Frequency Of Exchanges Research Articles

Nitrate bioreduction dynamics in hyporheic zone sediments under cyclic changes of chemical compositions

Hyporheic zone (HZ) is the hotspot of contaminant biotransformation in ecosystems that affects water quality in both groundwater and river water. HZ is characterized by its dynamic changes in water flow direction that lead to the cyclic changes in aqueous chemical compositions such as dissolved oxygen (DO), nitrate, dissolved organic carbon, and their concentrations. Here we report a study on the effects of cyclic changes in the chemical conditions on the rates of nitrate bioreduction in sediments from a hyporheic zone, and the corresponding dynamics of the synthesis and decay of nitrate reductases. The results indicated that the rate of nitrate bioreduction in the second and third cycles was faster than that in the first one because the nitrate reductases produced in the first cycle still partially maintained their reactivity. The presence of DO significantly decreased the rates of nitrate reduction and nitrate reductase synthesis, but such an inhibition effect diminished in the later cycle. The coupled changes in nitrate concentrations and functional enzymes and genes abundances were generally consistent with an enzyme-based biogeochemical kinetic model. Overall the results indicated that enzyme growth dynamics and functions were complexly affected by the cyclic changes of environmental conditions, and implied that HZ sediments have a memory-type system behavior in reducing nitrate that would be affected by the frequency and magnitude of groundwater and river water exchanges, and chemical compositions in the groundwater and river water.

Analyzing and validating simulated tempering implementations at phase transition regimes

This work presents a comprehensive analysis of key elements determining the efficiency of Simulated Tempering implementations for lattice models. Important aspects like the proper choice of the replicas temperature set ϒR, their quantity R and adequate estimation of the weight factors (establishing the probabilities of jumps between the replicas) are considered. A number of tests to validate distinct ST implementations – as well as to characterize convergence and fluctuations (this latter, after reaching the steady condition) of the thermodynamic estimators – is proposed. Also, by combining the ST method with the so called fixed exchange frequency protocol (to determine ϒR), a new procedure to calculate critical temperatures is developed. As cases studies, two commonly addressed lattice models are discussed, the Blume–Emery–Griffiths and Bell–Lavis. Their detailed investigation at the coexistence condition or under first order phase transition regimes allows to properly inspect factors like, pace of convergence, tunneling between replicas and minimal values of the highest replica temperature TR, affecting a good overall performance of the ST method.

Balkan herbaria: do we have to worry about them?

The Balkan Peninsula has 57 herbaria listed in Index Herbariorum that have almost 5.5 million herbarium sheets. The aim of this study was to determine the status of these herbaria, in terms of their current technical capacities and manpower, their activities, and their communication with botanical societies via herbarium exchanges and loans. Data were gathered through a survey of 24 questions passed to the herbaria curators or other herbarium staff. Fifty-six percentage of the herbaria responded (32/57). Through the analysis of the data gathered, the current state, needs, potential and future perspectives for these Balkan herbaria were evaluated for the full individual question responses. The Balkan herbaria are mostly owned by universities, institutes and museums (30/32; 94%), and the majority have almost no formal protection of their collections (17/32; 53%). They are not sufficiently financed and functioned with too few staff. They are also not following modern herbarium standards, with problems mainly with insects and moulds (29/32; 91%), and with air conditioning mostly not used (18/27; 67%). Their exchange and borrowing frequencies are very low. Generally, there is little public access to the databases, and only a small fraction of the material has been digitized. The awareness of the problems of these herbaria at higher decision-making levels is low. Therefore, we can conclude that these herbarium collections in the Balkan Peninsula are under serious threat. Societies must be aware of this and must do as much as possible to preserve these collections and to enhance their active maintenance and use.

