Commuting Quantum Circuits with Few Outputs are Unlikely to be Classically Simulatable

We study the classical simulatability of commuting quantum circuits with n input qubits and O(log n) output qubits, where a quantum circuit is classically simulatable if its output probability distribution can be sampled up to an exponentially small additive error in classical polynomial time. First, we show that there exists a commuting quantum circuit that is not classically simulatable unless the polynomial hierarchy collapses to the third level. This is the first formal evidence that a commuting quantum circuit is not classically simulatable even when the number of output qubits is exponentially small. Then, we consider a generalized version of the circuit and clarify the condition under which it is classically simulatable. Lastly, we apply the argument for the above evidence to Clifford circuits in a similar setting and provide evidence that such a circuit augmented by a depth-1 non-Clifford layer is not classically simulatable. These results reveal subtle differences between quantum and classical computation.Comment: 19 pages, 6 figures; v2: Theorems 1 and 3 improved, proofs modifie

Case studies on the socio-economic characteristics and lifestyles subsistence and informal fisheries in South Africa

To develop a management strategy for informal fishers, a necessary first step is information about the nature of these fishers, their numbers and their socio-economic status. To accomplish this, a survey of socio-economic conditions and use of marine resources was undertaken in 1999 at 20 localities where fishing occurs around the coast of South Africa, concentrating on subsistence or small- to micro-scale artisanal commercial fishers. In each locality, 16–31 “fisher households” were surveyed by questionnaires, focus-group discussions and interviews with key informants. Demographic analyses revealed a low level of migrancy (~5%), an average of 5.3 persons per household and a mean age of 27. Only ~20% of fishers were women and ~15% were children. Poverty was prevalent: unemployment averaged 40.3% (much higher than the national norm of 29.3%). Mean adult equivalent income per month spanned R193–R735 among regions, and was not correlated with size of settlement. Education levels were low, only ~33% of people >20 years old having completed primary school. Migrancy was highest in rural areas (but still much less than the national norm), intermediate in towns and least in metropolitan areas. Household size, participation of women and poverty all followed similar trends. Comparing regions, the East Coast and the province of KwaZulu-Natal had higher migrancy rates, larger household sizes, greater poverty, and greater participation by women in fishing, than on the South and West coasts. Household expenditure on food was ~R450 per month on the South-East and KwaZulu-Natal coasts and ~R750 on the West Coast, and exceeded 60% of income (a measure of “food security”) in about half the households surveyed. Harvested resources were sold, consumed or used as bait. In all regions, the two most frequently harvested resources were fish (mostly sold, predominantly fished by men) and intertidal rocky-shore invertebrates (largely consumed, and involving women to a greater degree). On the West Coast, rock lobster Jasus lalandii was the third-most important resource, but on the South and KwaZulu-Natal coasts this species was replaced by estuarine invertebrates. Abalone Haliotis midae, oysters, sandy-beach invertebrates and kelp or seaweeds made up the balance. Diversity of harvested resources increased west to east, following biogeographic trends. The resources could be divided into those of high value (rock lobsters, abalone and, to a lesser extent, fish) and those of lower value (such as limpets, mussels and bait organisms). It is argued that high-value resources are best used to create micro- and small-scale commercial enterprises that can serve to uplift poor fishers. Lowvalue resources constitute subsistence resources, for which preferential rights should be established for subsistence fishers, including development of exclusive-use zones where necessary. Emerging characteristics of fishing communities that were helpful in defining subsistence fishers in the South African context were poverty, harvest for self-use (whether by consumption or sale to meet basic needs of food security), use of low-technology gear, and concentration of effort on or from shores or in estuaries. At least portions of the catches of all resources are sold, and the majority of equipment is purchased, so any definition of subsistence fishers cannot exclude those who sell part of their catch or do not use hand-made equipment. Some success was evident with co-management, encouraging further exploration of this style of management for subsistence fishers. Keywords: informal fishers, socio-economics of fishers, subsistence fishersAfrican Journal of Marine Science 2002, 24: 439–46

Assessment of resource availability and sustainability for subsistence fishers in South Africa, with a review of resource management procedures

