33 research outputs found
Recommended from our members
Condition and postrelease mortality of angled Northern Pike temporarily retained on stringers
Anglers typically use stringers to keep fish intended for harvest from spoiling or for high-grading purposes (i.e., culling). However, relatively few studies have examined the effects of temporary stringer retention on the physical condition and postrelease mortality of fish. In this study, our objective was to investigate the lethal and sublethal effects of temporarily retaining Northern Pike Esox lucius on stringers
Using a novel biologging approach to assess how different handling practices influence the post-release behaviour of Northern Pike across a wide range of body sizes
There is a growing body of research focused on how angled fish respond to catch-and-release (C&R). However, most of those studies do not span a wide range of body sizes for the targeted species. Physical injury and physiological responses to C&R can be size-dependent, and methods used for landing fish of different sizes vary. As such, studying the response to C&R across a range of fish sizes may help inform best practices that improve outcomes for released fish. Northern Pike (Esox lucius) widely ranges in body size. Anglers may land them by hand, cradle, or net, and they are often released voluntarily or to comply with regulations. We angled 25 Northern Pike (total length 620–1030 mm) from one population and recorded fight, handling, and unhooking times across landing methods (i.e., hand, cradle, net). Prior to release, a pop-off biologging package was temporarily affixed to each fish to monitor locomotor activity, depth, and water temperature during a 12-h period post-release to understand how the interaction of landing method and body size influenced post-release behaviour and short-term fate. Fight and handling time increased with increasing body size. Northern Pike landed with a cradle or net had shorter fight times but longer handling times, compared to fish landed by hand. Post-release locomotor activity was greater for larger fish and those landed with a net. Fish 775mm landed by hand had reduced locomotor activity compared to fish landed with a net. There was no post-release mortality observed. Collectively, anglers should use a net for Northern Pike >775 mm to avoid long fight times and reduce post-release exhaustion, but also attempt to reduce the extent of handling associated with fish landed by net
Recognition of the Major Histocompatibility Complex (MHC) class Ib molecule H2-Q10 by the natural killer cell receptor Ly49C
Murine natural killer (NK) cells are regulated by the interaction of Ly49 receptors with major histocompatibility complex class I molecules (MHC-I). Although the ligands for inhibitory Ly49 were considered to be restricted to classical MHC (MHC-Ia), we have shown that the non-classical MHC molecule (MHC-Ib) H2-M3 was a ligand for the inhibitory Ly49A. Here we establish that another MHC-Ib, H2-Q10, is a bona fide ligand for the inhibitory Ly49C receptor. H2-Q10 bound to Ly49C with a marginally lower affinity (∼5 μm) than that observed between Ly49C and MHC-Ia (H-2Kb/H-2Dd, both ∼1 μm), and this recognition could be prevented by cis interactions with H-2K in situ. To understand the molecular details underpinning Ly49·MHC-Ib recognition, we determined the crystal structures of H2-Q10 and Ly49C bound H2-Q10. Unliganded H2-Q10 adopted a classical MHC-I fold and possessed a peptide-binding groove that exhibited features similar to those found in MHC-Ia, explaining the diverse peptide binding repertoire of H2-Q10. Ly49C bound to H2-Q10 underneath the peptide binding platform to a region that encompassed residues from the α1, α2, and α3 domains, as well as the associated β2-microglobulin subunit. This docking mode was conserved with that previously observed for Ly49C·H-2Kb. Indeed, structure-guided mutation of Ly49C indicated that Ly49C·H2-Q10 and Ly49C·H-2Kb possess similar energetic footprints focused around residues located within the Ly49C β4-stand and L5 loop, which contact the underside of the peptide-binding platform floor. Our data provide a structural basis for Ly49·MHC-Ib recognition and demonstrate that MHC-Ib represent an extended family of ligands for Ly49 molecules
Exploring diurnal variation using piecewise linear splines:an example using blood pressure
Background: There are many examples of physiological processes that follow a circadian cycle and researchers are interested in alternative methods to illustrate and quantify this diurnal variation. Circadian blood pressure (BP) deserves additional attention given uncertainty relating to the prognostic significance of BP variability in relation to cardiovascular disease. However, the majority of studies exploring variability in ambulatory blood pressure monitoring (ABPM) collapse the data into single readings ignoring the temporal nature of the data. Advanced statistical techniques are required to explore complete variation over 24 h.
Methods: We use piecewise linear splines in a mixed-effects model with a constraint to ensure periodicity as a novel application for modelling daily blood pressure. Data from the Mitchelstown Study, a cross-sectional study of Irish adults aged 47–73 years (n = 2047) was utilized. A subsample (1207) underwent 24-h ABPM. We compared patterns between those with and without evidence of subclinical target organ damage (microalbuminuria). Results: We were able to quantify the steepest rise and fall in SBP, which occurred just after waking (2.23 mmHg/30 min) and immediately after falling asleep (−1.93 mmHg/30 min) respectively. The variation about an individual’s trajectory over 24 h was 12.3 mmHg (standard deviation). On average those with microalbuminuria were found to have significantly higher SBP (7.6 mmHg, 95% CI 5.0–10.1) after adjustment for age, sex and BMI. Including an interaction term between each linear spline and microalbuminuria did not improve model fit.
