980 resultados para Vertical take-off
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Proteins stored in insect hemolymph may serve (is a source of amino acids and energy for metabolism, and development. The expression of the main storage proteins was assessed in bacterial-challenged honey bees using real-time (RT)-PCH and Western blot.. After ensuring that. the immune system had, been activated by measuring the ensuing expression (, the innate immune response genes, defensin-1 (def-1) and prophenoloxidase (pro PO), we verified the expression of four genes encoding storage proteins. The levels of vitellogenin (vg) mRNA and of the respective protein. were significantly lowered in bees injected with bacteria or water only (injury). An equivalent response was observed in orally-infected bees. The levels of apolipophorin II/I (apoLP-II/I) and hexamerin (hex 70a) mRNAs did not significantly change, but levels of Hex 70a protein subunit showed a substantial decay after bacterial challenge or injury. Infection also caused a strong reduction in the levels of apoLP-III transcripts. Our findings are consistent with a down-regulation, of the express and accumulation of storage proteins as a consequence of activation of the immune system, suggesting that this phenomenon. represents a strategy to redirect resources to combat injury or infection. (C) 2009 Wiley Periodicals, Inc.
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What are the social factors that can change apathy to action? Two survey-based field studies were conducted with National Tertiary Education Union members, to investigate the interplay between individual and group-based psychological processes in union support. The first study was conducted in an industrially calm context and the second, following a national strike in the Australian university sector. Drawing on social identity theory, the studies investigated both individual and group-related factors including: (a) instrumental and ideological attitudes; (b) employee identity; (c) perceptions of employment-related threat, and of relations with management; and (d) normative support for the union amongst fellow employees. Consistent with predictions, groupbased factors (i.e., perceived context and normative support) moderated the role of instrumental and ideological beliefs in the behavioural expression of union support. A subset of participants, who responded at both times, provided additional evidence for the importance of contextually activated group-processes to changes in union behaviour.
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There is a widely held paradigm that mangroves are critical for sustaining production in coastal fisheries through their role as important nursery areas for fisheries species. This paradigm frequently forms the basis for important management decisions on habitat conservation and restoration of mangroves and other coastal wetlands. This paper reviews the current status of the paradigm and synthesises the information on the processes underlying these potential links. In the past, the paradigm has been supported by studies identifying correlations between the areal and linear extent of mangroves and fisheries catch. This paper goes beyond the correlative approach to develop a new framework on which future evaluations can be based. First, the review identifies what type of marine animals are using mangroves and at what life stages. These species can be categorised as estuarine residents, marine-estuarine species and marine stragglers. The marine-estuarine category includes many commercial species that use mangrove habitats as nurseries. The second stage is to determine why these species are using mangroves as nurseries. The three main proposals are that mangroves provide a refuge from predators, high levels of nutrients and shelter from physical disturbances. The recognition of the important attributes of mangrove nurseries then allows an evaluation of how changes in mangroves will affect the associated fauna. Surprisingly few studies have addressed this question. Consequently, it is difficult to predict how changes in any of these mangrove attributes would affect the faunal communities within them and, ultimately, influence the fisheries associated with them. From the information available, it seems likely that reductions in mangrove habitat complexity would reduce the biodiversity and abundance of the associated fauna, and these changes have the potential to cause cascading effects at higher trophic levels with possible consequences for fisheries. Finally, there is a discussion of the data that are currently available on mangrove distribution and fisheries catch, the limitations of these data and how best to use the data to understand mangrove-fisheries links and, ultimately, to optimise habitat and fisheries management. Examples are drawn from two relatively data-rich regions, Moreton Bay (Australia) and Western Peninsular Malaysia, to illustrate the data needs and research requirements for investigating the mangrove-fisheries paradigm. Having reliable and accurate data at appropriate spatial and temporal scales is crucial for mangrove-fisheries investigations. Recommendations are made for improvements to data collection methods that would meet these important criteria. This review provides a framework on which to base future investigations of mangrove-fisheries links, based on an understanding of the underlying processes and the need for rigorous data collection. Without this information, the understanding of the relationship between mangroves and fisheries will remain limited. Future investigations of mangrove-fisheries links must take this into account in order to have a good ecological basis and to provide better information and understanding to both fisheries and conservation managers.
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Light is generally regarded as the most likely cue used by zooplankton to regulate their vertical movements through the water column. However, the way in which light is used by zooplankton as a cue is not well understood. In this paper we present a mathematical model of diel vertical migration which produces vertical distributions of zooplankton that vary in space and time. The model is used to predict the patterns of vertical distribution which result when animals are assumed to adopt one of three commonly proposed mechanisms for vertical swimming. First, we assume zooplankton tend to swim towards a preferred intensity of light. We then assume zooplankton swim in response to either the rate of change in light intensity or the relative rate of change in light intensity. The model predicts that for all three mechanisms movement is fastest at sunset and sunrise and populations are primarily influenced by eddy diffusion at night in the absence of a light stimulus. Daytime patterns of vertical distribution differ between the three mechanisms and the reasons for the predicted differences are discussed. Swimming responses to properties of the light field are shown to be adequate for describing diel vertical migration where animals congregate in near surface waters during the evening and reside at deeper depths during the day. However, the model is unable to explain how some populations halt their ascent before reaching surface waters or how populations re-congregate in surface waters a few hours before sunrise, a phenomenon which is sometimes observed in the held. The model results indicate that other exogenous or endogenous factors besides light may play important roles in regulating vertical movement.
