A literature review of type I SLCA—making the logic underlying methodological choices explicit

Purpose

The Social Life Cycle Assessment guidelines (UNEP-SETAC 2009) distinguish two different SLCA approaches, type I and type II. Few comprehensive and analytical reviews have been undertaken to examine the multiplicity of approaches that have been developed within type I SLCA. This paper takes on the task of exploring the evaluation methods used in type I SLCA methods.

Methods

In order to tackle this work, a critical literature review was undertaken, covering a total of 32 reviewed articles, ranging from 2006 to 2015. Those articles have been selected for they make explicit reference to type I, performance reference points (PRPs), corporate behavior assessment, and social performance assessment or if their assessment methods generated a result located at the same point as the inventory data, with regards to the impact pathway. The selected articles were analyzed with a focus on the inventory data used, the aggregation of inventory data on the functional unit, and the type of characterization and weighting methods used. This analysis allowed to make explicit the often implicit logic underlying the evaluation methods and to identify the common denominators of type I SLCA.

Results and discussion

The analysis highlighted the multiplicity of approaches that are comprised within type I SLCA today, both in terms of the data collected (in particular, its positioning along the impact pathway); the presence of some optional steps, such as the scaling of inventory data on the functional unit (FU); and in terms of the different characterization and weighting steps. With regards to data collection, this review has highlighted that the furthest indicators are positioned along the impact pathway, the hardest it is to justify the link between them and the activities of companies in the product system. The analysis also suggested that an important differentiating factor among type I SLCA methods lies in “what the inventory data is assessed against” at the characterization step and how it is ultimately weighted. To illustrate this, a typology of six characterization methods and five types of weighting methods was presented.

Conclusions

It is interesting to identify which approaches are most appropriate to respond to the various questions that SLCA aims to respond to. A question that arises is what approaches are most likely to tell us anything about the impact of a product system on social well-being? This question is particularly relevant in the absence of well-documented impact pathways between activities within product systems and impact on social well-being.

     

YAP and TAZ are essential for basal and squamous cell carcinoma initiation

YAP and TAZ are key downstream regulators of the Hippo pathway, regulating cell proliferation and differentiation. YAP and TAZ activation has been reported in different cancer types. However, it remains unclear whether they are required for the initiation of major skin malignancies like basal cell carcinoma (BCC) and squamous cell carcinoma (SCC). Here, we analyze the expression of YAP and TAZ in these skin cancers and evaluate cancer initiation in knockout mouse models. We show that YAP and TAZ are nuclear and highly expressed in different BCC types in both human and mice. Further, we find that cells with nuclear YAP and TAZ localize to the invasive front in well‐differentiated SCC, whereas nuclear YAP is homogeneously expressed in spindle cell carcinoma undergoing EMT. We also show that mouse BCC and SCC are enriched for YAP gene signatures. Finally, we find that the conditional deletion of YAP and TAZ in mouse models of BCC and SCC prevents tumor formation. Thus, YAP and TAZ are key determinants of skin cancer initiation, suggesting that targeting the YAP and TAZ signaling pathway might be beneficial for the treatment of skin cancers.     

Effect of NH4 +:NO3 - ratios on growth and nitrogen uptake by onions

The modelling of ion uptake by plants requires the measurement of kinetic and growth parameters under specific conditions. The objective of this study was to evaluate the effect of nine NH _inf4 ^sup+ :NO _inf3 ^sup− ratios on onions (Allium cepa L.). Twenty-eight to 84 day-old onion plants were treated with NH _inf4 ^sup+ :NO_f3/sup− ratios ranging from 0 to 100% of each ionic species in one mM solutions in a growth chamber. Maximum N influx (I_max) was assessed using the N depletion method. Except at an early stage, ionic species did not influence significantly I_max, the Michaelis constant (K_m) and the minimum concentration for net uptake (C_min). I_max for ammonium decreased from 101 to 59 pmole cm^-2 s^-1 while I_max for nitrate increased from 26 to 54 pmole cm^-2 s^-1 as the plant matured. On average, K_m and C_min values were 14.29 μM, and 5.06 μM for ammonium, and 11.90 μM and 4.54 μM for nitrate, respectively. In general, the effect of NH₄ ⁺:NO₃ ^- ratios on root weight, shoot weight and total weight depended on plant age. At an early stage, maximum plant growth and N uptake were obtained with ammonium as the sole source of N. At later stages, maximum plant growth and N uptake were obtained as the proportion of nitrate increased in the nutrient solution. The was no apparent nutrient deficiency whatever NH₄ ⁺:NO₃ ^- ratio was applied, although ammonium reduced the uptake of cations and increased the uptake of phosphorus. The research was supported by the Natural Sciences and Engineering Research Council of Canada.     

