Macquarie Harbour, Tasmania-seasonal oceanographic surveys in 1985

Seasonal oceanographic surveys of Macquarie Harbour suggested the existence of a three-layer system: a surface layer responsive to seasonal heating and cooling and to river runoff, a slowly changing mid-level layer, and (in the deeper basins) a marine layer fed by tides flooding over the sill

Digital Ethnography as a Way to Explore Information Grounds on Twitter

Information grounds are social settings where information, people, and place come together to create information flow within a physical environment (Karen E. Pettigrew, 1998). Information grounds also facilitate the opportunistic discovery of information within social settings created temporarily by people gathered for some purpose other than seeking information, but the social environment stimulates spontaneous information sharing (K. E. Pettigrew, 1999), such as in hair salons, doctor's waiting rooms and other public places. Professional and scholarly use of social media is a rapidly emerging area of research. In this regard, qualitative analysis of data gathered from Twitter is a relatively unexplored area of Library and Information Science (LIS) research. This paper details the results of a qualitative study of Twitter using digital ethnography, in order to investigate the use of Twitter by IT professionals in forming communities of practice. This study is relevant to Library and Information Science (LIS) research as LIS professionals are part of the IT community of practice. This study used information grounds theory (K. E. Fisher, 2005) to explore Twitter as an online information ground. The research used online observation - conceptualised here as online ethnography or digital ethnography - and interviews to collect data. The online observations helped the researcher to understand the norms and culture of the participants along with patterns of behaviour. Interviews were used to understand the information grounds of the virtual environment through the participants' individual perspectives and their information experiences. A total of eleven participants were interviewed after a total of 734 tweets from these same participants were downloaded and analysed. Both interview and Twitter data were analysed using constructivist grounded theory (Charmaz, 2006). The findings highlight a variety of information sharing types, the role of information sharing in professional contexts, and the influences of Twitter on communication and social engagement, including a counterintuitive finding that professionals use Twitter not so much to seek or share information as much as to seek out a network of like-minded people. The significance of this study is in providing a fundamental understanding of the ways in which social media is used for professional reasons. It also proposes a systematic, qualitative data collection and data analysis approach to future research around Twitter and social media in general. This contribution not only helps LIS researchers, but can also help information professionals in the use of social media for professional purposes

Mechanism-based model characterizing bidirectional interaction between PEGylated liposomal CKD-602 (S-CKD602) and monocytes in cancer patients

S-CKD602 is a PEGylated liposomal formulation of CKD-602, a potent topoisomerase I inhibitor. The objective of this study was to characterize the bidirectional pharmacokinetic-pharmacodynamic (PK-PD) interaction between S-CKD602 and monocytes. Plasma concentrations of encapsulated CKD-602 and monocytes counts from 45 patients with solid tumors were collected following intravenous administration of S-CKD602 in the phase I study. The PK-PD models were developed and fit simultaneously to the PK-PD data, using NONMEM®. The monocytopenia after administration of S-CKD602 was described by direct toxicity to monocytes in a mechanism-based model, and by direct toxicity to progenitor cells in bone marrow in a myelosuppression-based model. The nonlinear PK disposition of S-CKD602 was described by linear degradation and irreversible binding to monocytes in the mechanism-based model, and Michaelis-Menten kinetics in the myelosuppression-based model. The mechanism-based PK-PD model characterized the nonlinear PK disposition, and the bidirectional PK-PD interaction between S-CKD602 and monocytes. © 2012 Cárdenas et al, publisher and licensee Dove Medical Press Ltd

Resonance as the Mechanism of Daytime Periodic Breathing in Patients with Heart Failure

