An Alternative Approach to the Calculation and Analysis of Connectivity in the World City Network

Empirical research on world cities often draws on Taylor's (2001) notion of an 'interlocking network model', in which office networks of globalized service firms are assumed to shape the spatialities of urban networks. In spite of its many merits, this approach is limited because the resultant adjacency matrices are not really fit for network-analytic calculations. We therefore propose a fresh analytical approach using a primary linkage algorithm that produces a one-mode directed graph based on Taylor's two-mode city/firm network data. The procedure has the advantage of creating less dense networks when compared to the interlocking network model, while nonetheless retaining the network structure apparent in the initial dataset. We randomize the empirical network with a bootstrapping simulation approach, and compare the simulated parameters of this null-model with our empirical network parameter (i.e. betweenness centrality). We find that our approach produces results that are comparable to those of the standard interlocking network model. However, because our approach is based on an actual graph representation and network analysis, we are able to assess cities' position in the network at large. For instance, we find that cities such as Tokyo, Sydney, Melbourne, Almaty and Karachi hold more strategic and valuable positions than suggested in the interlocking networks as they play a bridging role in connecting cities across regions. In general, we argue that our graph representation allows for further and deeper analysis of the original data, further extending world city network research into a theory-based empirical research approach.Comment: 18 pages, 9 figures, 2 table

Managing soil fertility diversity to enhance resource use efficiencies in smallholder farming systems: a case from Murewa District, Zimbabwe

Smallholder farms in sub-Saharan African exhibit substantial heterogeneity in soil fertility, and nutrient resource allocation strategies that address this variability are required to increase nutrient use efficiencies. We applied the Field-scale resource Interactions, use Efficiencies and Long-term soil fertility Development (FIELD) model to explore consequences of various manure and fertilizer application strategies on crop productivity and soil organic carbon (SOC) dynamics on farms varying in resource endowment in a case study village in Murewa District, Zimbabwe. FIELD simulated a rapid decline in SOC and maize yields when native woodlands were cleared for maize cultivation without fertilizer inputs coupled with removal of crop residues. Applications of 10 t manure ha-1 year-1 for 10 years were required to restore maize productivity to the yields attainable under native woodland. Long-term application of manure at 5 and 3 t ha-1 resulted in SOC contents comparable to zones of high and medium soil fertility observed on farms of wealthy cattle owners. Targeting manure application to restore SOC to 50–60% of contents under native woodlands was sufficient to increase productivity to 90% of attainable yields. Short-term increases in crop productivity achieved by reallocating manure to less fertile fields were short-lived on sandy soils. Preventing degradation of the soils under intensive cultivation is difficult, particularly in low input farming systems, and attention should be paid to judicious use of the limited nutrient resources to maintain a degree of soil fertility that supports good crop response to fertilizer applicatio

The stability of blood gases and CO-oximetry under slushed ice and room temperature conditions

ObjectivesHuman blood gas stability data is limited to small sample sizes and questionable statistical techniques. We sought to determine the stability of blood gases under room temperature and slushed iced conditions in patients using survival analyses.MethodsWhole blood samples from ∼200 patients were stored in plastic syringes and kept at room temperature (22-24 °C) or in slushed ice (0.1-0.2 °C) before analysis. Arterial and venous pO2 (15-150 mmHg), pCO2 (16-72 mmHg), pH (6.73-7.52), and the CO-oximetry panel [total hemoglobin (5.4-19.3 g/dL), percentages of oxyhemoglobin (O2Hb%, 20-99%), carboxyhemoglobin (COHb, 0.1-5.4%) and methemoglobin (MetHb, 0.2-4.6%)], were measured over 5-time points. The Royal College of Pathologists of Australasia's (RCPA's) criteria determined analyte instability. Survival analyses identified storage times at which 5% of the samples for various analytes became unstable.ResultsCOHb and MetHb were stable up to 3 h in slushed ice and at room temperature; pCO2, pH was stable at room temperature for about 60 min and 3 h in slushed ice. Slushed ice shortened the storage time before pO2 became unstable (from 40 to 20 min), and the instability increased when baseline pO2 was ≥60 mmHg. The storage time for pO2, pCO2, pH, and CO-oximetry, when measured together, were limited by the pO2.ConclusionsWhen assessing pO2 in plastic syringes, samples kept in slushed ice harm their stability. For simplicity's sake, the data support storage times for blood gas and CO-oximetry panels of up to 40 min at room temperature if following RCPA guidelines

