Explosively-induced ground vibration in civil engineering construction

Research has been undertaken to improve techniques used in the prediction of ground vibration caused by civil engineering construction works. In particular, the effects of explosive excavation of rock for subsurface structures is considered. Factors affecting the input and propagation of explosive energy in the rock mass are investigated, and recommendations made on procedures for trial blasting and the most effective data processing and presentation for the derived predictive equations. These developments are supported by blasting trials at two major road construction sites, where vibration measurements were taken during conventional and innovative blasting operations. A critical review of contemporary dynamic structural damage and intrusion criteria is provided. It is concluded that vibration prediction and control techniques, together with workable damage/intrusion criteria, can be applied which substantially mitigate vibration hazard. The distribution of vibration associated risk between employer and contractor is discussed and contractual options presented. Techniques to determine the engineering properties of rock masses by analysis of stress waves from explosive and hammer impact sources have been developed and successfully tested. The advantages and limitations of the most promising seismic methods are discussed and field seismic classifications are compared with known rock mass properties and established geotechnical classification systems. The research shows that both rock mass properties and 'site specific' laws of vibration decay may be obtained during the trial blasting sequence of a site investigation programme

From problems in the North to the problematic North : Northern devolution through the lens of history

Current debates about Northern English cities and their role in national economic strategies cannot be read simply through the lens of contemporary politics. We therefore take the Northern Powerhouse as our starting point in a chapter which traces a long history of policy and planning discourses about the North of England. We use David Russell’s chronology of key historical moments in which Northern English cities hold a particular charge in cultural narratives of the nation to guide our analysis of contemporaneous tensions in debates about planning and governance. A focus on representations about the North of England over the course of the last two centuries reveals four interlocking themes: namely the role of London in directing debates about the North; a tension between political and spatial approaches to planning; the characterisation of cities in the North of England as intrinsically problematic places; and the continued issue of poverty in these cities

Security that matters: critical infrastructure and objects of protection

Critical infrastructure protection is prominently concerned with objects that appear indispensable for the functioning of social and political life. However, the analysis of material objects in discussions of critical infrastructure protection has remained largely within the remit of managerial responses, which see matter as simply passive, a blank slate. In security studies, critical approaches have focused on social and cultural values, forms of life, technologies of risk or structures of neoliberal globalization. This article engages with the role of "things" or of materiality for theories of securitization. Drawing on the materialist feminism of Karen Barad, it shows how critical infrastructure in Europe neither is an empty receptacle of discourse nor has "essential" characteristics; rather, it emerges out of material-discursive practices. Understanding the securitization of critical infrastructure protection as a process of materialization allows for a reconceptualization of how security matters and its effects

Mortality and pulmonary complications in patients undergoing surgery with perioperative SARS-CoV-2 infection: an international cohort study

Background: The impact of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) on postoperative recovery needs to be understood to inform clinical decision making during and after the COVID-19 pandemic. This study reports 30-day mortality and pulmonary complication rates in patients with perioperative SARS-CoV-2 infection. Methods: This international, multicentre, cohort study at 235 hospitals in 24 countries included all patients undergoing surgery who had SARS-CoV-2 infection confirmed within 7 days before or 30 days after surgery. The primary outcome measure was 30-day postoperative mortality and was assessed in all enrolled patients. The main secondary outcome measure was pulmonary complications, defined as pneumonia, acute respiratory distress syndrome, or unexpected postoperative ventilation. Findings: This analysis includes 1128 patients who had surgery between Jan 1 and March 31, 2020, of whom 835 (74·0%) had emergency surgery and 280 (24·8%) had elective surgery. SARS-CoV-2 infection was confirmed preoperatively in 294 (26·1%) patients. 30-day mortality was 23·8% (268 of 1128). Pulmonary complications occurred in 577 (51·2%) of 1128 patients; 30-day mortality in these patients was 38·0% (219 of 577), accounting for 81·7% (219 of 268) of all deaths. In adjusted analyses, 30-day mortality was associated with male sex (odds ratio 1·75 [95% CI 1·28–2·40], p\textless0·0001), age 70 years or older versus younger than 70 years (2·30 [1·65–3·22], p\textless0·0001), American Society of Anesthesiologists grades 3–5 versus grades 1–2 (2·35 [1·57–3·53], p\textless0·0001), malignant versus benign or obstetric diagnosis (1·55 [1·01–2·39], p=0·046), emergency versus elective surgery (1·67 [1·06–2·63], p=0·026), and major versus minor surgery (1·52 [1·01–2·31], p=0·047). Interpretation: Postoperative pulmonary complications occur in half of patients with perioperative SARS-CoV-2 infection and are associated with high mortality. Thresholds for surgery during the COVID-19 pandemic should be higher than during normal practice, particularly in men aged 70 years and older. Consideration should be given for postponing non-urgent procedures and promoting non-operative treatment to delay or avoid the need for surgery. Funding: National Institute for Health Research (NIHR), Association of Coloproctology of Great Britain and Ireland, Bowel and Cancer Research, Bowel Disease Research Foundation, Association of Upper Gastrointestinal Surgeons, British Association of Surgical Oncology, British Gynaecological Cancer Society, European Society of Coloproctology, NIHR Academy, Sarcoma UK, Vascular Society for Great Britain and Ireland, and Yorkshire Cancer Research