Rationale: In patients with chronic heart failure, daytime oscillatory breathing at rest is associated with a high risk of mortality. Experimental evidence, including exaggerated ventilatory responses to CO2 and prolonged circulation time, implicates the ventilatory control system and suggests feedback instability (loop gain > 1) is responsible. However, daytime oscillatory patterns often appear remarkably irregular versus classic instability (Cheyne-Stokes respiration), suggesting our mechanistic understanding is limited. Objectives: We propose that daytime ventilatory oscillations generally result from a chemoreflex resonance, in which spontaneous biological variations in ventilatory drive repeatedly induce temporary and irregular ringing effects. Importantly, the ease with which spontaneous biological variations induce irregular oscillations (resonance “strength”) rises profoundly as loop gain rises toward 1. We tested this hypothesis through a comparison of mathematical predictions against actual measurements in patients with heart failure and healthy control subjects. Methods: In 25 patients with chronic heart failure and 25 control subjects, we examined spontaneous oscillations in ventilation and separately quantified loop gain using dynamic inspired CO2 stimulation. Measurements and Main Results: Resonance was detected in 24 of 25 patients with heart failure and 18 of 25 control subjects. With increased loop gain—consequent to increased chemosensitivity and delay—the strength of spontaneous oscillations increased precipitously as predicted (r = 0.88), yielding larger (r = 0.78) and more regular (interpeak interval SD, r = −0.68) oscillations (P < 0.001 for all, both groups combined). Conclusions: Our study elucidates the mechanism underlying daytime ventilatory oscillations in heart failure and provides a means to measure and interpret these oscillations to reveal the underlying chemoreflex hypersensitivity and reduced stability that foretells mortality in this population

Emotions in business-to-business service relationships

Emotion in business-to-business service relationships regarding cargo services is explored. The service relationship is characterised by mutual trust and cooperation. Contact is mainly via telephone or e-mail with some face-to-face interactions and participants providing a complex, multi-skilled seamless service. Experience rather than training plays a vital role with long-term service relationships built up and maintained. Emotional sensitivity is acquired partly by experience and a repeat customer base but mainly through a genuine desire to help and get to know others. In contrast to the view of emotional labour bringing managerial control or adverse affects to service staff, the emotion engendered by this work is authentic expression bringing personal satisfaction

MultiMetEval: comparative and multi-objective analysis of genome-scale metabolic models

Comparative metabolic modelling is emerging as a novel field, supported by the development of reliable and standardized approaches for constructing genome-scale metabolic models in high throughput. New software solutions are needed to allow efficient comparative analysis of multiple models in the context of multiple cellular objectives. Here, we present the user-friendly software framework Multi-Metabolic Evaluator (MultiMetEval), built upon SurreyFBA, which allows the user to compose collections of metabolic models that together can be subjected to flux balance analysis. Additionally, MultiMetEval implements functionalities for multi-objective analysis by calculating the Pareto front between two cellular objectives. Using a previously generated dataset of 38 actinobacterial genome-scale metabolic models, we show how these approaches can lead to exciting novel insights. Firstly, after incorporating several pathways for the biosynthesis of natural products into each of these models, comparative flux balance analysis predicted that species like Streptomyces that harbour the highest diversity of secondary metabolite biosynthetic gene clusters in their genomes do not necessarily have the metabolic network topology most suitable for compound overproduction. Secondly, multi-objective analysis of biomass production and natural product biosynthesis in these actinobacteria shows that the well-studied occurrence of discrete metabolic switches during the change of cellular objectives is inherent to their metabolic network architecture. Comparative and multi-objective modelling can lead to insights that could not be obtained by normal flux balance analyses. MultiMetEval provides a powerful platform that makes these analyses straightforward for biologists. Sources and binaries of MultiMetEval are freely available from https://github.com/PiotrZakrzewski/MetEv​al/downloads

Metabolic analysis of the interaction between plants and herbivores

Insect herbivores by necessity have to deal with a large arsenal of plant defence metabolites. The levels of defence compounds may be increased by insect damage. These induced plant responses may also affect the metabolism and performance of successive insect herbivores. As the chemical nature of induced responses is largely unknown, global metabolomic analyses are a valuable tool to gain more insight into the metabolites possibly involved in such interactions. This study analyzed the interaction between feral cabbage (Brassica oleracea) and small cabbage white caterpillars (Pieris rapae) and how previous attacks to the plant affect the caterpillar metabolism. Because plants may be induced by shoot and root herbivory, we compared shoot and root induction by treating the plants on either plant part with jasmonic acid. Extracts of the plants and the caterpillars were chemically analysed using Ultra Performance Liquid Chromatography/Time of Flight Mass Spectrometry (UPLCT/MS). The study revealed that the levels of three structurally related coumaroylquinic acids were elevated in plants treated on the shoot. The levels of these compounds in plants and caterpillars were highly correlated: these compounds were defined as the ‘metabolic interface’. The role of these metabolites could only be discovered using simultaneous analysis of the plant and caterpillar metabolomes. We conclude that a metabolomics approach is useful in discovering unexpected bioactive compounds involved in ecological interactions between plants and their herbivores and higher trophic levels.

