The modern use of the extended humeral head (cuff tear arthropathy) hemiarthroplasty.

Today, the treatment of osteoarthritis in the rotator cuff-deficient population is largely dominated by reverse shoulder arthroplasty (RSA). Despite the popularity of and increased familiarity with this procedure, the complication rate of RSA remains significant. An extended humeral head hemiarthroplasty may provide a less invasive alternative for select patients with cuff tear arthropathy (CTA) and preserved glenohumeral active elevation. With the indications for reverse arthroplasty expanding to younger patients, there are concerns about the longevity of this implant, as well as the associated revision burden. In the setting of failed RSA, the bone stock available for glenosphere baseplate fixation can be inadequate for reimplantation. The treatment strategies for complex shoulder deformities and failed RSA are limited by patient-specific issues, such as anatomy and risk factors. In this review, we discuss the potential role of extended humeral head hemiarthroplasty (CTA hemiarthroplasty) as a primary surgical option in select patients (1) who have preserved elevation \u3e 90°, (2) who have maintained stability (intact coracoacromial ligament), and (3) who desire to circumvent the complications associated with RSA. Furthermore, CTA hemiarthroplasty may be used for severe glenoid erosion, for a fragmented acromion, and in the revision setting for failed RSA aimed at a reliable salvage procedure

Long-term decline and geographical variation in the numbers of moulting Common Eiders Somateria mollissima in Shetland

The 1977 survey was funded and led by the Nature Conservancy Council. Surveys from 1980 to 2019 were funded by the Sullom Voe Association and led by the Shetland Oil Terminal Environmental Advisory Group (SOTEAG).Capsule: Numbers of moulting Common Eiders Somateria mollissima counted in Shetland during surveys from 1977 to 2019 decreased from approximately 14,500 to an estimated 3600 individuals, a 75% population decline. Aims: To report results of extensive surveys of Eiders across Shetland during the annual complete moult period, review historical surveys, and evaluate long-term population changes and the possible underlying causes for change. Methods: Extensive areas of coastal Shetland were surveyed for Eiders during the annual moult period from July to September, every one to five years from 1977 to 2019. Spatial sampling was variable between surveys from 1977 to 1993 but more systematic and standardised during all surveys from 1996 to 2019. Overall population change, changes in numbers of birds within areas categorised as either exposed or sheltered coast, and change in the proportion of adult males to females/juveniles were assessed. Results: Surveys from 1977 to 1993 indicated a 55% decrease, from approximately 14,500–6500 individuals, and surveys from 1996 to 2019 showed a 45% decrease, from an estimated 6700–3600 individuals, indicating an overall population decrease of approximately 75% from 1977 to 2019. From 1996 to 2019, Eider numbers decreased in areas of exposed coast by approximately 90% but increased by at least 70% in the more sparsely populated sheltered areas, and the overall proportion of adult males to females/juveniles reduced by one-third. Conclusion: From 1977 to 2019, a substantial decline of approximately 75% occurred in the Shetland Eider population at the time of moult. Shetland Eiders are not S. m. mollissima but morphologically and genetically akin to S. m. faeroeensis, the Faroese subspecies, the rarest subspecies worldwide, so this decline is of high conservation concern. Causes of the decline largely remain unknown, but ecological datasets on Shetland Eiders are few and detailed studies, including remote tracking of individuals’ movements throughout the year, would be worthwhile.Publisher PDFPeer reviewe

Time course of changes in torque and neuromuscular parameters during a sustained isometric forearm flexion task to fatigue anchored to a constant rating of perceived exertion

