2,501 research outputs found
Regulation of NKG2D-Dependent NK Cell Functions: The Yin and the Yang of Receptor Endocytosis.
Natural-killer receptor group 2, member D (NKG2D) is a well characterized natural killer (NK) cell activating receptor that recognizes several ligands poorly expressed on healthy cells but up-regulated upon stressing stimuli in the context of cancer or viral infection. Although NKG2D ligands represent danger signals that render target cells more susceptible to NK cell lysis, accumulating evidence demonstrates that persistent exposure to ligand-expressing cells causes the decrease of NKG2D surface expression leading to a functional impairment of NKG2D-dependent NK cell functions. Upon ligand binding, NKG2D is internalized from the plasma membrane and sorted to lysosomes for degradation. However, receptor endocytosis is not only a mechanism of receptor clearance from the cell surface, but is also required for the proper activation of signalling events leading to the functional program of NK cells. This review is aimed at providing a summary of current literature relevant to the molecular mechanisms leading to NKG2D down-modulation with particular emphasis given to the role of NKG2D endocytosis in both receptor degradation and signal propagation. Examples of chronic ligand-induced down-regulation of NK cell activating receptors other than NKG2D, including natural cytotoxicity receptors (NCRs), DNAX accessory molecule-1 (DNAM1) and CD16, will be also discussed
Papillomavirus E5: the smallest oncoprotein with many functions
Papillomaviruses (PVs) are established agents of human and animal cancers. They infect cutaneous and mucous epithelia. High Risk (HR) Human PVs (HPVs) are consistently associated with cancer of the uterine cervix, but are also involved in the etiopathogenesis of other cancer types. The early oncoproteins of PVs: E5, E6 and E7 are known to contribute to tumour progression. While the oncogenic activities of E6 and E7 are well characterised, the role of E5 is still rather nebulous. The widespread causal association of PVs with cancer makes their study worthwhile not only in humans but also in animal model systems. The Bovine PV (BPV) system has been the most useful animal model in understanding the oncogenic potential of PVs due to the pivotal role of its E5 oncoprotein in cell transformation. This review will highlight the differences between HPV-16 E5 (16E5) and E5 from other PVs, primarily from BPV. It will discuss the targeting of E5 as a possible therapeutic agent
Freely chosen positive intergroup imagery causes improved outgroup emotions and encourages increased contact seeking immediately and at follow up
In two ethnic contexts, we focus on volitional imagined contact as a potential method to increase individuals’ readiness to voluntarily initiate intergroup contact and engage in responses with implications for reconciliation. In Study 1, we used a quasi-experimental design to determine the causal role of volitional (vs. non-volitional) valenced imagined contact with a refugee on downstream processes. Irrespective of volition, positive visualizations led to more positive outgroup emotions, action tendencies and contact seeking, however manipulated volition amplified the differential impact of valenced contact on outgroup emotions: Negative contact was more detrimental when freely chosen, than forced, whereas positive contact was equally beneficial irrespective of volition. Study 2 investigated factors driving individuals’ choices for positive (vs. negative) imagined contact in conflict-laden Cyprus and assessed immediate and longer-term consequences of such choices for interethnic contact seeking. In both studies, participants chose to engage in imagined contact of a valence that aligned with their prior contact histories consistent with an evaluative fit mechanism. Volitional valenced imagery predicted participants’ active and self-initiated contact seeking immediately and after a 2-week period. Hence, volitional intergroup imagery as a ‘mental contact script’ prepares individuals for actual intergroup contact and behaviors with implications for intergroup reconciliation and cohesion
Interactions between nutrition and gastrointestinal infections with parasitic nematodes in goats
Parasitic nematodes of the digestive tract remain one of the main constraints to goat production both in temperate and tropical
countries. The usual mode of control of these gastrointestinal nematodes (GIN) based on the repeated use of anthelmintics
is now strongly questioned because of the increasing development of resistance to these molecules. Among the alternative
methods to anthelmintics currently available, the manipulation of host nutrition in order to improve the host resistance and/or
resilience to parasitic infections seems to represent one of the most promising options to reduce the dependence on conventional
chemotherapy and to favour the sustainable control of gastro intestinal nematode infections. This paper will review the available
information on the interactions between nutrition and nematode parasitism in dairy or meat goats both in temperate and tropical
