427 research outputs found
Actors, actions, and initiative in normative system specification
The logic of norms, called deontic logic, has been used to specify normative constraints for information systems. For example, one can specify in deontic logic the constraints that a book borrowed from a library should be returned within three weeks, and that if it is not returned, the library should send a reminder. Thus, the notion of obligation to perform an action arises naturally in system specification. Intuitively, deontic logic presupposes the concept of anactor who undertakes actions and is responsible for fulfilling obligations. However, the concept of an actor has not been formalized until now in deontic logic. We present a formalization in dynamic logic, which allows us to express the actor who initiates actions or choices. This is then combined with a formalization, presented earlier, of deontic logic in dynamic logic, which allows us to specify obligations, permissions, and prohibitions to perform an action. The addition of actors allows us to expresswho has the responsibility to perform an action. In addition to the application of the concept of an actor in deontic logic, we discuss two other applications of actors. First, we show how to generalize an approach taken up by De Nicola and Hennessy, who eliminate from CCS in favor of internal and external choice. We show that our generalization allows a more accurate specification of system behavior than is possible without it. Second, we show that actors can be used to resolve a long-standing paradox of deontic logic, called the paradox of free-choice permission. Towards the end of the paper, we discuss whether the concept of an actor can be combined with that of an object to formalize the concept of active objects
Subpopulations of bovine WC1+ γδ T cells rather than CD4+CD25highFoxp3+ T cells act as immune regulatory cells ex vivo
Regulatory T cells (Treg) are regarded essential components for maintenance of immune homeostasis. Especially CD4+CD25high T cells are considered to be important regulators of immune reactivity. In humans and rodents these natural Treg are characterized by their anergic nature, defined as a non-proliferative state, suppressive function and expression of Foxp3. In this study the potential functional role of flowcytometry-sorted bovine white blood cell populations, including CD4+CD25high T cells and γδ T cell subpopulations, as distinct ex vivo regulatory cells was assessed in co-culture suppression assays. Our findings revealed that despite the existence of a distinct bovine CD4+CD25high T cell population, which showed Foxp3 transcription/expression, natural regulatory activity did not reside in this cell population. In bovine co-culture suppression assays these cells were neither anergic nor suppressive. Subsequently, the following cell populations were tested functionally for regulatory activity: CD4+CD25low T cells, WC1+, WC1.1+ and WC1.2+ γδ T cells, NK cells, CD8+ T cells and CD14+ monocytes. Only the WC1.1+ and WC1.2+ γδ T cells and CD14+ monocytes proved to act as regulatory cells in cattle, which was supported by the fact that these regulatory cells showed IL-10 transcription/expression. In conclusion, our data provide first evidence that cattle CD4+CD25highFoxp3+ and CD4+CD25low T cells do not function as Treg ex vivo. The bovine Treg function appears to reside in the γδ T cell population, more precisely in the WC1.1+ and the WC1.2+ subpopulation, major populations present in blood of cattle in contrast to non-ruminant species
Attitude of patients, healthcare professionals, and noninjured lay persons towards online video instructions on mild traumatic brain injury
__Background:__ The objective of this study was to determine the attitude of patients, healthcare professionals, and noninjured lay persons towards adding a video with discharge instructions to patient care for patients with mild traumatic brain injury (MTBI). A survey was conducted at the emergency department (ED). Participants consisted of MTBI patients (n = 50), healthcare professionals (n = 50), and noninjured lay persons (n = 50). The participants viewed a video with discharge instructions on MTBI and filled out a questionnaire that measured their attitude towards the use of a video as part of discharge instructions.
__Findings:__ Nearly all healthcare professionals (94%) and 70% of the noninjured lay persons considered the video to be a valuable addition to oral discharge instructions. For 84% of patients, verbal information from the doctor is of importance. And, 50% of patients would like to receive additional video discharge instructions.
__Conclusions:__ The majority of noninjured lay persons and healthcare professionals and half of the MTBI patients consider a video with discharge instructions to be a valuable addition to patient care. Video discharge instructions are a relative low-cost measure that could enhance patient care at the ED, provided that this does not compromise the personal contact between patient and healthcare professional
Current Perspectives on the Management of Herpesvirus Infections in Solid Organ Transplant Recipients
Solid organ transplant recipients (SOTRs) are at high risk of human herpesvirus (HHV)-related morbidity and mortality due to the use of immunosuppressive therapy. We aim to increase awareness and understanding of HHV disease burden in SOTRs by providing an overview of current prevention and management strategies as described in the literature and guidelines. We discuss challenges in both prevention and treatment as well as future perspectives.</p
CATT: a New and Non-Chemical Pest and Nematode Control Method in Strawberry Planting Stock
As an alternative to MeBr fumigation a 48h Controlled Atmosphere Temperature Treatment (CATT) was developed and scaled up by Wageningen UR in cooperation with the Dutch plant propagating association Plantum. This results in an excellent de-infestation and 99.8 % mortality of the strawberry tarsonemid mite (Phytonemus pallidus). This non-chemical and sustainable method provides a healthy production of highly qualified strawberry runners in the field. From 2009 CATT is up scaled to a commercial level and widely applied by Dutch nurseries. In 2011 this CATT method was successfully modified to eradicate also the root knot nematode Meloidogyne hapla (>99.7% mortality), which was not effectively controlled by MeBr fumigation. For an effective killing of the root knot nematodes, temperature must be raised to 40 ºC. In several experiments the optimum conditions for a high mortality of both tarsonemids and nematodes was studied. This leads into an adapted CATT of 20 hours at a temperature of 35 ºC and 50 % CO2 followed by 20 hours at a temperature of 40 ºC. In 2012 this adapted CATT was successfully upgraded and tested under field conditions. Additional research in 2013 leads to the conclusion that cross infection of plants by the bacterial Q-disease Xanthomonas fragariae during CATT treatment is unlikel
Unexplained diarrhoea in HIV-1 infected individuals
Background: Gastrointestinal symptoms, in particular diarrhoea, are common in non-treated HIV-1 infected individuals.
