455 research outputs found
Office Building Uses Ice Storage, Heat Recovery, and Cold-Air Distribution
Ice storage offers many opportunities
to use other tcchnologies, such as heat
recovery and cold-air distribution. In
fact, by using them, the designer can
improve the efficiency and lower the
construction cost of an ice system.
This paper presents a case study of a
large (550,000 square feet) office building
which combines these ideas into one HVAC
system. By integrating these technologies
to take advantage of the unique
characteristics of ice storage, the
engineers created a system that provided a
1-1/2 year simple payback. The system
reduces operating costs by over 0.22 per square
foot
Ordered spin-ice state in the geometrically frustrated metallic-ferromagnet Sm2Mo2O7
The recent discovery of Spin-ice is a spectacular example of non-coplanar
spin arrangements that can arise in the pyrochlore A2B2O7 structure. We present
magnetic and thermodynamic studies on the metallic-ferromagnet pyrochlore
Sm2Mo2O7. Our studies, carried out on oriented crystals, suggest that the Sm
spins have an ordered spin-ice ground state below about T* = 15 K. The
temperature- and field-evolution of the ordered spin-ice state are governed by
an antiferromagnetic coupling between the Sm and Mo spins. We propose that as a
consequence of a robust feature of this coupling, the tetrahedra aligned with
the external field adopt a "1-in, 3-out" spin structure as opposed to "3-in,
1-out" in dipolar spin ices, as the field exceeds a critical value
Single vibronic level emission spectroscopic studies of the ground state energy levels and molecular structures of jet-cooled HGeBr, DGeBr, HGeI, and DGeI
Single vibronic level dispersed fluorescence spectra of jet-cooled HGeBr, DGeBr, HGeI, and DGeI have been obtained by laser excitation of selected bands of the à A″1-X̃ A′1 electronic transition. The measured ground state vibrational intervals were assigned and fitted to anharmonicity expressions, which allowed the harmonic frequencies to be determined for both isotopomers. In some cases, lack of a suitable range of emission data necessitated that some of the anharmonicity constants and vibrational frequencies be estimated from those of HGeCl∕DGeCl and the corresponding silylenes (HSiX). Harmonic force fields were obtained for both molecules, although only four of the six force constants could be determined. The ground state effective rotational constants and force field data were combined to calculate average (rz) and approximate equilibrium (rze) structures. For HGeBr rze(GeH)=1.593(9)Å, rze(GeBr)=2.325(21)Å, and the bond angle was fixed at our CCSD(T)/aug-cc-pVTZ ab initio value of 93.6°. For HGeI we obtained rze(GeH)=1.589(1)Å, rze(GeI)=2.525(5)Å, and bond angle=93.2°. Franck-Condon simulations of the emission spectra using ab initio Cartesian displacement coordinates reproduce the observed intensity distributions satisfactorily. The trends in structural parameters in the halogermylenes and halosilylenes can be readily understood based on the electronegativity of the halogen substituent. ACKNOWLEDGMENT
Best practice considerations on the assessment of robotic assisted surgical systems:results from an international consensus expert panel
Background Health technology assessments (HTAs) of robotic assisted surgery (RAS) face several challenges in assessing the value of robotic surgical platforms. As a result of using different assessment methods, previous HTAs have reached different conclusions when evaluating RAS. While the number of available systems and surgical procedures is rapidly growing, existing frameworks for assessing MedTech provide a starting point, but specific considerations are needed for HTAs of RAS to ensure consistent results. This work aimed to discuss different approaches and produce guidance on evaluating RAS. Methods A consensus conference research methodology was adopted. A panel of 14 experts was assembled with international experience and representing relevant stakeholders: clinicians, health economists, HTA practitioners, policy makers, and industry. A review of previous HTAs was performed and seven key themes were extracted from the literature for consideration. Over five meetings, the panel discussed the key themes and formulated consensus statements. Results A total of ninety-eight previous HTAs were identified from twenty-five total countries. The seven key themes were evidence inclusion and exclusion, patient- and clinician-reported outcomes, the learning curve, allocation of costs, appropriate time horizons, economic analysis methods, and robotic ecosystem/wider benefits. Conclusions Robotic surgical platforms are tools, not therapies. Their value varies according to context and should be considered across therapeutic areas and stakeholders. The principles set out in this paper should help HTA bodies at all levels to evaluate RAS. This work may serve as a case study for rapidly developing areas in MedTech that require particular consideration for HTAs.</p
Online drug scenes and harm reduction from below as phronesis
This article presents a theoretical critique of notion of harm reduction on the basis of an empirical investigation of a variety of online manifestations of drug culture. Taking a multi-case study approach to drug use related forums, blogs and ‘story sites’ focused on NPS/’legal high’ use and non-medicinal prescription drug use, our analysis of data leads us to describe the culture of ‘harm reduction from below’ it reveals in terms the Aristotelian concept of phronesis. We argue that peer-to-peer co-creation of knowledge, sharing and support constitutes an emergent and constantly evolving form of ‘practical wisdom’ with respect to drugs. Drawing on Flyvbjerg’s (2001, 2007) accounts of phronetic social science as a practice, which proposes a permeable boundary between theoretical and practical inquiry, and Stenger’s (2005) account of the ‘collective voice from below’ as always embedded within an ‘ecology of practices’, we offer an interpretation of the online dimension of drug taking in terms of drug users’ shared aim of ‘doing drugs well’. The investigation of online life in terms of the multiple contexts of drug-related communicative exchange thus allows us to identify harm reduction from below as an ethical practice inherent to a variety of online drug scenes themselves
