How inter-firm networks influence the development of agglomerations

Non-market interactions are increasingly regarded as key explanations for spatial concentration. Consistently, both innovation and local knowledge spillovers play a central role in recent theories of agglomeration. According to these theories, exchange of localised knowledge gives firms an innovative advantage which results in better economic performance. However, it has turned out to be difficult to open the black box of economies of scale using empirical tests.\ud Since interactions get considerable attention in recent agglomeration theory, social network methods and theory are promising approaches to research spatial agglomerations. Even more so because simultaneously, there is an increasing emphasis on interfirm ties in the network field.\ud The goal of our research is to explore how interfirm networks influence the development of agglomerations. Firstly we provide a review on network and innovation literature in the field of spatial clusters. Secondly, we discuss measurement issues related to networks and innovation and ways to overcome them. Finally, we present preliminary results of our network study among high tech firms in the Dutch region of Twente

Soil and plant factors driving the community of soil-borne microorganisms across chronosequences of secondary succession of chalk grasslands with a neutral pH

Although soil pH has been shown to be an important factor driving microbial communities, relatively little is known about the other potentially important factors that shape soil-borne microbial community structure. This study examined plant and microbial communities across a series of neutral pH fields (pH=7.0-7.5) representing a chronosequence of secondary succession after former arable fields were taken out of production. These fields ranged from 17 to >66 years since the time of abandonment, and an adjacent arable field was included as a reference. Hierarchical clustering analysis, nonmetric multidimensional scaling and analysis of similarity of 52 different plant species showed that the plant community composition was significantly different in the different chronosequences, and that plant species richness and diversity increased with time since abandonment. The microbial community structure, as analyzed by phylogenetic microarrays (PhyloChips), was significantly different in arable field and the early succession stage, but no distinct microbial communities were observed for the intermediate and the late succession stages. The most determinant factors in shaping the soil-borne microbial communities were phosphorous and NH4+. Plant community composition and diversity did not have a significant effect on the belowground microbial community structure or diversit

Role of snow and glacier melt in controlling river hydrology in Liddar watershed (western Himalaya) under current and future climate

This is the publisher's version, also available electronically from http://onlinelibrary.wiley.com/doi/10.1029/2011WR011590/abstract.[1] Snowmelt and icemelt are believed to be important regulators of seasonal discharge of Himalayan rivers. To analyze the long term contribution of snowmelt and glacier/icemelt to river hydrology we apply a water budget model to simulate hydrology of the Liddar watershed in the western Himalaya, India for the 20th century (1901–2010) and future IPCC A1B climate change scenario. Long term (1901–2010) temperature and precipitation data in this region show a warming trend (0.08°C yr−1) and an increase in precipitation (0.28 mm yr−1), with a significant variability in seasonal trends. In particular, winter months have undergone the most warming, along with a decrease in precipitation rates; precipitation has increased throughout the spring. These trends have accelerated the melting and rapid disappearance of snow, causing a seasonal redistribution in the availability of water. Our model results show that about 60% of the annual runoff of the Liddar watershed is contributed from the snowmelt, while only 2% is contributed from glacier ice. The climate trend observed from the 1901 to 2010 time period and its impact on the availability of water will become significantly worse under the IPCC climate change scenarios. Our results suggest that there is a significant shift in the timing and quantity of water runoff in this region of the Himalayas due to snow distribution and melt. With greatly increased spring runoff and its reductions in summer potentially leading to reduced water availability for irrigation agriculture in summer

Late Glacial to mid Holocene lacustrine ostracods from southern Anatolia, Turkey:A palaeoenvironmental study with pollen and stable isotopes

This study investigates the ostracod assemblages obtained from a sediment core from a paleolake in the Sağlık plain in south-central Anatolia (Turkey). In addition to ostracods, oxygen and. carbon stable isotopes of ostracod shells were analysed and pollen analysis of the core undertaken. The sediments comprise the Late Glacial and early Holocene interval with an approximate 14C age from 18,000 to 6700 14C years ago, after applying a correction for reservoir effects. Eight podocopid ostracod species were recorded, among them Cyprideis torosa and Candona sp. which were used for stable oxygen and carbon isotope analyses. C. torosa dominated during the Late Glacial while Candona sp. dominated most of the early Holocene assemblages. Both forms of C. torosa disappear abruptly close to the onset of the Holocene. Around this time, ostracod preservation was dominated by many black coloured valves and carapaces. Based on ostracod assemblage data and isotope analyses, relatively wet phases were identified for the Older Dryas, Younger Dryas, and during the mid-Holocene at around 7500 14C years ago. Relatively dry phases were identified during the Allerød interstadial, at the end of YD, and at about 6700 14C years ago. An oligotrophic and brackish lake persisted until shortly before the end of the YD, when, according to the δ 13C values, conditions gradually became more eutrophic. The sudden disappearance of C. torosa at the end of the YD seems the consequence of anoxic bottom water conditions and/or eutrophication. Alternating wet and dry phases characterize the early Holocene, with a longer period of wet and oligotrophic conditions around 7500 14C years ago (ca. 8300 calBP). Ostracod assemblages and isotope records indicate a dry and more productive lake around 6700 14C years ago (ca. 7550 calBP)

