Microwave amplification with nanomechanical resonators

Sensitive measurement of electrical signals is at the heart of modern science and technology. According to quantum mechanics, any detector or amplifier is required to add a certain amount of noise to the signal, equaling at best the energy of quantum fluctuations. The quantum limit of added noise has nearly been reached with superconducting devices which take advantage of nonlinearities in Josephson junctions. Here, we introduce a new paradigm of amplification of microwave signals with the help of a mechanical oscillator. By relying on the radiation pressure force on a nanomechanical resonator, we provide an experimental demonstration and an analytical description of how the injection of microwaves induces coherent stimulated emission and signal amplification. This scheme, based on two linear oscillators, has the advantage of being conceptually and practically simpler than the Josephson junction devices, and, at the same time, has a high potential to reach quantum limited operation. With a measured signal amplification of 25 decibels and the addition of 20 quanta of noise, we anticipate near quantum-limited mechanical microwave amplification is feasible in various applications involving integrated electrical circuits.Comment: Main text + supplementary information. 14 pages, 3 figures (main text), 18 pages, 6 figures (supplementary information

What happened to anti-malarial markets after the Affordable Medicines Facility-malaria pilot? Trends in ACT availability, price and market share from five African countries under continuation of the private sector co-payment mechanism

BACKGROUND: The private sector supplies anti-malarial treatment for large proportions of patients in sub-Saharan Africa. Following the large-scale piloting of the Affordable Medicines Facility-malaria (AMFm) from 2010 to 2011, a private sector co-payment mechanism (CPM) provided continuation of private sector subsidies for quality-assured artemisinin combination therapies (QAACT). This article analyses for the first time the extent to which improvements in private sector QAACT supply and distribution observed during the AMFm were maintained or intensified during continuation of the CPM through 2015 in Kenya, Madagascar, Nigeria, Tanzania and Uganda using repeat cross-sectional outlet survey data. RESULTS: QAACT market share in all five countries increased during the AMFm period (p < 0.001). According to the data from the last ACTwatch survey round, in all study countries except Madagascar, AMFm levels of private sector QAACT availability were maintained or improved. In 2014/15, private sector QAACT availability was greater than 70% in Nigeria (84.3%), Kenya (70.5%), Tanzania (83.0%) and Uganda (77.1%), but only 11.2% in Madagascar. QAACT market share was maintained or improved post-AMFm in Nigeria, Tanzania and Uganda, but statistically significant declines were observed in Kenya and Madagascar. In 2014/5, QAACT market share was highest in Kenya and Uganda (48.2 and 47.5%, respectively) followed by Tanzania (39.2%), Nigeria (35.0%), and Madagascar (7.0%). Four of the five countries experienced significant decreases in median QAACT price during the AMFm period. Private sector QAACT prices were maintained or further reduced in Tanzania, Nigeria and Uganda, but prices increased significantly in Kenya and Madagascar. SP prices were consistently lower than those of QAACT in the AMFm period, with the exception of Kenya and Tanzania in 2011, where they were equal. In 2014/5 QAACT remained two to three times more expensive than the most popular non-artemisinin therapy in all countries except Tanzania. CONCLUSIONS: Results suggest that a private sector co-payment mechanism for QAACT implemented at national scale for 5 years was associated with positive and sustained improvements in QAACT availability, price and market share in Nigeria, Tanzania and Uganda, with more mixed results in Kenya, and few improvements in Madagascar. The subsidy mechanism as implemented over time across countries was not sufficient on its own to achieve optimal QAACT uptake. Supporting interventions to address continued availability and distribution of non-artemisinin therapies, and to create demand for QAACT among providers and consumers need to be effectively implemented to realize the full potential of this subsidy mechanism. Furthermore, there is need for comprehensive market assessments to identify contemporary market barriers to high coverage with both confirmatory testing and appropriate treatment