Although various enteric pathogens have been implicated, the aetiology of diarrhoea remains unexplained in a large
proportion of HIV-1 infected patients. Our aim is to identify the cause of diarrhoea for patients that remain negative in
routine diagnostics.
Methods: In this study stool samples of 196 HIV-1 infected persons, including 29 persons with diarrhoea, were
examined for enteropathogens and HIV-1. A search for unknown and unexpected viruses was performed using
virus discovery cDNA-AFLP combined with Roche-454 sequencing (VIDISCA-454).
Results: HIV-1 RNA was detected in stool of 19 patients with diarrhoea (66%) compared to 75 patients (45%)
without diarrhoea. In 19 of the 29 diarrhoea cases a known enteropathogen could be identified (66%). Next to these
known causative agents, a range of recently identified viruses was identified via VIDISCA-454: cosavirus, Aichi virus,
human gyrovirus, and non-A non-B hepatitis virus. Moreover, a novel virus was detected which was named
immunodeficiency-associated stool virus (IASvirus). However, PCR based screening for these viruses showed that
none of these novel viruses was associated with diarrhoea. Notably, among the 34% enteropathogen-negative
cases, HIV-1 RNA shedding in stool was more frequently observed (80%) compared to enteropathogen-positive
cases (47%), indicating that HIV-1 itself is the most likely candidate to be involved in diarrhoea.
Conclusion: Unexplained diarrhoea in HIV-1 infected patients is probably not caused by recently described or previously
unknown pathogens, but it is more likely that HIV-1 itself plays a role in intestinal mucosal abnormalities which leads to
diarrhoea
Broeikasgasmodule BBPR
De Nederlandse melkveehouderij draagt via de emissies van lachgas en methaan bij aan de emissies van broeikasgassen. De uitbreiding van het BedrijfsBegrotingsProgramma Rundvee (BBPR) met een boeikasgasmodule maakt het mogelijk om de kosteneffectiviteit van emissiereducerende maatregelen in één rekengang te berekenen. De kosteneffectiviteit is het verschil in financieel saldo gedeeld door het verschil in emissie. De emissie van het gemiddelde melkveebedrijf in Nederland bedraagt volgens de berekening met de broeikasgasmodule van BBPR 0.8 kg CO2-equivalenten per kg melk voor bedrijven op minerale grondsoorten en 1.3 kg CO2-equivalenten per kg melk voor bedrijven op veengrond. Het verhogen van het aandeel maïs in het rantsoen verlaagt de emissie slechts vrij gering, maar levert financieel voordeel op. Minder weidegang resulteert in een aanzienlijke emissiereductie, maar is een dure maatregel. Het gebruik van nitraatloze voorjaarsmeststoffen levert slechts een geringe bijdrage aan de emissiereductie. Mestvergisting, volgens het principe van co-vergisting van aangevoerde snijmaïskuil, kan de emissie tot 24% reduceren, maar is voor een gemiddeld bedrijf te duur
Impact of sarcopenia on acute radiation-induced toxicity in head and neck cancer patients
Background and purpose: Sarcopenia is related to late radiation-induced toxicities and worse survival in head and neck cancer (HNC) patients. This study tested the hypothesis that sarcopenia improves the performance of current normal tissue complication probability (NTCP) models of radiation-induced acute toxicity in HNC patients. Material/methods: This was a retrospective analysis in a prospective cohort of HNC patients treated from January 2007 to December 2018 with (chemo)radiotherapy. Planning CT scans were used for evaluating skeletal muscle mass. Characteristics of sarcopenic and non-sarcopenic patients were compared. The impact of sarcopenia was analysed by adding sarcopenia to the linear predictors of current NTCP models predicting physician- and patient-rated acute toxicities. Results: The cut-off values of sarcopenia in the study population (n = 977) were established at skeletal muscle index = 2, p = 3 dysphagia (week 3-6 during RT, p 0.99). Conclusion: Sarcopenia in HNC patients was an independent prognostic factor for radiation-induced physician-rated acute grade >= 3 dysphagia, which might be explained by its impact on swallowing muscles. However, addition of sarcopenia did not improve the NTCP model performance. (c) 2022 The Author(s). Published by Elsevier B.V. Radiotherapy and Oncology 170 (2022) 122-128 This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/)
- …