The Dictyostelium MAP kinase kinase DdMEK1 regulates chemotaxis and is essential for chemoattractant-mediated activation of guanylyl cyclase.

We have identified a MAP kinase kinase (DdMEK1) that is required for proper aggregation in Dictyostelium. Null mutations produce extremely small aggregate sizes, resulting in the formation of slugs and terminal fruiting bodies that are significantly smaller than those of wild-type cells. Time-lapse video microscopy and in vitro assays indicate that the cells are able to produce cAMP waves that move through the aggregation domains. However, these cells are unable to undergo chemotaxis properly during aggregation in response to the chemoattractant cAMP or activate guanylyl cyclase, a known regulator of chemotaxis in Dictyostelium. The activation of guanylyl cyclase in response to osmotic stress is, however, normal. Expression of putative constitutively active forms of DdMEK1 in a ddmek1 null background is capable, at least partially, of complementing the small aggregate size defect and the ability to activate guanylyl cyclase. However, this does not result in constitutive activation of guanylyl cyclase, suggesting that DdMEK1 activity is necessary, but not sufficient, for cAMP activation of guanylyl cyclase. Analysis of a temperature-sensitive DdMEK1 mutant suggests that DdMEK1 activity is required throughout aggregation at the time of guanylyl cyclase activation, but is not essential for proper morphogenesis during the later multicellular stages. The activation of the MAP kinase ERK2, which is essential for chemoattractant activation of adenylyl cyclase, is not affected in ddmek1 null strains, indicating that DdMEK1 does not regulate ERK2 and suggesting that at least two independent MAP kinase cascades control aggregation in Dictyostelium.     

Biological response of endothelial cells and its modulation by cytokines: prospects for therapy and bioprocesses

Endothelial cells are involved in important pathological situations. They could be the target for infectious processes as for example in Cowdriosis, an important disease in cattle due to the rickettsia Cowdria ruminantium prevalent in the south of the Sahara. They are also connected to angiogenic processes related to tumor invasion. Our results indicate that AIDS related Kaposi sarcoma cells may be of endothelial origin. We conclude from our data the mobility of those cells, related to the expression of the metalloproteinases (especially the 92 kD form of the enzyme), is an important factor in Kaposi saroma dissemination and is the main factor limiting the scale up of Cowdriosis vaccine production in Bovine Umbilical Endothelial Cell line. We showed that PMA and TNF increased the 92 kD Metallaproteinase and that TGFβ, produced in an inactive form in cultures of Human Umbilical Vein Endothelial Cells, is a potential inhibitor of Kaposi sarcoma spreading, and could also be useful in improving our process for Cowdria ruminantium vaccine production, since it reduces the sensitivity of the cells to mechanical stress without affecting significantly the overall infectious process. This revised version was published online in June 2006 with corrections to the Cover Date.     

Severity of sepsis alters the effects of superoxide anion inhibition in a rat sepsis model.

Previous analysis showed that selective inhibitors of five different host inflammatory mediators administered for sepsis, although beneficial with severe sepsis and high-control mortality rates, were ineffective or harmful with less severe sepsis. We hypothesized that severity of sepsis would also influence inhibition of superoxide anion, another inflammatory mediator. To test this, 6-h infusions of M40401, a selective SOD mimetic, or placebo were given to antibiotic-treated rats (n=547) starting 3 h after challenge with differing doses of intravenous Escherichia coli designed to produce low- or high-control mortality rates. There was a positive and significant (P=0.0008) relationship between the efficacy of M40401 on survival rate and control mortality rates. M40401 increased or decreased the log (odds ratio of survival) (means +/- SE), dependent on whether control mortality rates were greater or less than the median (66%) (+0.19 +/- 0.12 vs. -0.25 +/- 0.10, P=0.01). In a subset of animals examined (n=152) at 9 h after E. coli challenge, M40401 increased (mean effect +/- SE compared with control) mean arterial blood pressure (8 +/- 5 mmHg) and decreased platelets (-37 +/- 22 cells x 10(3)/ml) with high-control mortality rates but had opposing effects on each parameter (-3 +/- 3 mmHg and 28 +/- 19 cells x 10(3)/ml, respectively) with low rates (P < or = 0.05 for the differing effects of M40401 on each parameter with high- vs. low-control mortality rates). A metaregression analysis of published preclinical sepsis studies testing SOD preparations and SOD mimetics showed that most (16 of 18) had control mortality rates >66%. However, across experiments from published studies, these agents were less beneficial as control mortality rate decreased (P=0.03) in a relationship not altered (P=not significant) by other variables associated with septic challenge or regimen of treatment and which was similar, compared with experiments with M40401 (P=not significant). Thus, in these preclinical sepsis models, possibly related to divergent effects on vascular function, inhibition of superoxide anion improved survival with more severe sepsis and high-control mortality rates but was less effective or harmful with less severe sepsis. Extrapolated clinically, inhibition of superoxide anion may be most efficacious in septic patients with severe sepsis and a high risk of death.     