Experiences of being exposed to intimate partner violence during pregnancy
In this study a phenomenological approach was used in order to enter deeply into the experience of living with violence during pregnancy. The aim of the study was to gain a deeper understanding of women's experiences of being exposed to intimate partner violence (IPV) during pregnancy. The data were collected through in-depth interviews with five Norwegian women; two during pregnancy and three after the birth. The women were between the age of 20 and 38 years. All women had received support from a professional research and treatment centre. The essential structure shows that IPV during pregnancy is characterized by difficult existential choices related to ambivalence. Existential choices mean questioning one's existence, the meaning of life as well as one's responsibility for oneself and others. Five constituents further explain the essential structure: Living in unpredictability, the violence is living in the body, losing oneself, feeling lonely and being pregnant leads to change. Future life with the child is experienced as a possibility for existential change. It is important for health professionals to recognize and support pregnant women who are exposed to violence as well as treating their bodies with care and respect
Access and utilisation of maternity care for disabled women who experience domestic abuse:a systematic review
BACKGROUND: Although disabled women are significantly more likely to experience domestic abuse during pregnancy than non-disabled women, very little is known about how maternity care access and utilisation is affected by the co-existence of disability and domestic abuse. This systematic review of the literature explored how domestic abuse impacts upon disabled women’s access to maternity services. METHODS: Eleven articles were identified through a search of six electronic databases and data were analysed to identify: the factors that facilitate or compromise access to care; the consequences of inadequate care for pregnant women’s health and wellbeing; and the effectiveness of existing strategies for improvement. RESULTS: Findings indicate that a mental health diagnosis, poor relationships with health professionals and environmental barriers can compromise women’s utilisation of maternity services. Domestic abuse can both compromise, and catalyse, access to services and social support is a positive factor when accessing care. Delayed and inadequate care has adverse effects on women’s physical and psychological health, however further research is required to fully explore the nature and extent of these consequences. Only one study identified strategies currently being used to improve access to services for disabled women experiencing abuse. CONCLUSIONS: Based upon the barriers and facilitators identified within the review, we suggest that future strategies for improvement should focus on: understanding women’s reasons for accessing care; fostering positive relationships; being women-centred; promoting environmental accessibility; and improving the strength of the evidence base
DNA methylation on N6-adenine in mammalian embryonic stem cells
It has been widely accepted that 5-methylcytosine is the only form of DNA methylation in mammalian genomes. Here we identify N6-methyladenine as another form of DNA modification in mouse embryonic stem cells. Alkbh1 encodes a demethylase for N6-methyladenine. An increase of N6-methyladenine levels in Alkbh1-deficient cells leads to transcriptional silencing. N6-methyladenine deposition is inversely correlated with the evolutionary age of LINE-1 transposons; its deposition is strongly enriched at young (6 million years old) L1 elements. The deposition of N6-methyladenine correlates with epigenetic silencing of such LINE-1 transposons, together with their neighbouring enhancers and genes, thereby resisting the gene activation signals during embryonic stem cell differentiation. As young full-length LINE-1 transposons are strongly enriched on the X chromosome, genes located on the X chromosome are also silenced. Thus, N6-methyladenine developed a new role in epigenetic silencing in mammalian evolution distinct from its role in gene activation in other organisms. Our results demonstrate that N6-methyladenine constitutes a crucial component of the epigenetic regulation repertoire in mammalian genomes
Perspectives on supporting fathers affected by postnatal depression and a history of violence
Intimate partner violence in the perinatal period is a significant problem that remains underscreened, underdiagnosed and undertreated. The establishment of evidence-based guidelines to enable health visitors to identify couples experiencing violence and offer appropriate support has been hampered by the complex interplay between maternal and paternal mental health problems and violence. This study explored the experiences of UK fathers who voluntarily engaged with services designed to eliminate their ideation to violence. The findings indicate that the tendency to violence is increased by stresses associated with the transition to parenthood. Men felt pressured by concerns for their partner's mental health, changes in the relationship, sleep disturbances and the burden of infant care they assumed when the mother was unable to cope. Health visitors are ideally placed to assess for factors linked to the emergence of violence and put in place interventions to minimise occurrence
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