Conclusion: We have introduced a practical method for the analysis of ABPM where we can determine the rate of increase or decrease for different periods of the day. This may be particularly useful in examining chronotherapy effects of antihypertensive medication. It offers new measures of short-term BP variability as we can quantify the variation about an individual’s trajectory but also allows examination of the variation in slopes between individuals (random-effects)
Increasing frailty is associated with higher prevalence and reduced recognition of delirium in older hospitalised inpatients: results of a multi-centre study
Purpose:
Delirium is a neuropsychiatric disorder delineated by an acute change in cognition, attention, and consciousness. It is common, particularly in older adults, but poorly recognised. Frailty is the accumulation of deficits conferring an increased risk of adverse outcomes. We set out to determine how severity of frailty, as measured using the CFS, affected delirium rates, and recognition in hospitalised older people in the United Kingdom.
Methods:
Adults over 65 years were included in an observational multi-centre audit across UK hospitals, two prospective rounds, and one retrospective note review. Clinical Frailty Scale (CFS), delirium status, and 30-day outcomes were recorded.
Results:
The overall prevalence of delirium was 16.3% (483). Patients with delirium were more frail than patients without delirium (median CFS 6 vs 4). The risk of delirium was greater with increasing frailty [OR 2.9 (1.8–4.6) in CFS 4 vs 1–3; OR 12.4 (6.2–24.5) in CFS 8 vs 1–3]. Higher CFS was associated with reduced recognition of delirium (OR of 0.7 (0.3–1.9) in CFS 4 compared to 0.2 (0.1–0.7) in CFS 8). These risks were both independent of age and dementia.
Conclusion:
We have demonstrated an incremental increase in risk of delirium with increasing frailty. This has important clinical implications, suggesting that frailty may provide a more nuanced measure of vulnerability to delirium and poor outcomes. However, the most frail patients are least likely to have their delirium diagnosed and there is a significant lack of research into the underlying pathophysiology of both of these common geriatric syndromes
Using a novel biologging approach to assess how different handling practices influence the post-release behaviour of Northern Pike across a wide range of body sizes
There is a growing body of research focused on how angled fish respond to catch-and-release (C&R). However, most of those studies do not span a wide range of body sizes for the targeted species. Physical injury and physiological responses to C&R can be size-dependent, and methods used for landing fish of different sizes vary. As such, studying the response to C&R across a range of fish sizes may help inform best practices that improve outcomes for released fish. Northern Pike (Esox lucius) widely ranges in body size. Anglers may land them by hand, cradle, or net, and they are often released voluntarily or to comply with regulations. We angled 25 Northern Pike (total length 620–1030 mm) from one population and recorded fight, handling, and unhooking times across landing methods (i.e., hand, cradle, net). Prior to release, a pop-off biologging package was temporarily affixed to each fish to monitor locomotor activity, depth, and water temperature during a 12-h period post-release to understand how the interaction of landing method and body size influenced post-release behaviour and short-term fate. Fight and handling time increased with increasing body size. Northern Pike landed with a cradle or net had shorter fight times but longer handling times, compared to fish landed by hand. Post-release locomotor activity was greater for larger fish and those landed with a net. Fish 775mm landed by hand had reduced locomotor activity compared to fish landed with a net. There was no post-release mortality observed. Collectively, anglers should use a net for Northern Pike >775 mm to avoid long fight times and reduce post-release exhaustion, but also attempt to reduce the extent of handling associated with fish landed by net
Insights into the electric double-layer capacitance of two-dimensional electrically conductive metal-organic frameworks
Two-dimensional electrically conductive
metal-organic frameworks (MOFs) have emerged as promising model electrodes for
use in electric double-layer capacitors (EDLCs). However, a number of
fundamental questions about the behaviour of this class of materials in EDLCs
remain unanswered, including the effect of the identity of the metal node and
organic linker molecule on capacitive performance and the limitations of current
conductive MOFs in these devices relative to traditional activated carbon
electrode materials. Herein, we address both these questions via a detailed
study of the capacitive performance of the framework Cu3(HHTP)2
(HHTP = 2,3,6,7,10,11-hexahydroxytriphenylene) with an acetonitrile-based
electrolyte, finding a specific capacitance of 110 – 114 F g−1 at
current densities of 0.04 – 0.05 A g−1 and a modest rate
capability. By, directly comparing its
performance with the previously reported analogue, Ni3(HITP)2
(HITP = 2,3,6,7,10,11-hexaiminotriphenylene), we illustrate that capacitive
performance is largely independent of the identity of the metal node and
organic linker molecule in these nearly isostructural MOFs. Importantly, this
result suggests that EDLC performance in general is uniquely defined by the 3D
structure of the electrodes and the electrolyte, a significant finding not
demonstrated using traditional electrode materials. Finally, we probe the
limitations of Cu3(HHTP)2 in EDLCs, finding a limited cell
voltage window of 1.3 V and only a modest capacitance retention of 81 % over
30,000 cycles, both significantly lower than state-of-the-art porous carbons.
