Anthropogenic vs. natural habitats: Higher microbial biodiversity pays the trade-off of lower connectivity

Climate change and anthropogenic disturbances are known to influence soil biodiversity. The objectives of this study were to compare the community composition, species coexistence patterns, and ecological assembly processes of soil microbial communities in a paired setting featuring a natural and an anthropogenic ecosystem facing each other at identical climatic, pedological, and vegetational conditions. A transect gradient from forest to seashore allowed for sampling across different habitats within both sites. The field survey was carried out at two adjacent strips of land within the Po River delta lagoon system (Veneto, Italy) one of which is protected within a natural preserve and the other has been converted for decades into a tourist resort. The anthropogenic pressure interestingly led to an increase in the α-diversity of soil microbes but was accompanied by a reduction in β-diversity. The community assembly mechanisms of microbial communities differentiate in natural and anthropic ecosystems: for bacteria, in natural ecosystems deterministic variables and homogeneous selection play a main role (51.92%), while stochastic dispersal limitation (52.15%) is critical in anthropized ecosystems; for fungi, stochastic dispersal limitation increases from 38.1% to 66.09% passing from natural to anthropized ecosystems. We are on calcareous sandy soils and in more natural ecosystems a variation of topsoil pH favors the deterministic selection of bacterial communities, while a divergence of K availability favors stochastic selection. In more anthropized ecosystems, the deterministic variable selection is influenced by the values of SOC. Microbial networks in the natural system exhibited higher numbers of nodes and network edges, as well as higher averages of path length, weighted degree, clustering coefficient, and density than its equivalent sites in the more anthropically impacted environment. The latter on the other hand presented a stronger modularity. Although the influence of stochastic processes increases in anthropized habitats, niche-based selection also proves to impose constraints on communities. Overall, the functionality of the relationships between groups of microorganisms co-existing in communities appeared more relevant to the concept of functional biodiversity in comparison to the plain number of their different taxa. Fewer but functionally more organized lineages displayed traits underscoring a better use of the resources than higher absolute numbers of taxa when those are not equally interconnected in their habitat exploitation. However, considering that network complexity can have important implications for microbial stability and ecosystem multifunctionality, the extinction of complex ecological interactions in anthropogenic habitats may impair important ecosystem services that soils provide us.

Combined forest and soil management after a catastrophic event

At the end of October 2018, a storm of unprecedented strength severely damaged the forests of the eastern sector of the Italian Alps. The affected forest area covers 42,500 ha. The president of one of the damaged regions asked for help from the University of Padua. After eight months of discussion, the authors of this article wrote a consensus text. The sometimes asper debate brought to light some crucial aspects: 1) even experienced specialists may have various opinions based on scientific knowledge that lead to conflicting proposals for action. For some of them there is evidence that to restore a destroyed natural environment it is more judicious to do nothing; 2) the soil corresponds to a living structure and every ecosystem's management should be based on it; 3) faced with a catastrophe, people and politicians find themselves unarmed, also because they rarely have the scientific background to understand natural processes. Yet politicians are the only persons who make the key decisions that drive the economy in play and therefore determine the near future of our planet. This article is an attempt to respond directly to a governor with a degree in animal production science, who formally and prudently asked a university department called "Land, Environment, Agriculture and Forestry" for help before taking decisions; 4) the authors also propose an artistic interpretation of facts (uncontrolled storm) and conclusions (listen to the soil). Briefly, the authors identify the soil as an indispensable source for the renewal of the destroyed forest, give indications on how to prepare a map of the soils of the damaged region, and suggest to anchor on this soil map a series of silvicultural and soil management actions that will promote the soil conservation and the faster recovery of the natural dynamic stability and resilience.

ELECTRONIC SUPPLEMENTARY MATERIAL

Supplementary material is available for this article at 10.1007/s11629-019-5890-0 and is accessible for authorized users.

A novel G/C single-nucleotide polymorphism in the double 28-bp repeat thymidylate synthase allele

Thymidylate synthase (TYMS) is the main molecular target for fluoropyrimidine anticancer drugs, and its expression has been correlated with the number of repeats of a 28-bp sequence in the 5'-untranslated region of the TYMS gene and with the presence of a G --> C single-nucleotide polymorphism in the second repeat of 3R alleles. Based on this double polymorphism, three main TYMS alleles have so far been identified: TYMS 2R, TYMS 3RC and TYMS 3RG. During genetic analysis of TYMS polymorphisms in 100 colorectal cancer patients, three patients revealed an unexpected 113-bp band after electrophoresis of the restriction fragment length polymorphism analysis. Subsequent sequencing revealed two 28-bp repeats in the 5'-untranslated region and the presence in both repeats of cytosine instead of guanine at the 12th nucleotide. This allele variant (TYMS 2RC) has not been previously described in man. All three patients were heterozygotes for TYMS 2RC and experienced grade 2-3 chemotherapy-related toxicity.

