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Covariate-constrained randomization routine for achieving baseline balance in cluster-randomized trials
In cluster-randomized trials, groups or clusters of individuals, rather than individuals themselves, are randomly allocated to intervention or control. In this article, we describe a new command, ccrand, that implements a covariateconstrained randomization procedure for cluster-randomized trials. It can ensure balance of one or more baseline covariates between trial arms by restriction to allocations that meet specified balance criteria. We provide a brief overview of the theoretical background, describe ccrand and its options, and illustrate it using an example
Aufbau eines Monitoring-Systems für Obst und Gemüse im Naturkosthandel
Oberstes Ziel des Projektes war eine Verbesserung der Qualitätssicherung in der ökologischen Lebensmittelwirtschaft. Durch regelmäßige und risikoorientierte Probenziehung von Obst und Gemüse im Naturkosthandel konnten mögliche Pestizid-Belastungen aufgespürt, Ursachen recherchiert und abgestellt werden. Im Vordergrund stand die Analyse auf Pflanzenschutz-, Schädlingsbekämpfungs- und Lagerschutzmittel. Mit Abschluss des Projekts liegt erstmals eine umfangreiche Datensammlung zur Pestizidbelastung von ökologisch erzeugtem Obst und Gemüse vor.
Während der Projektlaufzeit wurden 677 Obst- und Gemüseproben auf jeweils mindestens 250 Pestizide untersucht. Die Ergebnisse belegen deutlich, dass ökologisch produziertes Obst und Gemüse signifikant weniger Pflanzenschutzmittel enthalten als vergleichbare Ware aus konventionellem Anbau.
Bei 95 Prozent aller Proben im BNN-Monitoring wurden keine Pestizide, nur sehr geringe Spuren oder im Ökolandbau erlaubte Pflanzenschutzmittel in zulässiger Menge entdeckt. Dabei waren bei 86 Prozent aller Proben keine Verunreinigungen nachweisbar. Rückstände oberhalb des Streubereichs des BNN-Orientierungswerts wurden bei 4,4 Prozent der Proben analysiert. Nur bei 5 Obst- und Gemüseproben war die gesetzliche Höchstmenge überschritten, das entspricht 0,7 Prozent. Zum Vergleich: Bei konventionellem Obst und Gemüse in der EU halten mehr als fünf Prozent der Proben die Rückstandshöchstmenge nicht ein.
Jeder Rückstandsfund im Projekt war Anlass für ausführliche Recherchen. Auf diese Weise konnten bisher unbekannte Schwachstellen bei Anbau, Lagerung, Transport und Weiterverarbeitung in der Naturkostbranche aufgedeckt und abgestellt werden.
Als häufigste Ursache für Rückstandsfunde wurden Lücken bei der Qualitätssicherung bei Anbau, Transport, Lagerung, Verarbeitung und Handel ausgemacht. Weitere Ursachen waren Abdrift von Pflanzenschutzmitteln sowie Altlasten von längst verbotenen Pestiziden.
Die verbesserte Prävention von Rückstandsfällen sowie das rechtzeitige Auffinden belasteter Ware sind ein entscheidender Beitrag zu mehr Verbraucherschutz im Naturkosthandel. Gleichzeitig konnten durch die positiven Ergebnisse das Vertrauen der Verbraucher in ökologisch produziertes Obst und Gemüse gestärkt werden
Paired Housing or a Socially-Paired Context Decreases Ethanol Conditioned Place Preference in Male Rats
Alcohol abuse dramatically affects individuals’ lives nationwide. The 2020 National Survey on Drug Use and Health (NSDUH) estimated that 10.2% of Americans suffer from alcohol use disorder. Although social support has been shown to aid in general addiction prevention and rehabilitation, the benefits of social support are not entirely understood. The present study sought to compare the benefits of social interaction on the conditioned ethanol approach behavior in rats through a conditioned place preference (CPP) paradigm in which a drug is paired with one of two distinct contexts. In experiment 1A, rats were single-housed and received conditioning trials in which ethanol was paired with the less preferred context. In experiment 1B, rats underwent procedures identical to experiment 1A, but were pair-housed throughout the paradigm. In experiment 1C, rats were single-housed, but concurrently conditioned to a socially-paired context and an ethanol-paired context. By comparing the time spent between the ethanol-paired environment and the saline-paired or socially-paired environment, we extrapolated the extent of ethanol approach behavior in the pair-housed, single-housed, and concurrently conditioned rats. Our results revealed that social interaction, both in pair-housed animals or concurrently socially-conditioned animals, diminished the ethanol approach behavior, which highlights the importance of social support in addiction prevention, treatment, and recovery programs
How useful are patient portals for hospitals in rural areas?
