Relating Plant Spatial Pattern, Plant Biodiversity, and Ecosystem Function to Management Practices in Experimental Restored Wetlands

Understanding the effects of management practices on shifting relationships between structure and function over the course of ecosystem development should be a central goal of ecosystem restoration. Yet many of these relationships, such as those between plant biodiversity, spatial pattern of vegetation and community metabolism, remain poorly understood. In a decade-long experiment, we investigated the impact of different initial planting treatments and of nutrient enrichment on relationships among plant biodiversity, plant spatial pattern, and ecosystem function in restored wetland ecosystems. In 2003, six identical and hydrologically-isolated 0.18 ha experimental wetland cells were constructed in marginal farmland in northeast Ohio. Cells were subjected to one of three initial planting and management treatments, which were later simplified into two treatment groups. In 2010 and 2011, nitrogen and phosphorus fertilizers were applied to one cell from each of the three treatments to simulate agricultural run-off. Changes and differences in ecosystem function were assessed by measuring aquatic community metabolism, above ground biomass, soil organic matter, and nutrient concentrations. Structure was characterized through annual plant biodiversity inventories and aerial photographs of plant cover that were analyzed to quantify vegetation spatial patterns. We found significant relationships among plant biodiversity, plant spatial pattern, and planting treatments. We observed significant and sustained differences in plant biodiversity, resulting from both planting treatment and habitat attributes of cells. Relationships between ecosystem function and both biodiversity and spatial pattern were more ambiguous. We found no direct relationships between biodiversity or spatial metrics and any measures of ecosystem function. These findings support the importance of initial wetland structure in achieving plant biodiversity in restored wetlands, but provide little additional evidence that species diversity has a major effect on nutrient retention, primary productivity, or soil organic matter in restored wetland systems. Over multiple years, biodiversity metrics correlated positively with spatial metrics, including mean patch shape complexity and contagion. This suggests that restored wetland landscapes comprised of patches with complex shapes (high edge-to-area ratios) that are highly clumped are home to a more diverse array of plant species. Links between biodiversity and spatial pattern suggest that aerial imagery may provide wetland managers with a robust tool for assessing plant biodiversity

Dynamic Formant Trajectories in German Read Speech : Impact of Predictability and Prominence

Phonetic structures expand temporally and spectrally when they are difficult to predict from their context. To some extent, effects of predictability are modulated by prosodic structure. So far, studies on the impact of contextual predictability and prosody on phonetic structures have neglected the dynamic nature of the speech signal. This study investigates the impact of predictability and prominence on the dynamic structure of the first and second formants of German vowels. We expect to find differences in the formant movements between vowels standing in different predictability contexts and a modulation of this effect by prominence. First and second formant values are extracted from a large German corpus. Formant trajectories of peripheral vowels are modeled using generalized additive mixed models, which estimate nonlinear regressions between a dependent variable and predictors. Contextual predictability is measured as biphone and triphone surprisal based on a statistical German language model. We test for the effects of the information-theoretic measures surprisal and word frequency, as well as prominence, on formant movement, while controlling for vowel phonemes and duration. Primary lexical stress and vowel phonemes are significant predictors of first and second formant trajectory shape. We replicate previous findings that vowels are more dispersed in stressed syllables than in unstressed syllables. The interaction of stress and surprisal explains formant movement: unstressed vowels show more variability in their formant trajectory shape at different surprisal levels than stressed vowels. This work shows that effects of contextual predictability on fine phonetic detail can be observed not only in pointwise measures but also in dynamic features of phonetic segments