conditions. It will refer to quantitative aspects of the diet (influence of the protein and/or energy parts) as well as to qualitative
components (effects of plant secondary metabolites on worm biology) and will discuss the specificities of goats in regard of
theses interactions
Innovative 3-D Printing Processing Techniques for Flexible and Wearable Planar Rectennas
This work demonstrates the use of a low-cost, lossy, flexible substrate processed by novel 3-D printing techniques which significantly mitigate its intrinsic losses, thus providing performance comparable to those of traditional substrates. These processing techniques are applied to both microstrip and coplanar waveguide structures; they are first derived theoretically, starting from the electromagnetic theory of modes propagation, then numerically validated by full-wave analysis, and finally experimentally verified. The design of a miniaturized 868 MHz rectenna, adopting a coplanar-fed patch antenna based on the proposed fabrication approach, is presented. By means of nonlinear/electromagnetic co-design, the antenna is directly matched to the rectifier. A 30-dB power range starting from -20 dBm is considered. Direct matching allows to get rid of a dedicated matching network and its associated losses, resulting in a slight efficiency increase and a significant reduction of the overall dimensions. Finally, the 3-Dprinted prototype is presented: the overall rectenna performance proves that design freedom enabled by 3-D printing paves the way to the use of low-cost flexible dielectric materials, even with poor electromagnetic properties, to realize wearable battery-free wireless nodes
Verso l'economia circolare
Il volume raccoglie contributi sull'economia circolare, declinazione di un\u2019economia che analizza e spiega le emergenze dell\u2019inquinamento globale in generale e di quello collegato ai rifiuti in particolare, ma anche un\u2019economia che, normativa-mente, propone soluzioni ai quei problemi come richiesto dall'Unione Europea che ha inserito nei suoi piani strategici l\u2019economia circolare.
Non bastano gli incentivi per le buone pratiche, \ue8 necessaria la riscoperta di impostazioni teoriche capaci di mettere al centro le interdipendenze settoriali e la rigenerazione dei fattori produttivi. Dunque principi dell\u2019economia circolare che inducano a ricercare nuovi modelli di business che le aziende utilizzeranno per essere inserite in un nuovo sistema economico, quello che dovrebbe sostituire, o affiancare, l\u2019attuale economia lineare
Intermittent Behavior in the AMOC-AMV Relationship
The connection between the Atlantic meridional overturning circulation (AMOC) and the Atlantic multidecadal variability (AMV) is inspected in a suite of pre-industrial integrations from the 6th phase of the Coupled Model Inter-comparison Project (CMIP6), using a change-point detection method to identify different AMOC-AMV co-variability regimes. A key finding of this study is that models robustly simulate multi-decadal windows where the AMV and the AMOC are essentially uncorrelated. These regimes coexist with longer periods with relatively high correlation. Drops and recoveries of correlation are found to be often abrupt and confined in a temporal window of the order of 10 years. Phenomenological evidence suggests that the no-correlation regimes may be explained by drops in the variance of the AMOC: a less variable meridional heat transport leads to a suppressed co-variability of the AMV, leaving a larger role for non-AMOC drivers, consistent with a non-stationary AMOC-stationary noise interpretative framework
Detection of bovine papillomavirus type 2 in the peripheral blood of cattle with urinary bladder tumours: possible biological role
Bovine papillomavirus type 2 (BPV-2) infection has been associated with urinary bladder tumours in adult cattle grazing on bracken fern-infested land. In this study, we investigated the
simultaneous presence of BPV-2 in whole blood and urinary bladder tumours of adult cattle in an attempt to better understand the biological role of circulating BPV-2. Peripheral blood samples were collected from 78 cattle clinically suffering from a severe chronic enzootic haematuria. Circulating BPV-2 DNA was detected in 61 of them and in two blood samples from healthy cows. Fifty of the affected animals were slaughtered at public slaughterhouses and neoplastic proliferations in the urinary bladder were detected in all of them. BPV-2 DNA was amplified and sequenced in 78% of urinary bladder tumour samples and in 38.9% of normal samples as a control. Circulating episomal BPV-2 DNA was detected in 78.2% of the blood samples. Simultaneous presence of BPV-2 DNA in neoplastic bladder and blood samples was detected in 37 animals. Specific viral E5 mRNA and E5 oncoprotein were also detected in blood by RT-PCR
and Western blot/immunocytochemistry, respectively. It is likely that BPV-2 can persist and be maintained in an active status in the bloodstream, in particular in the lymphocytes, as a reservoir of viral infection that, in the presence of co-carcinogens, may cause the development of urinary bladder tumours
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