TYMS polymorphism analysis prediction of bolus 5-fluorouracil toxicity

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Background: Currently there is no protocol for selecting colorectal cancer patients at risk for drug toxicity prior to 5-fluorouracil(5FU)-based chemotherapy. Thymidylate synthase (TYMS) is 5FU main molecular target and its expression is linked to cellular sensitivity or resistance to the drug. Three genetic polymorphisms have been shown to influence TYMS expression: a polymorphic tandem repeat sequence (2 or 3 repeats; 2R and 3R) and a single nucleotide polymorphism, G > C, within the promoter enhancer region and a 6 bp deletion in the 3’UTR of the gene. Methods: This prospective study endpoint was to test weather TYMS polymorphisms might predict high grade toxic events in Caucasian patients with colo- rectal carcinoma treated with adjuvant bolus 5-FU-based chemotherapy. 142 patients, 98 males, mean age 66,7±9,1 were studied at the first cycle of treatment. TYMS genotypes were determined from the peripheral blood mononuclear cells by polymerase chain reaction and restriction fragment length polymorphism. Toxic event occurrence was collected through self-administered questionnaire and physical examination and scored through WHO scales. Results: 40% of patients had no or minimal adverse events while 35% suffered grade 3–4 toxicity. At univariate analysis, there was a trend of association between 3R/3R genotype and a reduced risk of adverse events (chi test for trend, p=0.057) and again a significant association between 6bp/6bp genotype and high grade toxicity (chi test for trend, p=0.03). Analysing all the three polymorphism together, 77% of patients bearing 6bp/6bp combined with at least one 3RG allele suffered grade 3–4 toxicity, while patients bearing homozigote 6bp deletion had no or minimal side effects in 90% of cases. The other genotype combinations had an intermediate toxic risk. The differences were statistically significant (chi test p=0.02). Conclusions: TYMS combined 5’UTR and 3’UTR polymorphism analysis may help in predicting high grade toxic events in Caucasian patients treated with repeated boluses of 5-FU. Funded by AIRC-Veneto.

No significant financial relationships to disclose.

Evaluation of microcomputer nutritional teaching games in 1,876 children at school

OBJECTIVE

We evaluated in a prospective study microcomputer nutritional teaching games and their contribution to the children's acquisition of nutritional knowledge and improvement of eating habits.

MATERIAL AND METHODS

One thousand eight hundred seventy-six children aged 7-12 years took part in this study at school. All 16 schools of the same school district were randomized into two groups: games group and control group, both receiving conventional nutritional teaching by their teachers. The children in the games group played computer games during the conventional nutritional teaching period (2 hours a week for 5 weeks). At completion of the study, dietetic knowledge and dietary records were evaluated in both groups.

RESULTS

Dietary knowledge tests results were better in the games group (p<0.001). The children in the games group had a significantly better balanced diet for an energy intake of about 1900 kilocalories: more carbohydrate (46.4 +/- 0.2% vs 45.7 +/- 0.2%, p<0.05), less fat (37.1 +/- 0.1% vs 37.6 +/- 0.2%, p<0.05), less protein (16.5 +/- 0.1% vs 16.7 +/- 0.1%, p<0.05), less saccharose (11.5 +/- 0.1% vs 12.2 +/- 0.2%, p<0.001), more calcium (p<0.001) and more fiber (p<0.05). The games group had a better snack at 10 a.m., a less copious lunch and less nibbling (p<0.001).

CONCLUSION

The children in the games group had slightly but significantly better nutritional knowledge and dietary intake compared to children in the control group. Using our micro computer nutritional teaching games at school provides an additional and modern support to conventional teaching.

Multicenter randomized evaluation of a nutritional education software in obese patients

OBJECTIVE

To study the efficacy of the nutritional education software, Nutri-Expert, in the management of obese adult patients.

MATERIAL AND METHODS

Two groups of obese patients were followed up over one year in a randomized study: the first group received close traditional management (seven nutritional visits over the year, with physicians and dietitians conjointly) and the second one also used at home by Minitel the Nutri-Expert system. 557 patients were enrolled in the study by 16 French centers of diabetology and nutrition. Body mass index (BMI), tests of dietetic knowledge, dietary records and centralized biological measurements were assessed at inclusion, 6 and 12 months. 341 patients were evaluable at the end of the year.

RESULTS

The group using Nutri-Expert scored significantly better in the tests of dietetic knowledge than the control group. For all patients, nutritional education led to a significant improvement in BMI, dietary records and biological measurements, without significant difference between the two groups. Five years after the end of the study, the weight of 148 patients was recorded; mean BMI was significantly lower than the initial value but there was no significant difference between the two groups.

CONCLUSION

In the management of obese patients, Nutri-Expert system has a role to play in reinforcing nutritional knowledge; if regular follow-up is not possible, or if a large series of obese patients is to be treated, Nutri-Expert could partly replace traditional management, for example between visits.

Quantitative analysis of ribonucleoside triphosphates in human lymphoid cells by micellar electrokinetic capillary chromatography

Micellar electrokinetic capillary chromatography (MECC) was applied to develop an analytical method for quantitation of ribonucleoside triphosphates (rNTPs) in human lymphoid cells obtained from patients with B-chronic lymphocytic leukaemia (B-CLL) and cutaneous lymphomas. The results of this analysis showed a significant depression of intracellular rNTPs in patients with B-CLL, compared with rNTPs of healthy controls. These data are in agreement with other studies in which rNTP separations were performed with traditional high-performance liquid chromatography. MECC has proved to be a useful tool for intracellular rNTPs determination, revealing possible new applications in the study of the metabolic state of human cells. In addition, this method can be useful in monitoring the effect of many drugs (antiviral, antineoplastic) which interfere with nucleotide metabolism.