Insulin therapy and dietary adjustments to normalize glycemia and prevent nocturnal hypoglycemia after evening exercise in type 1 diabetes: a randomized controlled trial

Introduction Evening-time exercise is a frequent cause of severe hypoglycemia in type 1 diabetes, fear of which deters participation in regular exercise. Recommendations for normalizing glycemia around exercise consist of prandial adjustments to bolus insulin therapy and food composition, but this carries only short-lasting protection from hypoglycemia. Therefore, this study aimed to examine the impact of a combined basal-bolus insulin dose reduction and carbohydrate feeding strategy on glycemia and metabolic parameters following evening exercise in type 1 diabetes. Methods Ten male participants (glycated hemoglobin: 52.4±2.2 mmol/mol), treated with multiple daily injections, completed two randomized study-days, whereby administration of total daily basal insulin dose was unchanged (100%), or reduced by 20% (80%). Participants attended the laboratory at ∼08:00 h for a fasted blood sample, before returning in the evening. On arrival (∼17:00 h), participants consumed a carbohydrate meal and administered a 75% reduced rapid-acting insulin dose and 60 min later performed 45 min of treadmill running. At 60 min postexercise, participants consumed a low glycemic index (LGI) meal and administered a 50% reduced rapid-acting insulin dose, before returning home. At ∼23:00 h, participants consumed a LGI bedtime snack and returned to the laboratory the following morning (∼08:00 h) for a fasted blood sample. Venous blood samples were analyzed for glucose, glucoregulatory hormones, non-esterified fatty acids, β-hydroxybutyrate, interleukin 6, and tumor necrosis factor α. Interstitial glucose was monitored for 24 h pre-exercise and postexercise. Results Glycemia was similar until 6 h postexercise, with no hypoglycemic episodes. Beyond 6 h glucose levels fell during 100%, and nine participants experienced nocturnal hypoglycemia. Conversely, all participants during 80% were protected from nocturnal hypoglycemia, and remained protected for 24 h postexercise. All metabolic parameters were similar. Conclusions Reducing basal insulin dose with reduced prandial bolus insulin and LGI carbohydrate feeding provides protection from hypoglycemia during and for 24 h following evening exercise. This strategy is not associated with hyperglycemia, or adverse metabolic disturbances

Content Analysis in Mass Communication: Assessment and Reporting of Intercoder Reliability

As a method specifically intended for the study of messages, content analysis is fundamental to mass communication research. Intercoder reliability, more specifically termed intercoder agreement, is a measure of the extent to which independent judges make the same coding decisions in evaluating the characteristics of messages, and is at the heart of this method. Yet there are few standard and accessible guidelines available regarding the appropriate procedures to use to assess and report intercoder reliability, or software tools to calculate it. As a result, it seems likely that there is little consistency in how this critical element of content analysis is assessed and reported in published mass communication studies. Following a review of relevant concepts, indices, and tools, a content analysis of 200 studies utilizing content analysis published in the communication literature between 1994 and 1998 is used to characterize practices in the field. The results demonstrate that mass communication researchers often fail to assess (or at least report) intercoder reliability and often rely on percent agreement, an overly liberal index. Based on the review and these results, concrete guidelines are offered regarding procedures for assessment and reporting of this important aspect of content analysis

Linking marine communities and ecosystems : invertebrates mediate nutrient availability in intertidal communities

While community ecologists have traditionally focused on local-scale processes, it has become apparent that a broader perspective, which explores the community-level ramifications of material fluxes within and between ecosystems, is necessary to effectively evaluate bottom-up influences on community structure and dynamics. In this dissertation, I employed ecosystem principles to understand these processes in rocky intertidal communities. I specifically examined the roles of sessile invertebrates in mediating the transfers and transformations of carbon and nitrogen in intertidal ecosystems. First, I quantified the links between nearshore pelagic and rocky intertidal systems. By assimilating suspended particulate organic material (seston), mussels and other sessile invertebrates serve as mediators of material exchange from pelagic to benthic ecosystems. I evaluated these trophic linkages along productivity gradients on the coasts of New Zealand and Oregon, which allowed me to address the influences of seston quality and quantity on the growth and ammonium excretion rates of mussels. My results highlight the necessity of simultaneously considering both seston quantity (total organic particulates) and quality (phytoplankton availability) in evaluating benthic-pelagic coupling. Second, I assessed the utilization of invertebrate-excreted ammonium by macroalgae in high-intertidal pools. Sessile invertebrates not only serve as mediators of material transfer into intertidal ecosystems, they also chemically transform that material, converting particulate organic nitrogen, which is unusable by macroalgae, into ammonium, which algae readily assimilate. l showed that especially in high-zone pools, which are isolated from the ocean for 80% of the time, invertebrate-excreted ammonium is an important nitrogen source for macroalgae. Ammonium accumulated in tide pools and was subsequently taken up by algae. This novel positive interaction influenced community structure: macroalgal species richness increased with the rate of invertebrate-mediated ammonium loading in pools. Finally, by experimentally manipulating macroalgae and invertebrates in laboratory mesocosms, I quantified the effect of ammonium loading on algal growth. I demonstrated that algal nitrogen assimilation rates increased with the rate of ammonium accumulation in tide pools, which resulted in enhanced growth when invertebrates were present. Together, these studies suggest that by merging community and ecosystem perspectives we can gain unique and important insights into the bottom-up processes influencing intertidal systems

Quantifying the top-down effects of grazers on a rocky shore: selective grazing and the potential for competition