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A fully explicit formula for the eigenvalues of Casimir invariants for U-q(gl(m/n)) is given which applies to all unitary irreps. This is achieved by making some interesting observations on atypicality indices for irreps occurring in the tensor product of unitary irreps of the same type. These results have applications in the determination of link polynomials arising from unitary irreps of U-q(gl(m/n)).
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The digenean originally designated Lepidapedon (Lepidapedon) ostorhinchi is redescribed from its type-host, Oplegnathus woodwardi [= Ostorhinchus conwaii], from the waters off Western Australia. The discovery of a uroproct indicates that the generic designation is wrong and the worm should be Paralepidapedon ostorhinchi (Korotaeva, 1974) n. comb. It is distinct from its nearest relative, P. hoplognathi (Yamaguti, 1938), in having: a prominent post-oral ring; a distinct oesophagus; short anterior diverticula on the caeca; a long external seminal vesicle, ensheathed in a membrane bound gland-cell mass; and less anteriorly extensive vitellarium.
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Background-Coronary artery bypass graft surgery with cardiopulmonary bypass is a safe, routine procedure. Nevertheless, significant morbidity remains, mostly because of the body`s response to the nonphysiological nature of cardiopulmonary bypass. Few data are available on the effects of off-pump coronary artery bypass graft surgery (OPCAB) on cardiac events and long-term clinical outcomes. Methods and Results-In a single-center randomized trial, 308 patients undergoing coronary artery bypass graft surgery were randomly assigned: 155 to OPCAB and 153 to on-pump CAB (ONCAB). Primary composite end points were death, myocardial infarction, further revascularization (surgery or angioplasty), or stroke. After 5-year follow-up, the primary composite end point was not different between groups (hazard ratio 0.71, 95% CI 0.41 to 1.22; P=0.21). A statistical difference was found between OPCAB and ONCAB groups in the duration of surgery (240 +/- 65 versus 300 +/- 87.5 minutes; P<0.001), in the length of ICU stay (19.5 +/- 17.8 versus 43 +/- 17.0 hours; P<0.001), time to extubation (4.6 +/- 6.8 versus 9.3 +/- 5.7 hours; P<0.001), hospital stay (6 +/- 2 versus 9 +/- 2 days; P<0.001), higher incidence of atrial fibrillation (35 versus 4% of patients; P<0.001), and blood requirements (31 versus 61% of patients; P<0.001), respectively. The number of grafts per patient was higher in the ONCAB than the OPCAB group (2.97 versus 2.49 grafts/patient; P<0.001). Conclusions-No difference was found between groups in the primary composite end point at 5-years follow-up. Although OPCAB surgery was related to a lower number of grafts and higher episodes of atrial fibrillation, it had no significant implications related to long-term outcomes.
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Background. We aimed at investigating the influence of diabetic neuropathy and previous history of plantar ulcers on electromyography (EMG) of the thigh and calf and on vertical ground reaction forces during gait. Methods. This study involved 45 adults divided into three groups: a control group (n = 16), diabetic neuropathic group (n = 19) and diabetic neuropathic group with previous history of plantar ulceration (it = 10). EMG of the right vastus lateralis, lateral gastrocnemius and tibialis anterior were studied during the stance phase. The peaks and time of peak occurrence were determined and a co-activation index between tibialis anterior and lateral gastrocnemius. In order to represent the effect of the changes in EMG, the first and second peaks and the minimum value of the vertical ground reaction force were also determined. Inter-group comparisons of the electromyographical and ground reaction forces variables were made using three MANCOVA (peaks and times of EMG and peaks of force) and one ANCOVA (co-activation index). Findings. The ulcerated group presented a delayed in the time of the lateral gastrocnemius and vastus lateralis peak occurrence in comparison to control`s. The lateral gastrocnemius delay may be related to the lower second vertical peak in diabetic subjects. However, the delay of the vastus lateralis did not cause any significant change on the first vertical peak. Interpretations. The vastus lateralis and lateral gastrocnemius delay demonstrate that ulcerated diabetic neuropathic patients have a motor deficit that could compromise their ability to walk, which was partially confirmed by changes on ground reaction forces during the push-off phase. (c) 2007 Elsevier Ltd. All rights reserved.
