Introduction: Patients presenting to the emergency department (ED) with hypotension have a high mortality rate and require careful yet rapid resuscitation. The use of cardiac point of care ultrasound (PoCUS) in the ED has progressed beyond the basic indications of detecting pericardial fluid and activity in cardiac arrest. We examine if finding left ventricular dysfunction (LVD) on emergency physician performed PoCUS reliably predicts the presence of cardiogenic shock in hypotensive ED patients. Methods: We prospectively collected PoCUS findings performed in 135 ED patients with undifferentiated hypotension as part of an international study. Patients with clearly identified etiologies for hypotension were excluded, along with other specific presumptive diagnoses. LVD was defined as identification of a generally hypodynamic LV in the setting of shock. PoCUS findings were collected using a standardized protocol and data collection form. All scans were performed by PoCUS-trained emergency physicians. Final shock type was defined as cardiogenic or non-cardiogenic by independent specialist blinded chart review. Results: All 135 patients had complete follow up. Median age was 56 years, 53% of patients were male. Disease prevalence for cardiogenic shock was 12% and the mortality rate was 24%. The presence of LVD on PoCUS had a sensitivity of 62.50% (95%CI 35.43% to 84.80%), specificity of 94.12% (88.26% to 97.60%), positive-LR 10.62 (4.71 to 23.95), negative-LR 0.40 (0.21 to 0.75) and accuracy of 90.37% (84.10% to 94.77%) for detecting cardiogenic shock. Conclusion: Detecting left ventricular dysfunction on PoCUS in the ED may be useful in confirming the underlying shock type as cardiogenic in otherwise undifferentiated hypotensive patients.

Introduction: Although use of point of care ultrasound (PoCUS) protocols for patients with undifferentiated hypotension in the Emergency Department (ED) is widespread, our previously reported SHoC-ED study showed no clear survival or length of stay benefit for patients assessed with PoCUS. In this analysis, we examine if the use of PoCUS changed fluid administration and rates of other emergency interventions between patients with different shock types. The primary comparison was between cardiogenic and non-cardiogenic shock types. Methods: A post-hoc analysis was completed on the database from an RCT of 273 patients who presented to the ED with undifferentiated hypotension (SBP <100 or shock index > 1) and who had been randomized to receive standard care with or without PoCUS in 6 centres in Canada and South Africa. PoCUS-trained physicians performed scans after initial assessment. Shock categories and diagnoses recorded at 60 minutes after ED presentation, were used to allocate patients into subcategories of shock for analysis of treatment. We analyzed actual care delivered including initial IV fluid bolus volumes (mL), rates of inotrope use and major procedures. Standard statistical tests were employed. Sample size was powered at 0.80 (α:0.05) for a moderate difference. Results: Although there were expected differences in the mean fluid bolus volume between patients with non-cardiogenic and cardiogenic shock, there was no difference in fluid bolus volume between the control and PoCUS groups (non-cardiogenic control 1878 mL (95% CI 1550 – 2206 mL) vs. non-cardiogenic PoCUS 1687 mL (1458 – 1916 mL); and cardiogenic control 768 mL (194 – 1341 mL) vs. cardiogenic PoCUS 981 mL (341 – 1620 mL). Likewise there were no differences in rates of inotrope administration, or major procedures for any of the subcategories of shock between the control group and PoCUS group patients. The most common subcategory of shock was distributive. Conclusion: Despite differences in care delivered by subcategory of shock, we did not find any significant difference in actual care delivered between patients who were examined using PoCUS and those who were not. This may help to explain the previously reported lack of outcome difference between groups.

Introduction: Point of care ultrasound has been reported to improve diagnosis in non-traumatic hypotensive ED patients. We compared diagnostic performance of physicians with and without PoCUS in undifferentiated hypotensive patients as part of an international prospective randomized controlled study. The primary outcome was diagnostic performance of PoCUS for cardiogenic vs. non-cardiogenic shock. Methods: SHoC-ED recruited hypotensive patients (SBP < 100 mmHg or shock index > 1) in 6 centres in Canada and South Africa. We describe previously unreported secondary outcomes relating to diagnostic accuracy. Patients were randomized to standard clinical assessment (No PoCUS) or PoCUS groups. PoCUS-trained physicians performed scans after initial assessment. Demographics, clinical details and findings were collected prospectively. Initial and secondary diagnoses including shock category were recorded at 0 and 60 minutes. Final diagnosis was determined by independent blinded chart review. Standard statistical tests were employed. Sample size was powered at 0.80 (α:0.05) for a moderate difference. Results: 273 patients were enrolled with follow-up for primary outcome completed for 270. Baseline demographics and perceived category of shock were similar between groups. 11% of patients were determined to have cardiogenic shock. PoCUS had a sensitivity of 80.0% (95% CI 54.8 to 93.0%), specificity 95.5% (90.0 to 98.1%), LR+ve 17.9 (7.34 to 43.8), LR-ve 0.21 (0.08 to 0.58), Diagnostic OR 85.6 (18.2 to 403.6) and accuracy 93.7% (88.0 to 97.2%) for cardiogenic shock. Standard assessment without PoCUS had a sensitivity of 91.7% (64.6 to 98.5%), specificity 93.8% (87.8 to 97.0%), LR+ve 14.8 (7.1 to 30.9), LR- of 0.09 (0.01 to 0.58), Diagnostic OR 166.6 (18.7 to 1481) and accuracy of 93.6% (87.8 to 97.2%). There was no significant difference in sensitivity (-11.7% (-37.8 to 18.3%)) or specificity (1.73% (-4.67 to 8.29%)). Diagnostic performance was also similar between other shock subcategories. Conclusion: As reported in other studies, PoCUS based assessment performed well diagnostically in undifferentiated hypotensive patients, especially as a rule-in test. However performance was similar to standard (non-PoCUS) assessment, which was excellent in this study.