Electronic medical records (EMR) are a relatively new development and the move away from paper records is incentivized by allocating funds to hospitals who undertake this change. In part, the funds are allocated as part of Meaningful Use, which also sets quantitative goals for hospitals in conjunction with the move towards EMR. Hospitals in poor, rural areas of North Carolina with a high percentage of Medicaid patients must meet Meaningful Use requirements in order to receive maximum funding under these federal guidelines. As part of my internship, I focused on the usage of the patient portal at Halifax Regional Medical Center (HRMC), a hospital in one of the poorest counties in North Carolina. The results indicated that the poor and aging population in the area was ill prepared to handle electronic communications with providers through a portal, yet HRMC would still be subject to the requirement under the proposed MU Stage 3 to enroll 25% of patients in the portal. While these numbers seem reasonable for counties with a highly educated workforce and availability of high education institutions, Halifax County is struggling to educate adults about computer usage and use of email as a means of secure communication. In addition, HRMC is competing with primary care practices, where many patients regular visit physicians, for portal usage since some physicians outsource lab testing to HRMC, but will use their own portal to make the results available to patients. HRMC is used as an example of the effort undertaken by rural hospitals in poor counties within North Carolina to meet Meaningful Use Requirements; this effort is not only taking up significant resources in developing and administrating the portal, but also effort in getting patients to enroll in the portal and providing sufficient security for the patient data housed in the portal. This paper attempts to determine how useful resources spent towards enrolling patients in portals are for rural hospitals and whether the funds spent on a portal may not be better used towards getting the population ready for the use of a portal and securing the information in the portal. Using studies about what prerequisites must be met for an effective use of a patient portal, this paper aims at determining whether portal usage should be priority for rural hospitals. Or whether funds should be better spent on securing EMR and delay portal usage in favor of securing electronic records first.Master of Public Healt
Oxytocin Attenuates Expression, but Not Acquisition, of Sucrose Conditioned Place Preference in Rats
Maladaptation of reward processing for natural rewards, such as sucrose or sugar, may play a role in the development of diseases such as obesity and diabetes. Furthermore, uncovering mechanisms to disrupt or reverse maladaptation of reward-seeking behaviors for natural reinforcers can provide insight into treatment of such diseases, as well as disorders such as addiction. As such, studying the effects of potential pharmacotherapeutics on maladaptive sugar-seeking behavior offers valuable clinical significance. Sucrose conditioned place preference (CPP) paradigms can offer insight into aspects of reward processes as it provides a way to assess acquisition and expression of context-reward associations. The present study examined the effect of peripheral oxytocin injections on sucrose CPP in rats. Oxytocin, when administered prior to CPP test, attenuated expression of sucrose CPP. However, oxytocin, when administered during sucrose conditioning, did not affect subsequent place preference. These findings suggest oxytocin sufficiently attenuates expression of sucrose-associated place preference
Roughness of enamel surfaces after different bonding and debonding procedures: An in vitro study
Background and Aim: Maintaining an intact enamel surface is an essential aspect of orthodontic therapy; however, various therapeutic measures can affect this surface. The aim of our study was to evaluate roughness of the enamel surface after different conditioning and polishing procedures. Materials and Methods: 42 bovine incisors were submitted to conventional abrasion (using 37% phosphoric acid), to air abrasion, and a combination of the two. Brackets were put in place and then debonded, and the remaining adhesive removed with a carbide bur or via air abrasion. The enamel surface's roughness was assessed using a confocal laser scanning microscope (CLSM). Results: Mean roughness (Ra) was 33.1. There were no statistically significant differences among the six groups, or in Rq values. Under CLSM, the roughness after polishing via air abrasion appeared even. Although it was macroscopically smoother after polishing with a carbide bur, the surface showed a wave-like pattern. Conclusion: The method of enamel conditioning revealed no significant effect on the enamel surface after debonding. Neither polishing via air abrasion nor carbide bur resulted in differences in superficial roughness. However, the carbide bur left a wave-like pattern on the enamel surfac
Multiproxy reconstruction of oceanographic conditions in the southern epeiric Kupferschiefer Sea (Late Permian) based on redox-sensitive trace elements, molybdenum isotopes and biomarkers
The key drivers controlling the redox state of seawater and sediment pore waters in low energy environments can be inferred from redox-sensitive trace elements (RSTE), molecular biomarkers and trace metal isotopes. Here, we apply a combination these tools to the Upper Permian Kupferschiefer (T1) from the Thuringian Basin, deposited in the southern part of the semi-enclosed Kupferschiefer Sea. Enrichment patterns of the RSTEs molybdenum (Mo) and