Information density and phonetic structure: Explaining segmental variability

There is growing evidence that information-theoretic principles influence linguistic structures. Regarding speech several studies have found that phonetic structures lengthen in duration and strengthen in their spectral features when they are difficult to predict from their context, whereas easily predictable phonetic structures are shortened and reduced spectrally. Most of this evidence comes from studies on American English, only some studies have shown similar tendencies in Dutch, Finnish, or Russian. In this context, the Smooth Signal Redundancy hypothesis (Aylett and Turk 2004, Aylett and Turk 2006) emerged claiming that the effect of information-theoretic factors on the segmental structure is moderated through the prosodic structure. In this thesis, we investigate the impact and interaction of information density and prosodic structure on segmental variability in production analyses, mainly based on German read speech, and also listeners' perception of differences in phonetic detail caused by predictability effects. Information density (ID) is defined as contextual predictability or surprisal (S(unit_i) = -log2 P(unit_i|context)) and estimated from language models based on large text corpora. In addition to surprisal, we include word frequency, and prosodic factors, such as primary lexical stress, prosodic boundary, and articulation rate, as predictors of segmental variability in our statistical analysis. As acoustic-phonetic measures, we investigate segment duration and deletion, voice onset time (VOT), vowel dispersion, global spectral characteristics of vowels, dynamic formant measures and voice quality metrics. Vowel dispersion is analyzed in the context of German learners' speech and in a cross-linguistic study. As results, we replicate previous findings of reduced segment duration (and VOT), higher likelihood to delete, and less vowel dispersion for easily predictable segments. Easily predictable German vowels have less formant change in their vowel section length (VSL), F1 slope and velocity, are less curved in their F2, and show increased breathiness values in cepstral peak prominence (smoothed) than vowels that are difficult to predict from their context. Results for word frequency show similar tendencies: German segments in high-frequency words are shorter, more likely to delete, less dispersed, and show less magnitude in formant change, less F2 curvature, as well as less harmonic richness in open quotient smoothed than German segments in low-frequency words. These effects are found even though we control for the expected and much more effective effects of stress, boundary, and speech rate. In the cross-linguistic analysis of vowel dispersion, the effect of ID is robust across almost all of the six languages and the three intended speech rates. Surprisal does not affect vowel dispersion of non-native German speakers. Surprisal and prosodic factors interact in explaining segmental variability. Especially, stress and surprisal complement each other in their positive effect on segment duration, vowel dispersion and magnitude in formant change. Regarding perception we observe that listeners are sensitive to differences in phonetic detail stemming from high and low surprisal contexts for the same lexical target.Informationstheoretische Faktoren beeinflussen die Variabilität gesprochener Sprache. Phonetische Strukturen sind länger und zeigen erhöhte spektrale Distinktivität, wenn sie aufgrund ihres Kontextes leicht vorhersagbar sind als Strukturen, die schwer vorhersagbar sind. Die meisten Studien beruhen auf Daten aus dem amerikanischen Englisch. Nur wenige betonen die Notwendigkeit für mehr sprachliche Diversität. Als Resultat dieser Erkenntnisse haben Aylett und Turk (2004, 2006) die Smooth Signal Redundancy Hypothese aufgestellt, die besagt, dass der Effekt von Vorhersagbarkeit auf phonetische Strukturen nicht direkt, sondern nur die prosodische Struktur umgesetzt wird. In dieser Arbeit werden der Einfluss und die Interaktion von Informationsdichte und prosodischen Strukturen auf segmentelle Variabilität im Deutschen sowie die Wahrnehmungsfähigkeit von Unterschieden im phonetischen Detail aufgrund ihrer Vorhersagbarkeit untersucht. Informationsdichte (ID) wird definiert als kontextuelle Vorhersagbarkeit oder Surprisal (S(unit_i) = -log2 P(unit_i|context)). Zusätzlich zu Surprisal verwenden wir auch Wortfrequenz und prosodische Faktoren, wie primäre Wortbetonung, prosodische Grenze und Sprechgeschwindigkeit als Variablen in der statistischen Analyse. Akustisch-phonetische Maße sind Segmentlänge und -löschung, voice onset time (VOT), Vokaldispersion, globale und dynamische vokalische Eigenschaften und Stimmqualität. Vokaldispersion wird nicht nur im Deutschen, sondern auch in einer sprachübergreifenden Analyse und im Kontext von L2 untersucht. Wir können vorherige Ergebnisse, die auf dem Amerikanischen beruhten, für das Deutsche replizieren. Reduzierte Segmentlänge und VOT, höhere Wahrscheinlichkeit der Löschung und geringere Vokaldispersion werden auch für leicht vorhersagbare Segmente im Deutschen beobachtet. Diese zeigen auch weniger Formantenbewegung, reduzierte Kurvigkeit in F2 sowie erhöhte Behauchtheitswerte als Vokale, die schwer vorhersagbar sind. Die Ergebnisse für Wortfrequenz zeigen ähnliche Tendenzen: Deutsche Segmente in hochfrequenten Wörtern sind kürzer, werden eher gelöscht, zeigen reduzierte Werte für Vokaldispersion, Formantenbewegungen und Periodizität als deutsche Segmente in Wörtern mit geringer Frequenz. Obwohl wir bekannte Effekte für Betonung, Grenze und Tempo auf segmentelle Variabilität in den Modellen beobachten, sind die Effekte von ID signifikant. Die sprachübergreifende Analyse zeigt zudem, dass diese Effekte auch robust für die meisten der untersuchten Sprachen sind und sich in allen intendierten Sprechgeschwindigkeiten zeigen. Surprisal hat allerdings keinen Einfluss auf die Vokaldispersion von Sprachlernern. Des weiteren finden wir Interaktionseffekte zwischen Surprisal und den prosodischen Faktoren. Besonders für Wortbetonung lässt sich ein stabiler positiver Interaktionseffekt mit Surprisal feststellen. In der Perzeption sind Hörer durchaus in der Lage, Unterschiede zwischen manipulierten und nicht manipulierten Stimuli zu erkennen, wenn die Manipulation lediglich im phonetischen Detail des Zielwortes aufgrund von Vorhersagbarkeit besteht