Assessing connectivity between the river channel and floodplains during high flows using hydrodynamic modeling and particle tracking analysis

River-floodplain connectivity is vital to hydrological and biogeochemical processes in river corridors over multiple spatiotemporal scales. In the present study, an approach of particle tracking in conjunction with two-dimensional hydrodynamic modeling was developed to study the dynamics of river-floodplain connectivity during flood periods and applied to the study of McCarran Ranch in the lower Truckee River, Nevada, U.S. The hydrodynamic model was calibrated and validated for flood events of different magnitudes of peak flow discharge. The outputs of the hydrodynamic model were further applied to determine the lateral transboundary flux during high flows. Lagrangian particle trajectories were then performed to quantify the flow path length and residence time on floodplains. The exchange frequency between the river mainstem and the floodplain were also examined.The results show that the hydrodynamic model reproduce hydrographs well. The river-floodplain exchange is sensitive to the magnitudes of the flood events. Larger floods cause shorter residence times and flow path lengths on the floodplains but lead to larger transboundary flux within the river reaches. The particle analysis results also show that higher discharge introduces less frequent exchange between the river channel and floodplains. Furthermore, comparison of the river-floodplain exchange properties among river reaches with different levels of sinuosity show that meandering reaches can introduce considerably higher exchange flux than a straight reach, leading to complex exchange behaviors within the river-floodplain system.

Postpartum maternal distress: a multidimensional illness requiring a multilevel, multidiscipline response.

Australia's federal, state, territory and local governments all have responsibilities, often overlapping, for policy and delivery of primary mental health care to postpartum women. Identification and treatment of postpartum distress is carried out by a broad range of professionals from diverse disciplines. Although there is evidence to show that anxiety and stress are important aspects of postpartum distress, substantially greater emphasis has been given to identification and treatment of depression. In addition, relatively little attention has been given to incorporating positive and negative social experiences in healthcare policy and practice. This study aimed to extend the postpartum literature by: (1) comparing the levels of depression, anxiety and stress (i.e. distress indicators) in a non-clinical sample of postpartum mothers to those in the general non-clinical population; (2) comparing the prevalence of anxiety and stress to that of depression in postpartum mothers; and (3) examining the consequences of negative social exchange, alongside perceived social support, on postpartum distress indicators. A self-report survey was completed by 242 postpartum women assessing levels of perceived social support, frequency of negative social exchange and distress indicators. Postpartum mothers were found to have significantly higher depression, anxiety and stress than the general population, and had anxiety and stress levels that were similar in severity to depression. In addition, both negative social exchanges and perceived social support were found to be important for postpartum depression, anxiety and stress. These findings suggest that Australia's primary postpartum mental health care policy and practice guidelines, delivered through a broad range of professionals, may benefit from giving anxiety and stress equal weight to depression and by embracing the important effects, for good and for ill, of positive and negative social interactions.

Microfluidic perfusion modulates growth and motor neuron differentiation of stem cell aggregates.

Microfluidic technologies provide many advantages for studying differentiation of three-dimensional (3D) stem cell aggregates, including the ability to control the culture microenvironment, isolate individual aggregates for longitudinal tracking, and perform imaging-based assays. However, applying microfluidics to studying mechanisms of stem cell differentiation requires an understanding of how microfluidic culture conditions impact cell phenotypes. Conventional cell culture techniques cannot directly be applied to the microscale, as microscale culture varies from macroscale culture in multiple aspects. Therefore, the objective of this work was to explore key parameters in microfluidic culture of 3D stem cell aggregates and to understand how these parameters influence stem cell behavior and differentiation. These studies were done in the context of differentiation of embryonic stem cells (ESCs) to motor neurons (MNs). We assessed how media exchange frequency modulates the biochemical microenvironment, including availability of exogenous factors (e.g. nutrients, small molecule additives) and cell-secreted molecules, and thereby impacts differentiation. The results of these studies provide guidance on how key characteristics of 3D cell cultures can be considered when designing microfluidic culture parameters. We demonstrate that discontinuous perfusion is effective at supporting stem cell aggregate growth. We find that there is a balance between the frequency of media exchange, which is needed to ensure that cells are not nutrient-limited, and the need to allow accumulation of cell-secreted factors to promote differentiation. Finally, we show how microfluidic device geometries can influence transport of biomolecules and potentially promote asymmetric spatial differentiation. These findings are instructive for future work in designing devices and experiments for culture of cell aggregates.

Event-Triggered Exponential Synchronization for Complex-Valued Memristive Neural Networks With Time-Varying Delays.