Quantum nondemolition measurement of mechanical motion quanta

The fields of opto- and electromechanics have facilitated numerous advances in the areas of precision measurement and sensing, ultimately driving the studies of mechanical systems into the quantum regime. To date, however, the quantization of the mechanical motion and the associated quantum jumps between phonon states remains elusive. For optomechanical systems, the coupling to the environment was shown to preclude the detection of the mechanical mode occupation, unless strong single photon optomechanical coupling is achieved. Here, we propose and analyse an electromechanical setup, which allows to overcome this limitation and resolve the energy levels of a mechanical oscillator. We find that the heating of the membrane, caused by the interaction with the environment and unwanted couplings, can be suppressed for carefully designed electromechanical systems. The results suggest that phonon number measurement is within reach for modern electromechanical setups.Comment: 8 pages, 5 figures plus 24 pages, 11 figures supplemental materia

Participant Observation as Ethnography or Ethnography as Participant Observation in Organizational Research

There is a strong tradition of observational research in most areas of the social sciences, especially in Anthropology and Sociology. However, in business and management research observation is often seen as a poor relative to questionnaire surveys and qualitative interviewing. This chapter discusses the use of observational techniques especially for less experienced researchers planning their first major investigation, exploring the difference between participant and non-participant approaches, different techniques of data collection, recording and analysis. Rather than seeking to provide a full guide to conducting participant observation, an impractical task in a single chapter, this offering discusses some of the key issues facing researchers in Business and Management who choose to conduct this sort of research, exploring different approaches to participant observation and some of the ethical and practical challenges associated with the collection and analysis of observational data. The chapter draws on the author’s experience of conducting participant observation in organizations with examples of both employee (Sandiford and Seymour, 2002; Seymour and Sandiford, 2013) and customer perspectives (Sandiford and Divers, 2011). It will also draw from ‘classic’ observational studies such as Mars and Nicod (1984) and more recent examples such as Watson and Watson (2012).Peter John Sandifor

Do anti-malarials in Africa meet quality standards? The market penetration of non quality-assured artemisinin combination therapy in eight African countries

BACKGROUND: Quality of artemisinin-based combination therapy (ACT) is important for ensuring malaria parasite clearance and protecting the efficacy of artemisinin-based therapies. The extent to which non quality-assured ACT (non-QAACT), or those not granted global regulatory approval, are available and used to treat malaria in endemic countries is poorly documented. This paper uses national and sub-national medicine outlet surveys conducted in eight study countries (Benin, Kinshasa and Kantanga [Democratic Republic of the Congo, DRC], Kenya, Madagascar, Nigeria, Tanzania, Uganda and Zambia) between 2009 and 2015 to describe the non-QAACT market and to document trends in availability and distribution of non-QAACT in the public and private sector. RESULTS: In 2014/15, non-QAACT were most commonly available in Kinshasa (83%), followed by Katanga (53%), Nigeria (48%), Kenya (42%), and Uganda (33%). Non-QAACT accounted for 20% of the market share in the private sector in Kenya, followed by Benin and Uganda (19%), Nigeria (12%) and Zambia (8%); this figure was 27% in Katanga and 40% in Kinshasa. Public sector non-QAACT availability and distribution was much lower, with the exception of Zambia (availability, 85%; market share, 32%). Diverse generics and formulations were available, but non-QAACT were most commonly artemether-lumefantrine (AL) or dihydroartemisinin-piperaquine (DHA PPQ), in tablet formulation, imported, and distributed in urban areas at either pharmacies or drug stores. The number of unique manufacturers supplying non-QAACT to each country ranged from 9 in Uganda to 92 in Nigeria. CONCLUSIONS: Addressing the availability and distribution of non-QAACT will require effective private sector engagement and evidence-based strategies to address provider and consumer demand for these products. Given the variation in non-QAACT markets observed across the eight study countries, active efforts to limit registration, importation and distribution of non-QAACT must be tailored to the country context, and will involve addressing complex and challenging aspects of medicine registration, private sector pharmaceutical regulation, local manufacturing and drug importation. These efforts may be critical not only to patient health and safety, but also to effective malaria control and protection of artemisinin drug efficacy in the face of spreading resistance

