Desiccation, postharvest maturity and seed aging of tall oat-grass

The objectives of this work were to determine whether and at which seed physiological maturity stage the diquat desiccant affects the tall oat-grass (Arrhenatherum elatius) seed quality and yield, as well as the proper storage period between harvest and sowing. Diquat desiccation was evaluated in applications during milk or dough seed maturation stages. Seeds conventionally produced and stored under traditional storage conditions were used for the analyses. Seed samples were drawn every 30th day after harvest (DAH). After the 240th DAH, samples were drawn every 90th day up the to 690th DAH. The highest yield were obtained by desiccation applied at the beginning of the seed dough stage, with a satisfactory seed quality. Both final germination and seedling growth parameters achieved their maximum values between 180th and 240th DAH. Oat-grass seeds preserved satisfactory level of final germination (75%) up to 420th DAH. The application of diquat desiccant at the beginning of seed dough maturity stage can be a good solution for seed production of tall oat-grass. Early spring is the best sowing period for freshly harvested seeds of tall oat-grass regarding germination and seedling growth.

Genesis and Evolution of Brittle Structures In Southwestern Finland and Western South Africa. Insights into Fault Reactivation, Fluid Flow and Structural Maturity in Precambrian Cratons

The bedrock of old crystalline cratons is characteristically saturated with brittle structures formed during successive superimposed episodes of deformation and under varying stress regimes. As a result, the crust effectively deforms through the reactivation of pre-existing structures rather than by through the activation, or generation, of new ones, and is said to be in a state of 'structural maturity'. By combining data from Olkiluoto Island, southwestern Finland, which has been investigated as the potential site of a deep geological repository for high-level nuclear waste, with observations from southern Sweden, it can be concluded that the southern part of the Svecofennian shield had already attained structural maturity during the Mesoproterozoic era. This indicates that the phase of activation of the crust, i.e. the time interval during which new fractures were generated, was brief in comparison to the subsequent reactivation phase. Structural maturity of the bedrock was also attained relatively rapidly in Namaqualand, western South Africa, after the formation of first brittle structures during Neoproterozoic time. Subsequent brittle deformation in Namaqualand was controlled by the reactivation of pre-existing strike-slip faults.In such settings, seismic events are likely to occur through reactivation of pre-existing zones that are favourably oriented with respect to prevailing stresses. In Namaqualand, this is shown for present day seismicity by slip tendency analysis, and at Olkiluoto, for a Neoproterozoic earthquake reactivating a Mesoproterozoic fault. By combining detailed field observations with the results of paleostress inversions and relative and absolute time constraints, seven distinctm superimposed paleostress regimes have been recognized in the Olkiluoto region. From oldest to youngest these are: (1) NW-SE to NNW-SSE transpression, which prevailed soon after 1.75 Ga, when the crust had sufficiently cooled down to allow brittle deformation to occur. During this phase conjugate NNW-SSE and NE-SW striking strike-slip faults were active simultaneous with reactivation of SE-dipping low-angle shear zones and foliation planes. This was followed by (2) N-S to NE-SW transpression, which caused partial reactivation of structures formed in the first event; (3) NW-SE extension during the Gothian orogeny and at the time of rapakivi magmatism and intrusion of diabase dikes; (4) NE-SW transtension that occurred between 1.60 and 1.30 Ga and which also formed the NW-SE-trending Satakunta graben located some 20 km north of Olkiluoto. Greisen-type veins also formed during this phase. (5) NE-SW compression that postdates both the formation of the 1.56 Ga rapakivi granites and 1.27 Ga olivine diabases of the region; (6) E-W transpression during the early stages of the Mesoproterozoic Sveconorwegian orogeny and which also predated (7) almost coaxial E-W extension attributed to the collapse of the Sveconorwegian orogeny. The kinematic analysis of fracture systems in crystalline bedrock also provides a robust framework for evaluating fluid-rock interaction in the brittle regime; this is essential in assessment of bedrock integrity for numerous geo-engineering applications, including groundwater management, transient or permanent CO2 storage and site investigations for permanent waste disposal. Investigations at Olkiluoto revealed that fluid flow along fractures is coupled with low normal tractions due to in-situ stresses and thus deviates from the generally accepted critically stressed fracture concept, where fluid flow is concentrated on fractures on the verge of failure. The difference is linked to the shallow conditions of Olkiluoto - due to the low differential stresses inherent at shallow depths, fracture activation and fluid flow is controlled by dilation due to low normal tractions. At deeper settings, however, fluid flow is controlled by fracture criticality caused by large differential stress, which drives shear deformation instead of dilation.

