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Host shifts of parasites are often causing devastating effects in the new hosts. The Varroa genus is known for a lineage of Varroa destructor that shifted to the Western honey bee, Apis mellifera, with disastrous effects on wild populations and the beekeeping industry. Despite this, the biology of Varroa spp. remains poorly understood in its native distribution range, where it naturally parasitizes the Eastern honey bee, Apis cerana. Here, we combined mitochondrial and nuclear DNA analyses with the assessment of mite reproduction to determine the population structure and host specificity of V. destructor and Varroa jacobsonii in Thailand, where both hosts and several Varroa species and haplotypes are sympatric. Our data confirm previously described mite haplogroups, and show three novel haplotypes. Multiple infestations of single host colonies by both mite species and introgression of alleles between V. destructor and V. jacobsonii suggest that hybridization occurs between the two species. Our results indicate that host specificity and population genetic structure in the genus Varroa is more labile than previously thought. The ability of the host shifted V. destructor haplotype to spillback to A. cerana and to hybridize with V. jacobsonii could threaten honey bee populations of Asia and beyond.
OBJECTIVES/SPECIFIC AIMS: Costs associated with the treatment of skin diseases accounted for greater than 4% of total US healthcare spending in 2013, an increase of $46 billion (170%) since 2004. Considering the increase in novel treatments and spending, cost-utility analyses (CUAs) may provide a better understanding of costs in dermatology. In this study, we conduct a systematic overview of study quality among CUAs related to dermatology. METHODS/STUDY POPULATION: We queried studies from the Tufts Medical Center Cost-Effectiveness Analysis Registry (www.cearegistry.org), a database supplying information on all peer-reviewed cost-effectiveness analysis through 2014. Database methodology was previously discussed here. We queried studies using keywords from the 24 major skin disease categories (e.g., diseases relating to actinic damage were searched by using “actinic,” “actinic keratosis”). We collected data on study design, reporting methods, and analyzed relevant data stratified by 2 time-periods (1976–2008 and 2009–2014) chosen to encompass a comparable number of studies. RESULTS/ANTICIPATED RESULTS: In total, 42 and 50 studies corresponding to the 2 time-periods were retrieved (representing 14/24 disease categories). Based on the recommended data reporting guidelines for CUAs, study quality remained largely unchanged across the 2 phases. Across the 2 time-periods, a societal perspective was used in 19% and 12% of studies, costs and (quality adjusted life-years) QALYs were discounted in 67% and 72% of studies, a correct (incremental cost-effectiveness ratio) ICER was reported in 67% and 72% of studies, and a sensitivity analysis was included in 88% and 84% of studies, respectively. DISCUSSION/SIGNIFICANCE OF IMPACT: Our findings suggest the quality of dermatology-related CUAs, as evaluated by recommended data reporting guidelines, to be generally stable during the analyzed time-periods. However, the quality of our results may be limited by the small number of CUAs within dermatology (10/24 disease categories did not have CUAs across any time-period). Moving forward, we encourage researchers within dermatology to pursue additional investigation towards cost-effective practices while adhering closely to recommended quality reporting guidelines for CUAs.
The spatial pattern of accumulation rate can be inferred from internal layers in glaciers and ice sheets. Non-dimensional analysis determines where finite strain can be neglected (‘shallow-layer approximation’) or approximated with a local one-dimensional flow model (‘local-layer approximation’), and where gradients in strain rate along particle paths must be included (‘deep layers’). We develop a general geophysical inverse procedure to infer the spatial pattern of accumulation rate along a steady-state flowband, using measured topography of the ice-sheet surface, bed and a ‘deep layer’. A variety of thermomechanical ice-flow models can be used in the forward problem to calculate surface topography and ice velocity, which are used to calculate particle paths and internal-layer shapes. An objective tolerance criterion prevents over-fitting the data. After making site-specific simplifications in the thermomechanical flow algorithm, we find the accumulation rate along a flowband through Taylor Mouth, a flank site on Taylor Dome, Antarctica, using a layer at approximately 100 m depth, or 20% of the ice thickness. Accumulation rate correlates with ice-surface curvature. At this site, gradients along flow paths critically impact inference of both the accumulation pattern, and the depth-age relation in a 100 m core.
This article began as a study of the structure of infinite permutation groups
in which point stabilisers are finite and all infinite normal subgroups are transitive. That led to two variations. One is the generalisation in which point stabilisers are merely assumed to satisfy min-n, the minimal condition on normal subgroups. The groups
are then of two kinds. Either they have a maximal finite normal subgroup, modulo which they have either one or two minimal nontrivial normal subgroups, or they have a regular normal subgroup
which is a divisible abelian
-group of finite rank. In the latter case the point stabilisers are finite and act irreducibly on a
-adic vector space associated with
. This leads to our second variation, which is a study of the finite linear groups that can arise.
