Sequential multiple assignment randomised trial to develop an adaptive mobile health intervention to increase physical activity in people poststroke in the community setting in Ireland: TAPAS trial protocol.

INTRODUCTION: Stroke is the second-leading cause of death and disability globally. Participation in physical activity (PA) is a cornerstone of secondary prevention in stroke care. Given the heterogeneous nature of stroke, PA interventions that are adaptive to individual performance are recommended. Mobile health (mHealth) has been identified as a potential approach to supporting PA poststroke. To this end, we aim to use a Sequential Multiple Assignment Randomised Trial (SMART) design to develop an adaptive, user-informed mHealth intervention to improve PA poststroke. METHODS AND ANALYSIS: The components included in the 12-week intervention are based on empirical evidence and behavioural change theory and will include treatments to increase participation in Structured Exercise and Lifestyle or a combination of both. 117 participants will be randomly assigned to one of the two treatment components. At 6 weeks postinitial randomisation, participants will be classified as responders or non-responders based on participants' change in step count. Non-responders to the initial treatment will be randomly assigned to a different treatment allocation. The primary outcome will be PA (steps/day), feasibility and secondary clinical and cost outcomes will also be included. A SMART design will be used to evaluate the optimum adaptive PA intervention among community-dwelling, ambulatory people poststroke. ETHICS AND DISSEMINATION: Ethical approval has been granted by the Health Service Executive Mid-Western Ethics Committee (REC Ref: 026/2022). The findings will be submitted for publication and presented at relevant national and international academic conferences TRIALS REGISTRATION NUMBER: NCT05606770.

Combined use of stable isotopes and hydrochemical characteristics to determine streamflow sources in the Jonkershoek catchment, South Africa.

The stable isotopes of water (18O, 2H) and other hydrochemical properties were used to assess seasonal changes between sources of stream water and flow pathways in baseflow conditions for two headwater sub-catchments (∼3 km2) of the Jonkershoek, a mountainous catchment in the Western Cape of South Africa. The sub-catchments differ in land cover, one is dominated by indigenous fynbos vegetation and the other by pine plantation. Stream water, higher elevation springs, and lower elevation groundwater samples were collected monthly from January 2018 to January 2019, and were analysed for stable isotopes, electrical conductivity (EC) and pH. The stream water isotopic values resembled those of groundwater during the dry and wet seasons. Results indicated a steady contribution of spring discharge to streams during the dry season, with rainfall contribution less evident. Wet season flows were attributed to interflow including perennial and ephemeral springs. Spatial variations in EC between the sub-catchments were indicative of a greater proportional input from subsurface water, more evaporation and/or more mineral dissolution in the pine-dominated sub-catchment. The spatiotemporal variability in EC was significantly larger than for the stable isotopes. These findings enabled conceptualization of streamflow generation processes that can support strategic water resource management practices in this region.

Limited oxygen production in the Mesoarchean ocean.

The Archean Eon was a time of predominantly anoxic Earth surface conditions, where anaerobic processes controlled bioessential element cycles. In contrast to "oxygen oases" well documented for the Neoarchean [2.8 to 2.5 billion years ago (Ga)], the magnitude, spatial extent, and underlying causes of possible Mesoarchean (3.2 to 2.8 Ga) surface-ocean oxygenation remain controversial. Here, we report δ15N and δ13C values coupled with local seawater redox data for Mesoarchean shales of the Mozaan Group (Pongola Supergroup, South Africa) that were deposited during an episode of enhanced Mn (oxyhydr)oxide precipitation between ∼2.95 and 2.85 Ga. Iron and Mn redox systematics are consistent with an oxygen oasis in the Mesoarchean anoxic ocean, but δ15N data indicate a Mo-based diazotrophic biosphere with no compelling evidence for a significant aerobic nitrogen cycle. We propose that in contrast to the Neoarchean, dissolved O2 levels were either too low or too limited in extent to develop a large and stable nitrate reservoir in the Mesoarchean ocean. Since biological N2 fixation was evidently active in this environment, the growth and proliferation of O2-producing organisms were likely suppressed by nutrients other than nitrogen (e.g., phosphorus), which would have limited the expansion of oxygenated conditions during the Mesoarchean.

The truth is in the isotopes: Authenticating regionally unique South African lamb.

Stable isotope ratios (13C/12C and 15N/14N) of South African lambs from different regions were measured by isotope ratio mass spectrometry (IRMS). Homogenised and defatted meat of the Longissimus lumborum muscle was assessed. The Rûens and Hantam Karoo regions had the lowest (P≤0.05) δ13C values related to the presence of C3 plants (lucerne and Karoo bushes, respectively). The Northern Karoo, Namibia and Bushmanland had the highest δ13C values likely due to a high proportion of dietary C4 grass species. The δ15N values were highest for Central Karoo, Semi-extensive, Namibia and Hantam Karoo, while Rûens and Feedlot had the lowest nitrogen isotope values (P≤0.05). Classification of origin (Karoo vs. Non-Karoo) using discriminant analysis allowed 95% and 90% correct classification of the samples for the estimation model and validation models, respectively. The results confirm that IRMS provides sufficient discriminative power to classify lamb meat of varying origin.