Objective: This study examined the time course of changes in torque and electromyographic (EMG) and mechanomyographic (MMG) responses during a sustained isometric task anchored to a constant perception of exertion (RPE). Methods: Twelve college-aged men performed an isometric forearm flexion task to failure anchored to RPE=7 (OMNI-RES scale). The amplitude (AMP) and frequency (MPF) of the EMG and MMG signals from the biceps brachii were recorded. Repeated measures ANOVAs were used to examine differences for the normalized (%MVIC) torque and neuromuscular parameters. Results: The time to task failure (TTF) was 678.0±468.1s. Torque decreased significantly (p\u3c0.001, ηp 2=0.774) across time and all subjects reduced torque to zero. Post-hoc comparisons indicated that the torque values from 20–100% TTF were less than the value at 10% TTF. There were no significant (p\u3e0.05) changes from 10–100% TTF for the EMG and MMG parameters. Conclusion: We hypothesize that RPE was maintained by various mechanisms throughout the task: group III/IV afferent neurons, adequate blood flow, and a combination of reduced contractile efficiency, collective afferent feedback (group III/IV afferents) from muscles involved with forearm flexion, and motivation that resulted in an initial decrease, plateau, and final decline in torque to zero, respectively

Ipsilateral and Contralateral Torque Responses to Bilateral and Unilateral Maximal, Fatiguing, Isokinetic Leg Extensions

Background: Few studies have compared performance fatigability (PF) for bilateral versus unilateral isokinetic tasks. Objectives: The purpose of this study was to examine: Mode- specific testing responses to isokinetic fatigue, differences in PF between bilateral and unilateral leg extensions, and the effects of fatiguing, unilateral, dynamic leg extensions on contralateral isokinetic peak torque (PT) and maximal voluntary isometric contraction (MVIC). Methods: Eight men (mean ± SD: age= 22.5 ± 2.5 yr.) completed pre- and post-testing for PT and MVIC following 50 bilateral, unilateral right or left leg maximal, isokinetic leg extensions at 180°·s-1, on three separate days. Fatigue-induced decreases in PT and MVIC were used to quantify PF. The data were analyzed with a 4-way repeated measures ANOVA, follow up, and post-hoc analyses. Results: The results indicated that there were no differences (p \u3e 0.05) in PF for the bilateral versus unilateral fatiguing tasks, decreases in PT (p \u3c 0.001 - 0.016; d = 0.54 - 2.58) and MVIC (p \u3c 0.001 - 0.006; η2p = 0.682 - 0.962) for the exercised legs during unilateral fatigue, and a contralateral increase (p = 0.007) in PT following the right leg fatiguing task. Conclusion: The results indicated that PT was more sensitive to fatiguing isokinetic tasks than was MVIC. In addition, there was a facilitation of PT in the contralateral leg following unilateral right leg fatigue. The differences in PT and MVIC testing may be attributable to the timing and/ or relative contributions of peripheral and central fatigue

Performance analysis of d-dimensional quantum cryptography with mode-dependent diffraction

We analyze the degraded performance of QKD that results from mode-dependent diffraction in spatial-mode-encoded QKD systems. A pre-compensation method is proposed to solve this problem without sacrificing the security

The Effects of Anchor Schemes on Performance Fatigability, Neuromuscular Responses and the Perceived Sensations That Contributed to Task Termination

The present study examined the effect of anchor schemes on the time to task failure (TTF), performance fatigability, neuromuscular responses, and the perceived sensations that contributed to task termination following the sustained, isometric forearm flexion tasks. Eight women completed sustained, isometric forearm flexion tasks anchored to RPE = 8 (RPEFT) and the torque (TRQFT) that corresponded to RPE = 8. The subjects performed pre-test and post-test maximal isometric contractions to quantify performance fatigability and changes in electromyographic amplitude (EMG AMP) and neuromuscular efficiency (NME). In addition, the subjects completed a post-test questionnaire (PTQ) to quantify the contributions of perceived sensations to task termination. Repeated measure ANOVAs were used to assess the mean differences for TTF, performance fatigability, and neuromuscular responses. Wilcoxon Signed Rank Tests were used to assess the differences between anchor schemes for the average values from the PTQ item scores. For TTF, the RPEFT was longer than the TRQFT (174.9 ± 85.6 vs. 65.6 ± 68.0 s; p = 0.006). Collapsed across the anchor scheme, there were decreases in torque (23.7 ± 5.5 Nm vs. 19.6 ± 4.9 Nm; p \u3c 0.001) and NME (1.00 ± 0.00 vs. 0.76 ± 0.15; p = 0.003). There were no significant (p \u3e 0.577) changes for EMG AMP. For the PTQ, there were no differences (p \u3e 0.05) between anchor schemes. There were, however, inter-individual differences in the response scores. The current findings indicated that performance fatigability was likely due to peripheral fatigue (based on NME), not central fatigue (based on EMG AMP). Furthermore, the use of a PTQ may serve as a simple tool to assess the contributions of perceived sensations to task termination

