Grain coarsening in contact metamorphic carbonates: effects of second-phase particles, fluid flow and thermal perturbations

Under contact metamorphic conditions, carbonate rocks in the direct vicinity of the Adamello pluton reflect a temperature-induced grain coarsening. Despite this large-scale trend, a considerable grain size scatter occurs on the outcrop-scale indicating local influence of second-order effects such as thermal perturbations, fluid flow and second-phase particles. Second-phase particles, whose sizes range from nano- to the micron-scale, induce the most pronounced data scatter resulting in grain sizes too small by up to a factor of 10, compared with theoretical grain growth in a pure system. Such values are restricted to relatively impure samples consisting of up to 10 vol.% micron-scale second-phase particles, or to samples containing a large number of nano-scale particles. The obtained data set suggests that the second phases induce a temperature-controlled reduction on calcite grain growth. The mean calcite grain size can therefore be expressed in the form D 1⁄4 C2 eQ*/RT(dp/fp)m*, where C2 is a constant, Q* is an activation energy, T the temperature and m* the exponent of the ratio dp/fp, i.e. of the average size of the second phases divided by their volume fraction. However, more data are needed to obtain reliable values for C2 and Q*. Besides variations in the average grain size, the presence of second-phase particles generates crystal size distribution (CSD) shapes characterized by lognormal distributions, which differ from the Gaussian-type distributions of the pure samples. In contrast, fluid-enhanced grain growth does not change the shape of the CSDs, but due to enhanced transport properties, the average grain sizes increase by a factor of 2 and the variance of the distribution increases. Stable d18O and d13C isotope ratios in fluid-affected zones only deviate slightly from the host rock values, suggesting low fluid/rock ratios. Grain growth modelling indicates that the fluid-induced grain size variations can develop within several ka. As inferred from a combination of thermal and grain growth modelling, dykes with widths of up to 1 m have only a restricted influence on grain size deviations smaller than a factor of 1.1.To summarize, considerable grain size variations of up to one order of magnitude can locally result from second-order effects. Such effects require special attention when comparing experimentally derived grain growth kinetics with field studies.

Influence of local anaesthesia on pain and distress induced by two bloodless castration methods in young lambs

To assess short- and long-term effects of bloodless castration methods with and without local anaesthesia, behavioural and cortisol responses of lambs were used as indicators of pain and distress. Seventy lambs, aged 2-7 days, were control-handled or castrated by Burdizzo or rubber ring methods with and without local anaesthesia. Either 5 mL of diluted lidocaine (4 mg/kg) or physiological sodium chloride solution was distributed in both spermatic cords and the scrotal neck. The serum cortisol response was monitored for 48 h, and behavioural and clinical traits were followed for three months. Local anaesthesia tended to reduce behavioural and cortisol responses after Burdizzo castration and provided a significant reduction after rubber ring castration. Prolonged pain after rubber ring castration with anaesthesia was not evident. If combined with local anaesthesia, both the rubber ring and the Burdizzo methods are acceptable methods for castration of lambs up to one week of age.

The influence of the surgeon's and the hospital's caseload on survival and local recurrence after colorectal cancer surgery

BACKGROUND: Past studies have identified surgeon- and institution- related characteristics as prognostic factors in colorectal cancer surgery. The present work assesses the influence of the surgeon's and the hospital's caseload on long-term results of colorectal cancer surgery. METHODS: The data on 2706 patients from 2, randomized, colorectal cancer trials (Swiss Group for Clinical Cancer Research [SAKK] 40/81, SAKK 40/87) investigating adjuvant intraportal and systemic chemotherapy and 1 concurrent registration study (SAKK 40/88) were reviewed. A first analysis included 1809 eligible, nonmetastatic patients from all 3 studies. A subsequent subgroup analysis included 915 eligible patients from both randomized trials. Overall survival (OS), disease-free survival (DFS), and local recurrence (LR) were analyzed in multivariate models taking into account the possible effect of clustering. The main potential covariates were surgeon's annual caseload (>5 operations/year vs < or =5 operations/year), hospital's annual caseload (>26 operations/year vs < or =26 operations/year), tumor site, T stage, and nodal status. RESULTS: Primary analysis of all 3 studies combined found a high surgeon's caseload to be positively associated with OS (P = .025) and marginally with DFS (P = .058). Separate analysis for each trial, however, showed that a high surgeon's caseload was beneficial for outcome in both randomized trials but not in the registration study. A subgroup analysis of 915 patients with 376 rectal and 539 colonic primaries from both randomized trials, therefore, was performed. Neither age, gender, year of operation, adjuvant chemotherapy (intraportal vs systemic vs operation alone), hospital academic status (university vs non-university), training status of the surgeon (certified surgeon vs surgeon-in-training), nor inclusion in 1 of the 2 randomized trials (SAKK 40/81 vs SAKK 40/87) was a significant predictor of outcome. However, both high surgeon's and high hospital's annual caseloads were independent, beneficial prognostic factors for OS (P = .0003, P = .044) and DFS (P = .0008, P = .020), and marginally significant factors for LR (P = .057, P = .055). CONCLUSIONS: High surgeon's and hospital's annual caseloads are strong, independent prognostic factors for extending overall and disease-free survival and reducing the rate of local recurrence in 2 randomized colorectal cancer trials.

