Association of Diagnostic Blood Loss from Phlebotomy and Hospital-Acquired Anemia During Admission with Acute Myocardial Infarction

Introduction: Acute, hospital-acquired anemia (HAA) during admission with AMI is associated with higher mortality and worse health status, and often occurs in the absence of recognized bleeding. Diagnostic blood loss from phlebotomy is readily modifiable, but the relationship between diagnostic blood loss and HAA is unclear. Methods: We studied 17,676 AMI patients in the Health Facts database who were not anemic at admission and did not undergo coronary bypass surgery, focusing on the development of moderate-severe HAA (Hgb decline to < 11 g/dl during hospitalization), since this degree of HAA has been shown to be prognostically important. Health Facts included the lab tests, as well as date and time of every blood draw. Patients¡¯ total diagnostic blood loss was calculated by multiplying the number and types of blood tubes drawn by the standard blood volume for each tube type. Hierarchical modified Poisson regression was used to test the association between phlebotomy volume and the development of moderate-severe HAA, accouting for clustering by hospital site and adjusting for demographics, comorbidities, disease severity and treatment variables. Sensitivity analyses were conducted after excluding patients with documented bleeding and after stratifying by length of stay (LOS). Results: Moderate-severe HAA developed in 3,549 patients (20%). Total diagnostic blood loss ranged from 12ml to 1864ml, and mean phlebotomy volume was significantly higher in patients with (182¡À149 ml) vs. without HAA (86.2¡À55.9 ml, p<0.001). The risk of developing HAA was greater with increasing phlebotomy volume (per 50 ml: RR 1.17 (95% CI1.13-1.21)). After multivariable adjustment, each 50 ml of blood drawn for laboratory tests was associated with a 14% increase in risk of HAA (RR 1.14 (95% CI 1.11-1.17)). Results were similar in patients without documented bleeding (RR 1.14 (95% CI1.11-1.16) per 50 ml) and stratified by LOS (LOS ¡Ü 4 days: RR 1.30 (95% CI 1.15-1.46) per 50 ml; LOS ¡Ý 4 days RR 1.11 (95% CI 1.09-1.14) per 50 ml). Conclusion: Blood loss from more frequent phlebotomy is independently associated with the development of moderate-severe HAA. These findings suggest that HAA may be preventable by implementing strategies to limit both the number of blood draws and the volume of blood removed for diagnostic testing

On the Deformation Mechanics of Hyperelastic Porous Materials

The understanding of the deformation mechanics within porous structures is an important field of study as these materials exist in nature as well as can be manufactured industrially influencing our lives daily. The motivation of the research contained within this manuscript was inspired by the desire to understand the mechanics of an elastomeric closed–cell porous material. This type of porous material is often used in load–bearing applications such as sport helmet liners and packing material which can be subjected to large deformations at high rates. Additionally, short term transient effects were explored. In order to investigate the deformation mechanics of a closed cell elastomeric foam, a polychloroprene (neoprene) material was chosen as it was available in both rubber form and a foam with relatively consistent cell size. Compression tests were conducted on the polychloroprene rubber at strain rates ranging from 0.001/s to 2700/s which identified that it had a hyper–viscoelastic behaviour with a significant strain rate dependence. A newly developed constitutive model was created to capture the response of the polychloroprene rubber. A coupled finite element model of the polychloroprene foam was created and compared to experimental tests for validation. The model slightly over predicted the stress level response of the experimental tests. The model was used to identify momentum dissipation mechanisms that contributed to the low wave speed measurement of approximately 70 m/s determined from the model. The investigation of wave transit times through use of the model was key to interpreting experimental data. Of the morphological factors investigated, it was determined that wall thickness had the most significant impact on the stress response of the foam. The pore–scale model was useful for visualizing wavepropagation effects and deformation mechanics which was not feasible experimentally