The availability of resources and their suitability for subsistence and small-scale commercial fishers in South Africa were assessed and appropriate options for the management of resources recommended. Assessment of current resource utilization and recommendations for future subsistence and/or small-scale commercial use were based on information gathered during a nationwide survey of 144 subsistence fishing communities in South Africa and a review of relevant published and unpublished literature. Current patterns of resource use in three regions of the coast (West, South and East coasts) revealed that most true subsistence fisheries occur in the eastern half of the country. These fisheries are primarily focused on invertebrate species found on intertidal rocky shores and sandy beaches, or in estuaries. Fish are harvested by rod or handline, netting or traditional fishing methods (fishtraps, spearing, baited baskets). No “new” or previously underutilized resources were identified as suitable for subsistence fishing in any of the three regions. The potential for several new small-scale commercial fisheries was identified, but the need to retain certain resources for subsistence fisheries (rather than converting them to small-scale commercial fisheries) was evident in certain areas. Resources with high commercial value were not considered suitable for subsistence fishing, but rather for the introduction of small-scale commercial fisheries. The overall management strategy for the subsistence sector, which is currently in the process of being developed, must ensure sufficient flexibility to be able to take into account regional and site-specific requirements. It will also need to develop co-management structures, protect traditional fishing practices, avoid user conflict and provide for no-take areas, all within the framework of sustainable resource utilization.Keywords: estuarine resources, fisheries management, intertidal resources, subsistence fisheries, subtidal resourcesAfrican Journal of Marine Science 2002, 24: 489–50

Perceptions of subsistence and informal fishers in South Africa regarding the management of living marine resources

Following the legal recognition of subsistence fishers in 1998 through the promulgation of the Marine Living Resources Act, a Subsistence Fisheries Task Group (SFTG) was appointed by national government to provide recommendations on the management of subsistence fishing in South Africa. To achieve effective management, the SFTG recognized that fishers' needs, perceptions and concerns must be understood and incorporated into future management strategies. As a result, information from fishers was gathered through a five-month research programme that included questionnaire surveys, focus-group meetings, a “roadshow” and a national workshop. Research findings indicated that the fishers' responses centred on four key themes related to (1) the criteria for defining a subsistence fisher, (2) current management practices, (3) resource use and (4) livelihood strategies. Feedback from fishers revealed several issues that have led to uncertainty and dissatisfaction among informal and subsistence fishers. However, these perceptions need to be contextualized within the historical circumstances of fisheries management in South Africa, and it must be recognized that attitudes will only change when management approaches embrace the needs, perceptions and concerns of the users. The information outlined in this paper was instrumental in guiding the formulation of the SFTG recommendations regarding the definition of subsistence fishers and their future management in South Africa.Keywords: fisheries management, perceptions about fisheries, subsistence fishersAfrican Journal of Marine Science 2002, 24: 463–47

Crested macaque facial movements are more intense and stereotyped in potentially risky social interactions

One contribution of 13 to a theme issue 'Cognition, communication and social bonds in primates'. Ambiguity in communicative signals may lead to misunderstandings and thus reduce the effectiveness of communication, especially in unpredictable interactions such as between closely matched rivals or those with a weak social bond. Therefore, signals used in these circumstances should be less ambiguous, more stereotyped and more intense. To test this prediction, we measured facial movements of crested macaques (Macaca nigra) during spontaneous social interaction, using the Facial Action Coding System for macaques (MaqFACS). We used linear mixed models to assess whether facial movement intensity and variability varied according to the interaction outcome, the individuals' dominance relationship and their social bond. Movements were least intense and most variable in affiliative contexts, and more intense in interactions between individuals who were closely matched in terms of dominance rating. We found no effect of social bond strength. Our findings provide evidence for a reduction in ambiguity of facial behaviour in risky social situations but do not demonstrate any mitigating effect of social relationship quality. The results indicate that the ability to modify communicative signals may play an important role in navigating complex primate social interactions. This article is part of the theme issue 'Cognition, communication and social bonds in primates'

