Political Systems and Political Networks:The Structure of Parliamentarians’ Retweet Networks in 19 Countries

Social scientists have long studied international differences in political culture and communication. An influential strand of theory within political science argues that different types of political systems generate different parliamentary cultures: Systems with proportional representation generate cross-party cohesion, whereas majoritarian systems generate division. To contribute to this long-standing discussion, we study parliamentarian retweets across party lines using a database of 2.3 million retweets by 4,018 incumbent parliamentarians across 19 countries during 2018. We find that there is at most a tenuous relationship between democratic systems and cross-party retweeting: Majoritarian systems are not unequivocally more divisive than proportional systems. Moreover, we find important qualitative differences: Countries are not only more or less divisive, but they are cohesive and divisive in different ways. To capture this complexity, we complement our quantitative analysis with Visual Network Analysis to identify four types of network structures: divided, bipolar, fringe party, and cohesive.</p

Thermal noises and noise compensation in high-reflection multilayer coating

Thermal fluctuations of different origin in the substrate and in the coating of optical mirrors produce phase noise in the reflected wave. This noise determines the ultimate stabilization capability of high-Q cavities used as a reference system. In particular this noise is significant in interferometric laser gravitational wave antennas. It is shown that simple alteration of a mirror multilayer coating may provide suppression of phase noise produced by thermorefractive, thermoelastic, photothermal and thermoradiation induced fluctuations in the coating.Comment: 10 pages, 5 figure

Irrigation water strategies for the Buriti Vermelho watershed: towards a higher water productivity.

RESUMO: Com a necessidade de se utilizar a água de forma cada vez mais eficientemente, faz necessário melhorar a produtividade de uso da água em escala de bacia hidrográfica. Este estudo objetivou avaliar a produtividade de uso da água e a possibilidade de aumentar a área irrigada na bacia hidrográfica do Buriti Vermelho, Brasil. o modelo de Solo-Água-Atmosfera-Planta (SWAP) foi utilizado nas simulações. A bacia do Buriti Vermelho possui agricultura de sequeiro (soja e milho), e irrigada (milho, feijão e trigo). A produtividade de uso da água (CWP) foi calculada em função da lâmina total de água aplicada, que inclui a soma da irrigação e da precipitação. Avaliou-se também o período ideal para o plantio da soja, buscando-se o rendimento ótimo e a maior CWP. A CWP variou de 0,32 kg m-3, para a cultura da soja, a 1,90 kg m-3 para o trigo. Para o período estudado houve uma redução da CWP com o aumento da lâmina de irrigação. A irrigação mostrou ter grande influência no rendimento das culturas do feijão, do trigo e do milho. O rendimento ótimo e a máxima produtividade de uso da água para a soja foram observados no mês de novembro. O cenário futuro mostrou que haverá decréscimo na CWP e que será necessário aplicar mais água para se conseguir as mesmas produtividades. ABSTRACT: As water is required to be used more efficiently, the crop water productivity should be improved. The main objective of this paper was to assess both the crop water productivity and the possibility to expand irrigated land in the Buriti Vermelho experimental watershed, Brazil. Soil-Water-Atmosphere-Plant (SWAP) model was used to perform the analysis. Buriti Vermelho contains both rain fed (soybean and corn) and irrigated (corn, common beans and wheat) crops. The crop water productivity was calculated as a function of total applied water, which includes the sum of irrigation and precipitation. An additional study was performed to verify the most ideal rainfed soybean growth period. The crop water productivity varied from 0.32 kg m-3 for soybeans to 1.90 kg m-3 for wheat. The crop water productivity decreased when the irrigation amount increased. Irrigation showed to have a big influence on the crop yield of common beans, wheat and rainfed corn, caused by a combination of low rainfall and low actual evapotranspiration values with higher irrigation requirements. The results showed November as being the most optimal growth period for soybeans. This month showed both the optimal yield as maximum crop water productivity. The future forecasts a decrease in crop water productivity, what means more water will be needed to reach the same amount of crop yield