Controls on buffering and coastal acidification in a temperate estuary

Estuaries may be uniquely susceptible to the combined acidification pressures of atmospherically driven ocean acidification (OA), biologically driven CO2 inputs from the estuary itself, and terrestrially derived freshwater inputs. This study utilized continuous measurements of total alkalinity (TA) and the partial pressure of carbon dioxide (pCO2) from the mouth of Great Bay, a temperate northeastern U.S. estuary, to examine the potential influences of endmember mixing and biogeochemical transformation upon estuary buffering capacity (β–H). Observations were collected hourly over 28 months representing all seasons between May 2016 and December 2019. Results indicated that endmember mixing explained most of the observed variability in TA and dissolved inorganic carbon (DIC), concentrations of which varied strongly with season. For much of the year, mixing dictated the relative proportions of salinity-normalized TA and DIC as well, but a fall season shift in these proportions indicated that aerobic respiration was observed, which would decrease β–H by decreasing TA and increasing DIC. However, fall was also the season of weakest statistical correspondence between salinity and both TA and DIC, as well as the overall highest salinity, TA and β–H. Potential biogeochemically driven β–H decreases were overshadowed by increased buffering capacity supplied by coastal ocean water. A simple modeling exercise showed that mixing processes controlled most monthly changes in TA and DIC, obscuring impacts from air–sea exchange or metabolic processes. Advective mixing contributions may be as important as biogeochemically driven changes to observe when evaluating local estuarine and coastal OA

A study of a novel modular variable geometry frame arranged as a robotic surface

The novel concept of a variable geometry frame is introduced and explored through a three-dimensional robotic surface which is devised and implemented using triangular modules. The link design is optimized using surplus motor dimensions as firm constraints, and round numbers for further arbitrary constraints. Each module is connected by a passive six-bar mechanism that mimics the constraints of a spherical joint at each triangle intersection. A three dimensional inkjet printer is used to create a six-module prototype designed around surplus stepper motors powered by an old computer power supply as a proof-of-concept example. The finite element method is applied to the static and dynamic loading of this device using linear three dimensional (6 degrees of freedom per node) beam elements to calculate the cartesian displacement and force and the angular displacement and torque at each joint. In this way, the traditional methods of finding joint forces and torques are completely bypassed. An efficient algorithm is developed to linearly combine local stiffness matrices into a full structural stiffness matrix for the easy application of loads. This is then decomposed back into the local matrices to easily obtain joint variables used in the design and open-loop control of the surface. Arbitrary equation driven surfaces are approximated ensuring that they are within the joints limits. Moving shapes are then calculated by considering the initial position of the surface, the desired position of the surface, and intermediate shapes at discrete times along the desired path. There are no sensors on the prototype, but feedback models and state estimators are developed for future use. These models include shape sampling methods derived from existing meshing algorithms, trajectory planning using sinusoidal acceleration profiles, spline-based path approximation to allow lower curvature paths able to be traversed more quickly and/or able to be travelled with a constant velocity and optimized by iteratively calculating actuator saturation with no discontinuities, and the optimal tracking of a desired path (modeled with a time-varying ricatti equation)

Variability of USA East Coast surface total alkalinity distributions revealed by automated instrument measurements

Seawater total alkalinity (TA) is one important determinant used to monitor the ocean carbon cycle, whose spatial distributions have previously been characterized along the United States East Coast via discrete bottle samples. Using these data, several regional models for TA retrievals based on practical salinity (S) have been developed. Broad-scale seasonal or interannual variations, however, are not well resolved in these models and existing data are highly seasonally biased. This study reports findings from the first long duration deployment of a new, commercially available TA titrator aboard a research vessel and the continuous underway surface TA measurements produced. The instrument, operated on seven East Coast USA cruises during six months in 2017 and for two months in 2018 on the summertime East Coast Ocean Acidification survey (ECOA-2), collected a total of nearly 11,000 surface TA measurements. Data from these efforts, along with a newly synthesized set of more than 11,000 regional surface TA observations, are analyzed to re-examine distributions of TA and S along the United States East Coast. Overall, regional distributions of S and TA generally agreed with prior findings, but linear TA:S regressions varied markedly over time and deviated from previously developed models. This variability is likely due to a combination of biological, seasonal, and episodic influences and indicates that substantial errors of ±10–20 μmol kg−1 in TA estimation from S can be expected due to these factors. This finding has likely implications for numerical ecosystem modeling and inorganic carbon system calculations. New results presented in this paper provide refined surface TA:S relationships, present more data in space and time, and improve TA modeling uncertainty