The effect of transportation and lairage on the faecal shedding and post-slaughter contamination of carcasses with Escherichia coli O157 and O26 in young calves (4–7-day-old) was assessed in a cohort study at a regional calf-processing plant in the North Island of New Zealand, following 60 calves as cohorts from six dairy farms to slaughter. Multiple samples from each animal at pre-slaughter (recto-anal mucosal swab) and carcass at post-slaughter (sponge swab) were collected and screened using real-time PCR and culture isolation methods for the presence of E. coli O157 and O26 (Shiga toxin-producing E. coli (STEC) and non-STEC). Genotype analysis of E. coli O157 and O26 isolates provided little evidence of faecal–oral transmission of infection between calves during transportation and lairage. Increased cross-contamination of hides and carcasses with E. coli O157 and O26 between co-transported calves was confirmed at pre-hide removal and post-evisceration stages but not at pre-boning (at the end of dressing prior to chilling), indicating that good hygiene practices and application of an approved intervention effectively controlled carcass contamination. This study was the first of its kind to assess the impact of transportation and lairage on the faecal carriage and post-harvest contamination of carcasses with E. coli O157 and O26 in very young calves.

Regulatory activity to maintain the status of the independent milk company as a viable competitive force in the milk industry has been a central focus of regulatory policy since the 1930's. Some authorities question the degree of emphasis on preservation under the law, but most feel that there is an important element of protection embodied in regulatory activity affecting the industry. We feel that this aspect of the law is important and is the focus of this article.

Legal protection of the independent dairy is afforded from three sources. The Robinson-Patman Act, which prohibits firms from discriminating in price where the effect may be to substantially lessen competition, has been enforced extensively by the Federal Trade Commission (FTC) on behalf of independent milk companies. For example, of 53 complaints filed by the FTC from June 1950 to June 1964, nine were against dairy companies. Independent firms have protected their own position under the law in treble damage private litigation. As a group, the national and regional dairy concerns have been involved in almost continuous treble damage litigation on charges of discriminatory pricing in recent years.

We present a novel process methodology for the controlled cutting of nanotubes and other nanostructures to well-controlled lengths and sizes. The continuing increase in complexity of electronic devices, coupled with decreasing size of individual elements, are placing more stringent demands on the resolution and accuracy of fabrication patterns. The ability to fabricate on a nanometer scale guarantees a continuation in miniaturization of functional devices. Particularly interesting is the application of nanotubes' chemical and electronic properties which vary with their dimensions and structure. One realization of this process includes the use of photolithography or electron beam lithography to place protective resist patterns over the nanostructures to be cut. Those sections which are not covered by the resist pattern are removed by reactive ion etching. This is a scaleable process which permits the simultaneous cutting of many nanostructures and ensembles of nanostructures. The lengths, shapes or length distributions can be predicted from theory and thus specified for a given application requirement. Nanostructures which can be cut in this process include nanotubes, nanofibers and nanoplanes. Large scale production of nanostructures with uniform length or specific size-distribution can be used in electronic applications such as field-emission transistors, optoelectronic elements, single electron devices and sensors.

Characterization of thin surficial films of oxides has become the focus of increased interest due to their applications in microelectronics. The ability to experimentally determine the electronic structure and optical properties of oxide materials permits the direct study of the interband transitions from the valence to the conduction band states. In the past years there has been much progress in the quantitative analysis of transmission electron energy loss spectroscopy (TEELS) in the electron microscope

Here we employed reflection electron energy loss function (REELS) as well as vacuum ultraviolet (VUV) spectroscopy to determine the dielectric functions of oxide materials, i.e. Al2O3, ZrO2 and SrTiO3. The two main steps in the analysis are the removal of the effects of multiple scattering from the REELS spectra followed by application of the Kramers-Kronig dispersion transforms to the single scattering energy loss function to determine the conjugate optical variable and then the complex dielectric function. The surface and bulk plasma resonance spectra for these oxide materials have been determined from VUV and REELS, along with the influence of primary electron energy on the REELS results. The relative contribution of surface and bulk plasmon oscillation in REELS has been investigated. Comparison with VUV results and existing TEELS results indicate that Kramers-Kronig analysis can also be applied to REELS spectra and the corresponding conjugate optical properties can be obtained. Quantitative studies of the electronic structure and optical properties of thin surficial films using VUV and REELS or TEELS, represent a new avenue to determine the properties of these increasingly important films.