[Influence of local anaesthesia on pain and distress induced by bloodless castration methods in young lambs]

Behavioural and cortisol responses of lambs were used as indicators of pain and distress to assess short- and long-term effects of bloodless castration methods with and without local anaesthesia. Eighty lambs, aged 2-7 days, were control handled or castrated by crushing- Burdizzo- or rubber ring method with and without local anaesthesia. Either 4 mg/kg diluted lidocaine, or corresponding volumes of physiologic sodium chloride solution were distributed in both spermatic cords and the scrotal neck. The serum cortisol response was monitored for 48 h, behavioural- and clinical traits over a 3-month period. The crushing castration method was excluded from the study after 10 lambs had been castrated, since this method showed severe local reactions. Local anaesthesia significantly reduced behavioural and cortisol responses after rubber ring castration and tendentially after Burdizzo castration. Prolonged or chronic pain after rubber ring castration with anaesthesia was not evident. If combined with local anaesthesia, both the rubber ring and the Burdizzo method are acceptable methods for castration of lambs up to one week of age.

[Influence of local anaesthesia on short- and long-term pain induced in calves by three bloodless castration methods]

Behavioural and cortisol responses of calves were used as indicators of pain to assess short- and long-term effects of three bloodless castration methods with and without local anaesthesia. Eighty calves, aged 21 to 28 days, were control handled (20) or castrated by Burdizzo (25), rubber ring (25), or crushing technique (10). Either a total volume of 10 ml of Lidocaine or NaCl was distributed in both spermatic cords and the scrotal neck. The plasma cortisol response was monitored for 72 hours, and behavioural and clinical traits over a three-month period. Castration success was assessed by degree of atrophy and histological tissue examination. The crushing technique cannot be recommended due to incomplete castration success, and the evaluation was stopped after 10 animals. Local anaesthesia reduced the level of indicators of acute pain after Burdizzo and rubber ring technique. It did, however, not result in a totally painless castration. When castration is performed at the age of 3 to 4 weeks, the rubber ring but not the Burdizzo method showed evidence of chronic pain lasting for several weeks.

The influence of local and systemic preconditioning on oxygenation, metabolism and survival in critically ischaemic skin flaps in pigs

Stress proteins represent a group of highly conserved intracellular proteins that provide adaptation against cellular stress. The present study aims to elucidate the stress protein-mediated effects of local hyperthermia and systemic administration of monophosphoryl lipid A (MPL) on oxygenation, metabolism and survival in bilateral porcine random pattern buttock flaps. Preconditioning was achieved 24h prior to surgery by applying a heating blanket on the operative site (n = 5), by intravenous administration of MPL at a dosage of 35 microg/kg body weight (n = 5) or by combining the two (n = 5). The flaps were monitored with laser Doppler flowmetry, polarographic microprobes and microdialysis until 5h postoperatively. Semiquantitative immunohistochemistry was performed for heat shock protein 70 (HSP70), heat shock protein 32 (also termed haem oxygenase-1, HO-1), and inducible nitrc oxide synthase (iNOS). The administration of MPL increased the impaired microcirculatory blood flow in the proximal part of the flap and partial oxygen tension in the the distal part by approximately 100% each (both P<0.05), whereas both variables remained virtually unaffected by local heat preconditioning. Lactate/pyruvate (L/P) ratio and glycerol concentration (representing cell membrane disintegration) in the distal part of the flap gradually increased to values of approximately 500 mmol/l and approximately 350 micromol/l, respectively (both P<0.01), which was substantially attenuated by heat application (P<0.01 for L/P ratio and P<0.05 for glycerol) and combined preconditioning (P<0.01 for both variables), whereas the effect of MPL was less marked (not significant). Flap survival was increased from 56% (untreated animals) to 65% after MPL (not significant), 71% after heat application (P<0.05) and 78% after both methods of preconditioning (P<0.01). iNOS and HO-1 were upregulated after each method of preconditioning (P<0.05), whereas augmented HSP70 staining was only observed after heat application (P<0.05). We conclude that local hyperthermia is more effective in preventing flap necrosis than systemic MPL administration because of enhancing the cellular tolerance to hypoxic stress, which is possibly mediated by HSP70, whereas some benefit may be obtained with MPL due to iNOS and HO-1-mediated improvement in tissue oxygenation.