Sweet's syndrome associated with cellulitis - a challenging diagnosis

Sweet's syndrome is a neutrophilic dermatosis with worldwide distribution that has been associated with inflammatory autoimmune diseases, infections, malignancies, drugs, and pregnancy. The disease is idiopathic in up to 50% of patients. A 64-year-old woman, diagnosed with right limb cellulitis (4 days of evolution), was seen at our department, due to persistent cellulitis and progressive appearance of painful nodules and plaques in both shins and the right forearm (2 days of evolution). Taken together, clinical, laboratory and pathological data suggested the diagnosis of Sweet's syndrome, probably secondary to cellulitis of the right inferior limb. We suggest that cellulitis may be associated with Sweet's syndrome, a rare association in the literature

Factors associated with persistent hypertension after puerperium among women with pre-eclampsia/eclampsia in Mulago hospital, Uganda

<p>Abstract</p> <p>Background</p> <p>Women with severe pre-eclampsia/eclampsia are at risk of developing chronic hypertension in future. Chronic hypertension may manifest initially as persistent hypertension at the end of the puerperium. The objective was to determine the incidence and maternal biochemical, hematological and socio-demographic risk factors for persistent hypertension in patients with pre-eclampsia/eclampsia.</p> <p>Methods</p> <p>This was a prospective cohort study conducted from November 2008 to May 2009 at Mulago hospital labor ward and postnatal clinic. Participants were 200 women managed for pre-eclampsia/eclampsia and followed up to the end of the puerperium. Data was collected through using pre-coded interviewer-administered questionnaires, checking medical records and laboratory investigations. STATA (release 9) software was used for data analysis. At bivariate analysis, the relative risk of persistent hypertension was estimated at the 95% confidence level. Using multivariate logistic regression analysis, factors that were independently associated with persistent hypertension were evaluated.</p> <p>Results</p> <p>Fifty four (27.7%) out of the total 195 women had persistent hypertension after puerperium. Serum creatinine and the age of the patient were the only factors associated with persistence of hypertension after puerperium.</p> <p>Conclusion</p> <p>Nearly every one in four mothers with pre-eclampsia/eclampsia are at risk of persistent hypertension after the puerperium. Serum creatinine, serum uric acid and participants' age were the only factors independently associated with persistence of hypertension after the puerperium.</p

Designing an automated clinical decision support system to match clinical practice guidelines for opioid therapy for chronic pain

Abstract Background Opioid prescribing for chronic pain is common and controversial, but recommended clinical practices are followed inconsistently in many clinical settings. Strategies for increasing adherence to clinical practice guideline recommendations are needed to increase effectiveness and reduce negative consequences of opioid prescribing in chronic pain patients. Methods Here we describe the process and outcomes of a project to operationalize the 2003 VA/DOD Clinical Practice Guideline for Opioid Therapy for Chronic Non-Cancer Pain into a computerized decision support system (DSS) to encourage good opioid prescribing practices during primary care visits. We based the DSS on the existing ATHENA-DSS. We used an iterative process of design, testing, and revision of the DSS by a diverse team including guideline authors, medical informatics experts, clinical content experts, and end-users to convert the written clinical practice guideline into a computable algorithm to generate patient-specific recommendations for care based upon existing information in the electronic medical record (EMR), and a set of clinical tools. Results The iterative revision process identified numerous and varied problems with the initially designed system despite diverse expert participation in the design process. The process of operationalizing the guideline identified areas in which the guideline was vague, left decisions to clinical judgment, or required clarification of detail to insure safe clinical implementation. The revisions led to workable solutions to problems, defined the limits of the DSS and its utility in clinical practice, improved integration into clinical workflow, and improved the clarity and accuracy of system recommendations and tools. Conclusions Use of this iterative process led to development of a multifunctional DSS that met the approval of the clinical practice guideline authors, content experts, and clinicians involved in testing. The process and experiences described provide a model for development of other DSSs that translate written guidelines into actionable, real-time clinical recommendations.http://deepblue.lib.umich.edu/bitstream/2027.42/78267/1/1748-5908-5-26.xmlhttp://deepblue.lib.umich.edu/bitstream/2027.42/78267/2/1748-5908-5-26.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/78267/3/1748-5908-5-26-S3.TIFFhttp://deepblue.lib.umich.edu/bitstream/2027.42/78267/4/1748-5908-5-26-S2.TIFFhttp://deepblue.lib.umich.edu/bitstream/2027.42/78267/5/1748-5908-5-26-S1.TIFFPeer Reviewe