Activation of sub-3 nm organic particles in the particle size magnifier using humid and dry conditions

The accurate measurement of aerosol particles and clusters smaller than 3 nm in diameter is crucial for the understanding of new particle formation processes. The particle counters used for measuring these particles are typically calibrated with metal or salt particles under dry conditions, which does not always represent the field conditions where these instruments are later used. In this study, we calibrated the All nano Condensation Nucleus Counter (nCNC), consisting of the PSM (Particle Size Magnifier) and a laminar flow butanol based CPC (Condensational Particle Counter), with well-defined biogenic oxidation products from beta-caryophyllene oxidation and compared it to a calibration with tungsten oxide under the same conditions. The organic particles were detected less efficiently than the inorganic ones. This resulted in a higher cut-off size for beta-caryophyllene oxidation products than for tungsten oxide. At the same PSM settings, the cut-off size for tungsten oxide was 1.2 nm and for beta-caryophyllene oxidation products 1.9 nm. However, repeating the calibration of the biogenic particles at 13% relative humidity at 31 degrees C, increased their detection efficiency in the PSM, increasing the cut-off diameter to 1.6 nm. Additionally, we present a comparison of the ion concentrations measured with the PSM and the NAIS (Neutral Cluster and Air Ion Spectrometer) during new particle formation experiments in the CLOUD (Cosmics Leaving Outdoors Droplets) chamber. In these experiments, we produced particles from different organic precursors, such as alpha-pinene, beta-caryophyllene and isoprene, as well as iodine. This way, we could determine the shift in cut-off diameter of the PSM for several different atmospherically relevant chemical compounds and compare it to the laboratory calibrations. We saw a diameter shift for the organic precursors of +0.3 nm in the PSM compared to the NAIS. These two approaches agreed well with each other and show that it is important to know the chemical composition of the measured particles to determine the exact size distribution using a supersaturation scanning method.Peer reviewe

Parasite-stress promotes in-group assortative sociality: the cases of strong family ties and heightened religiosity

Throughout the world people differ in the magnitude with which they value strong family ties or heightened religiosity. We propose that this cross-cultural variation is a result of a contingent psychological adaptation that facilitates in-group assortative sociality in the face of high levels of parasite-stress while devaluing in-group assortative sociality in areas with low levels of parasite-stress. This is because in-group assortative sociality is more important for the avoidance of infection from novel parasites and for the management of infection in regions with high levels of parasite-stress compared with regions of low infectious disease stress. We examined this hypothesis by testing the predictions that there would be a positive association between parasite-stress and strength of family ties or religiosity. We conducted this study by comparing among nations and among states in the United States of America. We found for both the international and the interstate analyses that in-group assortative sociality was positively associated with parasite-stress. This was true when controlling for potentially confounding factors such as human freedom and economic development. The findings support the parasite-stress theory of sociality, that is, the proposal that parasite-stress is central to the evolution of social life in humans and other animals

AUTOEVALUACIÓN DEL PROGRAMA DE MEDICINA VETERINARIA Y ZOOTECNIA CON FINES DE ACREDITACIÓN DE CALIDAD

Las Facultades de Medicina Veterinaria y Zootecnia y Agronomía se crearon en la ciudad de Montería como dependencias de la Universidad Nacional de Colombia según la Ley 103 del Congreso Nacional, de fecha 29 de Diciembre de 1962, pero dicha Ley no tuvo cumplimiento. Ante el anhelo frustrado de no contar con una Universidad seccional, pretendida con la Ley 103, el Gobierno Departamental dictó el Decreto 0319 de 1964 por el cual se le otorgó personería jurídica a la Universidad de Córdoba. En el año 1966 el Congreso de República expidió la Ley 37 por medio de la cual se crea la Universidad de Córdoba como una entidad autónoma y descentralizada que se acogía al Decreto-Ley 0277 de 1958 que regía para las universidades departamentales. Sólo hasta el año de 1970, mediante una sentencia de Estado, se enmienda el error y se le da el carácter nacional a la Institución por haber sido creada mediante Ley de la República

Cerebrospinal fluid dynamics in idiopathic intracranial hypertension : a literature review and validation of contemporary findings