Influence of the background wind on the local soil moisture-precipitation feedback

The importance of soil moisture anomalies on airmass convection over semiarid regions has been recognized in several studies. The underlying mechanisms remain partly unclear. An open question is why wetter soils can result in either an increase or a decrease of precipitation (positive or negative soil moisture–precipitation feedback, respectively). Here an idealized cloud-resolving modeling framework is used to explore the local soil moisture–precipitation feedback. The approach is able to replicate both positive and negative feedback loops, depending on the environmental parameters. The mechanism relies on horizontal soil moisture variations, which may develop and intensify spontaneously. The positive expression of the feedback is associated with the initiation of convection over dry soil patches, but the convective cells then propagate over wet patches where they strengthen and preferentially precipitate. The negative feedback may occur when the wind profile is too weak to support the propagation of convective features from dry to wet areas. Precipitation is then generally weaker and falls preferentially over dry patches. The results highlight the role of the midtropospheric flow in determining the sign of the feedback. A key element of the positive feedback is the exploitation of both low convective inhibition (CIN) over dry patches (for the initiation of convection) and high CAPE over wet patches (for the generation of precipitation).

Local and general anaesthesia do not influence outcome of transfemoral aortic valve implantation.

BACKGROUND There is great variability for the type of anaesthesia used during TAVI, with no clear consensus coming from comparative studies or guidelines. We sought to detect regional differences in the anaesthetic management of patients undergoing transcatheter aortic valve implantation (TAVI) in Europe and to evaluate the relationship between type of anaesthesia and in-hospital and 1year outcome. METHODS Between January 2011 and May 2012 the Sentinel European TAVI Pilot Registry enrolled 2807 patients treated via a transfemoral approach using either local (LA-group, 1095 patients, 39%) or general anaesthesia (GA-group, 1712 patients, 61%). RESULTS A wide variation in LA use was evident amongst the 10 participating countries. The use of LA has increased over time (from a mean of 37.5% of procedures in the first year, to 57% in last 6months, p<0.01). MI, major stroke as well as in-hospital death rate (7.0% LA vs 5.3% GA, p=0.053) had a similar incidence between groups, confirmed in multivariate regression analysis after adjusting for confounders. Dividing our population in tertiles according to the Log-EuroSCORE we found similar mortality under LA, whilst mortality was higher in the highest risk tertile under GA. Survival at 1year, compared by Kaplan-Meier analysis, was similar between groups (log-rank: p=0.1505). CONCLUSIONS Selection of anaesthesia appears to be more influenced by national practice and operator preference than patient characteristics. In the absence of an observed difference in outcomes for either approach, there is no compelling argument to suggest that operators and centres should change their anaesthetic practice.

Ultrasonographic guided axillary plexus blocks with low volumes of local anaesthetics: a crossover volunteer study

Our study group recently evaluated an ED(95) local anaesthetic volume of 0.11 ml.mm(-2) cross-sectional nerve area for the ulnar nerve. This prospective, randomised, double-blind crossover study investigated whether this volume is sufficient for brachial plexus blocks at the axillary level. Ten volunteers received an ultrasonographic guided axillary brachial plexus block either with 0.11 ('low' volume) or 0.4 ('high' volume) ml.mm(-2) cross-sectional nerve area with mepivacaine 1%. The mean (SD) volume was in the low volume group 4.0 (1.0) and 14.8 (3.8) ml in the high volume group. The success rate for the individual nerve blocks was 27 out of 30 in the low volume group (90%) and 30 out of 30 in the high volume group (100%), resulting in 8 out of 10 (80%) vs 10 out of 10 (100%) complete blocks in the low vs the high volume groups, respectively (NS). The mean (SD) sensory onset time was 25.0 (14.8) min in the low volume group and 15.8 (6.8) min in the high volume group (p < 0.01). The mean (SD) duration of sensory block was 125 (38) min in the low volume group and 152 (70) min in the high volume group (NS). This study confirms our previous published ED(95) volume for mepivacaine 1% to block peripheral nerves. The volume of local anaesthetic has some influence on the sensory onset time.