Staying home: An evaluation of North Carolina’s Urgent Repair Program

Among other programs of the North Carolina Housing Finance Agency (NCHFA), the Urgent Repair Program (URP) finances home repairs and modification for low-income households with special needs. URP aims to improve quality of life and choice for individuals who might otherwise have to endure substandard, unsafe housing conditions or enter institutional care settings. This evaluation assesses the program’s outcomes and impact in three areas: (1) effectiveness, or how well URP prevents displacement and improves quality of life for participants; (2) spatial equity, or how the geographic distribution of URP investment compares to the distribution of need; and (3) cost efficiency, or how the program’s public costs compare to its public benefits. Participant surveys, GIS mapping, and cost/benefit analysis were used to evaluate URP’s performance in these three areas, respectively. Findings revealed that URP has largely succeeded at improving participants’ quality of life, addressing spatially concentrated need, and creating savings to public health insurance systems: Overall satisfaction with URP among surveyed participants was 90.7%; URP is highly active in 76% of the counties with high proportions of eligible households; and Every $1 of URP funding could save up to$19 of Medicaid/Medicare spending. Recommendations for improving the program include: Improving program administration guidelines regarding project monitoring, quality control, and communication among local administrators, applicants/participants, and contractors; Increasing outreach to potential local program administrators in six underserved, high-need counties (Alleghany, Ashe, Beaufort, Bladen, Chatham, and Jones); and Coordinating with the North Carolina Department of Health and Human Services to enhance the provision of publicly-funded home and community-based long-term care services. Overall, this study provides evidence of URP’s positive statewide impact and fiscal cost effectiveness, supporting the program’s popularity and its important role in advancing opportunities for community living and aging in place for North Carolinians.Master of City and Regional Plannin

High shear stress from a resonance phenomenon in Wave bioreactor revealed by computational fluid dynamics simulation

Wave bioreactors are getting a wide acceptance for the culture of human cells. These bioreactors are attractive for sensitive cells such as stem cells or immune cells, in suspension, aggregates or adherently growing on microcarriers. The optimization of the mixing, the oxygen transfer rate and the shear stress require a deep understanding of the hydrodynamics taking place in the Wave bioreactor bag. In the present study, we perform numerical simulations (Ansys-FLUENT) to characterize the flow conditions in a 10L cellbag [1]. The numerical simulations were carried out to investigate the fluid structures for nine different operating conditions of rocking speed and angle. The mixing and the shear stress induced by the liquid motion were studied. We observed that these increased with the cellbag angle from 4˚ to 7˚ but that the highest rocking velocities were not systematically associated with the highest mixing and shear stress. As a matter of fact, the lowest studied rocking speed, 15 rpm, generated the highest fluid velocity, mixing and shear stress compared to the higher speeds of 22 and 30 rpm. It was concluded that a resonance phenomenon was responsible for this behavior. Please click Additional Files below to see the full abstract

Dynamic Formant Trajectories in German Read Speech: Impact of Predictability and Prominence

Phonetic structures expand temporally and spectrally when they are difficult to predict from their context. To some extent, effects of predictability are modulated by prosodic structure. So far, studies on the impact of contextual predictability and prosody on phonetic structures have neglected the dynamic nature of the speech signal. This study investigates the impact of predictability and prominence on the dynamic structure of the first and second formants of German vowels. We expect to find differences in the formant movements between vowels standing in different predictability contexts and a modulation of this effect by prominence. First and second formant values are extracted from a large German corpus. Formant trajectories of peripheral vowels are modeled using generalized additive mixed models, which estimate nonlinear regressions between a dependent variable and predictors. Contextual predictability is measured as biphone and triphone surprisal based on a statistical German language model. We test for the effects of the information-theoretic measures surprisal and word frequency, as well as prominence, on formant movement, while controlling for vowel phonemes and duration. Primary lexical stress and vowel phonemes are significant predictors of first and second formant trajectory shape. We replicate previous findings that vowels are more dispersed in stressed syllables than in unstressed syllables. The interaction of stress and surprisal explains formant movement: unstressed vowels show more variability in their formant trajectory shape at different surprisal levels than stressed vowels. This work shows that effects of contextual predictability on fine phonetic detail can be observed not only in pointwise measures but also in dynamic features of phonetic segments