Mapping Societal Risk. Main report

Het RIVM heeft in samenwerking met TNO twee methoden uitgewerkt om in een bepaald gebied de kans op een ongeval met een groot aantal slachtoffers (het groepsrisico) inzichtelijker te maken. Uitgangspunt is een zogeheten gebiedsgerichte benadering. Het groepsrisico wordt veroorzaakt door de aanwezige gevaarlijke stoffen in een gebied, zoals bij bedrijven en tijdens het transport ervan. De nieuwe benadering maakt het groepsrisico op een kaart inzichtelijk. In de oorspronkelijke, wetenschappelijke weergave in een grafiek ontbreekt dit overzicht. De methoden geven het groepsrisico (GR) weer op twee kaarten: de GR-gebiedskaart en de GR-bijdragekaart. De GR-gebiedskaart geeft inzicht in de grootte van het groepsrisico in een bepaald gebied. De GR-bijdragekaart zoomt in op de deelgebieden die het meeste bijdragen aan het groepsrisico. De twee kaarten zijn een aanvulling op de oorspronkelijke weergave, die het groepsrisico in een grafiek weergeeft. De kaarten worden bij voorkeur samen gebruikt bij het maken van beleid, zoals vergunningaanvragen of bestemmingsplannen. Daarnaast kunnen de kaarten worden ingezet bij de ontwikkeling van veiligheidsbeleid en de verantwoording van het groepsrisico door overheden. De methoden zijn in drie casussen getoetst op hun bruikbaarheid. Een voorbeeld is het vervoer van gevaarlijke stoffen over het spoor in Dordrecht. De resultaten van het onderzoek zijn in workshops voorgelegd aan betrokken partijen. Het onderzoek is in twee rapporten weergegeven. Het hoofdrapport beschrijft hoe je de methoden kunt toepassen. Het toelichtende rapport gaat in op de onderzoeksmethode.In collaboration with TNO, RIVM has elaborated two methods aimed at providing improved insight into the risk of a large number of individuals (societal risk) being involved in an accident in a certain area. The basic principle of these methods is the so-called area-specific approach in which societal risk is caused by hazardous materials present at a location, such as at industrial complexes or on units of a transportation system. By presenting societal risk on a map, this new approach provides increased insight, which was lacking in the graphical representation of the original, scientific presentation. Both methods present societal risk (SR) on a map: the SR-area map and the SR-contribution map. The SR-area map shows the level of the societal risk in a specified area; the SR-contribution map zooms in on the locations that contribute most to the societal risk. Both maps are supplements to the original presentation, which represents societal risk in graphical form. The maps are preferably used together when applied to policy-making, such as licence requests and land use planning. They can also be used by the appropriate governmental authorities for developing safety policy and in the justification process for policy-making on societal risk. The methods have been validated for usefulness in three case-studies, one of which is the transportation of hazardous materials by rail through the city of Dordrecht. The results of the study have been presented to all concerned parties. The study is described in two reports. The main report describes the usefulness of the methods. The explanatory report delves more deeply into the research methods used.VRO

Visual cue training to improve walking and turning after stroke:a study protocol for a multi-centre, single blind randomised pilot trial

Visual information comprises one of the most salient sources of information used to control walking and the dependence on vision to maintain dynamic stability increases following a stroke. We hypothesize, therefore, that rehabilitation efforts incorporating visual cues may be effective in triggering recovery and adaptability of gait following stroke. This feasibility trial aims to estimate probable recruitment rate, effect size, treatment adherence and response to gait training with visual cues in contrast to conventional overground walking practice following stroke.Methods/design: A 3-arm, parallel group, multi-centre, single blind, randomised control feasibility trial will compare overground visual cue training (O-VCT), treadmill visual cue training (T-VCT), and usual care (UC). Participants (n = 60) will be randomly assigned to one of three treatments by a central randomisation centre using computer generated tables to allocate treatment groups. The research assessor will remain blind to allocation. Treatment, delivered by physiotherapists, will be twice weekly for 8 weeks at participating outpatient hospital sites for the O-VCT or UC and in a University setting for T-VCT participants.Individuals with gait impairment due to stroke, with restricted community ambulation (gait spee