Glucose control, organ failure, and mortality in pediatric intensive care

©2008 The Society of Critical Care Medicine and the World Federation of Pediatric Intensive and Critical Care SocietiesObjective: In ventilated children, to determine the prevalence of hyperglycemia, establish whether it is associated with organ failure, and document glycemic control practices in Australasian pediatric intensive care units (PICUs). Design: Prospective inception cohort study. Setting: All nine specialist PICUs in Australia and New Zealand. Patients: Children ventilated >12 hrs excluding those with diabetic ketoacidosis, on home ventilation, undergoing active cardiopulmonary resuscitation on admission, or with do-not-resuscitate orders. Interventions: None. Measurements and Main Results: All blood glucose measurements for up to 14 days, clinical and laboratory values needed to calculate Paediatric Logistic Organ Dysfunction (PELOD) scores, and insulin use were recorded in 409 patients. Fifty percent of glucose measurements were >6.1 mmol/L, with 89% of patients having peak values >6.1 mmol/L. The median time to peak blood glucose was 7 hrs. Hyperglycemia was defined by area under the glucose-time curve >6.1 mmol/L above the sample median. Thirteen percent of hyperglycemic subjects died vs. 3% of nonhyperglycemic subjects. There was an independent association between hyperglycemia and a PELOD score ≥10 (odds ratio 3.41, 95% confidence interval 1.91-6.10) and death (odds ratio 3.31, 95% confidence interval 1.26-7.7). Early hyperglycemia, defined using only glucose data in the first 48 hrs, was also associated with these outcomes but not with PELOD ≥10 after day 2 or with worsening PELOD after day 1. Five percent of patients received insulin. Conclusions: Hyperglycemia is common in PICUs, occurs early, and is independently associated with organ failure and death. However, early hyperglycemia is not associated with later or worsening organ failure. Australasian PICUs seldom use insulin.Yung Michael, Wilkins Barry, Norton Lynda, Slater Anthony for the Paediatric Study Grou

Iontophoretic estradiol skin delivery and tritium exchange in ultradeformable liposomes

NoThis work evaluated the in vitro transdermal iontophoretic delivery of tritiated estradiol from ultradeformable liposomes compared with saturated aqueous solution (control). Effects of current density and application time on tritium exchange with water were also determined. Penetration studies used three Protocols. Protocol I involved occluded passive steady state estradiol penetration from ultradeformable liposomes and control. The effect of current densities on drug penetration rates was also assessed (Protocol II). In Protocol III, three consecutive stages of drug penetration (first passive, iontophoresis and second passive) through the same human epidermal membranes were monitored. Such an experimental design investigated the possible effect of high current density (0.8 mA/cm2) on skin integrity. The tritium exchange study showed that extent of exchange correlated well with current density and time of application, with some shielding of estradiol by the liposomal structure. Liposomes enhanced estradiol passive penetration after occlusion. Protocol II showed that estradiol flux increased linearly with current density, although being delivered against electroosmotic flow. In Protocol III, reduction in flux of the second passive stage to near that of the first reflected a reversibility of the structural changes induced in skin by current

Electroporation and ultradeformable liposomes; human skin barrier repair by phospholipid.

NoThis work investigated the effect of electroporation on human epidermal penetration of a model neutral lipophilic compound (estradiol) from saturated aqueous solution and when encapsulated in ultradeformable liposomes. Total amount penetrated and skin deposition were compared with values obtained from passive diffusion. The effect of electrical pulsing on liposome size was investigated. The action of phosphatidylcholine on skin that was structurally altered by such pulses was determined. Electroporation did not affect liposome size. Skin pulsing considerably increased estradiol penetration and skin deposition from solution, relative to passive delivery, with subsequent partial recovery of skin resistance to molecular penetration. Surprisingly, with liposomes, electroporation did not markedly affect estradiol skin penetration. Importantly, liposomal phosphatidylcholine applied during or after pulsing accelerated skin barrier repair, i.e. provided an anti-enhancer or retardant effect

Electrically assisted skin delivery of liposomal estradiol; phospholipid as damage retardant.

NoElectrically assisted skin delivery of liposomal estradiol; phospholipid as damage retardant