Manchester Metropolitan University

About: Manchester Metropolitan University is a education organization based out in Manchester, Manchester, United Kingdom. It is known for research contribution in the topics: Population & Context (language use). The organization has 5435 authors who have published 16202 publications receiving 442561 citations. The organization is also known as: Manchester Polytechnic & MMU.

Time reversible and symplectic integrators for molecular dynamics simulations of rigid molecules

Abstract: Molecular dynamics integrators are presented for translational and rotational motion of rigid molecules in microcanonical, canonical, and isothermal-isobaric ensembles. The integrators are all time reversible and are also, in some approaches, symplectic for the microcanonical ensembles. They are developed utilizing the quaternion representation on the basis of the Trotter factorization scheme using a Hamiltonian formalism. The structure is similar to that of the velocity Verlet algorithm. Comparison is made with standard integrators in terms of stability and it is found that a larger time step is stable with the new integrators. The canonical and isothermal-isobaric molecular dynamics simulations are defined by using a chain thermostat approach according to generalized Nose–Hoover and Andersen methods.

Anxiety disorders in patients with COPD: a systematic review.

Abstract: BACKGROUND: There is a growing interest in the role of comorbid anxiety in patients with COPD. Comorbid anxiety has a major impact on physical functioning, health-related quality of life, and healthcare utilization. However, the prevalence of clinical anxiety, particularly specific anxiety diagnoses, in patients with COPD remains unclear. OBJECTIVE: We performed a systematic review of studies that report the prevalence of clinical anxiety and specific anxiety disorders in patients with COPD. METHODS: We searched for articles in CINAHL, EMBASE, MEDLINE, and PsycINFO, from 1966 to January 31, 2012, with a focus on studies that utilized clinical interviews for a robust psychiatric diagnosis in patients with COPD. RESULTS: Of 410 studies identified, 10 met the inclusion criteria for review. The studies had small to modest sample sizes (n = 20–204) and included mainly male COPD subjects (71% male). The prevalence of clinical anxiety ranged from 10–55% among in-patients and 13–46% among out-patients with COPD. The reported prevalence of specific anxiety disorders ranged considerably, and included generalized anxiety disorder (6–33%), panic disorder (with and without agoraphobia) (0–41%), specific phobia (10–27%), and social phobia (5–11%). Women were significantly more likely to have a clinical anxiety disorder, particularly specific phobia and panic disorder. CONCLUSIONS: There is a high prevalence of clinical anxiety in patients with COPD. Social phobia and specific phobia appear to be particularly prevalent, yet they have received little attention within existing literature. Further research into effective management and screening for clinical anxiety disorders is warranted.

Abundance determines the functional role of bacterial phylotypes in complex communities.

Abstract: Bacterial communities are essential for the functioning of the Earth's ecosystems 1 . A key challenge is to quantify the functional roles of bacterial taxa in nature to understand how the properties of ecosystems change over time or under different environmental conditions 2 . Such knowledge could be used, for example, to understand how bacteria modulate biogeochemical cycles 3 , and to engineer bacterial communities to optimize desirable functional processes 4 . Communities of bacteria are, however, extraordinarily complex with hundreds of interacting taxa in every gram of soil and every millilitre of pond water 5 . Little is known about how the tangled interactions within natural bacterial communities mediate ecosystem functioning, but high levels of bacterial diversity have led to the assumption that many taxa are functionally redundant 6 . Here, we pinpoint the bacterial taxa associated with keystone functional roles, and show that rare and common bacteria are implicated in fundamentally different types of ecosystem functioning. By growing hundreds of bacterial communities collected from a natural aquatic environment (rainwater-filled tree holes) under the same environmental conditions, we show that negative statistical interactions among abundant phylotypes drive variation in broad functional measures (respiration, metabolic potential, cell yield), whereas positive interactions between rare phylotypes influence narrow functional measures (the capacity of the communities to degrade specific substrates). The results alter our understanding of bacterial ecology by demonstrating that unique components of complex communities are associated with different types of ecosystem functioning.

Active, non‐spring‐like muscle movements in human postural sway: how might paradoxical changes in muscle length be produced?

Abstract: In humans, during standing the calf muscles soleus and gastrocnemius actively prevent forward toppling about the ankles. It has been generally assumed that these postural muscles behave like springs with dynamic stiffness reflecting their mechanical properties, reflex gain including higher derivatives, and central control. Here, for the first time, we have used an ultrasound scanner and automated image analysis to record the tiny muscular movements occurring in normal standing. This new, non-invasive technique resolves changes in muscle length as small as 10 mum without disturbing the standing process. This technical achievement has allowed us to test the long-established mechano-reflex, muscle spring hypothesis that muscle length changes in a spring-like way during sway of the body. Our results contradict that hypothesis. Muscle length changes in a non-spring-like manner: on average, shortening during forward sway and lengthening during backwards sway (paradoxical movements). This counter-intuitive result is a consequence of the fact that calf muscles generate tension through a series elastic component (SEC, Achilles tendon and foot) which limits maximal ankle stiffness to 92 +/- 20% of that required to balance the body. Paradoxical movements cannot be generated by stretch reflexes with constant intrafusal drive but might be produced by reflex coupling of extrafusal (alpha) and intrafusal (beta, gamma) drive or by positive force feedback. Standing requires the predictive ability to produce the observed muscle movements preceded (110 +/- 50 ms) by corresponding changes in integrated EMG signal. We suggest higher level anticipatory control is more plausible.

Enchanted Spaces: The Séance, Affect, and Geographies of Religion

Abstract: This article calls for the geographies of religion and belief to attend to the sensuous, vitalistic, and affectual forces through which spaces of the religious, spiritual, and the sacred are performed Not only do we need to recognize and explore these forces themselves, but our analyses of how religious-sacred spaces (re)produce or challenge societal and cultural discourses can also be enhanced if we focus on affect and embodiment Through the case study of nineteenth-century spiritualism and the key space of the seance, these points are exemplified and substantiated Finally, I explore some of the implications of recognizing these sensations for the study of geographies of religion and belief through Bennett's (2001) nonreductionist and nonteleological notion of enchantment