Runaway Massive Binaries and Cluster Ejection Scenarios

The production of runaway massive binaries offers key insights into the evolution of close binary stars and open clusters. The stars HD 14633 and HD 15137 are rare examples of such runaway systems, and in this work we investigate the mechanism by which they were ejected from their parent open cluster, NGC 654. We discuss observational characteristics that can be used to distinguish supernova ejected systems from those ejected by dynamical interactions, and we present the results of a new radio pulsar search of these systems as well as estimates of their predicted X-ray flux assuming that each binary contains a compact object. Since neither pulsars nor X-ray emission are observed in these systems, we cannot conclude that these binaries contain compact companions. We also consider whether they may have been ejected by dynamical interactions in the dense environment where they formed, and our simulations of four-body interactions suggest that a dynamical origin is possible but unlikely. We recommend further X-ray observations that will conclusively identify whether HD 14633 or HD 15137 contain neutron stars.Comment: Accepted to ApJ, 11 page

Dimensions of Segmental Variability: Interaction of Prosody and Surprisal in Six Languages

Contextual predictability variation affects phonological and phonetic structure. Reduction and expansion of acoustic-phonetic features is also characteristic of prosodic variability. In this study, we assess the impact of surprisal and prosodic structure on phonetic encoding, both independently of each other and in interaction. We model segmental duration, vowel space size and spectral characteristics of vowels and consonants as a function of surprisal as well as of syllable prominence, phrase boundary, and speech rate. Correlates of phonetic encoding density are extracted from a subset of the BonnTempo corpus for six languages: American English, Czech, Finnish, French, German, and Polish. Surprisal is estimated from segmental n-gram language models trained on large text corpora. Our findings are generally compatible with a weak version of Aylett and Turk's Smooth Signal Redundancy hypothesis, suggesting that prosodic structure mediates between the requirements of efficient communication and the speech signal. However, this mediation is not perfect, as we found evidence for additional, direct effects of changes in surprisal on the phonetic structure of utterances. These effects appear to be stable across different speech rates

Effect of fluid resuscitation on mortality and organ function in experimental sepsis models

Introduction Several recent studies have shown that a positive fluid balance in critical illness is associated with worse outcome. We tested the effects of moderate vs. high-volume resuscitation strategies on mortality, systemic and regional blood flows, mitochondrial respiration, and organ function in two experimental sepsis models. Methods 48 pigs were randomized to continuous endotoxin infusion, fecal peritonitis, and a control group (n = 16 each), and each group further to two different basal rates of volume supply for 24 hours [moderate-volume (10 ml/kg/h, Ringer's lactate, n = 8); high-volume (15 + 5 ml/kg/h, Ringer's lactate and hydroxyethyl starch (HES), n = 8)], both supplemented by additional volume boli, as guided by urinary output, filling pressures, and responses in stroke volume. Systemic and regional hemodynamics were measured and tissue specimens taken for mitochondrial function assessment and histological analysis. Results Mortality in high-volume groups was 87% (peritonitis), 75% (endotoxemia), and 13% (controls). In moderate-volume groups mortality was 50% (peritonitis), 13% (endotoxemia) and 0% (controls). Both septic groups became hyperdynamic. While neither sepsis nor volume resuscitation strategy was associated with altered hepatic or muscle mitochondrial complex I- and II-dependent respiration, non-survivors had lower hepatic complex II-dependent respiratory control ratios (2.6 +/- 0.7, vs. 3.3 +/- 0.9 in survivors; P = 0.01). Histology revealed moderate damage in all organs, colloid plaques in lung tissue of high-volume groups, and severe kidney damage in endotoxin high-volume animals. Conclusions High-volume resuscitation including HES in experimental peritonitis and endotoxemia increased mortality despite better initial hemodynamic stability. This suggests that the strategy of early fluid management influences outcome in sepsis. The high mortality was not associated with reduced mitochondrial complex I- or II-dependent muscle and hepatic respiration

CEDAR, an online resource for the reporting and exploration of complexome profiling data

Complexome profiling is an emerging ‘omics’ approach that systematically interrogates the composition of protein complexes (the complexome) of a sample, by combining biochemical separation of native protein complexes with mass-spectrometry based quantitation proteomics. The resulting fractionation profiles hold comprehensive information on the abundance and composition of the complexome, and have a high potential for reuse by experimental and computational researchers. However, the lack of a central resource that provides access to these data, reported with adequate descriptions and an analysis tool, has limited their reuse. Therefore, we established the ComplexomE profiling DAta Resource (CEDAR, www3.cmbi.umcn.nl/cedar/), an openly accessible database for depositing and exploring mass spectrometry data from complexome profiling studies. Compatibility and reusability of the data is ensured by a standardized data and reporting format containing the “minimum information required for a complexome profiling experiment” (MIACE). The data can be accessed through a user-friendly web interface, as well as programmatically using the REST API portal. Additionally, all complexome profiles available on CEDAR can be inspected directly on the website with the profile viewer tool that allows the detection of correlated profiles and inference of potential complexes. In conclusion, CEDAR is a unique, growing and invaluable resource for the study of protein complex composition and dynamics across biological systems