Measurement of Sibling Violence: A Two-Factor Model of Severity

The measurement of violence is a major challenge in aggression research. Because of the heterogeneous nature of violent behavior, problems arise when applying blanket measures to inherently distinct subtypes of aggression. Incidents of intersibling violence (ISV) exacerbate these problems because siblinghood represents a unique offender–victim situation. This research explored whether an existing two-factor model for severe violence found in a sample of 250 adult offenders (age M = 26.8, SD = 5.9) could be generalized to deliberate severe ISV in a sample of 111 young offenders (age M = 14.83, SD = 1.45). Exploratory factor analysis revealed a two-factor model encompassing severe ISV perpetration with weapon use (Factor 1) and severe ISV perpetration without weapon use (Factor 2). The results provide strong empirical support for the two-factor model of violence severity previously established with adult offenders. This analysis demonstrates construct validity of the severity measures among the different types of offenders studied and provides support for generalization across populations

Microbial engineering for production of N-functionalized amino acids and amines

Mindt M, Walter T, Kugler P, Wendisch VF. Microbial engineering for production of N-functionalized amino acids and amines. Biotechnology Journal . 2020;15(7): 1900451.N‐ functionalized amines play important roles in nature and occur, for example, in the antibiotic vancomycin, the immunosuppressant cyclosporine, the cytostatic actinomycin, the siderophore aerobactin, the cyanogenic glucoside linamarin, and the polyamine spermidine. In the pharmaceutical and fine‐chemical industries N‐ functionalized amines are used as building blocks for the preparation of bioactive molecules. Processes based on fermentation and on enzyme catalysis have been developed to provide sustainable manufacturing routes to N‐ alkylated, N‐ hydroxylated, N‐ acylated, or other N‐ functionalized amines including polyamines. Metabolic engineering for provision of precursor metabolites is combined with heterologous N‐ functionalizing enzymes such as imine or ketimine reductases, opine or amino acid dehydrogenases, N‐ hydroxylases, N‐ acyltransferase, or polyamine synthetases. Recent progress and applications of fermentative processes using metabolically engineered bacteria and yeasts along with the employed enzymes are reviewed and the perspectives on developing new fermentative processes based on insight from enzyme catalysis are discussed

Evidence for 'critical slowing down' in seagrass:a stress gradient experiment at the southern limit of its range

The theory of critical slowing down, i.e. the increasing recovery times of complex systems close to tipping points, has been proposed as an early warning signal for collapse. Empirical evidence for the reality of such warning signals is still rare in ecology. We studied this on Zostera noltii intertidal seagrass meadows at their southern range limit, the Banc d'Arguin, Mauritania. We analyse the environmental covariates of recovery rates using structural equation modelling (SEM), based on an experiment in which we assessed whether recovery after disturbances (i.e. seagrass & infauna removal) depends on stress intensity (increasing with elevation) and disturbance patch size (1 m(2) vs. 9 m(2)). The SEM analyses revealed that higher biofilm density and sediment accretion best explained seagrass recovery rates. Experimental disturbances were followed by slow rates of recovery, regrowth occurring mainly in the coolest months of the year. Macrofauna recolonisation lagged behind seagrass recovery. Overall, the recovery rate was six times slower in the high intertidal zone than in the low zone. The large disturbances in the low zone recovered faster than the small ones in the high zone. This provides empirical evidence for critical slowing down with increasing desiccation stress in an intertidal seagrass system

Low oxygen affects photophysiology and the level of expression of two-carbon metabolism genes in the seagrass <i>Zostera muelleri</i>

© 2017, Springer Science+Business Media B.V. Seagrasses are a diverse group of angiosperms that evolved to live in shallow coastal waters, an environment regularly subjected to changes in oxygen, carbon dioxide and irradiance. Zostera muelleri is the dominant species in south-eastern Australia, and is critical for healthy coastal ecosystems. Despite its ecological importance, little is known about the pathways of carbon fixation in Z. muelleri and their regulation in response to environmental changes. In this study, the response of Z. muelleri exposed to control and very low oxygen conditions was investigated by using (i) oxygen microsensors combined with a custom-made flow chamber to measure changes in photosynthesis and respiration, and (ii) reverse transcription quantitative real-time PCR to measure changes in expression levels of key genes involved in C4 metabolism. We found that very low levels of oxygen (i) altered the photophysiology of Z. muelleri, a characteristic of C3 mechanism of carbon assimilation, and (ii) decreased the expression levels of phosphoenolpyruvate carboxylase and carbonic anhydrase. These molecular-physiological results suggest that regulation of the photophysiology of Z. muelleri might involve a close integration between the C3 and C4, or other CO2 concentrating mechanisms metabolic pathways. Overall, this study highlights that the photophysiological response of Z. muelleri to changing oxygen in water is capable of rapid acclimation and the dynamic modulation of pathways should be considered when assessing seagrass primary production

Connecting the Dots: Responses of Coastal Ecosystems to Changing Nutrient Concentrations

Empirical relationships between phytoplankton biomass and nutrient concentrations established across a wide range of different ecosystems constitute fundamental quantitative tools for predicting effects of nutrient management plans. Nutrient management plans based on such relationships, mostly established over trends of increasing rather than decreasing nutrient concentrations, assume full reversibility of coastal eutrophication. Monitoring data from 28 ecosystems located in four well-studied regions were analyzed to study the generality of chlorophyll a versus nutrient relationships and their applicability for ecosystem management. We demonstrate significant differences across regions as well as between specific coastal ecosystems within regions in the response of chlorophyll a to changing nitrogen concentrations. We also show that the chlorophyll a versus nitrogen relationships over time constitute convoluted trajectories rather than simple unique relationships. The ratio of chlorophyll a to total nitrogen almost doubled over the last 30-40 years across all regions. The uniformity of these trends, or shifting baselines, suggest they may result from large-scale changes, possibly associated with global climate change and increasing human stress on coastal ecosystems. Ecosystem management must, therefore, develop adaptation strategies to face shifting baselines and maintain ecosystem services at a sustainable level rather than striving to restore an ecosystem state of the past. © 2011 American Chemical Society.This research is a contribution to the Thresholds Integrated Project (contract FP6-003933-2) and WISER (contract FP7-226273), funded by the European Commission.Peer Reviewe

Search for CP Violation in D0→KS0π0D^{0}\to K_{S}^{0}\pi^{0}, D0→π0π0D^{0}\to \pi^{0}\pi^{0} and D0→KS0KS0D^{0}\to K_{S}^{0}K_{S}^{0}

We have searched for CP-violating asymmetries in neutral charm meson decays in 13.7 fb^-1 of e^+e^- collision data at sqrt{s} = 10.6 GeV with the CLEO detector. The measured asymmetries in the rate of D0 and D0bar decays to K0sPi0, Pi0Pi0 and K0sK0s final states are (+0.1 +- 1.3)%, (+0.1 +- 4.8)% and (-23 +- 19)%, respectively.Comment: 11 pages postscript, also available through http://w4.lns.cornell.edu/public/CLN