The effect of grazers on the diversity, distribution, and composition of their principal food source has rarely been described for the high intertidal zone of rocky shores, a model system for studying the potential effects of climate change. Along rocky, wave-swept shores in central California, the microphytobenthos (MPB) supports diverse assemblages of limpets and littorine snails, which, at current benign temperatures, could potentially partition food resources in a complementary fashion, thereby enhancing secondary productivity. Two limpet species in particular, Lottia scabra and L. austrodigitalis, may partition components of the MPB, and are likely to affect the composition of the MPB on which they graze. In this study, we describe the composition, nutritional value (C:N ratio), and fluorescence (an index of chlorophyll density) of ungrazed, L. scabra-grazed and L. austrodigitalis-grazed MPB, each as a function of temperature. Fluorescence decreased with increased average daily maximum temperature for ungrazed MPB, but temperature had no discernible effects on either fluorescence or the composition of the MPB of grazed assemblages. L. austrodigitalis and L. scabra did not partition the MPB, and did not exhibit complementarity. Both species exhibited an ordered grazing scheme, in which limpets grazed down certain components of the MPB before others, and grazing increased the C:N ratio of the MPB, decreasing its nutritional value. Taken together, these results suggest that L. austrodigitalis and L. scabra may experience increased competition as warming temperatures reduce the available MP

Comparative Population Genomics and Biophysical Modeling of Shrimp Migration in the Gulf of Mexico Reveals Current-Mediated Connectivity

The Gulf of Mexico experiences frequent perturbations, both natural and anthropogenic. To better understand the impacts of these events, we must inventory natural variability within the ecosystem, communities, species, and populations, and contextualize these findings in relation to physical features. Here, we present an integrated study of comparative population genomics and biophysical oceanography. Targeting three species of mesopelagic shrimp common to the Gulf of Mexico midwater (Acanthephyra purpurea, Systellaspis debilis, and Robustosergia robusta), we analyzed genetic diversity and population connectivity as proxies for species health and resilience, respectively. We also simulated a range of vertical migratory behaviors for the shrimp to infer the relationship between diel vertical migration and horizontal transmission between the Gulf of Mexico and the greater Atlantic Ocean. This study aims to establish biological baselines and characterize these values in terms of the prevailing oceanographic feature of the midwater: the Gulf Loop Current. Generally, the oplophorid species (A. purpurea and S. debilis) exhibit lower genetic diversity and higher interpopulation homogeneity compared to the sergestid (R. robusta). Biophysical simulations suggest the differences in vertical migratory regimes between these two groups have important implications for horizontal transport out of the Gulf of Mexico. Because of the difference in vertical migration patterns, access to the Gulf Loop Current varies across taxa and impacts inter-basin migration. Our findings suggest a negative correlation between surface abundance and genetic diversity in these three shrimp species. We hypothesize that this correlation may be due to the relationships between surface abundance and access to the fastest moving waters of the Gulf Loop Current

Critical assessment and validation of a time-integrating fluvial suspended sediment sampler

Delivery of fine sediment to fluvial systems is of considerable concern given the physical and ecological impacts of elevated levels in drainage networks. Although it is possible to measure the transfer of fine sediment at high frequency by using a range of surrogate and automated technologies, the demands for assessing sediment flux and sediment properties at multiple spatially distributed locations across catchments can often not be met using established sampling techniques. The time-integrated mass-flux sampler (TIMS) has the potential to bridge this gap and further our understanding of fine sediment delivery in fluvial systems. However, these devices have undergone limited testing in the field. The aim of this paper was to provide a critical validation of TIMS as a technique for assessing fluvial fine sediment transfer. Fine sediment flux and sediment properties were assessed over 2 years with individual sampling periods of approximately 30 days. Underestimation of sediment flux ranged between 66% and 99% demonstrating that TIMS is unsuitable for assessing absolute sediment loads. However, assessment of relative efficiency showed that six of seven samplers produced statistically strong relationships with the reference sediment load (P < 0.05). Aggregated data from all sites produced a highly significant relationship between reference and TIMS loads (R2 = 0.80; P < 0.001) demonstrating TIMS may be suitable for characterizing patterns of suspended sediment transfer. Testing also illustrated a consistency in sediment properties between multiple samplers in the same channel cross section. TIMS offers a useful means of assessing spatial and temporal patterns of fine sediment transfer across catchments where expensive monitoring frameworks cannot be commissioned

Paediatric Outpatient Parenteral Antimicrobial Therapy (OPAT): an e-survey of the experiences of parents and clinicians.

BackgroundLittle evidence exists about parental satisfaction and their influence on referral to paediatric Outpatient Parenteral Antimicrobial Therapy (OPAT).AimThis study aimed to examine the experiences of parents, children and clinicians of OPAT at a large tertiary children's hospital.MethodA prospective e-survey, using closed and open questions, of parents (n = 33) of 33 children who had received OPAT (3 children completed a survey), and clinicians (n = 31) involved in OPAT at a tertiary hospital. Data were collected September 2016 to July 2018.ResultsData were analysed using simple descriptive statistics. The results show that OPAT offered benefits (less stress, re-establishment of family life) compared to hospital-based treatment for parents and children, although some were anxious. Clinicians' referral judgements were based on child, home, and clinical factors. Some clinicians found the process of referral complex.ConclusionMost parents and children were satisfied with the OPAT service and preferred the option of home-based treatment as it promoted the child's comfort and recovery and supported family routines