Nature dependent tourism - Combining big data and local knowledge

The ability to quantify nature's value for tourism has significant implications for natural resource management and sustainable development policy. This is especially true in the Eastern Caribbean, where many countries are embracing the concept of the Blue Economy. The utilization of user-generated content (UGC) to understand tourist activities and preferences, including the use of artificial intelligence and machine learning approaches, remains at the early stages of development and application. This work describes a new effort which has modelled and mapped multiple nature dependent sectors of the tourism industry across five small island nations. It makes broad use of UGC, while acknowledging the challenges and strengthening the approach with substantive input, correction, and modification from local experts. Our approach to measuring the nature-dependency of tourism is practical and scalable, producing data, maps and statistics of sufficient detail and veracity to support sustainable resource management, marine spatial planning, and the wider promotion of the Blue Economy framework.

Pulmonary rehabilitation in bronchiectasis: a propensity-matched study

International guidelines recommend pulmonary rehabilitation for patients with bronchiectasis, supported by small trials and data extrapolated from chronic obstructive pulmonary disease (COPD). However, it is unknown whether real-life data on completion rates and response to pulmonary rehabilitation are similar between patients with bronchiectasis and COPD.Using propensity score matching, 213 consecutive patients with bronchiectasis referred for a supervised pulmonary rehabilitation programme were matched 1:1 with a control group of 213 patients with COPD. Completion rates, change in incremental shuttle walk (ISW) distance and change in Chronic Respiratory Disease Questionnaire (CRQ) score with pulmonary rehabilitation were compared between groups.Completion rate was the same in both groups (74%). Improvements in ISW distance and most domains of the CRQ with pulmonary rehabilitation were similar between the bronchiectasis and COPD groups (ISW distance: 70 versus 63 m; CRQ-Dyspnoea: 4.8 versus 5.3; CRQ-Emotional Function: 3.5 versus 4.6; CRQ-Mastery: 2.3 versus 2.9; all p>0.20). However, improvements in CRQ-Fatigue with pulmonary rehabilitation were greater in the COPD group (bronchiectasis 2.1 versus COPD 3.3; p=0.02).In a real-life, propensity-matched control study, patients with bronchiectasis show similar completion rates and improvements in exercise and health status outcomes as patients with COPD. This supports the routine clinical provision of pulmonary rehabilitation to patients with bronchiectasis.

ATP-independent DNA renaturation catalyzed by a protein from Ustilago maydis

A protein that catalyzes the renaturation of complementary strands of DNA has been purified from mitotic cells of the lower eukaryote Ustilago maydis. The most highly purified fraction contains a polypeptide with a molecular mass of 20 kDa as determined by SDS/PAGE and glycerol gradient sedimentation. DNA reannealing is enhanced by the presence of a divalent cation but does not require ATP nor any other nucleotide triphosphate. Reassociation proceeds with fast kinetics as more than 60% of the DNA is reannealed within 4 min at a 30:1 nucleotide/protein monomer ratio, results which suggest that the protein acts in a stoichiometric fashion. Amino acid analysis revealed that the protein contained an elevated level of basic residues and low levels of tryptophan and tyrosine. The protein binds to an oligonucleotide of ten residues but not to one having only five. As judged by agarose gel assays, the protein does not catalyze strand-transfer reactions but does promote the annealing of a 58-residue polynucleotide onto single-stranded circles and gapped linear duplexes. These latter reactions are dependent on the presence of DNA sequence similarity between the pairing partners.

In vitro analysis of a type I DNA topoisomerase activity from cultured tobacco cells

The role of DNA topoisomerases in plant cell metabolism is currently under investigation in our laboratory. Using a purified type I topoisomerase from cultured tobacco, we have carried out a biochemical characterization of enzymatic behavior. The enzyme relaxes negatively supercoiled DNA in the presence of MgCl2, and to a lesser extent in the presence of KCl. Phosphorylation of the topoisomerase does not influence its activity and it is not stimulated by the presence of histones H1 or H5. The enzyme may act in either a processive or distributive manner depending on reaction conditions. The anti-tumor drug, camptothecin, induces significant breakage by the enzyme on purified DNA molecules unless destabilized by the addition of KCl. The tobacco topoisomerase I can catalyze the formation of stable nucleosomes on circular DNA templates, suggesting a role for the enzyme in chromatin assembly.

Purification and characterization of a type-I topoisomerase from cultured tobacco cells

Cultured tobacco (Nicotiana tabacum, var Xanthi) cells contain a topoisomerase that removes positive and negative supercoils from DNA. The enzyme has an estimated molecular mass of 30,000 daltons under denaturing conditions, but may exist as a multimeric protein in the native state. Activity is enhanced significantly by either MgCl(2) or CaCl(2), but other divalent cations are much less effective in stimulating DNA relaxation. The purified enzyme acts by altering the linking number in topological steps of one and is inhibited by berenil or camptothecin, not novobiocin. Taken together, these data identify this enzyme as a type I topoisomerase.

Studies on the ATP requirements of in vitro chromatin assembly

To gain a more complete understanding of the process of in vitro chromatin assembly, an examination of the energy requirements of nucleosome formation must be undertaken. The experiments outlined in this manuscript address this issue by making use of the Xenopus laevis S-150 cell-free extract. The S-150 catalyzes chromatin assembly on circular DNA templates dependent either on the exogenous addition of ATP or regeneration of endogenous ATP. We define two distinct, but temporally ordered, phases of the overall process. The first, nucleosome formation, occurs in the presence of endogenous levels of ATP, while the second phase, chromatin assembly, which we define as the development of properly spaced nucleosomes, requires a higher level of ATP. Both phases lead to a distribution of molecules with similar superhelical densities. Taken together, these data suggest that chromatin assembly may consist of two distinct steps differing in their strategy cofactor requirement. The experiments presented in this manuscript support the concept that nucleosomes first assemble, perhaps randomly, on the DNA and are gradually matured into a canonical chromatin structure with periodic spacing.

Olfactory aversion conditioning and overeating: a review and some data

The present study evaluated the efficacy of olfactory aversion conditioning in the management of overeating problems. 42 overweight female subjects were assigned to one of three treatment conditions: olfactory aversion therapy, attention placebo control, and no-contact control. One experimenter administered the 8-wk. treatment phase. The aversion therapy procedure entailed the pairing of selected target foods (CSs) with noxious odors (UCSs). There were 25 pairings of the CS and UCSs during each weekly session. Four noxious odors were employed, one each week, to prevent habituation to the UCS. The attention-placebo control procedure was identical except that "air" was substituted for the putative UCS of the aversion therapy condition. At the end of the treatment period the aversion therapy group had lost 4.7 lb.; the attention placebo controls had lost 3.6 lb. and the no-contact controls 0.5 lb. The difference between the aversion therapy group and the no-contact controls was significant and that between the attention placebo group and the no-contact controls approached significance. At a follow-up 8 wk. after the end of the treatment period the weights of all groups had risen to pretreatment levels and there were no differences between them. These results indicate that olfactory aversion therapy is not an efficient technique in promoting weight-loss.