This article solves the event-triggered exponential synchronization problem for a class of complex-valued memristive neural networks with time-varying delays. The drive-response complex-valued memristive neural networks are translated into two real-valued memristive neural networks through the method of separating the complex-valued memristive neural networks into real and imaginary parts. In order to reduce the information exchange frequency between the sensor and the controller, a novel event-triggered mechanism with the event-triggering functions is introduced in wireless communication networks. Some sufficient conditions are established to achieve the event-triggered exponential synchronization for drive-response complex-valued memristive neural networks with time-varying delays. In addition, to guarantee that the Zeno behavior cannot occur, a positive lower bound for the interevent times is explicitly derived. Finally, numerical simulations are provided to illustrate the effectiveness and superiority of the obtained theoretical results.

Pairing and Exchanging between Daypyrum villosum Chromosomes 6V#2 and 6V#4 in the Hybrids of Two Different Wheat Alien Substitution Lines.

Normal pairing and exchanging is an important basis to evaluate the genetic relationship between homologous chromosomes in a wheat background. The pairing behavior between 6V#2 and 6V#4, two chromosomes from different Dasypyrum villosum accessions, is still not clear. In this study, two wheat alien substitution lines, 6V#2 (6A) and 6V#4 (6D), were crossed to obtain the F1 hybrids and F2 segregating populations, and the testcross populations were obtained by using the F1 as a parent crossed with wheat variety Wan7107. The chromosomal behavior at meiosis in pollen mother cells (PMCs) of the F1 hybrids was observed using a genomic in situ hybridization (GISH) technique. Exchange events of two alien chromosomes were investigated in the F2 populations using nine polymerase chain reaction (PCR) markers located on the 6V short arm. The results showed that the two alien chromosomes could pair with each other to form ring- or rod-shaped bivalent chromosomes in 79.76% of the total PMCs, and most were pulled to two poles evenly at anaphase I. Investigation of the F2 populations showed that the segregation ratios of seven markers were consistent with the theoretical values 3:1 or 1:2:1, and recombinants among markers were detected. A genetic linkage map of nine PCR markers for 6VS was accordingly constructed based on the exchange frequencies and compared with the physical maps of wheat and barley based on homologous sequences of the markers, which showed that conservation of sequence order compared to 6V was 6H and 6B > 6A > 6D. In the testcross populations with 482 plants, seven showed susceptibility to powdery mildew (PM) and lacked amplification of alien chromosomal bands. Six other plants had amplification of specific bands of both the alien chromosomes at multiple sites, which suggested that the alien chromosomes had abnormal separation behavior in about 1.5% of the PMCs in F1, which resulted in some gametes containing two alien chromosomes. In addition, three new types of chromosome substitution were developed. This study lays a foundation for alien allelism tests and further assessment of the genetic relationship among 6V#2, 6V#4, and their wheat homoeologous chromosomes.

Probe Mössbauer Diagnostics of Charge Ordering in Manganites CaCuxMn7–xO12 (0 ≤ x ≤ 1)

We present the results of our 57Fe probe Mossbauer study in manganites CaCuxMn6.96–x57Fe0.04O12 (0 ≤ x ≤ 1). We have established that for compositions 0 ≤ x ≤ 0.15 near the structural R$$\bar {3}$$ ↔ Im$$\bar {3}$$ transition (at T ≈ TCO), an increase in the temperature leads to a decrease in the content of the rhombohedral phase (R$$\bar {3}$$) against a background of the “nucleation” and gradual increase in the fraction of the cubic phase (Im$$\bar {3}$$), in which all octahedral positions of manganese are equivalent due to the electron exchange Mn3+ ↔ Mn4+. The increase in the electron exchange frequency is assumed to be related to a weakening of the electron–lattice interaction of Jahn–Teller Mn3+ cations as x → 0.4. An increase in the copper content leads to a sharp decrease in the phase transition temperature TCO. A single component corresponding to the cubic phase (Im$$\bar {3}$$) is present in the spectrum starting from x ≥ 0.4. Based on our Mossbauer data, we have constructed a T–x phase diagram.