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Background: The Cambridge Cognitive Examination (CAMCOG) is a useful test in screening for Alzheimer`s disease (AD). However, the interpretation of CAMCOG cut-off scores is problematic and reference values are needed for different educational strata. Given the importance of earlier diagnoses of mild dementia, new cut-off values are required which take into account patients with low levels of education. This study aims to evaluate whether the CAMCOG can be used as an accurate screening test among AD patients and normal controls with different educational levels. Methods: Cross-sectional assessment was undertaken of 113 AD and 208 elderly controls with heterogeneous educational levels (group 1: 1-4 years; group 2: 5-8 years; and group 3: >= 9 years) from a geriatric clinic. submitted to a thorough diagnostic evaluation for AD including the Cambridge Examination for Mental Disorders of the Elderly (CAMDEX). Controls had no cognitive or mood complaints. Sensitivity (SE) and specificity (SP) for the CAMCOG in each educational group was assessed with receiver-operator-characteristic (ROC) curves. Results: CAMCOG mean values were lower when education was reduced in both diagnostic groups (controls - group 1: 87; group 2: 91; group 3: 96; AD - group 1: 63; group 2: 62; group 3: 77). Cutoff scores for the three education groups were 79, 80 and 90, respectively. SE and SP varied among the groups (group 1: 88.1% and 83.5%; group 2: 84.6% and 96%; group 3: 70.8% and 90%). Conclusion: The CAMCOG can be used as a cognitive test for patients with low educational level with good accuracy. Patients with higher education showed lower scores than previously reported.
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Retinal neurons with distinct dendritic morphologies are likely to comprise different cell types, subject to three important caveats. First, it is necessary to avoid creating “artificial” cell types based on arbitrary criteria—for example, the presence of two or three primary dendrites. Second, it is essential to take into account changes in morphology with retinal eccentricity and cell density. Third, the retina contains imperfections like any natural system and a significant number of retinal neurons display aberrant morphologies or make aberrant connections that are not typical of the population as a whole. Many types of retinal ganglion cells show diverse patterns of tracer coupling, with the simplest pattern represented by the homologous coupling shown by On-Off direction-selective (DS) ganglion cells in the rabbit retina. Neighboring DS ganglion cells with a common preferred direction have regularly spaced somata and territorial dendritic fields, whereas DS ganglion cells with different preferred directions may have closely spaced somata and overlapping dendritic fields.
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Objective To delineate the effects of extracorporeal bypass on biomarkers of hemostasis, fibrinolysis, and inflammation and clinical sequelae. Methods Patients were assigned prospectively and randomly to either on-pump (n=41) or off-pump (n=51) coronary bypass surgery. The concentrations of C-reactive protein, fibrinogen, D-dimer, and plasminogen activator inhibitor type-1 in blood were quantified before and after (1 and 24 h) surgery. Similar surgical and anesthetic procedures were used for both groups. Clinical events were assessed during initial hospitalization and at the end of I year. Results The concentrations of plasminogen activator inhibitor type-1 and D-dimer were greater compared with preoperative values 1 and 24 h after surgery in both groups, but their concentrations increased to a greater extent 24 h after surgery in the on-pump group (P<0.01). The concentration of C-reactive protein did not change appreciably immediately after surgery in either group but increased in a parallel manner 24 h after either on-pump or off-pump surgery (P<0.01). Bypass surgery in the on-pump group was associated with greater blood loss during surgery and more bleeding after surgery (P <= 0.01). The incidence of all other complications was similar in the two groups. Conclusion On-pump surgery was associated with biochemical evidence of a prothrombotic state early after surgery but no greater incidence of thrombotic events was observed. The prothrombotic state might be a consequence of extracorporeal bypass, compensation in response to more bleeding, or both in patients undergoing on-pump surgery. Coron Artery Dis 20:100-105 (C) 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins.
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Background/Aims: The expression of cancer/testis antigens (CTAs) on additional normal tissues or stem cells may restrict their use as cancer targets. The objective of the present study was to evaluate the mRNA levels of some CTAs in a variety of tissues. Materials and Methods: mRNA of pericytes, fibroblasts and mesenchymal stem cells (MSCs) derived from adult and fetal tissues, human umbilical vein endothelial cells, MSC-derived adipocytes, selected normal tissues and control cancer cell lines (CLs) were extracted and quantitative polymerase chain reaction was performed for MAGED1, PRAME, CTAG1B, MAGEA3 and MAGEA4. Results: MAGED1 was expressed in all normal tissues and cells evaluated. CTAG1B was expressed at levels comparable to control CLs on MSCs derived from arterial, fetal skin, adipose tissue and saphenous vein, heart, brain and skin tissues. MAGEA4 was detected only in fibroblasts and differentiated adipocytes from MSCs, at levels comparable to the control CLs. Conclusion: The potential use of CTAs in immunotherapy should take into account the potential off-target effects on MSCs.