Graphical determination of network limits for wind power integration

A graphical method is presented for determining the capability of individual system nodes to accommodate wind power generation. The method is based upon constructing a capability chart for each node at which a wind farm is to be connected. The capability chart defines the domain of allowable power injections at the candidate node, subject to constraints imposed by voltage limits, voltage stability and equipment capability limits being satisfied. The chart is first derived for a two-bus model, before being extended to a multi-node power system. The graphical method is employed to derive the chart for a two-node system, as well as its application to a multi-node power system, considering the IEEE 30-bus test system as a case study. Although the proposed method is derived with the intention of determining the wind farm capacity to be connected at a specific node, it can be used for the analysis of a PQ bus loading as well as generation.

And We’d Like to Thank…::Romania’s Integration into the European Union, 1989-2007

Conditionality is formally a key determinant of many non-member states’ relations with the EU. It is particularly so for states intent on membership. As the case of Romania shows, the EU’s use of conditionality is far from consistent. Relations can develop and accession take place without the requisite conditions being met. This follows from the use the EU makes of the flexibility evident in its evolving and generally vague definitions of the conditions that need to be met. Hence it was often extraneous factors over which Romania had either limited or no influence that were responsible for key developments in relations. These factors include the geopolitical and strategic interests of the EU and its member states, the actions of the Commission and the agenda-setting and constraining effects of rhetorical commitments and timetables, and the dynamics of the EU’s evolving approach to eastern enlargement.

Nigrocin-2 peptides from Chinese Odorrana frogs – integration of UPLC/MS/MS with molecular cloning in amphibian skin peptidome analysis

Peptidomics is a powerful set of tools for the identification, structural elucidation and discovery of novel regulatory peptides and for monitoring the degradation pathways of structurally and catalytically important proteins. Amphibian skin secretions, arising from specialized granular glands, often contain complex peptidomes containing many components of entirely novel structure and unique site-substituted analogues of known peptide families. Following the discovery that the granular gland transcriptome is present in such secretions in a PCR-amenable form, we designed a strategy for peptide structural characterization involving the integration of ‘shotgun’ cloning of cDNAs encoding peptide precursors, deduction of putative bioactive peptide structures, and confirmation of these structures using tandem MS/MS sequencing. Here, we illustrate this strategy by means of elucidation of the primary structures of nigrocin-2 homologues from the defensive skin secretions of four species of Chinese Odorrana frogs, O. schmackeri, O. livida, O. hejiangensis and O. versabilis. Synthetic replicates of the peptides were found to possess antimicrobial activity. Nigrocin-2 peptides occur widely in the skin secretions of Asian ranid frogs and in those of the Odorrana group, and are particularly well-represented and of diverse structure in some species. Integration of the molecular analytical technologies described provides a means for rapid structural characterization of novel peptides from complex natural libraries in the absence of systematic online database information.

Respiratory viral infection in lower airways of asymptomatic children.

Aim: The aim of this study was to determine if asthmatic children have viruses more commonly detected in lower airways during asymptomatic periods than normal children. Methods: Fifty-five asymptomatic children attending elective surgical procedures (14 with stable asthma, 41 normal controls) underwent non-bronchoscopic bronchoalveolar lavage. Differential cell count and PCR for 13 common viruses were performed. Results: Nineteen (35%) children were positive for at least one virus, with adenovirus being most common. No differences in the proportion of viruses detected were seen between asthmatic and normal ‘control’ children. Viruses other than adenovirus were associated with higher neutrophil counts, suggesting that they caused an inflammatory response in both asthmatics and controls (median BAL neutrophil count, 6.9% for virus detected vs. 1.5% for virus not detected, p = 0.03). Conclusions: Over one-third of asymptomatic children have a detectable virus (most commonly adenovirus) in the lower airway; however, this was not more common in asthmatics. Viruses other than adenovirus were associated with elevated neutrophils suggesting that viral infection can be present during relatively asymptomatic periods in asthmatic children.

Managing time: integration of care and paid work amongst low income families and the role of the United Kingdom’s tax credit system

Under the New Labour Governments in the UK, successive reforms of the tax and benefit system sought to improve the financial benefits of paid work. Drawing on two waves of qualitative interviews with low-income working families this article examines the role of the UK tax credit system in shaping decisions about employment and unpaid care work. The article suggests that the financial support provided for lone parent participants by the tax credit system enhanced their temporal autonomy, permitting participation in paid work to align more closely with temporally situated notions of parental responsibility for caring. For couple families however, parental perceptions of responsibility for pre-school children, along with childcare constraints and the structure of the tax credit system served to constrain the autonomy of the main carer and implicitly encourage a gendered specialisation in caring or employment.