Multi-parallel qPCR provides increased sensitivity and diagnostic breadth for gastrointestinal parasites of humans: field-based inferences on the impact of mass deworming

BACKGROUND: Although chronic morbidity in humans from soil transmitted helminth (STH) infections can be reduced by anthelmintic treatment, inconsistent diagnostic tools make it difficult to reliably measure the impact of deworming programs and often miss light helminth infections. METHODS: Cryopreserved stool samples from 796 people (aged 2-81 years) in four villages in Bungoma County, western Kenya, were assessed using multi-parallel qPCR for 8 parasites and compared to point-of-contact assessments of the same stools by the 2-stool 2-slide Kato-Katz (KK) method. All subjects were treated with albendazole and all Ascaris lumbricoides expelled post-treatment were collected. Three months later, samples from 633 of these people were re-assessed by both qPCR and KK, re-treated with albendazole and the expelled worms collected. RESULTS: Baseline prevalence by qPCR (n = 796) was 17 % for A. lumbricoides, 18 % for Necator americanus, 41 % for Giardia lamblia and 15% for Entamoeba histolytica. The prevalence was <1% for Trichuris trichiura, Ancylostoma duodenale, Strongyloides stercoralis and Cryptosporidium parvum. The sensitivity of qPCR was 98% for A. lumbricoides and N. americanus, whereas KK sensitivity was 70% and 32%, respectively. Furthermore, qPCR detected infections with T. trichiura and S. stercoralis that were missed by KK, and infections with G. lamblia and E. histolytica that cannot be detected by KK. Infection intensities measured by qPCR and by KK were correlated for A. lumbricoides (r = 0.83, p < 0.0001) and N. americanus (r = 0.55, p < 0.0001). The number of A. lumbricoides worms expelled was correlated (p < 0.0001) with both the KK (r = 0.63) and qPCR intensity measurements (r = 0.60). CONCLUSIONS: KK may be an inadequate tool for stool-based surveillance in areas where hookworm or Strongyloides are common or where intensity of helminth infection is low after repeated rounds of chemotherapy. Because deworming programs need to distinguish between populations where parasitic infection is controlled and those where further treatment is required, multi-parallel qPCR (or similar high throughput molecular diagnostics) may provide new and important diagnostic information

Loss of heterozygosity at 18q21 is indicative of recurrence and therefore poor prognosis in a subset of colorectal cancers

Adjuvant therapies are increasingly used in colorectal cancers for the prevention of recurrence. These therapies have side-effects and should, thus, be used only if really beneficial. However, the development of recurrence cannot be predicted reliably at the moment of diagnosis, and targeting of adjuvant therapies is thus based only on the primary stage of the cancer. Loss of heterozygosity (LOH) in the long arm of chromosome 18 is suggested to be related to poor survival and possibly to the development of metastases. We studied the value of LOH at 18q21 as a marker of colorectal cancer prognosis, association with clinicopathological variables, tumour recurrence and survival of the patients. Of the 255 patients studied, 195 were informative as regards LOH status when analysed in primary colorectal cancer specimens using the polymerase chain reaction (PCR) and fragment analysis. LOH at 18q21 was significantly associated with the development of recurrence (P= 0.01) and indicated poor survival in patients of Dukes' classes B and C, in which most recurrences (82%) occurred. An increased rate of tumour recurrence is the reason for poor survival among patients with LOH at 18q21 in primary cancer. These patients are a possible target group for recurrence-preventing adjuvant therapies. © 1999 Cancer Research Campaig

Social odors conveying dominance and reproductive information induce rapid physiological and neuromolecular changes in a cichlid fish