Clinical Practice Pattern of Acquired Thrombotic Thrombocytopenic Purpura in Japan: A Nationwide Inpatient Database Analysis

Introduction: Acquired thrombotic thrombocytopenic purpura (TTP) is a medically emergent disorder that is almost always fatal without proper treatment. While daily plasma exchange is recommended by several guidelines, its optimal frequency is unclear, and until March 2018 plasma exchange up to only three times a week was reimbursed by Japanese health insurance. In addition, rituximab has not been approved for acquired TTP in Japan. While it is known that clinical practice guidelines for TTP treatment in Japan may differ from those in other countries, real-world practice patterns remain unknown. Thus, we evaluated patients' characteristics and clinical practice patterns using a large nationwide inpatient database. Methods: For this nationwide epidemiologic study, we used the Japanese Diagnosis Procedure Combination inpatient database, which includes discharge abstracts and administrative claims data from more than 1,200 acute-care hospitals and covers approximately 90% of all tertiary-care emergency hospitals in Japan. All hospitalized patients who were diagnosed with TTP (International Classification of Diseases-Tenth Revision, code M311) on admission and who received plasma exchange during hospitalization were included in the study. Patients younger than 18 years were excluded. When patients with the ICD code for TTP were admitted more than once during the study period, we used data only from the first admission. We then evaluated patients' characteristics and clinical practice patterns. Results: We identified 1,638 patients who were newly diagnosed with acquired TTP from July 2010 to March 2017. The median (interquartile range [IQR]) age was 64 (47-74) years, and 674 (41%) patients were male; 648 (40%) required ICU admission, 447 (34%) required catecholamine, and 497 (30%) required mechanical ventilation. Although relatively contraindicated, 658 (40%) patients received platelet transfusion. In-hospital mortality was 32% (n=529/1,638). Median (IQR) length of hospital stay was 45 (25-78) days, and median total cost was US$40,897 ($24,204-$64,012). Among survivors, 856 (77%) were discharged home and 235 (21%) required subacute rehabilitation or chronic care facility. The median (IQR) interval from admission to plasma exchange was 4 (2-10) days; 385 (24%) patients received plasma exchange on the day of admission. Median (IQR) frequency of plasma exchange within 7 days of initial exchange was 3 (2-5) days; median (IQR) duration of plasma exchange was 10 (4-21) days. Of the 1,519 (93%) patients who received steroids, 1,071 (71%) received steroid pulse therapy. Among the 529 (32%) patients administered immunosuppressants, 221 (13%) received cyclophosphamide, 152 (9.3%) rituximab, 140 (8.6%) cyclosporine, and 86 (5.3%) tacrolimus. Conclusions: We assessed real-world clinical practice for TTP patients in Japan for the first time using the nationwide inpatient database. Our analysis showed a disparity between guidelines and real-world clinical practice, especially regarding frequency of plasma exchange. Optimal treatment strategy, efficacy, and safety should be evaluated in future studies. Disclosures Miyakawa: Zenyaku Kogyo: Consultancy; Sanofi: Speakers Bureau; Ablynx: Speakers Bureau; Chugai: Speakers Bureau.

360o View of a Day Hospital Program Performing Exchange Transfusion and Outpatient Pain Management on Adults with Sickle Cell Disease