Influence of secondary infection on amputation in chronic critical limb ischemia

OBJECTIVES: To evaluate the influence of secondary infection on major amputation in chronic critical leg ischemia (CLI). DESIGN: Prospective, controlled observational study. MATERIALS AND METHODS: Sixty-seven patients with CLI and ischemic lesions participated in the study. Presence of infection was defined by clinical, laboratory and radiological criteria. Patients were categorized as having no local infection, soft tissue infection or osteomyelitis treated without antibiotics, amoxicillin/clavulanacid for 1 month or ciprofloxacin and clindamycin for 3 months, respectively. Clinical outcome was assessed at 2, 6 and 12 months. Study endpoints were major amputation and mortality. Analyses were performed using the Kaplan-Meier method. RESULTS: Forty-seven of 67 patients had a local infection. Major amputation was lower in patients with successful revascularization as compared to patients unsuitable for or with failed (without) revascularization (0% vs 26%, p<0.01). In patients with successful revascularization the probability of complete healing was lower with secondary infection (23% vs 71%, p=0.03). In patients without revascularization complete healing was rare (<10%), but secondary infection did not influenced major amputation, mortality or serious adverse events. CONCLUSION: Secondary infection reduces the likelihood of successful healing following revascularisation of CLI.

Transformation of local medicinal knowledge in the Andean Highlands: Case studies from Peru and Bolivia

In the Andean highlands, indigenous environmental knowledge is currently undergoing major changes as a result of various external and internal factors. As in other parts of the world, an overall process of erosion of local knowledge can be observed. In response to this trend, some initiatives that adopt a biocultural approach aim at actively strengthening local identities and revalorizing indigenous environmental knowledge and practices, assuming that such practices can contribute to more sustainable management of biodiversity. However, these initiatives usually lack a sound research basis, as few studies have focused on the dynamics of indigenous environmental knowledge in the Andes and on its links with biodiversity management. Against this background, the general objective of this research project was to contribute to the understanding of the dynamics of indigenous environmental knowledge in the Andean highlands of Peru and Bolivia by investigating how local medicinal knowledge is socially differentiated within rural communities, how it is transformed, and which external and internal factors influence these transformation processes. The project adopted an actor-oriented perspective and emphasized the concept of knowledge dialogue by analyzing the integration of traditional and formal medicinal systems within family therapeutic strategies. It also aimed at grasping some of the links between the dynamics of medicinal knowledge and the types of land use systems and biodiversity management. Research was conducted in two case study areas of the Andes, both Quechua-speaking and situated in comparable agro-ecological production belts - Pitumarca District, Department of Cusco (Southern Peruvian Highlands) and the Tunari National Park, Department of Cochabamba (Bolivian inner-Andean valleys). In each case study area, the land use systems and strategies of 18 families from two rural communities, their environmental knowledge related to medicine and to the local therapeutic flora, and an appreciation of the dynamics of this knowledge were assessed. Data were collected through a combination of disciplinary and participatory action-research methods. It was mostly analyzed using qualitative methods, though some quantitative ethnobotanical methods were also used. In both case studies, traditional medicine still constitutes the preferred option for the families interviewed, independently of their age, education level, economic status, religion, or migration status. Surprisingly and contrary to general assertions among local NGOs and researchers, results show that there is a revival of Andean medicine within the younger generation, who have greater knowledge of medicinal plants than the previous one, value this knowledge as an important element of their way of life and relationship with “Mother Earth” (Pachamama), and, at least in the Bolivian case, prefer to consult the traditional healer rather than go to the health post. Migration to the urban centres and the Amazon lowlands, commonly thought to be an important factor of local medicinal knowledge loss, only affects people’s knowledge in the case of families who migrate over half of the year or permanently. Migration does not influence the knowledge of medicinal plants or the therapeutic strategies of families who migrate temporarily for shorter periods of time. Finally, economic status influences neither the status of people’s medicinal knowledge, nor families’ therapeutic strategies, even though the financial factor is often mentioned by practitioners and local people as the main reason for not using the formal health system. The influence of the formal health system on traditional medicinal knowledge varies in each case study area. In the Bolivian case, where it was only introduced in the 1990s and access to it is still very limited, the main impact was to give local communities access to contraceptive methods and to vaccination. In the Peruvian case, the formal system had a much greater impact on families’ health practices, due to local and national policies that, for instance, practically prohibit some traditional practices such as home birth. But in both cases, biomedicine is not considered capable of responding to cultural illnesses such as “fear” (susto), “bad air” (malviento), or “anger” (colerina). As a consequence, Andean farmers integrate the traditional medicinal system and the formal one within their multiple therapeutic strategies, reflecting an inter-ontological dialogue between different conceptions of health and illness. These findings reflect a more general trend in the Andes, where indigenous communities are currently actively revalorizing their knowledge and taking up traditional practices, thus strengthening their indigenous collective identities in a process of cultural resistance.