Therapeutic Effect of Arsenicum album on Leukocytes

The therapeutic effects of homoeopathic Arsenicum album potencies were investigated in-vitro, using a continuous cell line (MT4), pre-intoxicated with arsenic trioxide (As2O3), and then treated with succussed and unsuccussed homoeopathic potencies, 6CH, 30CH and 200CH. This study aimed to verify the homoeopathic law of similars and to determine whether potencies diluted beyond Avogadro’s constant had physiological effects on cells; whether various potencies would cause different effects as suggested by the concept of hormesis; whether succussed and unsuccussed homoeopathic potencies had different effects on the cells; and to establish whether a biotechnological method could be used to evaluate the above. As2O3 was used to pre-intoxicate and the MTT assay was used to measure the percentage cytotoxicity and half maximal inhibitory concentration (IC50) of the cells. The homoeopathic potencies of Arsenicum album (6CH, 30CH and 200CH) were prepared by either succussing or allowing to diffuse for 30 s. After pre-intoxication of the MT4 cells with the IC50 As2O3 and treatment with succussed and unsuccussed Arsenicum album (6CH-200CH), the cell viability increased with increasing potency from 81% to 194% (over 72 h). The treatments and the times of exposure were found to be statistically significant determinants of cell viability, whereas succussion did not cause any significant variation in the results. The study provided evidence that a biotechnological method (namely cell viability) may be used to scientifically evaluate the physiological effects of homoeopathic potencies on human cells; it confirmed that the homoeopathic potencies did have therapeutic effects; and that succussion was not required in the potentization method in order to produce a curative remedy

Word order preference in sign influences speech in hearing bimodal bilinguals but not vice versa: Evidence from behavior and eye-gaze

We investigated cross-modal influences between speech and sign in hearing bimodal bilin- guals, proficient in a spoken and a sign language, and its consequences on visual attention during message preparation using eye-tracking. We focused on spatial expressions in which sign languages, unlike spoken languages, have a modality-driven preference to mention grounds (big objects) prior to figures (smaller objects). We compared hearing bimodal bilin- guals’ spatial expressions and visual attention in Dutch and Dutch Sign Language (N = 18) to those of their hearing non-signing (N = 20) and deaf signing peers (N = 18). In speech, hear- ing bimodal bilinguals expressed more ground-first descriptions and fixated grounds more than hearing non-signers, showing influence from sign. In sign, they used as many ground-first descriptions as deaf signers and fixated grounds equally often, demonstrating no influence from speech. Cross-linguistic influence of word order preference and visual attention in hearing bimodal bilinguals appears to be one-directional modulated by modality-driven difference

Development Value Chains meet Business Supply Chains

Value chain promotion is considered a key element of private sector development strategies and pro-poor growth. However, (value) chain concepts are rather complex and unclear. This paper unravels the concept of global value chains and studies the diversity of key value chain-related (supply chain, commodity chain, value chain) approaches. To this aim, we reviewed academic literature and donor agencies’ reports, and consulted a limited number of key informants of donor agencies. This paper distinguishes between the strategic management perspective and the development perspective and reviews added values and limitati ons of each approach. The results suggest that practioners use an eclectic approach towards the value chain concept, although the concept originates from clearly distinctive paths and could be susceptible to miscommunication and misuse. The authors avoid misunderstanding by explicitly opting for a public and pro-poor perspective of the concept of the Global Value Chain