Gender differences in clinical characteristics and outcome of acute heart failure in sub-Saharan Africa: results of the THESUS-HF study

Background: The impact of gender on the clinical characteristics, risk factors, co-morbidities, etiology, treatment and outcome of acute heart failure in sub-Saharan Africa has not been described before. The aim of this study was to evaluate the sex diffe rences in acute heart failure in sub-Saharan Africa using the data from The sub-Saharan Africa Survey of Heart Failure (THESUS-HF). Methods and results: 1,006 subjects were recruited into this prospective multicenter, international observational heart failure survey. The mean age of total population was 52.4 years (54.0 years for men and 50.7 years for women). The men were significantly older (p = 0.0045). Men also presented in poorer NYHA functional class (III and IV), p = 0.0364). Cigarette smoking and high blood pressure were significantly commoner in men (17.3 vs. 2.6 % and 60.0 vs. 51.0 % respectively). On the other hand, atrial fibrillation and valvular heart disease were significantly more frequent in women. The mean hemoglobin concentration was lower in women compared to men (11.7 vs. 12.6 g/dl, p ≤ 0.0001), while the blood urea and creatinine levels were higher in men (p \u3c 0.0001). LV systolic dysfunctional was also seen more in men. Men also had higher E/A ratio indicating higher LV filling pressure. Outcomes were similar in both sexes. Conclusions: Although the outcome of patients admitted for AHF in sub-Saharan regions is similar in men and women, some gender differences are apparent suggesting that in men more emphasis should be put on modifiable life risk factors, while in women prevention of rheumatic heart diseases and improved nutrition should be addressed vigorously

The causes, treatment, and outcome of acute heart failure in 1006 Africans From 9 countries

Background: Acute heart failure (AHF) in sub-Saharan Africa has not been well characterized. Therefore,wesought to describe the characteristics, treatment, and outcomes of patients admitted with AHF in sub-Saharan Africa. Methods: The Sub-Saharan Africa Survey of Heart Failure (THESUS–HF) was a prospective, multicenter, observational survey of patients with AHF admitted to 12 university hospitals in 9 countries. Among patients presenting with AHF, we determined the causes, treatment, and outcomes during 6 months of follow-up. Results: From July 1, 2007, to June 30, 2010, we enrolled 1006 patients presenting with AHF. Mean (SD) age was 52.3 (18.3) years, 511 (50.8%) were women, and the predominant race was black African (984 of 999 [98.5%]). Mean (SD) left ventricular ejection fraction was 39.5% (16.5%)... Conclusions: In African patients, AHF has a predominantly nonischemic cause, most commonly hypertension. The condition occurs in middle-aged adults, equally in men and women, and is associated with high mortality. The outcome is similar to that observed in non- African AHF registries, suggesting that AHF has a dire prognosis globally, regardless of the cause

Multisensory information facilitates reaction speed by enlarging activity difference between superior colliculus hemispheres in rats

Animals can make faster behavioral responses to multisensory stimuli than to unisensory stimuli. The superior colliculus (SC), which receives multiple inputs from different sensory modalities, is considered to be involved in the initiation of motor responses. However, the mechanism by which multisensory information facilitates motor responses is not yet understood. Here, we demonstrate that multisensory information modulates competition among SC neurons to elicit faster responses. We conducted multiunit recordings from the SC of rats performing a two-alternative spatial discrimination task using auditory and/or visual stimuli. We found that a large population of SC neurons showed direction-selective activity before the onset of movement in response to the stimuli irrespective of stimulation modality. Trial-by-trial correlation analysis showed that the premovement activity of many SC neurons increased with faster reaction speed for the contraversive movement, whereas the premovement activity of another population of neurons decreased with faster reaction speed for the ipsiversive movement. When visual and auditory stimuli were presented simultaneously, the premovement activity of a population of neurons for the contraversive movement was enhanced, whereas the premovement activity of another population of neurons for the ipsiversive movement was depressed. Unilateral inactivation of SC using muscimol prolonged reaction times of contraversive movements, but it shortened those of ipsiversive movements. These findings suggest that the difference in activity between the SC hemispheres regulates the reaction speed of motor responses, and multisensory information enlarges the activity difference resulting in faster responses