In May 2014, soon after the MA Conference in Nottingham, and soon after the passing of Roger Wheeler, a staunch member of the MA, who had been my teacher at school, I had the idea that my presidential address in April 2016 might be entitled ‘Inspiring Teachers’. The concept was a talk that might trace my mathematical experiences from grammar school sixth form, through my development in retirement as a contributor to masterclasses for the UK Mathematics Trust and the Royal Institution, learning from the students and from the inspiring teachers at whose masterclasses I assist, to the small understanding of Key Stage 2 Mathematics that I am gradually acquiring through an hour a week with some Year 6 students and their remarkable teachers in a local primary school.
A month or so later, when the organising committee was giving shape to Conference 2016, my words were taken as the title of the conference itself. It is deliberately ambiguous and it was gratifying to me to find this last April that its ambiguity had struck melodious chords with other speakers. My presidential address, however, was conceived as a lecture. Like all my lectures it was designed to be an oral presentation. It was not designed to be written down and published as an article. Please bear that in mind gentle reader, and judge accordingly. If you find something of value here I shall be delighted; if not, I shall not be surprised.
Objectives: The Centers for Medicare and Medicaid Services (CMS) issues National Coverage Determinations (NCDs) for medical interventions expected to have a significant impact on Medicare, the health insurance program for US citizens aged 65 years and older and certain people with disabilities under the age of 65 years. The objective of this study was to evaluate NCDs issued from 1999 to 2013 to identify key trends, and to discuss implications for future CMS policy.
Methods: We used the Tufts Medical Center Medicare National Coverage Determination Database to examine characteristics of NCDs from 1999 through 2013. We examined various characteristics of NCDs, including: whether the intervention under review is used for prevention or treatment of disease, the type of intervention considered, evidence limitations cited by CMS, and coverage determination outcome. We evaluated longitudinal trends in categorical and continuous variables in the database, using Cochran-Armitage trend tests and linear regression, respectively.
Results: We found that NCDs increasingly focus on preventive care (p = 0.072), pertain to diagnostic imaging (p = 0.033), and evaluate health education/behavioral therapy interventions (p = 0.051). CMS increasingly cites the lack of relevant outcomes (p = 0.019) and the lack of applicability of study results to the Medicare population (p < 0.001) as evidence limitations. CMS less often restricts coverage to certain population subgroups in NCDs (p < 0.001), but increasingly applies coverage with evidence development policies (p < 0.001).
Conclusions: Identified trends reflect broader changes in Medicare as CMS shifts its focus from treatment to prevention of disease, addresses potentially overutilized technologies, and attempts to issue flexible coverage policies.
Objectives: In recent years, there has been growth in the use of health technology assessment (HTA) for making decisions about the reimbursement, coverage, or guidance on the use of health technologies. Given this greater emphasis on the use of HTA, it is important to develop standards of good practice and to benchmark the various HTA organizations against these standards.
Methods: This study discusses the conceptual and methodological challenges associated with benchmarking HTA organizations and proposes a series of audit questions based on a previously published set of principles of good practice.
Results and Conclusions: It is concluded that a benchmarking exercise would be feasible and useful, although the question of who should do the benchmarking requires further discussion. Key issues for further research are the alternative methods for weighting the various principles and for generating an overall score, or summary statement of adherence to the principles. Any weighting system, if developed, would need to be explored in different jurisdictions to assess the extent to which the relative importance of the principles is perceived to vary. Finally, the development and precise wording of the audit questions requires further study, with a view to making the questions as unambiguous as possible, and the reproducibility of the assessments as high as possible.
The Tufts Cost-Effectiveness Analysis (CEA) Registry (www.cearegistry.org) is a publicly available comprehensive database of cost-utility analyses of health interventions published in the peer-reviewed medical and public health literature. This article discusses the database structure, methodology of data extraction, current trends in cost-utility analyses and impact of the Registry.
As in the past, the primary activity of the IAU Working Group on Cartographic Coordinates and Rotational Elements has been to prepare and publish a triennial (“2009”) report containing current recommendations for models for Solar System bodies (Archinal et al. (2011a)). The authors are B. A. Archinal, M. F. A'Hearn, E. Bowell, A. Conrad, G. J. Consolmagno, R. Courtin, T. Fukushima, D. Hestroffer, J. L. Hilton, G. A. Krasinsky, G. Neumann, J. Oberst, P. K. Seidelmann, P. Stooke, D. J. Tholen, P. C. Thomas, and I. P. Williams. An erratum to the “2006” and “2009” reports has also been published (Archinal et al. (2011b)). Below we briefly summarize the contents of the 2009 report, a plan to consider requests for new recommendations more often than every three years, three general recommendations by the WG to the planetary community, other WG activities, and plans for our next report.