The connection between career education and career maturity /

The value of career education is measured by the extent to which it enhances students' decision making skills regarding career planning. This is referred to as "career maturity". The purpose of this study was to examine what connections could be found between career education and career maturity within one career planning course. A senior level career planning class was studied in depth for one semester and five senior students participated in the study. The five students were interviewed three times during the semester to determine whether, and to what extent, students feel more prepared personally to make decisions as a result of a guided course of instruction. The current trend in education shows an increased emphasis on career education. The government mandates career education, students are in need of career planning courses, and parents want students to learn how to effectively make decisions concerning their future. With this increased emphasis comes the need to evaluate current career education programs which is why this study is significant and useful. The central findings were as follows: first, as a result of taking a career planning course students did increase their career maturity. Second, current career education planning curriculum was similar to the proposed course of study for career planning which comes into effect in September 1999. Current curriculum does help to prepare students to make informed educational and career decisions, a chief aim of the proposed curriculum. Knowing that this outcome is currently achieved will help when the course is being organized to fit the new curriculum.

The effect of pH and ethanol on the astringent sub-qualities of red wine, and the implications for optimum grape maturity /

The first objective of this study was to identify appropriate sensory descriptors to assess the astringent sub-qualities of red wine. The influence of pH and ethanol on the sensation of astringency in red wine was evaluated, using a de-alcoholized red wine. A portion of the wine was adjusted to the pH values of 3.2, 3.4, 3.6 and 3.8, and another portion was adjusted to ethanol concentrations of 0%, 6%, 12%, and 15%. In addition, the pH 3.4 and 3.6 treatments were adjusted to an ethanol concentration of 12% and 15% all wines were then assessed sensorially and seventeen terms were identified, through panel discussion, to describe the mouth-feel and taste qualities: velvet, aggressive, silk/satin, dry, fleshy, unripe, pucker viscosity, abrasive, heat, chewy, acidity, grippy/adhesive, bitter, balance, overall astringency, and mouth-coat. Descriptive analysis profiling techniques were used to train the panel and measure the intensity of these attributes. It was found that decreasing pH values (averaged across all ethanol concentrations) showed an increase in the overall astringency of the wine. The combined treatments of ethanol and pH, real wine parameters (pH 3.4 and 3.6; 12% and 15% ethanol) did not have an effect on the perception of the astringent sub-qualities of the wine. A time intensity study was also included using the pH and ethanol adjusted wines, which showed that as the ethanol level of the wines increased so did the time to maximum intensity. The second objective was to identify appropriate sensory descriptors to evaluate the influence of grape maturity and maceration technique (grape skin contact) on the astringency sub-qualities of red vinifera wines from Niagara. The grapes were harvested across two dates, representing an early harvest and a late harvest. A portion of the Cabernet Sauvignon grapes wine was divided into three maceration treatments of oneweek maceration, standard two-week maceration, three-week maceration, and MCM. Another portion of both the early and late harvest Cabernet Sauvignon grapes were chaptalized to yield a final ethanol concentration of 14.5%. The wines were assessed sensorially and thirteen terms were identified, through panel discussion, to describe the mouth-feel and taste qualities: carbon dioxide, pucker, acidity, silk/chamois, dusty/chalky/powdery, sandpaper, numbing, grippy/adhesive, dry, mouthcoat, bitter, balance and, overall astringency. Descriptive analysis techniques were used to train the panel and measure the intensity of these attributes. The data revealed few significant differences in the mouth-feel of the wines with respect to maturity; which included differences in overall astringency and balance. There were varietal differences between Cabernet Sauvignon, Cabernet Franc, and Pinot Noir and differences for Cabernet Sauvignon wines due to the length and manner of maceration and as a result of chaptalization. Statistical analysis revealed a more complex mouth-feel for the Pinot Noir wines; and an increase in the intensity of the astringent sub-qualities as a result of the addition of sugar to the wines. These findings have implications for how processing decisions, such as optimum grape maturity and vinification methods may affect red wine quality.