uranium (U) as well as biomarker data attest to the rapid development of euxinic conditions in
basin settings during early T1 times, which became progressively less extreme during T1
deposition. The evolution of redox conditions in basinal settings, and the associated delay in the
onset of euxinia at more shallow marginal sites, can be attributed to the interaction of sea-level
change with basin paleogeography. Euxinia in the southern Kupferschiefer Sea did not lead to
near-quantitative depletion of aqueous Mo, possibly due to short deepwater renewal times in the
Thuringian Basin, low aqueous H2S concentrations, the continuous resupply of RSTE during transgression and declining burial rates of RSTEs throughout T1 times. 30 Drawdown of RSTE is, however, indicated for euxinic lagoon environments. Moreover, admixture of freshwater supplied to these lagoons by rivers strongly impacted on local seawater chemistry. The highest Mo-isotope compositions of ~1.70‰ in basin sediments allows a minimum Kupferschiefer Sea
seawater composition of ~2.40‰ to be estimated. This composition is similar to the ~2.30‰
estimate for the Late Permian open ocean, and confirms a strong hydrographic connection
between the epeiric Kupferschiefer Sea and the global ocean. The substantial variation in Moisotope signatures is paralleled by diagnostic shifts in biomarkers responding to oxygenation in
different parts of the water column. Water column chemistry has been affected by variation in
sea level, hydrodynamic restriction, riverine freshwater influx and evaporitic conditions in
shallow lagoons. Elucidation of the relative role of each driving factor by a single geochemical
proxy is not feasible but the complex scenario can be disentangled by a multiproxy approach
K pojmu komunitní knihovna : hledání smyslu a uplatnění
Ačkoli je komunitní knihovna pojmem zmiňovaným i ve strategických dokumentech českého knihovnictví, dosud mu u nás nebyla věnována systematická pozornost, zvláště v návaznosti na výsledky výzkumů komunit. V následujícím koncepčním článku se autoři věnují vymezení pojmu komunita, přehledu významných zjištění na poli komunitních studií, stanovují základní hranice a orientaci komunitní knihovny z těchto zkoumání vyplývající. Následuje popis souvisejícího fenoménu sociál-ních inovací, v němž autoři spatřují rozvojový potenciál pro koncept komunitní knihovny. Na základě analýzy relevantní odborné literatury je v závěru navržen model konceptuálního rámce, který představuje průnik konceptu komunitní knihovny, komunity a perspektivy sociálních inovací. Studie upozorňuje na potřebu designu služeb komunitních knihoven pro marginalizované a nespravované komunity, včetně neuživatelů knihoven, a na význam sociálních inovací pro adekvátní uspokojování jejich potřeb. Hlavní přínos příspěvku spočívá v klasifikaci druhů komunit a představení rámcového modelu sociálních inovací v adekvátně pojatých komunitních službách.Although the community library is a term mentioned in the strategic documents of the Czech librarianship, systematic attention has not been paid to it, especially in connection with the results of community research. In the following conceptual paper, the authors focus on defining the concept of community, an overview of important findings in the field of community studies, setting the basic boundaries and orientation of the community library resulting from these investigations. The following is a description of the related phenomenon of social innovations in which the authors see the developmental potential of the community library. On the basis of relevant literature analysis, a conceptual framework model is proposed that addresses the intersection of concepts of the community library, the community and the perspectives of social innovation. The study highlights the need for library service design for marginalized and non-administered communities, including library non-users and the importance of social innovation to adequately meet their needs. The main contribution of the paper lies in the classification of communities and the introduction of the framework model of social innovation in adequately conceived community services
linking goal-directed and model-based behavior
In experimental psychology different experiments have been developed to assess
goal–directed as compared to habitual control over instrumental decisions.
Similar to animal studies selective devaluation procedures have been used.
More recently sequential decision-making tasks have been designed to assess
the degree of goal-directed vs. habitual choice behavior in terms of an
influential computational theory of model-based compared to model-free
behavioral control. As recently suggested, different measurements are thought
to reflect the same construct. Yet, there has been no attempt to directly
assess the construct validity of these different measurements. In the present
study, we used a devaluation paradigm and a sequential decision-making task to
address this question of construct validity in a sample of 18 healthy male
human participants. Correlational analysis revealed a positive association
between model-based choices during sequential decisions and goal-directed
behavior after devaluation suggesting a single framework underlying both
operationalizations and speaking in favor of construct validity of both
measurement approaches. Up to now, this has been merely assumed but never been
directly tested in humans
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