Purpose: Therapeutic erythrocytapheresis, known also as automated red blood cell exchange transfusion (RBC exchange), is standard of care for patients with sickle cell disease (SCD) presenting with severe complications and for primary prevention of CNS events in those with increased risks. There is limited data on the framework and experience of performing this procedure in a large adult population and even less on challenges and outcomes. Here, we present demographic and statistical data highlighting characteristics of the chronic exchange transfusion program at a comprehensive and multidisciplinary adult SCD center. Methods: Data were collected from adults (18 years and older) with a diagnosis of SCD that were receiving blood transfusions in the outpatient treatment facility from September 1st, 2017 to August 31st, 2018. Data gathered included age, gender, procedure indications and frequency, hemoglobin S percentage (Hb S%), target pre and post Hb S%, ferritin trend, and type of intravascular device used for procedure. Three hundred and forty-four (344) episodes of transfusions, were performed in 52 unique patients, corresponding to 21 % of the unique patients treated at our center during that period. Two hundred and sixty-two (262) of the transfusion procedures were RBC exchanges. These RBC exchanges were performed in 35 (14%) of the unique patients. Since a sizable proportion of our patients received pain treatment during RBC exchange, we explored how the pain visual analog score (VAS) changed while undergoing pain treatment during RBC exchange and in relation to multiple opiate doses. Descriptive and basic statistical analysis were performed on the data obtained for those receiving RBC exchange alone or in combination with pain management. Results: Thirty-five unique patients underwent RBC exchange during the study period. All but two (2) patients had the procedure via an implanted dual lumen Vortex port, one (1) by an arteriovenous fistula and one (1) via his native veins. Most of the RBC exchanges were performed as part of a chronic transfusion program for one of the following indications: primary prevention of stroke; secondary prevention of stroke; recurrent acute chest syndrome (ACS); intractable pain; presence of multiple comorbidities including pulmonary hypertension, chronic kidney disease and intractable leg ulcers. One patient received RBC exchange in preparation for bone marrow transplant. The three (3) other patients that only received one (1) RBC exchange during that period were previously on exchange transfusion but discontinued the procedure due lack of venous access or benefit from the procedure. The frequency of RBC exchange varied depending of the patient's specific indication for the procedure and the ability to reach a target Hb S% goal of < 30%. The RBC exchange occurred in patients as frequently as every four (4) to seven (7) weeks. The number of transfusions per patient/year ranged from one (1) to thirteen (13) with a mean and median of eight (8). Number of RBC units used per procedure ranged from four (4) to thirteen (13) with a mean of eight (8.6), with each unique patient usually receiving the same amount. Twenty-three (66%) unique patients received, at least once, acute pain treatment - oral, intravenous, or a combination during RBC exchange. The mean change of VAS between presentation and end of the pain management period was 1.9 (p<0.0001). Conclusion: Our data shows that therapeutic RBC exchange are performed on a regular basis on a small but significant subgroup of patients living with SCD and treated at a comprehensive SCD center. Intravenous opioid management of acute pain can be effectively performed while receiving RBC exchange which provides patients with multimodal interventions in the outpatient setting. The relationship between change in VAS and concurrent transfusion deserves further investigation. Although there are standard indications for RBC exchange, we and others use it for indications for which there is low level of evidence or no evidence of efficacy (i.e. leg ulcers). We found that there great variability on the frequency of the procedure, total number of RBC exchanges per year and number of RBC units used. Prospective studies are needed to better understand the short and long-term effects, complications and outcomes of chronic RBC exchange in adults living with SCD. Figure Disclosures Kato: Bayer: Research Funding; Novartis, Global Blood Therapeutics: Consultancy, Research Funding. De Castro:Pfizer: Consultancy; Novartis: Membership on an entity's Board of Directors or advisory committees; Global Blood Therapeutics: Membership on an entity's Board of Directors or advisory committees.

SOCIAL TIES AND SUICIDAL IDEATION AMONG OLDER ADULTS REFERRED FOR A BEHAVIORAL HEALTH EVALUATION

The association between the quality and nature of social relationships and suicidal outcomes across the lifespan is well established. However, social ties are rarely assessed in primary care and other clinical settings where older adults at high risk for suicide-related outcomes are seen. This study examined the unique associations between three indices of social ties (i.e., perceived social support, frequency of negative social exchanges, and degree of social integration) and death/suicidal ideation among 3,261 older veterans (aged 65+) who completed a clinical mental health/substance use (MH/SU) assessment upon referral to a Primary Care-Mental Health Integration (PCMHI) program. Data on sociodemographics, MH/SU conditions (e.g., depression, anxiety, and substance use), perceived health, the three indices of social ties, and death/suicidal ideation were extracted from clinical interviews. Veterans were on average 70.8 years old (+6.5 years) and primarily male. Approximately half were married and 60.3% were non-Hispanic white. Forty percent reported death ideation or suicidal ideation, as measured by the Paykel Suicide Scale. Logistic regression analyses revealed that, adjusting for covariates, while perceived social support was associated with a greater risk of reporting death ideation relative to no ideation, both social support and frequency of negative exchanges were uniquely associated with greater risk of reporting suicidal ideation relative to no ideation. Social integration was unrelated to odds of death or suicidal ideation. Findings underscore the value of integrating assessments of multiple aspects of social ties into routine PCMHI practice, as doing so has the potential to enhance suicide screening and intervention efforts.

Effectiveness of a simulator-based bridge resource management training module in the German Navy

IntroductionEmpirical data on the effectiveness of BRM trainings is still sparse and as far as studies were published, not very encouraging. Both O’Connor (2011) and Rottger, Vetter & Kowalski (201...

Aquaculture Feeds Can Be Outlaws for Eutrophication When Hidden in Rice Fields? A Case Study in Qianjiang, China.