Bone properties and skeletal maturity in adolescent males, as assessed by quantitative ultrasound

ABSTRACT Background: Previous studies have implied that weight-bearing, intense and prolonged physical activities optimize bone accretion during the grow^ing years. The majority of past inquiries have used dual-energy X-ray absorptiometry (DXA) to examine bone strength and hand-wrist radiography to determine skeletal maturity in children. Recently, quantitative ultrasound (QUS) technologies have been developed to examine bone properties and skeletal maturity in a safe, noninvasive and cost-effective manner. Objective: The purpose of this study was to compare bone properties and skeletal maturity in competitive male child and adolescent athletes with minimallyactive, age-matched controls, using QUS technology. >. Methods: In total, 224 males were included in the study. The 115 pre-pubertal boys aged 10-12 years consisted of control, minimally-active children (n=34), soccer players (n=26), gymnasts (n=25) and hockey players (n=30). In addition, the 109 late-pubertal boys aged 14-16 years consisted of control, minimally-active adolescents (n=31), soccer players (n=30), gymnasts (n=17) and hockey players (n=31). The athletic groups were elite level players that predominantly trained year-round. Physical activity, nutrition and sports participation were assessed with various questionnaires. Anthropometries, such as height, weight and relative body fat percentage (BF%) were assessed using standard measures. Skeletal strength and age were evaluated using bone QUS. Lastly, salivary testosterone (sT) concentration was measured using Radioimmunoassay (RIA). Results: Within each age group, there were no significant differences between the activity groups in age and pubertal stage. An age effect was apparent in all variables, as expected. A sport effect was noted in all physical characteristics: the child and adolescent gymnasts were shorter and lighter than other sports groups. Adiposity was greater in the controls and in the hockey players. All child subjects were pubertal stage (fanner) I or II, while adolescent subjects were pubertal stage IV or V. There were no differences in daily energy and mineral intakes between sports groups. In both age groups, gymnasts had a higher training volume than other athletic groups. Bone speed of sound (50s) was higher in adolescents compared with the children. Gymnasts had signifieantly higher radial 50S than controls, hockey and soccer players in both age cohorts. Hockey athletes also had higher radial 50S than controls and soccer players in the child and adolescent groups, respectiyely. Child gymnasts and soccer players had greater tibial 50S compared with the hockey players and control groups. Likewise, adolescent gymnasts and soccer players had higher tibial SoS compared with the control group. No interaction was apparent between age and type of activity in any of the bone measures. » Lastly, maturity as assessed by sT and secondary sex characteristics (Tanner stage) was not different between sports group within each age group. Despite the similarity in chronological age, androgen levels and sexual maturity, differences between activity groups were noted in skeletal maturity. In the younger group, hockey players had the highest bone age while the soccer players had the lowest bone age. In the adolescent group, gymnasts and hockey players were characterized by higher skeletal maturity compared with controls. An interaction between the age and sport type effects was apparent in skeletal maturity, reflecting the fact that among the children, the soccer players were significantly less mature than the rest of the groups, while in the adolescents, the controls were the least skeletally mature. Summary and Conclusions: In summary, radial and tibial SOS are enhanced by the unique loading pattern in each sport (i.e, upper and lower extremities in gymnastics, lower extremities in soccer), with no cumulative effect between childhood and adolescence. That is, the effect of sport participation on bone SOS was apparent already among the young athletes. Enhanced bone properties among athletes of specific sports suggest that participation in these sports can improve bone strength and potential bone health.

Enterprise Modelling Approach based on Maturity and Business Scope perspectives

This paper introduces a framework that supports users to implement enterprise modelling within collaborative companies. These enterprise models are the basis for a holistic interoperability measurement and management methodology which will be presented in the second part of the paper. The discipline of enterprise modelling aims at capturing all dimensions of an enterprise in a simplified model. Thus enterprise models are the appropriate basis for managing collaborative enterprise as they reduce the complexity of interoperability problems. Therefore, a first objective of this paper is to present an approach that enables companies to get the most effect out of enterprise modelling in a collaborative environment based on the maturity of their organisation relative to modelling. Within this first step, the user will get recommendations e.g. for the correct modelling language as well as the right level of detail.

The Developmental Sentence Analysis and the Grammatical Analysis of Elicited Language - Complex Level: a correlative study

This paper studies the Developmental Sentence Analysis (DSA), which measures syntactic maturity of spontaneous utterances, and the Grammatical Analysis of Elicited Language (GAEL), which uses a highly structured set of games and activities designed to elicit specific target sentences.