Mapping Societal Risk. Explanatory report

Het RIVM heeft in samenwerking met TNO twee methoden uitgewerkt om in een bepaald gebied de kans op een ongeval met een groot aantal slachtoffers (het groepsrisico) inzichtelijker te maken. Uitgangspunt is een zogeheten gebiedsgerichte benadering. Het groepsrisico wordt veroorzaakt door de aanwezige gevaarlijke stoffen in een gebied, zoals bij bedrijven en tijdens het transport ervan. De nieuwe benadering maakt het groepsrisico op een kaart inzichtelijk. In de oorspronkelijke, wetenschappelijke weergave in een grafiek ontbreekt dit overzicht. De methoden geven het groepsrisico (GR) weer op twee kaarten: de GR-gebiedskaart en de GR-bijdragekaart. De GR-gebiedskaart geeft inzicht in de grootte van het groepsrisico in een bepaald gebied. De GR-bijdragekaart zoomt in op de deelgebieden die het meeste bijdragen aan het groepsrisico. De twee kaarten zijn een aanvulling op de oorspronkelijke weergave, die het groepsrisico in een grafiek weergeeft. De kaarten worden bij voorkeur samen gebruikt bij het maken van beleid, zoals vergunningaanvragen of bestemmingsplannen. Daarnaast kunnen de kaarten worden ingezet bij de ontwikkeling van veiligheidsbeleid en de verantwoording van het groepsrisico door overheden. De methoden zijn in drie casussen getoetst op hun bruikbaarheid. Een voorbeeld is het vervoer van gevaarlijke stoffen over het spoor in Dordrecht. De resultaten van het onderzoek zijn in workshops voorgelegd aan betrokken partijen. Het onderzoek is in twee rapporten weergegeven. Het hoofdrapport beschrijft hoe je de methoden kunt toepassen. Het toelichtende rapport gaat in op de onderzoeksmethode.In collaboration with TNO, RIVM has elaborated two methods aimed at providing improved insight into the risk of a large number of individuals (societal risk) being involved in an accident in a certain area. The basic principle of these methods is the so-called area-specific approach in which societal risk is caused by hazardous materials present at a location, such as at industrial complexes or on units of a transportation system. By presenting societal risk on a map, this new approach provides increased insight, which was lacking in the graphical representation of the original, scientific presentation. Both methods present societal risk (SR) on a map: the SR-area map and the SR-contribution map. The SR-area map shows the level of the societal risk in a specified area; the SR-contribution map zooms in on the locations that contribute most to the societal risk. Both maps are supplements to the original presentation, which represents societal risk in graphical form. The maps are preferably used together when applied to policy-making, such as licence requests and land use planning. They can also be used by the appropriate governmental authorities for developing safety policy and in the justification process for policy-making on societal risk. The methods have been validated for usefulness in three case-studies, one of which is the transportation of hazardous materials by rail through the city of Dordrecht. The results of the study have been presented to all concerned parties. The study is described in two reports. The main report describes the usefulness of the methods. The explanatory report delves more deeply into the research methods used.VRO

Home-based reach-to-grasp training for people after stroke: study protocol for a feasibility randomized controlled trial

BackgroundThis feasibility study is intended to assess the acceptability of home-based task-specific reach-to-grasp (RTG) training for people with stroke, and to gather data to inform recruitment, retention, and sample size for a definitive randomized controlled trial. Methods/designThis is to be a randomized controlled feasibility trial recruiting 50 individuals with upper-limb motor impairment after stroke. Participants will be recruited after discharge from hospital and up to 12 months post-stroke from hospital stroke services and community therapy-provider services. Participants will be assessed at baseline, and then electronically randomized and allocated to group by minimization, based on the time post-stroke and extent of upper-limb impairment. The intervention group will receive 14 training sessions, each 1 hour long, with a physiotherapist over 6 weeks and will be encouraged to practice independently for 1 hour/day to give a total of 56 hours of training time per participant. Participants allocated to the control group will receive arm therapy in accordance with usual care. Participants will be measured at 7 weeks post-randomization, and followed-up at 3 and 6 months post-randomization. Primary outcome measures for assessment of arm function are the Action Research Arm Test (ARAT) and Wolf Motor Function Test (WMFT). Secondary measures are the Motor Activity Log, Stroke Impact Scale, Carer Strain Index, and health and social care resource use. All assessments will be conducted by a trained assessor blinded to treatment allocation. Recruitment, adherence, withdrawals, adverse events (AEs), and completeness of data will be recorded and reported. DiscussionThis study will determine the acceptability of the intervention, the characteristics of the population recruited, recruitment and retention rates, descriptive statistics of outcomes, and incidence of AEs. It will provide the information needed for planning a definitive trial to test home-based RTG training. Trial registrationISRCTN: ISRCTN5671658