These important insights will aid the design of
future conductive MOFs with greater EDLC performances
Recommended from our members
Research data supporting "Insights into the electric double-layer capacitance of two-dimensional electrically conductive metal-organic frameworks"
This data is primarily related to the synthesis and characterisation of Cu₃(HHTP)₂, and its electrochemical characterisation in symmetric electric double-layer capacitors with 1 M NEt₄BF₄ in acetonitrile electrolyte. The data provided here consists of:
- CIF Files (contains information of the CIF files used during modelling and simulations. These can also be found at: https://doi.org/10.5281/zenodo.4694845).
- Conductivity Measurement Data (contains results from the measurements used to calculate conductivity values).
- Electrochemistry Data (contains CV data from 3-electrode cells; CV, GCD, EIS, and long-term cycling stability data from composite Cu₃(HHTP)₂ EDLCs with 1 M NEt₄BF₄ in acetonitrile electrolyte; CV, GCD, and EIS data from a Cu₃(HHTP)₂ EDLCs with 1 M NEt₄BF₄ in acetonitrile electrolyte; characterisation data for a YP50F EDLC with 1 M NEt₄BF₄ in acetonitrile; and characterisation data for an acetylene black EDLC with 1 M NEt₄BF₄ in acetonitrile).
- Elemental Analysis Data (contains elemental analysis data).
- Gas Sorption Data (.xlsx, .txt - contains results from gas sorption measurements).
- XANES Data (contains XANES data from powder samples of Cu₃(HHTP)₂, pristine Cu₃(HHTP)₂ electrodes, cycled Cu₃(HHTP)₂ electrodes from EDLCs, and standard samples).
- XRD Data (contains PXRD data).• Oppenheimer Studentship, School of the Physical Sciences, University of Cambridge.
• Royal Society University Research Fellowship (UF100278), Royal Society.
• UK Materials and Molecular Modelling Hub for computational resources, which is partially funded by EPSRC (EP/P020194/1 and EP/T022213/1).
• Royal Society PhD funding, Royal Society.
• Winton Programme for the Physics of Sustainability, University of Cambridge.
• BP Next Generation Fellowship, Yusuf Hamied Department of Chemistry, University of Cambridge.
• UKRI Future Leaders Fellowship (MR/T043024/1), UK Research and Innovation
Recommended from our members
Insights into the electric double-layer capacitance of two-dimensional electrically conductive metal-organic frameworks.
Two-dimensional electrically conductive metal-organic frameworks (MOFs) have emerged as promising model electrodes for use in electric double-layer capacitors (EDLCs). However, a number of fundamental questions about the behaviour of this class of materials in EDLCs remain unanswered, including the effect of the identity of the metal node and organic linker molecule on capacitive performance, and the limitations of current conductive MOFs in these devices relative to traditional activated carbon electrode materials. Herein, we address both these questions via a detailed study of the capacitive performance of the framework Cu3(HHTP)2 (HHTP = 2,3,6,7,10,11-hexahydroxytriphenylene) with an acetonitrile-based electrolyte, finding a specific capacitance of 110-114 F g-1 at current densities of 0.04-0.05 A g-1 and a modest rate capability. By directly comparing its performance with the previously reported analogue, Ni3(HITP)2 (HITP = 2,3,6,7,10,11-hexaiminotriphenylene), we illustrate that capacitive performance is largely independent of the identity of the metal node and organic linker molecule in these nearly isostructural MOFs. Importantly, this result suggests that EDLC performance in general is uniquely defined by the 3D structure of the electrodes and the electrolyte, a significant finding not demonstrated using traditional electrode materials. Finally, we probe the limitations of Cu3(HHTP)2 in EDLCs, finding a limited stable double-layer voltage window of 1 V and only a modest capacitance retention of 81% over 30 000 cycles, both significantly lower than state-of-the-art porous carbons. These important insights will aid the design of future conductive MOFs with greater EDLC performances.• Oppenheimer Studentship, School of the Physical Sciences, University of Cambridge.
• Royal Society University Research Fellowship (UF100278), Royal Society.
• UK Materials and Molecular Modelling Hub for computational resources, which is partially funded by EPSRC (EP/P020194/1 and EP/T022213/1).
• Royal Society PhD funding, Royal Society.
• Winton Programme for the Physics of Sustainability, University of Cambridge.
• BP Next Generation Fellowship, Yusuf Hamied Department of Chemistry, University of Cambridge.
• UKRI Future Leaders Fellowship (MR/T043024/1), UK Research and Innovation