Equations to predict methane emissions from cows fed at maintenance energy level in pasture-based systems

Ruminant production is a vital part of food industry but it raises environmental concerns, partly due to the associated methane outputs. Efficient methane mitigation and estimation of emissions from ruminants requires accurate prediction tools. Equations recommended by international organizations or scientific studies have been developed with animals fed conserved forages and concentrates and may be used with caution for grazing cattle. The aim of the current study was to develop prediction equations with animals fed fresh grass in order to be more suitable to pasture-based systems and for animals at lower feeding levels. A study with 25 nonpregnant nonlactating cows fed solely fresh-cut grass at maintenance energy level was performed over two consecutive grazing seasons. Grass of broad feeding quality, due to contrasting harvest dates, maturity, fertilisation and grass varieties, from eight swards was offered. Cows were offered the experimental diets for at least 2 weeks before housed in calorimetric chambers over 3 consecutive days with feed intake measurements and total urine and faeces collections performed daily. Methane emissions were measured over the last 2 days. Prediction models were developed from 100 3-day averaged records. Internal validation of these equations, and those recommended in literature, was performed. The existing in greenhouse gas inventories models under-estimated methane emissions from animals fed fresh-cut grass at maintenance while the new models, using the same predictors, improved prediction accuracy. Error in methane outputs prediction was decreased when grass nutrient, metabolisable energy and digestible organic matter concentrations were added as predictors to equations already containing dry matter or energy intakes, possibly because they explain feed digestibility and the type of energy-supplying nutrients more efficiently. Predictions based on readily available farm-level data, such as liveweight and grass nutrient concentrations were also generated and performed satisfactorily. New models may be recommended for predictions of methane emissions from grazing cattle at maintenance or low feeding levels.

Influence of glycemic control on fetal lung maturity in gestations affected by diabetes or mild hyperglycemia

Objective. To evaluate the influence of glycemic control on fetal lung maturity in pregnancies affected by diabetes or mild hyperglycemia. Design. Cross-sectional study. Setting. Level III maternity center. Population. A total of 187 pregnant women were submitted to routine amniocentesis for the assessment of fetal lung maturity up to 72 hours before delivery. Methods. Fetal lung maturity thresholds were: Clements-positive at a dilution of 0.5; OD(650) nm >= 0.15; and lamellar body count (LBC) >= 32,000/mu l. The relation of test results with adequate (<= 6.7 mmol/l) or poor (> 6.7 mmol/l) glycemic mean (GM) at term and at preterm was evaluated. Main outcome measure. Delay in fetal lung maturity when glycemic control was poor. Results. Glycemic control was adequate in 146 (78.1%) women. Clements maturity rates were higher at term (91.9%) than at preterm (64.7%) when GM <= 6.7 mmol/l (p < 0.001), but not when control was inadequate. LBC median was higher at term (99.0; 62.0-154.0) than at preterm (66.5; 40.5-108.25) (p = 0.009) when GM <= 6.7 mmol/l, while GM > 6.7 mmol/l did not lead to any difference between these rates at term or preterm. When glycemic control was adequate, OD(650) nm medians at term and at preterm were similar. However, when GM > 6.7 mmol/l, OD(650) nm median at term (0.29; 0.22-0.40) was higher than that observed at preterm (0.15; 0.12-0.18) (p < 0.001). Conclusions. Our results suggest that in term pregnancies routine amniocentesis for the assessment of fetal lung maturity should be abandoned. In preterm pregnancies, or when glycemic control is inadequate it is recommended.

Technological maturity in the world petrochemical industry

Includes bibliography

Evaluation of maturity levels in the management of product development: case studies in the capital goods industry

In recent approaches to the management of product development process (PDP), maturity levels have attracted the attention of practitioners and researchers. The CMMI model contributes to evaluate the maturity levels and improvement of the product development process management. This paper, based on CMMI model, analyzes the practices adopted in two companies of the capital goods industry, which develop and manufacture equipment upon request. It was observed that on account of market conditioning factors and different practices adapted to PDP management, these companies are at different maturity levels. One company is at the initial level of maturity while the other at the most advanced one. It was also noted that the application of CMMI model can provide improvement to PDP management, as well as present guidelines to achieve higher maturity levels, adequate to companies' needs.