Charting the internal landscape: Affect associated with thoughts about major life domains explains life satisfaction

Studies of happiness have examined the impact of demographics, personality and emotions accompanying daily activities on life satisfaction. We suggest that how people feel while contemplating aspects of their lives, including their weight, children and future prospects, is a promising yet uncharted territory within the internal landscape of life satisfaction. In a sample of 811 American women, we assessed women’s feelings when thinking about major life domains and frequency of thoughts about each domain. Regression and dominance analyses showed that emotional valence of thoughts about major life domains was an important predictor of current and prior life satisfaction, surpassing, in descending order, demographics, participants’ feelings during recent activities, and their neuroticism and extraversion scores. Domains thought about more frequently were often associated with greater emotional valence. These results suggest that life satisfaction may be improved by modifying emotional valence and frequency of thoughts about life domains. Moreover, these thoughts appear to be an important and relatively stable component of well-being worthy of further study

Performance Fatigability and Neuromuscular Responses Are Not Joint Angle Specific Following a Sustained Isometric Forearm Flexion Task Anchored to a High Perceptual Intensity in Women

Objectives: To examine the effects of joint angle (JA) on maximal voluntary isometric contractions (MVIC) and neuromuscular responses following a sustained, isometric forearm flexion task anchored to a rating of perceived exertion (RPE) of 8 (RPE=8). Methods: Nine women (age: 20.7±2.9 yrs; height: 168.8±7.2 cm; body mass: 66.3±6.8 kg) performed 2,3s forearm flexion MVICs at JAs of 75°, 100°, and 125° prior to and following a sustained, isometric forearm flexion task anchored to RPE=8 to task failure (torque reduced to zero) at JA100. Electromyographic (EMG) and mechanomyographic (MMG) signals were recorded from the biceps brachii. Results: The MVIC at JA100 (collapsed across Time) was significantly greater (pppp\u3e0.05) differences between Time or JAs. Pre-test neuromuscular efficiency (normalized MVIC/normalized EMG AMP) was significantly greater (p=0.005) than post-test. Conclusion: Following a sustained, isometric forearm flexion task anchored to RPE=8 at JA100, the fatigue-induced MVIC and neuromuscular responses were not affected by JA

Fatiguing Joint Angle Does Not Influence Torque and Neuromuscular Responses Following Sustained, Isometric Forearm Flexion Tasks Anchored to Perceptual Intensity in Men

This study examined the effects of joint angle (JA) on maximal voluntary isometric contraction (MVIC) and neuromuscular responses following fatiguing tasks anchored to RPE. Nine men (mean ± SD: age = 20.7 ± 1.2 yrs) performed forearm flexion MVICs at elbow JAs of 75o and 125o before and after sustained, isometric forearm flexion tasks to failure at fatiguing joint angles (FJA) of 75o and 125o anchored to RPE = 8. The amplitude and frequency of the electromyographic and mechanomyographic signals were recorded. Neuromuscular efficiency was calculated by dividing normalized torque by normalized electromyographic amplitude. A dependent t-test was used to assess the mean difference for time to task failure (TTF) between FJA. Repeated measure ANOVAs were used to assess mean differences for pre-test to post-test MVIC and neuromuscular responses. There was no significant difference between FJA for TTF (p = 0.223). The MVIC (collapsed across FJA and MVIC JA) decreased from pre-test to post-test (51.1 ± 5.0 vs. 45.3 ± 5.6 Nm, p \u3c 0.001). Normalized neuromuscular parameters remained unchanged (p \u3e 0.05). The FJA resulted in similar torque and neuromuscular responses, and the decreases in MVIC were not tracked by changes in the neuromuscular parameters. Thus, the neuromuscular parameters were not sensitive to fatigue, and pre-test to post-test measures may be compared between different FJA