Epidemiol. Infect.124 (2000), 61–7

Occurrence ofClostridium perfringensβ2-toxin amongst animals, determined using genotyping and subtyping PCR assays

Page 61, Summary, line 7, should read:

‘… and the gene encoding β2-toxin was …’

The ‘middle sort of people’ is a social group that has been the subject of increased historical research in the last decade. Many studies have been written, and many definitions offered of the group, its identity, and its membership. As a result, these overlapping groups and contrasting methods of definition have caused the nature and identity of the group to remain elusive. This study charts the evolution of the historiography of the ‘middle sort’, and the many attempts to produce positive and accurate definitions of the group. It suggests that the identity of the ‘middle sort’ may, in fact, be more complex than is allowed for by existing studies, with different identities being adopted according to social context. It concludes that while the term ‘middle sort of people’ is an appropriate contemporary collective term for use by historians, it is much more problematic as a description of an active, cohesive social group in the early modern period.

Clostridium perfringens isolates are currently classified into one of five biotypes on the basis of the differential production of α-, β-, ε- and ι-toxins. Different biotypes are associated with different diseases of man and animals. In this study a multiple PCR assay was developed to detect the genes encoding these toxins. In addition, detection of the genes encoding the C. perfringens enterotoxin and β2-toxin allowed subtyping of the bacteria. C. perfringens isolates taken from a variety of animals, including foals, piglets or lambs, were genotyped using this assay. Most of the isolates were found to be genotype A and the gene encoding β-toxin was present in 50% of the isolates genotyped. A significant association between C. perfringens possessing the β2-toxin gene and diarrhoea in piglets was identified, suggesting that β2-toxin may play a key role in the pathogenesis of the disease.

The quantitative study of English land markets in the three centuries after the close of the middle ages is still in its infancy. The medievalists, exploiting the conveyances of customary tenants recorded in manorial court rolls, have shown how issues such as the devolution of land within families, the frequency with which land was sold and the behaviour of the land market at moments of demographic or economic stress can be addressed by the analysis of such data either aggregatively or by looking at the landholding histories of individual participants in the land market. Early modernists have invariably approached the study of the land market in a non-quantitative fashion, usually as part of an attempt to make observations about some other characteristic of English history. Stone looked at the land market in the sixteenth and early seventeenth centuries as part of his campaign to prove that the aristocracy was in decline, Macfarlane to show that the property-holding behaviour of the English was ‘individualistic’, Habbakuk to explore the strategies by which the English aristocracy maintained its supremacy and Mingay and others to settle the debate about the effect of enclosure on the small landowner. The early modern land market has rarely, if ever, been seen as worthy of discussion in its own right.

Precise and accurate knowledge of the optical properties of aluminum nitride (AlN) in the ultraviolet (UV) and visible (VIS) regions is important because of the increasing application of AlN in optical and electro-optical devices, including compact disks, phase shift lithography masks, and AlN/GaN multilayer devices. The interband optical properties in the vacuum ultraviolet (VUV) region of 6–44 eV have been investigated previously because they convey detailed information on the electronic structure and interatomic bonding of the material. In this work, we have combined spectroscopic ellipsometry with UV/VIS and VUV spectroscopy to directly determine the optical constants of AlN in this range, thereby reducing the uncertainty in the preparation of the low-energy data extrapolation essential for Kramers–Kronig analysis of VUV reflectance. We report the complex optical properties of AlN, over the range of 1.5–42 eV, showing improved agreement with theory when contrasted with earlier results.

The local electronic structure of ceramic materials can be determined from valence electron energy loss (Veel) spectra via the dielectric function. The quality of the data is comparable to vacuum ultraviolet spectroscopy with the added benefit of high spatial resolution. We have built and implemented a system for spectrum imaging which not only allows automatic data acquisition but also analysis of the full data set. The system consists of a Gatan PEELS and a Gatan Digiscan fitted to a VG HB501 UX STEM and home-built hardware additions. The hardware extensions allow to acquire 1, 2, 3, 4 or 8 spectra for each pixel and in the case of 2 spectra/pixel to vary the exposure time of the specimen to the primary electron beam by controlling the beam blanker (Fig. 1). The first spectrum (2 to 20 ms) contains an unsaturated zero loss peak and the second spectrum (0.05 to 100 s) at the same position the plasmon peak near to but below saturation (Fig. 2).