Secondary Forests and Local Livelihoods along a Gradient of Accessibility: A Case Study in Northern Laos

Rural livelihoods in developing countries can be enhanced by improving access to natural resources, services, and markets. In remote rural areas of the humid or semihumid tropics, forests represent an important resource for livelihoods. In countries like Laos, where most primary forest has been converted to secondary forest, and where an intricate and interlinked mosaic of forest and farmland prevails, people depend on secondary forests as a prime source of goods and services. The linkages between local livelihoods and secondary forest resources are subject to changes caused by improving accessibility. This article studies how accessibility affects the condition of forests and local livelihoods by comparing three villages along a gradient of accessibility in Phonxay district, Luang Prabang province, northern Laos. The results of this research show that accessibility strengthens the influence of the government and of markets, and that local livelihoods improve with increasing accessibility, while forest condition deteriorates.

Computational and experimental methodology for site-matched investigations of the influence of mineral mass fraction and collagen orientation on the axial indentation modulus of lamellar bone

Relationships between mineralization, collagen orientation and indentation modulus were investigated in bone structural units from the mid-shaft of human femora using a site-matched design. Mineral mass fraction, collagen fibril angle and indentation moduli were measured in registered anatomical sites using backscattered electron imaging, polarized light microscopy and nano-indentation, respectively. Theoretical indentation moduli were calculated with a homogenization model from the quantified mineral densities and mean collagen fibril orientations. The average indentation moduli predicted based on local mineralization and collagen fibers arrangement were not significantly different from the average measured experimentally with nanoindentation (p=0.9). Surprisingly, no substantial correlation of the measured indentation moduli with tissue mineralization and/or collagen fiber arrangement was found. Nano-porosity, micro-damage, collagen cross-links, non-collagenous proteins or other parameters affect the indentation measurements. Additional testing/simulation methods need to be considered to properly understand the variability of indentation moduli, beyond the mineralization and collagen arrangement in bone structural units.

Linking local knowledge, conservation practices and ecosystem diversity: comparing two communities in the Tunari National Park (Bolivia)

Combined approaches to conserve both biological and cultural diversity are seen as an alternative to classical nature conservation instruments. The objective of this study was to examine the influence of urbanization coupled with exclusive conservation measures, on land use, local knowledge and biodiversity in two Quechua speaking communities of Bolivia located within the Tunari National Park. We assessed and compared the links between land use, its transformation through conservation practices, local institutions and the worldviews of both communities and the implications they have for biodiversity at the level of ecosystems. Our results show that in both communities, people’s worldviews and environmental knowledge are linked with an integral and diversified use of their territory. However, the community most affected by urbanization and protected area regulations has intensified agriculture in a small area and has abandoned the use of large areas. This was accompanied by a loss of local environmental knowledge and a decrease in the diversity of ecosystems. The second community, where the park was not enforced, continues to manage their territory as a material expression of local environmental knowledge, while adopting community-based conservation measures with external support. Our findings highlight a case in which urbanization coupled with exclusive conservation approaches affects the components of both cultural and biological diversity. Actions that aim to enhance biocultural diversity in this context should therefore address the impact of factors identified as responsible for change in integrated social-ecological systems.