Growth plate cartilage shows different strain patterns in response to static versus dynamic mechanical modulation

Longitudinal growth of long bones and vertebrae occurs in growth plate cartilage. This process is partly regulated by mechanical forces, which are one of the underlying reasons for progression of growth deformities such as idiopathic adolescent scoliosis and early-onset scoliosis. This concept of mechanical modulation of bone growth is also exploited in the development of fusionless treatments of these deformities. However, the optimal loading condition for the mechanical modulation of growth plate remains to be identified. The objective of this study was to evaluate the effects of in vitro static versus dynamic modulation and of dynamic loading parameters, such as frequency and amplitude, on the mechanical responses and histomorphology of growth plate explants. Growth plate explants from distal ulnae of 4-week-old swines were extracted and randomly distributed among six experimental groups: baseline (\(n=10\)), control (\(n=10\)), static (\(n=10\)) and dynamic (\(n=3\times 10\)). For static and dynamic groups, mechanical modulation was performed in vitro using an Indexed CartiGen bioreactor. A stress relaxation test combined with confocal microscopy and digital image correlation was used to characterize the mechanical responses of each explant in terms of peak stress, equilibrium stress, equilibrium modulus of elasticity and strain pattern. Histomorphometrical measurements were performed on toluidine blue tissue sections using a semi-automatic custom-developed MATLAB toolbox. Results suggest that compared to dynamic modulation, static modulation changes the strain pattern of the tissue and thus is more detrimental for tissue biomechanics, while the histomorphological parameters are not affected by mechanical modulation. Also, under dynamic modulation, changing the frequency or amplitude does not affect the biomechanical response of the tissue. Results of this study will be useful in finding optimal and non-damaging parameters for the mechanical modulation of growth plate in fusionless treatments.     

Blunted responses to vasoconstrictors in mesenteric vasculature but not in portal vein of spontaneously hypertensive rats treated with relaxin

Relaxin (RLX), an ovarian polypeptide hormone that is particularly associated with gestation in viviparous species, has recently been shown to decrease blood pressure in virgin spontaneously hypertensive rats (SHR) upon chronic infusion. In this investigation, vascular reactivity to angiotensin II, arginine-vasopressin, and norepinephrine was studied in the perfused mesenteric artery and isolated portal vein of control and RLX-treated virgin spontaneously hypertensive rats. The latter received an intravenous infusion of 75 ng/hr purified rat RLX for 2 days, whereas the controls were given an equal infusion of saline. All of the animals were then killed and their tissues processed for in vitro study. In the perfused mesenteric artery, the concentration-response curves for arginine-vasopressin and norepinephrine were shifted to the right by a factor of about 2 (P less than 0.05 and P less than 0.005, respectively) after RLX treatment. In the isolated portal vein, the response to angiotensin II was not affected; the effect of norepinephrine was slightly displaced to the right (increase in EC50) and the maximum response remained unchanged. These results demonstrate that RLX treatment for 42 hr blunted the vascular response to vasoconstrictor agents in the mesenteric vasculature and are consistent with similar observations reported previously in the same tissue of 20-day-old pregnant rats. It is concluded that RLX may be involved in the blunted response to vasoconstrictor agents during gestation in the rat.     

Toxicité du champignon entomopathogèneCordyceps militaris pour des larves de culicides

Différents métabolites excrétés lors de la croissancein vitro deCordyceps militaris (L.)Link ont un effet toxique marqué sur les larves deCulex pipiens et d'Aedes atropalpus mais plus faible sur celles d'A. aegypti. Ces produits toxiques partiellement thermostables entraînent, suivant leur concentration, la mortalité d'une population entière deC. pipiens pipiens et d'A. atropalpus tandis qu'une proportion élevée deC. pipiens pipiens et d'A. atropalpus tandis qu'une proportion élevée des larves d'A. aegypti semble résistante à leur action. Nous pensons pouvoir utiliser ces résultats dans la recherche d'un synergisme entre ces métabolites toxiques et d'autres microorganismes ou insecticides dans un programme de lutte intégrée contre les larves de moustiques.     

A case of congenital non-spherocytic hemolytic anemia caused by enzyme deficiency in pyruvate kinase

About a familial observation of PK deficiency, the authors emphasize the important clinical and biochemical heterogeneity. Interest of isotopic explorations in the therapeutic decision of splenectomy.