Leaf level VOC emissions of single plants from Amazonian and Mediterranean ecosystems: Ontogeny and flooding as stress factor for VOC emissions

Die Vegetation ist die wichtigste Quelle von organischen flüchtigen Verbindungen (auf Englisch volatile organic compounds,VOCs), die einen bemerkenswerten Einfluss auf der Chemie und Physik der Atmosphäre haben. VOCs beeinflussen die oxidative Kapazität der Atmosphäre und tragen zu der Bildung und zum Wachstum von sekundären organischen Aerosolen bei, welche einerseits eine Streuung und Reflektierung der Energie verursachen und andererseits sich an der Bildung und Entwicklung von Wolken beteiligen. Ziel dieser Arbeit war die Beschreibung und der Vergleich von VOC Emissionen aus Pflanzen aus zwei verschiedenen Ökosystemen: Mediterranes Ökosystem und Tropisches Ökosystem. Für diese Aufgabe wurden gewöhnliche Pflanzen von beiden Ökosystemen untersucht. Siebzehn Pflanzenspezies aus der Mittelmeergebiet, welches bekannt ist für seine Vielfalt an VOC emittierenden Pflanzen, wurden in die Untersuchungen einbezogen. Im Gegensatz zum mediterranen Ökosystem sind nur wenig Information verfügbar über VOC Emissionen aus Blättern tropischer Baumspezies. Vor diesem Hintergrund wurden sechsundzwanzig Baumspezies aus verschiedenen Ökotypen des Amazonasbeckens (Terra firme, Várzea und Igapó) wurden auf VOC Emissionen auf Blattebene mit einem Küvetten-System untersucht. Analysen von flüchtigen organischen Verbindungen wurden online mit PTR-MS und offline mittels Sammlung auf entsprechenden Adsorbern (Kartuschen) und nachfolgender GC-FID Analyse untersucht. Die höchsten Emissionen wurden für Isoprene beobachtete, gefolgt durch Monoterpene, Methanol und Aceton. Die meisten Mittelmeer Spezies emittierten eine hohe Vielfalt an Monoterpenspezies, hingegen zeigten nur fünf tropische Pflanzenspezies eine Monoterpene mit einen sehr konservativen Emissionsprofil (α-Pinen>Limonen>Sabinen >ß-Pinen). Mittelmeerpflanzen zeigten zusätzlich Emissionen von Sesquiterpenen, während bei der Pflanzen des Amazonas Beckens keine Sesquiterpenemissionen gefunden wurden. Dieser letzte Befund könnte aber auch durch eine niedrigere Sensitivität des Messsystems während der Arbeiten im Amazonasgebiet erklärt werden. Zusätzlich zu den Isoprenoidemissionen waren Methanolemissionen als Indikator für Wachtumsvorgänge sehr verbreitet in den meisten Pflanzenspezies aus tropischen und mediterranen Gebieten. Einige Pflanzenspezies beider Ökosystemen zeigten Acetonemissionen. rnrnVOC Emissionen werde durch eine große Vielfalt an biotischen und abiotischen Faktoren wie Lichtintensität, Temperatur, CO2 und Trockenheit beeinflusst. Ein anderer, öfter übersehener Faktor, der aber sehr wichtig ist für das Amazonas Becken, ist die regelmäßige Überflutung. In dieser Untersuchung wir fanden heraus, dass am Anfang einer Wurzelanoxie, die durch die Überflutung verursacht wurde, Ethanol und Acetaldehyd emittiert werden können, vor allem in Pflanzenspezies, die schlechter an eine unzureichende Sauerstoffversorgung bei Flutung adaptiert sind, wie z.B. Vatairea guianensis. Die Spezies Hevea spruceana, welche besser an Überflutung adaptiert ist, könnte möglicherweise der gebildete Ethanol sofort remetabolisieren ohne es zu emittieren. Nach einer langen Periode einer Überflutung konnte allerdings keine Emission mehr beobachtet werden, was auf eine vollständige Adaptation mit zunehmender Dauer schließen lässt. Als Reaktion auf den ausgelösten Stress können Isoprenoidemissionen ebenfalls kurzfristig nach einigen Tage an Überflutung zunehmen, fallen dann aber dann nach einer langen Periode zusammen mit der Photosynthese, Transpiration und stomatäre Leitfähigkeit deutlich ab.rnrnPflanzen Ontogenese ist anscheinend von Bedeutung für die Qualität und Quantität von VOC Emissionen. Aus diesem Grund wurden junge und erwachsene Blätter einiger gut charakterisierten Pflanzen Spezies aus dem Mittelmeerraum auf VOC Emissionen untersucht. Standard Emissionsfaktoren von Isopren waren niedriger in jungen Blättern als in erwachsene Blätter. Hingegen wurden höhere Monoterpen- und Sesquiterpenemissionen in jungen Blätter einiger Pflanzenspezies gefunden. Dieser Befund deutet auf eine potentielle Rolle dieser VOCs als Abwehrkomponenten gegen Pflanzenfresser oder Pathogene bei jungen Blätter hin. In einigen Fällen variierte auch die Zusammensetzung der Monoterpen- und Sesquiterpenspezies bei jungen und erwachsenen Blättern. Methanolemissionen waren, wie erwartet, höher in jungen Blättern als in ausgewachsenen Blättern, was mit der Demethylierung von Pectin bei der Zellwandreifung erklärt werden kann. Diese Befunde zu Änderungen der Emissionskapazität der Vegetation können für zukünftige Modellierungen herangezogen werden. rn