Water eutrophication caused by agricultural production has become one of the most important factors that impede sustainable rural environmental governance in China. As a result, the Chinese central and local governments want to reduce the use of nitrogen and phosphorus fertilizer and gain socioeconomical profit simultaneously by promoting crayfish and rice integrated system (CRIS) in the rural areas with abundant water resources. In this article, we investigated whether CRIS in Qianjiang, Hubei, the origin place of the system in China, contributes to fulfilling the governments’ expectations. We found that CRIS efficaciously cuts the fertilizer rate in rice production and boosts farmers’ incomes because crayfish has a demand for water quality and holds a large internal market requirement. However, higher profit encourages farmers to expand crayfish production and thus discourages the initiatives in rice production. The area of the ditch for crayfish production expands ceaselessly and exceeds the limit of regulation of CRIS. As a result, the CRIS in the areas has emerged as a practice of aquaculture but in farmland. This is a regulatory gap. The input–output analysis of CRIS by material balance method can also reveal that excessive feed for crayfish has become a new source of agricultural pollution. Beyond that, due to the changed irrigation system and increased water exchange frequency of CRIS, the pollution has transformed from passive distribution to active, which will increase the risk of water eutrophication on a large area.

Reconsidering Calcium Dehydration as the Rate-Determining Step in Calcium Mineral Growth.

The dehydration of cations is generally accepted as the rate-limiting step in many processes. Molecular dynamics (MD) can be used to investigate the dynamics of water molecules around cations, and two different methods exist to obtain trajectory-based water dehydration frequencies. Here, these two different post-processing methods (direct method versus survival function) have been implemented to obtain calcium dehydration frequencies from a series of trajectories obtained using a range of accepted force fields. None of the method combinations reproduced the commonly accepted experimental water exchange frequency of 10–8.2 s–1. Instead, our results suggest much faster water dynamics, comparable with more accurate ab initio MD simulations and with experimental values obtained using neutron scattering techniques. We obtained the best agreement using the survival function method to characterize the water dynamics, and we show that different method combinations significantly affect the outcome. Our work strongly suggests that the fast water exchange kinetics around the calcium ions is not rate-limiting for reactions involving dissolved/solvated calcium. Our results further suggest that, for alkali and most of the earth alkali metals, mechanistic rate laws for growth, dissolution, and adsorption, which are based on the principle of rate-limiting cation dehydration, need careful reconsideration.

Non-Random Distribution of Reciprocal Translocation Breakpoints in the Pig Genome.

Balanced chromosome rearrangements are one of the main etiological factors contributing to hypoprolificacy in the domestic pig. Amongst domestic animals, the pig is considered to have the highest prevalence of chromosome rearrangements. To date over 200 unique chromosome rearrangements have been identified. The factors predisposing pigs to chromosome rearrangements, however, remain poorly understood. Nevertheless, here we provide empirical evidence which sustains the notion that there is a non-random distribution of chromosomal rearrangement breakpoints in the pig genome. We sought to establish if there are structural chromosome factors near which rearrangement breakpoints preferentially occur. The distribution of rearrangement breakpoints was analyzed across three level, chromosomes, chromosome arms, and cytogenetic GTG-bands (G-banding using trypsin and giemsa). The frequency of illegitimate exchanges (e.g., reciprocal translocations) between individual chromosomes and chromosome arms appeared to be independent of chromosome length and centromere position. Meanwhile chromosome breakpoints were overrepresented on some specific G-bands, defining chromosome hotspots for ectopic exchanges. Cytogenetic band level factors, such as the length of bands, chromatin density, and presence of fragile sites, were associated with the presence of translocation breakpoints. The characteristics of these bands were largely similar to that of hotspots in the human genome. Therefore, those hotspots are proposed as a starting point for future molecular analyses into the genomic landscape of porcine chromosome rearrangements.

Internally resonant wave energy exchange in weakly nonlinear lattices and metamaterials.