Publisher Copyright: © 2021, The Author(s).Background: Idiopathic intracranial hypertension (IIH) is a rare disease of unknown aetiology related possibly to disturbed cerebrospinal fluid (CSF) dynamics and characterised by elevated intracranial pressure (ICP) causing optic nerve atrophy if not timely treated. We studied CSF dynamics of the IIH patients based on the available literature and our well-defined cohort. Method: A literature review was performed from PubMed between 1980 and 2020 in compliance with the PRISMA guideline. Our study includes 59 patients with clinical, demographical, neuro-ophthalmological, radiological, outcome data, and lumbar CSF pressure measurements for suspicion of IIH; 39 patients had verified IIH while 20 patients did not according to Friedman’s criteria, hence referred to as symptomatic controls. Results: The literature review yielded 19 suitable studies; 452 IIH patients and 264 controls had undergone intraventricular or lumbar CSF pressure measurements. In our study, the mean CSF pressure, pulse amplitudes, power of respiratory waves (RESP), and the pressure constant (P0) were higher in IIH than symptomatic controls (p < 0.01). The mean CSF pressure was higher in IIH patients with psychiatric comorbidity than without (p < 0.05). In IIH patients without acetazolamide treatment, the RAP index and power of slow waves were also higher (p < 0.05). IIH patients with excess CSF around the optic nerves had lower relative pulse pressure coefficient (RPPC) and RESP than those without (p < 0.05). Conclusions: Our literature review revealed increased CSF pressure, resistance to CSF outflow and sagittal sinus pressure (SSP) as key findings in IIH. Our study confirmed significantly higher lumbar CSF pressure and increased CSF pressure waves and RAP index in IIH when excluding patients with acetazolamide treatment. In overall, the findings reflect decreased craniospinal compliance and potentially depleted cerebral autoregulation resulting from the increased CSF pressure in IIH. The increased slow waves in patients without acetazolamide may indicate issues in autoregulation, while increased P0 could reflect the increased SSP.Peer reviewe

Nursing students motivation toward their studies – a survey study

<p>Abstract</p> <p>Background</p> <p>This study focuses on Swedish nursing students' motivation toward their studies during their three year academic studies. Earlier studies show the importance of motivation for study commitment and result. The aim was to analyze nursing students' estimation of their degree of motivation during different semester during their education and to identify reasons for the degree of motivation.</p> <p>Methods</p> <p>A questionnaire asking for scoring motivation and what influenced the degree of motivation was distributed to students enrolled in a nursing programme. 315 students who studied at different semesters participated. Analyzes were made by statistical calculation and content analysis.</p> <p>Results</p> <p>The mean motivation score over all semesters was 6.3 (ranked between 0–10) and differed significantly during the semesters with a tendency to lower score during the 5th semester. Students (73/315) with motivation score <4 reported explanations such as negative opinion about the organisation of the programme, attitude towards the studies, life situation and degree of difficulty/demand on studies. Students (234/315) with motivation score >6 reported positive opinions to becoming a nurse (125/234), organization of the programme and attitude to the studies. The mean score value for the motivation ranking differed significantly between male (5.8) and female (6.8) students.</p> <p>Conclusion</p> <p>Conclusions to be drawn are that nursing students mainly grade their motivation positive distributed different throughout their entire education. The main motivation factor was becoming a nurse. This study result highlights the need of understanding the students' situation and their need of tutorial support.</p

Land, history or modernization? Explaining ethnic fractionalization

Ethnic fractionalization (EF) is frequently used as an explanatory tool in models of economic development, civil war and public goods provision. However, if EF is endogenous to political and economic change, its utility for further research diminishes. This turns out not to be the case. This paper provides the first comprehensive model of EF as a dependent variable. It contributes new data on the founding date of the largest ethnic group in each state. It builds political and international variables into the analysis alongside historical and geoclimatic parameters. It extends previous work by testing models of politically relevant EF. In addition, this research interprets model results in light of competing theories of nationalism and political change. Results show that cross-national variation in EF is largely exogenous to modern politico-economic change. However, the data are inconclusive with respect to competing geoclimatic, historical institutional and modernist theories of ethnogenesis

Is the Good Polity Attainable? Measuring the Quality of Democracy

This article introduces a discussion on defining, measuring, and assessing the quality of democracy. Providing a short overview of the papers of the Symposium, it places them within a broader context of current academic debate on various methodological, theoretical, and policy outreach dimensions of the topic

Lessons for sustainability from the world's most sustainable culture

Sustainable development is one of the key challenges faced by societies today. Yet it is not a new challenge; throughout history, societies have faced the need to live within environmental constraints. Some have done so well, and some poorly. One society which did well for tens of thousands of years is that of Aboriginal Australia. This paper explores some lessons from Aboriginal Australia which have resonance in the modern world and shows that countries which have learned those lessons are in fact more sustainable than those which have not. It thus suggests that there is much that the pantheon of human experience can teach the modern world as it endeavours to create a sustainable future

Northerners and Southerners Differ in Conflict Culture

The present study uses regression analysis of existing cross-national data sets to demonstrate that ingroup-outgroup discrimination and intergroup conflict management vary more along the north-south (latitudinal) axis than along the east-west axis of the Earth. Ingroup favoritism, outgroup rejection, political oppression, legal discrimination, and communication bullying are all less prevalent among Northerners than among Southerners in the Northern Hemisphere, but more prevalent among Northerners than among Southerners in the Southern Hemisphere. These findings provide a rich source for further research into how social conflicts are habitually experienced and handled by residents of northern versus southern habitats. A supplementary analysis specifies the extent to which ecological stressors-thermal stress, hydraulic stress, pathogenic stress, and subsistence stress-help explain why there are oppositely sloping north-south gradients of conflict culture above and below the equator. Taken in total, these results demonstrate the importance of considering latitude in forming a deeper understanding of conflict management and negotiation