Background: Social plasticity is a pervasive feature of animal behavior. Animals adjust the expression of their social behavior to the daily changes in social life and to transitions between life-history stages, and this ability has an impact in their Darwinian fitness. This behavioral plasticity may be achieved either by rewiring or by biochemically switching nodes of the neural network underlying social behavior in response to perceived social information. Independent of the proximate mechanisms, at the neuromolecular level social plasticity relies on the regulation of gene expression, such that different neurogenomic states emerge in response to different social stimuli and the switches between states are orchestrated by signaling pathways that interface the social environment and the genotype. Here, we test this hypothesis by characterizing the changes in the brain profile of gene expression in response to social odors in the Mozambique Tilapia, Oreochromis mossambicus. This species has a rich repertoire of social behaviors during which both visual and chemical information are conveyed to conspecifics. Specifically, dominant males increase their urination frequency during agonist encounters and during courtship to convey chemical information reflecting their dominance status. Results: We recorded electro-olfactograms to test the extent to which the olfactory epithelium can discriminate between olfactory information from dominant and subordinate males as well as from pre- and post-spawning females. We then performed a genome-scale gene expression analysis of the olfactory bulb and the olfactory cortex homolog in order to identify the neuromolecular systems involved in processing these social stimuli. Conclusions: Our results show that different olfactory stimuli from conspecifics' have a major impact in the brain transcriptome, with different chemical social cues eliciting specific patterns of gene expression in the brain. These results confirm the role of rapid changes in gene expression in the brain as a genomic mechanism underlying behavioral plasticity and reinforce the idea of an extensive transcriptional plasticity of cichlid genomes, especially in response to rapid changes in their social environment.Fundacao para a Ciencia e a Tecnologia (FCT, Portugal) [EXCL/BIA-ANM/0549/2012, Pest-OE/MAR/UI0331/2011]; Dwight W. and Blanche Faye Reeder Centennial Fellowship in Systematic and Evolutionary Biology; Institute for Cellular and Molecular Biology Fellowship; FCTinfo:eu-repo/semantics/publishedVersio

Incidence and prevalence of dementia in linked administrative health data in Saskatchewan, Canada: a retrospective cohort study.

Determining the epidemiology of dementia among the population as a whole in specific jurisdictions - including the long-term care population-is essential to providing appropriate care. The objectives of this study were to use linked administrative databases in the province of Saskatchewan to determine the 12-month incidence and prevalence of dementia for the 2012/13 period (1) among individuals aged 45 and older in the province of Saskatchewan, (2) according to age group and sex, and (3) according to diagnosis code and other case definition criteria

Outcomes of a Comparison Study into a Group-Based Infant Parenting Programme

This paper reports on a quantitative evaluation of a group-based programme designed to promote parent-infant attachment and child development. Whilst group-based parenting programmes are recommended for treating and preventing conduct disorder in older children, there is, as yet, little evidence as to whether they have a positive effect on very young children and their carers’. Recent UK Government initiatives to support families and improve parenting skills in the first 2 years of children’s lives have increased the demand for the delivery and evaluation of community-based programmes. Eighty mother–child dyads were recruited from nine areas to intervention (n = 54) and control condition (n = 26). Baseline measures were collected in the children’s home when the infants were on average 3-months-old, and follow-up measures were collected 6 months post-baseline (N = 63). Mothers’ positive play behaviours were independently coded from video recordings taken in the home. Other measures included self-reported maternal confidence and mental well-being, assessed infant development and home environment. Socio-demographic data was collected once at baseline. After controlling for baseline scores, control mothers were observed to be significantly less sensitive during play with their baby at the 6 months follow-up with a significant increase in confidence. No differences were found between the groups on the other measures. This paper provides limited evidence for the effectiveness of the Incredible Years Parents and Babies group-based programme delivered in the first year of life. Further evaluation, particularly with parents at increased risk of poorer outcomes is needed to confirm and extend these results