Temporal and spatial dynamics of CO2 air-sea flux in the Gulf of Maine

Ocean surface layer carbon dioxide (CO2) data collected in the Gulf of Maine from 2004 to 2008 are presented. Monthly shipboard observations are combined with additional higher‐resolution CO2 observations to characterize CO2 fugacity ( fCO2) and CO2 flux over hourly to interannual time scales. Observed fCO2 andCO2 flux dynamics are dominated by a seasonal cycle, with a large spring influx of CO2 and a fall‐to‐winter efflux back to the atmosphere. The temporal results at inner, middle, and outer shelf locations are highly correlated, and observed spatial variability is generally small relative to the monthly to seasonal temporal changes. The averaged annual flux is in near balance and is a net source of carbon to the atmosphere over 5 years, with a value of +0.38 mol m−2 yr−1. However, moderate interannual variation is also observed, where years 2005 and 2007 represent cases of regional source (+0.71) and sink (−0.11) anomalies. We use moored daily CO2 measurements to quantify aliasing due to temporal undersampling, an important error budget term that is typically unresolved. The uncertainty of our derived annual flux measurement is ±0.26 mol m−2 yr−1 and is dominated by this aliasing term. Comparison of results to the neighboring Middle and South Atlantic Bight coastal shelf systems indicates that the Gulf of Maine exhibits a similar annual cycle and range of oceanic fCO2 magnitude but differs in the seasonal phase. It also differs by enhanced fCO2 controls by factors other than temperature‐driven solubility, including biological drawdown, fall‐to‐winter vertical mixing, and river runoff

Complete Genome Sequences of Mycobacterium smegmatis Phages Chewbacca, Reptar3000, and Riparian, Isolated in Las Vegas, Nevada

Here, we present the complete genome sequences of Mycobacterium smegmatis phages Chewbacca, Reptar3000, and Riparian, isolated from soil in Las Vegas, NV. The phages were isolated and annotated by undergraduate students enrolled in the Phage Discovery course offered by the School of Life Sciences at the University of Nevada, Las Vega

Measuring quality in community nursing: A mixed methods study

AbstractBackgroundHigh-quality nursing care is crucial for patients with complex conditions and co-morbidities living at home, but such care is largely invisible to health planners and managers. Nursing care quality in acute settings is typically measured using a range of different quality measures; however, little is known about how service quality is measured in community nursing.ObjectiveTo establish which quality indicators are selected for community nursing; how these are selected and applied; and their usefulness to service users (patients and/or carers), commissioners and provider staff.DesignA mixed-methods study comprising three phases:1)A national survey of ‘Commissioning for Quality and Innovation’ indicators applied to community nursing care in 2014/2015. Data were analysed descriptively using SPSS 20.0.2)In-depth case study in five sites. Qualitative data were collected through observations, interviews, focus groups and documents. Thematic analysis was conducted using QSR NVivo 10.Findings from the first two phases were synthesised using a theoretical framework to examine how local and distal contexts affecting care provision impacted on selection and application of quality indicators for community nursing.3)Validity testing the findings and associated draft good practice guidance through a series of stakeholder engagement events held in venues across England.SettingThe national survey was conducted by telephone and e-mail. Each case study site comprised a Clinical Commissioning Group (CCG) and its associated provider of community nursing services.ParticipantsSurvey: 145 (68.7%) CCGs across England.Case study: NHS England national and regional quality leads (n=5); commissioners (n=19); provider managers (n=32); registered community nurses (n=45); adult patients (n=14) receiving care in their own homes and/or carers (n=7).FindingsA wide range of indicators was used nationally, with a major focus on organisational processes.Lack of nurse and service user involvement in indicator selection processes impacted negatively on their application and perceived usefulness. Indicator data collection was hampered by problematic IT software and connectivity and inter-organisational system incompatibility. Frontline staff considered indicators designed for acute settings inappropriate for use in community settings. Indicators did not reflect aspects of care such as time spent, kindness and respect, highly valued by frontline staff and service user participants.Workshop delegates (commissioners, provider managers, frontline staff and service users, n=242) endorsed the findings and draft good practice guidance.LimitationsOn-going service re-organisation during the study period affected access to participants in some sites. Limited available data precluded in-depth documentary analysis.ConclusionsCurrent quality indicators for community nursing are of limited use:Commissioners and provider managers should ensure that service users and frontline staff are involved in identifying and selecting indicators.Difficulties with connectivity and compatibility should be resolved before rolling new IT packages out into practice.Quality measures designed for acute settings should not be applied in community settings without modification.A mix of qualitative and quantitative methods should be used to determine service qualityFuture workResearch investigating appropriate modifications and associated costs of administering quality indicator schemes in integrated care settings.Funding detailsThe study was funded by the NIHR Health Service and Delivery Research programme