Quantity, provenance, and thermal maturity of organic matter at DSDP Holes 95-612 and 95-613

Using methods of analysis from organic geochemistry and organic petrography, we investigated six Pliocene to Maestrichtian samples from DSDP Site 612 and five Pliocene to Eocene samples from DSDP Site 613 for the quantity, type, and thermal maturity of organic matter. At both sites, organic carbon content is low in the Eocene samples (0.10 to 0.20%) and relatively high in the Pliocene/Miocene samples (0.87 to 1.15%). The Maestrichtian samples from Site 612 contain about 0.6% organic carbon. The organic matter is predominantly terrigenous, as indicated by low hydrogen index values from Rock-Eval pyrolysis and the dominance of long-chain wax alkanes in the extractable hydrocarbons. The organic matter is at a low level of thermal maturity; measured vitrinite reflectance values were between 0.27 and 0.44%.

"i Went To The Woods Because I Wished To Live Deliberately": How A College-Level Academic Course Can Influence A Lifetime

This study, using the portraiture methodology, provides an analysis of the lifelong significance of an undergraduate program that integrates literature with an outdoor experiential platform. With limited research on long-term effects of an academic outdoor experiential course on one's life, there is space to wonder about the prospect and nature of the long-term significance of an academic course that may offer technical skill, intrapersonal and interpersonal development, and also the delivery of subject matter related to a traditional or mainstream academic area of study. Utilizing an academic skills-oriented lens as well as a character strengths lens, portraits were crafted of four former participants of the University of Michigan's New England Literature Program (NELP) to shed light on the long-term influence of this type of course, crucial participant characteristics that contribute to the program's impact, and specific components of the program that are particularly integral to the course's efficacy. Since 1975, each spring term a small contingent of students and educators has lived in the woods in the New England region as a community of learners, artists and explorers. NELP is an exemplar of a longstanding undergraduate academic English course that integrates the literature of New England writers, exploratory writing and student experiences relating to regional literature and the land. Emergent themes of this course's long-term influence on former participants include increased collaborative skills, increased self-confidence and self-knowledge, a reinforcement of lifelong relationships with the outdoors, and nurtured creativity. For participants to reap benefit from this course, it was important for them to enter with maturity to conduct themselves with openness to new experiences, relationships, and extensive reflection. Findings relating to the integral components of such a program include that of being place-based, oriented towards process, and being an intentional, collaborative community.

A question of complexity:measuring the maturity of online enquiry communities

Online enquiry communities such as Question Answering (Q&A) websites allow people to seek answers to all kind of questions. With the growing popularity of such platforms, it is important for community managers to constantly monitor the performance of their communities. Although different metrics have been proposed for tracking the evolution of such communities, maturity, the process in which communities become more topic proficient over time, has been largely ignored despite its potential to help in identifying robust communities. In this paper, we interpret community maturity as the proportion of complex questions in a community at a given time. We use the Server Fault (SF) community, a Question Answering (Q&A) community of system administrators, as our case study and perform analysis on question complexity, the level of expertise required to answer a question. We show that question complexity depends on both the length of involvement and the level of contributions of the users who post questions within their community. We extract features relating to askers, answerers, questions and answers, and analyse which features are strongly correlated with question complexity. Although our findings highlight the difficulty of automatically identifying question complexity, we found that complexity is more influenced by both the topical focus and the length of community involvement of askers. Following the identification of question complexity, we define a measure of maturity and analyse the evolution of different topical communities. Our results show that different topical communities show different maturity patterns. Some communities show a high maturity at the beginning while others exhibit slow maturity rate. Copyright 2013 ACM.