) were transplanted into germ-free (GF) or specific pathogen-free (SPF) BALB/c mice. Recipient mice were fed OVA or immunized subcutaneously with OVA peptide (323–339) in complete Freund's adjuvant (CFA). Although the efficiency of transfer was less in GF recipients, similar proportions of cells from draining peripheral lymph node (LN) or MLN were proliferating 3–4 days later in vivo in GF and SPF mice. In separate experiments, mice were fed tolerogenic doses of OVA and then challenged with an immunogenic dose of OVA 4 days later. Ten days after immunization, lymphocytes were restimulated with OVA in vitro to assess antigen-specific proliferative responses. At both high and low doses of OVA, cells from both SPF and GF mice fed OVA prior to immunization had decreased proliferation compared to cells from control SPF or GF mice. In addition, secretion of interferon (IFN)-γ and interleukin (IL)-10 by OVA–TCR Tg+ lymphocytes was reduced in both SPF and GF mice fed OVA compared to control SPF or GF mice. Unlike previous reports indicating defective humoral responses to oral antigen in GF mice, our results indicate that commensal enteric bacteria do not enhance the induction of acquired, antigen-specific T cell tolerance to oral OVA
Carrying capacity and goat botanical diet composition in an arid ecosystem, Lavalle, Argentina
8 págs, 1 tabla.-- Comunicación presentada a la XLV Reunión Científica de la Sociedad Española para el Estudio de los Pastos: "Producciones agroganaderas: gestión eficiente y conservación del medio natural" (Gijón, 28 de mayo al 3 de junio de 2005).[ES] El trabajo se llevó a cabo en el departamento de Lavalle, Mendoza, Argentina. Las unidades de pastos, más importantes desde el punto de vista forrajero son: Algarrobal de Prosopis flexuosa; Matorral con Atriplex lampa (zampal); Matorral con Tricomaria usillo
(usillar); Matorral degradado con Larrea cuneifolia (jarillal) y Medanal. Los objetivos del estudio fueron estimar la capacidad sustentadora de las diferentes unidades y la composición botánica de la ingesta de los caprinos. La estimación de dicha capacidad, expresada en hectáreas por Unidades Ganadera Caprinas (ha UGC–1), se realizó mediante el método de Point Quadrat modificado para el Monte. Y por medio del análisis microhistológico de heces se determinó la composición estacional de la ingesta.Los valores medios anuales de capacidad sustentadora fueron: Algarrobal, 1,2;
Zampal, 1,7; Usillar, 3,5; Jarillal, 5,8 y Médanos, 4,3 ha UGC-1. La composición de la
ingesta varió durante las estaciones, observándose una predominancia de las especies arbustivas, las gramíneas perennes aparecieron en muy baja frecuencia en todas las estaciones. El Algarrobal y el Zampal son las unidades de mayor importancia forrajera, presentando receptividades ganaderas más altas y una oferta forrajera más estable a lo largo del año, respecto del resto de las unidades de pastos analizadas.[EN] The work was carried out in the department of Lavalle, Mendoza, Argentina. The units of pastures, more important from the forage matter are: Algarrobal of Prosopis flexuosa; Shrubland with Atriplex lampa (zampal); Shrubland with Tricomaria usillo (usillar); Shrubland degraded with Larrea cuneifolia (jarillal) and Dunes. The aims of the study were to estimate the carrying capacity of the different units and the botanical composition of goat diets. The carrying capacity, expressed in hectares by Units Goat (ha UG-1), was measured by the method of Point Quadrat modified for Monte and the seasonal
botanical composition of goat diets, was determined by microhistological analysis of
faeces. The annual average values of carrying capacity were: Algarrobal, 1.2; Zampal, 1.7; Usillar, 3.5; Jarillal, 5.8 and Dunes, 4.3 ha UG-1. The composition of the diet varied during the seasons, the predominance of the shrubs species were observed, the perennial grass appeared in low frequency in all the seasons. The Algarrobal and the Zampal are the units
of greater forage importance, where forage receptivity are higher and with more stable
production throughout the year, respect to the others units of pastures analyzed.Peer reviewe
Il back-reshoring manifatturiero nei processi di internazionalizzazione: inquadramento teorico ed evidenze empiriche
Obiettivo del paper. Il paper si prefigge di inquadrare il fenomeno del back-reshoring manifatturiero - ovvero la rilocalizzazione nel paese di origine delle attivit\ue0 produttive precedentemente delocalizzate all\u2019estero -nell\u2019ambito dei processi di internazionalizzazione dell\u2019impresa.
Metodologia. L\u2019approccio metodologico utilizzato \ue8 di tipo esplorativo, data la mancanza di una letteratura consolidata specifica. In particolare si \ue8 fatto ricorso a dati secondari raccolti in maniera originale attraverso una pluralit\ue0 di fonti.
Risultati. \uc8 stata identificata una definizione operativa di back-reshoring inserendo tale fenomeno in un framework teorico rappresentativo del processo evolutivo di internazionalizzazione dell\u2019impresa. Sulla base delle evidenze empiriche, sono state proposte delle direttrici di sviluppo per future attivit\ue0 di ricerca.
Implicazioni manageriali. Sono state evidenziate le conseguenze che il fenomeno pu\uf2 avere sulla competitivit\ue0 e le performance economica delle imprese che adottano strategie di reshoring.
Originalit\ue0 e limiti della ricerca. Il principale elemento di originalit\ue0 del lavoro \ue8 rappresentato dall\u2019utilizzo di una metodologia di ricerca esplorativa che ha coniugato l\u2019analisi della letteratura di International business e quella di Supply chain management con l\u2019analisi di evidenze empiriche raccolte in maniera originaria. Le scelte metodologiche effettuate rappresentano anche il principale limite del contributo, le cui conclusioni non sono generalizzabili ma costituiscono la base per ulteriori approfondimenti del dibattito scientifico, per i quali si sono identificate delle specifiche direttrici
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