To understand the interactions between production patterns common to children regardless of language environment and the early appearance of production effects based on perceptual learning from the ambient language requires the study of languages with diverse phonological properties. Few studies have evaluated early phonological acquisition patterns of children in non-Indo-European language environments. In the current study, across- and within-syllable consonant–vowel co-occurrence patterns in babbling were analyzed for a 6-month period for seven Ecuadorean Quichua learning children who were between 9 and 17 months of age at study onset. Their babbling utterances were compared to the babbling of six English-learning children between 9 and 22 months of age. Child patterns for both languages were compared with Quichua and English ambient language patterns. Babbling output was highly similar for the child groups: Quichua and English children's babbling demonstrated similar predicted within-syllable (coronal-front vowel, labial-central vowel, dorsal-back vowel) patterns, and across-syllable manner variegation patterns for consonants. These patterns were observed at significantly greater rates in the child groups than in the respective adult language input patterns, suggesting production system influences common to children across languages rather than ambient language perceptual learning effects during these children's babbling period.
The triple product property (TPP) for subsets of a finite group was introduced by Henry Cohn and Christopher Umans in 2003 as a tool for the study of the complexity of matrix multiplication. This note records some consequences of the simple observation that if (S1,S2,S3) is a TPP triple in a finite group G, then so is (dS1a,dS2b,dS3c) for any a,b,c,d∈G.
Let si:=∣Si∣ for 1≤i≤3. First we prove the inequality s1(s2+s3−1)≤∣G∣ and show some of its uses. Then we show (something a little more general than) that if G has an abelian subgroup of index v, then s1s2s3 ≤v2 ∣G∣.
An automated technique for the mapping of nanocrystal phases and orientations in a transmission electron microscope (TEM) is briefly described. It is primarily based on the projected reciprocal lattice geometry that is extracted automatically from precession electron diffraction (PED) enhanced spot patterns. The required hardware allows for a scanning-precession movement of the primary electron beam on the crystalline sample and can be interfaced to any newer or older mid-voltage TEM. Comprehensive open-access crystallographic databases that may be used in support of this technique are mentioned.
The photogalvanic effects, which require a system lacking inversion symmetry, become possible in SiGe based quantum well (QW) structures due to their built-in asymmetry. We report on observations of the circular and linear photogalvanic effects induced by infrared radiation in (001)-and (113)-orientedp–Si/Si1–xGex QW structures and analyse these observations in view of the possible symmetry of these structures. The circular photogalvanic effect arises due to optical spin orientation of free carriers in QWs with band splitting in k-space which results in a directed motion of free carriers in the plane of the QW. We discuss possible mechanisms that give rise to spin-splitting of the electronic subband states for different symmetries.
Fracture toughness data of stoichiometric FeAl and NiAl single crystals were measured in four-point-bending tests and the crystallographic orientations of the resultant fracture surfaces were determined.
For FeAl single crystals unexpectedly high fracture toughness values were measured even at low temperatures (17 MPa  at 77K). However, these crystals failed in a brittle manner for temperatures up to 300K. The crystallographic orientation of the fracture surfaces were strongly dependent on the environment due to hydrogen embrittlement.
The NiAl specimens were precracked and the fracture toughness was measured in the weakest crystal orientation. The fracture surfaces were similar to those obtained in previous investigations. Although the room temperature (RT) KIC-value was the highest for pure weak-oriented NiAl (7.5 MPa ) the BDT temperature was found in the same region where it occurs for the hard orientation (673K to 693K). The onset of the BDT will be discussed.
The strain distribution inside and in the vicinity of coherently strained self-organized islands has been investigated by high-resolution x-ray diffraction (HRXRD). Finite element method (FEM) calculations were carried out in order to calculate the strain field, which was then used to simulate x-ray reciprocal space maps on the basis of kinematical scattering theory. For Si0 75Ge0.25 islands an abrupt increase in the Ge-concentration at about one third of the island height has been found. This behavior can be attributed to different nucleation stages during growth. Highly strained buried CdSe quantum dots (QDs) strongly influence the surrounding ZnSe matrix. From reciprocal space maps and FEM simulations we were able to estimate the shape and size of the islands. The results are in agreement with transmission electron microscopy (TEM) and UHV atomic force microscopy (AFM) data.
Thin film ferroelectric capacitors have been integrated with resistors and active functions such as ESD protection into small miniaturized modules, which enable a board space saving of up to 80%. With the optimum materials and processes, integrated capacitors with capacitance densities of up to 100 nF/mm2 and breakdown voltages of up to 90 V have been achieved. The integration of these high density capacitors with extremely high breakdown voltage is a revolution in the world of integrated passive components and has not yet been achieved in any other passive integration technology.