Cross-Platform Mechanical Characterization of Lung Tissue

Published data on the mechanical strength and elasticity of lung tissue is widely variable, primarily due to differences in how testing was conducted across individual studies. This makes it extremely difficult to find a benchmark modulus of lung tissue when designing synthetic extracellular matrices (ECMs). To address this issue, we tested tissues from various areas of the lung using multiple characterization techniques, including micro-indentation, small amplitude oscillatory shear (SAOS), uniaxial tension, and cavitation rheology. We report the sample preparation required and data obtainable across these unique but complimentary methods to quantify the modulus of lung tissue. We highlight cavitation rheology as a new method, which can measure the modulus of intact tissue with precise spatial control, and reports a modulus on the length scale of typical tissue heterogeneities. Shear rheology, uniaxial, and indentation testing require heavy sample manipulation and destruction; however, cavitation rheology can be performed in situ across nearly all areas of the lung with minimal preparation. The Young’s modulus of bulk lung tissue using micro-indentation (1.4±0.4 kPa), SAOS (3.3±0.5 kPa), uniaxial testing (3.4±0.4 kPa), and cavitation rheology (6.1±1.6 kPa) were within the same order of magnitude, with higher values consistently reported from cavitation, likely due to our ability to keep the tissue intact. Although cavitation rheology does not capture the non-linear strains revealed by uniaxial testing and SAOS, it provides an opportunity to measure mechanical characteristics of lung tissue on a microscale level on intact tissues. Overall, our study demonstrates that each technique has independent benefits, and each technique revealed unique mechanical features of lung tissue that can contribute to a deeper understanding of lung tissue mechanics

‘Albania: €1’ or the story of ‘big policies, small outcomes’: how Albania constructs and engages its diaspora

Since the fall of the communist regime in the early 1990s, Albania has experienced one of the most significant emigrations in the world as a share of its population. By 2010 almost half of its resident population was estimated to be living abroad – primarily in neighbouring Greece and Italy, but also in the UK and North America. This chapter discusses the emergence and establishment of the Albanian diaspora, its temporal and geographical diversity, and not least its involvement with Albania itself. Albania’s policymaking and key institutions are considered, with a focus on matters of citizenship; voting rights; the debate on migration and development; and not least the complex ways in which kin-state minority policies – related to ethnic Albanians living in Kosovo, Montenegro, southern Serbia, Macedonia and Greece – are interwoven with Albania’s emigration policies

Civil conflict and sleeping sickness in Africa in general and Uganda in particular

Conflict and war have long been recognized as determinants of infectious disease risk. Re-emergence of epidemic sleeping sickness in sub-Saharan Africa since the 1970s has coincided with extensive civil conflict in affected regions. Sleeping sickness incidence has placed increasing pressure on the health resources of countries already burdened by malaria, HIV/AIDS, and tuberculosis. In areas of Sudan, the Democratic Republic of the Congo, and Angola, sleeping sickness occurs in epidemic proportions, and is the first or second greatest cause of mortality in some areas, ahead of HIV/AIDS. In Uganda, there is evidence of increasing spread and establishment of new foci in central districts. Conflict is an important determinant of sleeping sickness outbreaks, and has contributed to disease resurgence. This paper presents a review and characterization of the processes by which conflict has contributed to the occurrence of sleeping sickness in Africa. Conflict contributes to disease risk by affecting the transmission potential of sleeping sickness via economic impacts, degradation of health systems and services, internal displacement of populations, regional insecurity, and reduced access for humanitarian support. Particular focus is given to the case of sleeping sickness in south-eastern Uganda, where incidence increase is expected to continue. Disease intervention is constrained in regions with high insecurity; in these areas, political stabilization, localized deployment of health resources, increased administrative integration and national capacity are required to mitigate incidence. Conflict-related variables should be explicitly integrated into risk mapping and prioritization of targeted sleeping sickness research and mitigation initiatives

INFLUENCE OF ANESTHESIA, POSTANESTHETIC STATE, AND RESTRAINT ON SUPERIOR MESENTERIC ARTERIAL FLOW IN NORMAL RATS

To exclude possible confounding effects of anesthesia on splanchnic hemodynamics, two different awake postanesthetic models (PAM), restrained and unrestrained, have been used. However critical analysis of the splanchnic hemodynamic state in these models is not available. We conducted experiments using chronically implanted pulsed-Doppler flow probes on the superior mesenteric artery (SMA) in ketamine-anesthetized and in postanesthetic restrained and unrestrained normal rats. Baseline values of mean SMA flow were compared with those under anesthesia (30 min), PAM (restrained or unrestrained at 90 and 150 min), and reanesthesia. Sham-anesthetized unrestrained animals provided control values. The same animals (n = 7) underwent the restrained, unrestrained, and control experiments at least 5 days apart. Ketamine anesthesia did not significantly alter mean SMA flow (89 +/- 9% of baseline) compared with sham-anesthetized controls (99 +/- 9%). Mean SMA flow in both PAM, restrained and unrestrained, had a significant (P < 0.05) decrease at 90 min (78 +/- 8 and 83 +/- 12%) and at 150 min (68 +/- 14 and 78 +/- 14%) when compared with baseline and control. Reanesthesia returned SMA flows to baseline values (91 +/- 16%). The variability of mean SMA flow was significantly increased in both PAM. Maximum variability was observed in the restrained model (69 +/- 32%). These results indicate 1) that ketamine anesthesia does not significantly alter SMA flow and 2) that both the restrained and unrestrained PAM exhibit significant alterations of the splanchnic circulation for at least 2 h after complete recovery from anesthesia. Thus, in the absence of critical evaluation, results of splanchnic hemodynamic studies with these models should be questioned. Ketamine anesthesia administered intra-muscularly may be preferred to the awake PAM for the study of the splanchnic circulation