Isotope (δ13C, δ15N, δ2H) diet-tissue discrimination in African grey parrot Psittacus erithacus: implications for forensic studies.

Diet-tissue isotopic relationships established under controlled conditions are informative for determining the dietary sources and geographic provenance of organisms. We analysed δ13C, δ15N, and non-exchangeable δ2H values of captive African grey parrot Psittacus erithacus feathers grown on a fixed mixed-diet and borehole water. Diet-feather Δ13C and Δ15N discrimination values were +3.8 ± 0.3 ‰ and +6.3 ± 0.7 ‰ respectively; significantly greater than expected. Non-exchangeable δ2H feather values (-62.4 ± 6.4 ‰) were more negative than water (-26.1 ± 2.5 ‰) offered during feather growth. There was no positive relationship between the δ13C and δ15N values of the samples along each feather with the associated samples of food offered, or the feather non-exchangeable hydrogen isotope values with δ2H values of water, emphasising the complex processes involved in carbohydrate, protein, and income water routing to feather growth. Understanding the isotopic relationship between diet and feathers may provide greater clarity in the use of stable isotopes in feathers as a tool in determining origins of captive and wild-caught African grey parrots, a species that is widespread in aviculture and faces significant threats to wild populations. We suggest that these isotopic results, determined even in controlled laboratory conditions, be used with caution.

Effects of nutrient levels and average culture pH on the glycosylation pattern of camelid-humanized monoclonal antibody.

The impact of operating conditions on the glycosylation pattern of humanized camelid monoclonal antibody, EG2-hFc produced by Chinese hamster ovary (CHO) cells has been evaluated by a combination of experiments and modeling. Cells were cultivated under different levels of glucose and glutamine concentrations with the goal of investigating the effect of nutrient depletion levels and ammonia build up on the cell growth and the glycoprofiles of the monoclonal antibody (Mab). The effect of average pH reduction on glycosylation level during the entire culture time or during a specific time span was also investigated. The relative abundance of glycan structures was quantified by hydrophilic interaction liquid chromatography (HILIC) and the galactosylation index (GI) and the sialylation index (SI) were determined. Lower initial concentrations of glutamine resulted in lower glucose consumption and lower cell yield but increased GI and SI levels when compared to cultures started with higher initial glutamine levels. Similarly, reducing the average pH of culture resulted in lower growth but higher SI and GI levels. These findings indicate that there is a tradeoff between cell growth, resulting Mab productivity and the achievement of desirable higher glycosylation levels. A dynamic model, based on a metabolic flux analysis (MFA), is proposed to describe the metabolism of nutrients, cell growth and Mab productivity. Finally, existing software (GLYCOVIS) that describes the glycosylation pathways was used to illustrate the impact of extracellular species on the glycoprofiles.

Fragmentation of negative ions from N-linked carbohydrates, part 4. Fragmentation of complex glycans lacking substitution on the 6-antenna.

Negative ion CID spectra of N-linked glycans released from glycoproteins contain many ions that are diagnostic for specific structural features such as the detailed arrangement of antennae and the location of fucose residues. Identification of such ions requires reference glycans that are often difficult to acquire in a pure state. The recent acquisition of a sample of N-glycans from a patient lacking the enzyme N-acetylglucosaminyltransferase-2 provided an opportunity to investigate fragmentation of glycans lacking a 6-antenna. These glycans contained one or two galactose-N-acetylglucosamine-chains attached to the 3-linked mannose residue of the trimannosyl-chitobiose core with and without fucose substitution. The spectra from the patient sample clearly defined the antenna distribution and showed striking differences from the spectra of isomeric compounds obtained from normal subjects. Furthermore, they provided additional information on previously identified antenna-specific fragment ions and indicated the presence of additional ions that were diagnostic of fucose substitution. Glycans obtained from such enzyme-deficient patients can, thus, be a valuable way of obtaining spectra of specific isomers in a relatively pure state for interpretation of mass spectra.

Dispositional pessimism predicts delayed return to normal activities after inguinal hernia operation.

BACKGROUND: The traditional outcome measure to assess effectiveness of inguinal hernia operation was recurrence. Open mesh repair has reduced recurrence rates and attention is now turning to outcomes other than recurrence. The factors influencing the large variation in reported times of resumption of normal activities after inguinal hernia repair are many and diverse. The human factors influencing resumption of normal activity are rarely reported. METHODS: We undertook a prospective study of 206 patients undergoing primary inguinal hernia repair in an ambulatory setting in a public hospital to ascertain whether dispositional outlook on life affected resumption of normal activity after hernia repair. Outlook on life was assessed using the life orientation test. An independent observer assessed the patients preoperatively and determined timing of resumption of normal activities. RESULTS: Regression analysis showed a highly significant relationship between delayed return to normal activity and dispositional pessimism (P =.0004). DISCUSSION: Dispositional pessimism correlates strongly with delayed return to normal activities. Further studies of this kind will help to elucidate the human factors that affect recovery after operation. Studies which use return to normal activities as a measure of the outcome of a surgical technique should include an assessment of the patient's preoperative outlook on life. Surgeons should consider the personality of the patient presenting for groin hernia repair and may wish to tailor their counseling accordingly.