Psychological factors during rehabilitation of patients with Achilles or patellar tendinopathy:a cross-sectional study

OBJECTIVE: to examine psychological factors during rehabilitation of patients with Achilles or patellar tendinopathy as well as the association between psychological factors and tendinopathy severity, sport participation, and satisfaction with activity level and tendon function. DESIGN: cross-sectional study. SETTING: online survey platform. PARTICIPANTS: 119 patients (mean age: 44 years (SD 14)) diagnosed with Achilles or patellar tendinopathy. MAIN OUTCOME MEASURES: A range of patient-reported psychological and outcome measures were recorded. Multivariate regression analyses were performed to establish the association between each psychological factor and outcome measures, adjusted for relevant confounders. RESULTS: Psychological readiness and confidence to return to sports (I-PRRS) and pain catastrophizing (PCS) were significantly associated with tendinopathy severity (modified VISA), sport participation(OSTRC-O), and satisfaction. Kinesiophobia (TSK) and the importance to patients of returning to pre-injury activity level were significantly associated with sports participation and satisfaction. CONCLUSION: The current study provides evidence of impairments in psychological factors during rehabilitation of patients with Achilles and patellar tendinopathy. Most investigated psychological factors were associated with tendinopathy severity, function, participation, and satisfaction. Physical therapists should recognize patients with lack of psychological readiness to return to sports and also patients with kinesiophobia or catastrophizing thoughts when experiencing pain

Экспериментальные исследования интенсификации процессов теплообмена в энергетических котлах

Запропонована конструктивна схема удосконалення газорозподільних решітки, створено лабораторний стенд і проведені експериментальні дослідження в результаті яких отримані умови, які сприяють збільшенню відносної швидкості руху часток і середовища, створенню додаткової турбулентності потоку середовища, збільшенню кратності оновлення і формування міжфазної поверхні, що може привести до значного прискорення тепло- і масо переносу.The propose a design scheme to improve the gas distribution grid, established a laboratory bench and experimental studies have been obtained as a result of conditions that contribute to an increase in the relative velocity of the particles and the environment, creating more turbulence of flow, increasing the multiplicity of updating and the formation of the interphase surface, which can lead to a significant acceleration heat and mass transfer

Subtraction computed tomography imaging to detect endoleaks after endovascular aneurysm sealing with sac anchoring

Background Early detection of small type I endoleaks after endovascular aneurysm sealing is mandatory because they can rapidly progress and lead to severe complications. Recognition of endoleaks can be challenging due to the appearances on computed tomography unique to endovascular aneurysm sealing. We aimed to validate the accuracy and added value of subtraction computed tomography imaging using a post-processing software algorithm to improve detection of endovascular aneurysm sealing-associated endoleaks on postoperative surveillance imaging. Methods The computed tomography scans of 17 patients (16 males; median age: 78, range: 72–84) who underwent a post-endovascular aneurysm sealing computed tomography including both non-contrast and arterial phase series were used to validate the post processing software algorithm. Subtraction images are produced after segmentation and alignment. Initial alignment of the stent segmentations is automatically performed by registering the geometric centers of the 3D coordinates of both computed tomography series. Accurate alignment is then performed by translation with an iterative closest point algorithm. Accuracy of alignment was determined by calculating the root mean square error between matched 3D coordinates of stent segmentations. Results The median root mean square error after initial center of gravity alignment was 0.62 mm (IQR: 0.55–0.80 mm), which improved to 0.53 mm (IQR: 0.47–0.69 mm) after the ICP alignment. Visual inspection showed good alignment and no manual adjustment was necessary. Conclusions The possible merit of subtraction computed tomography imaging for the detection of small endoleaks during surveillance after endovascular aneurysm sealing was illustrated. Alignment of different computed tomography phases using a software algorithm was very accurate. Further studies are needed to establish the exact role of this technique during surveillance after endovascular aneurysm sealing compared to less invasive techniques like contrast-enhanced ultrasound