This paper presents a multiple-scales analysis approach capable of capturing internally resonant wave interactions in weakly nonlinear lattices and metamaterials. Example systems considered include a diatomic chain and a locally resonant metamaterial-type lattice. At a number of regions in the band structure, both the frequency and wave number of one nonlinear plane wave may relate to another in a near-commensurate manner (such as in a 2:1 or 3:1 ratio) resulting in an internal resonance mechanism. As shown herein, nonlinear interactions in the lattice couple these waves and enable energy exchange. Near such internal resonances, previously derived higher-order dispersion corrections for single plane wave propagation may break down, leading to singularities in the predicted nonlinear dispersion relationships. Using the presented multiple-scales approach and the two example systems, this paper examines internal resonance occurring (i) within the same branch and (ii) between different branches of the band structure, resolving the aforementioned singularity issue while capturing energy exchange. The multiple-scales evolution equations, together with a local stability analysis, uncover multiple stable fixed points associated with periodic energy exchange between internally resonant propagating modes. Response results generated using direct numerical simulation verify the perturbation-based predictions for amplitude-dependent dispersion corrections and slow-scale energy exchange; importantly, these comparisons verify the exchange frequency predicted by the multiple-scales approach.

(Eventual) stability and change across partnerships.

Does a new partnership differ from its preceding one? This study investigates whether relationship dynamics change as people transition from 1 partnership to another and examines a number of predictors that might explain variation in change trajectories. We draw on data gathered from 554 focal participants in the German Family Panel (pairfam) study surveyed at 4 time points spanning 2 intimate unions to answer these questions. Latent change score modeling results showed eventual stability in 5 of 7 constructs under investigation. When looking at overall change from Time 1 in Partnership 1 to Time 2 of Partnership 2, there were no mean-level changes in relationship and sexual satisfaction, perceptions of relational instability, or frequency of conflictual and intimate exchanges. Sexual frequency and partner admiration improved across partnerships. Further analyses showed much change unfolded in the interim; all constructs showed significant deterioration as Partnership 1 drew to a close, marked improvements as individuals moved from the end of Partnership 1 into their next union, and worsening across the 1st year of Partnership 2. Neuroticism and relationship length were the most consistent predictors of change across partnerships: Those in shorter Partnership 1 relationships and with higher neuroticism typically experienced decreases in functioning across partnerships. These findings provide support for an eventual stability conceptualization of relationship development across partnerships. (PsycINFO Database Record (c) 2019 APA, all rights reserved).

Early science education in preschools – the contribution of professional development and professional exchange in team meetings

ABSTRACTScience is an important domain in early childhood education. Though, initial results indicate that preschool teachers rarely offer science activities. Against this background professional development aims to encourage preschool teachers to provide science activities more frequently. In Germany, professional development is often offered as short-term courses. It is not clear whether the participation in these courses results in an increase of the frequency of science activities and which role the work environment plays for the frequency of science activities provided by preschool teachers. Therefore the present study investigated how a supportive work environment, assessed by the indicator professional exchange on early science education between preschool teachers, is related to their amount of professional development and the frequency of their science activities for preschool children. A questionnaire was completed by 301 preschool teachers. The results revealed a positive relation between the amount of professional development in science and the frequency of science activities. Further findings indicate that this relation is mediated by the frequency of professional exchange about science content. In addition, we found that preschool teachers without any professional development provided science activities more frequently, when science content was discussed in team meetings. Implications for practice are discussed.

Sinergias entre instituciones socioeducativas como respuesta ante las necesidades sociales. Una aproximación a través del análisis de redes sociales.

Las crisis sociales y económicas que han vivido y se viven en el madrileño barrio El Pozo-Entrevías (en el distrito de Puente de Vallecas) ha supuesto una transformación en la forma de relacionarse por parte de las entidades socioeducativas que se encuentran en él. El objetivo de este estudio es conocer y analizar cómo son las relaciones que existen entre las entidades seleccionadas como representativas de instituciones socioeducativas: un centro de educación infantil y primaria, un centro de educación secundaria y una ONG.Para describir y analizar dichas relaciones, se ha utilizado una metodología mixta apoyada en entrevistas semiestructuradas y hemos utilizado como metodología innovadora en educación, el Análisis de Redes Sociales (ARS), el cual nos permite analizar y comprender los vínculos de apoyo interinstitucionales. El análisis se realizó en torno a cuatro categorías: tipo de relación formal o informal, frecuencia de los intercambios, antigüedad y tipo de apoyo que intercambian. Las primeras aproximaciones de esta investigación piloto muestran que existen fuertes redes entre los centros educativos y las asociaciones como respuesta a las necesidades de un contexto caracterizado por enfrentarse a unas condiciones socioeconómicas desafiantes.