Observations of mesospheric gravity waves generated by geomagnetic activity

Gravity waves (GWs) play an important role in the dynamics and energetics of the mesosphere. Geomagnetic activity is a known source of GWs in the upper atmosphere. However, how deep the effects of geomagnetic activity induced GWs penetrate into the mesosphere remains an open question. We use temperature measurements from the SABER/TIMED instrument between 2002 and 2018 to study the variations of mesospheric GW activity following intense geomagnetic disturbances identified by AE and Dst indices. By considering several case studies, we show for the first time that the GWs forced by geomagnetic activity can propagate down to about 80 km in the high latitude mesosphere. Only regions above 55° latitudes show a clear response. The fraction of cases in which there is an unambiguous enhancement in GW activity following the onset of geomagnetic disturbance is smaller during summer than other seasons. Only about half of the events show an unambiguous increase in GW activity during non-summer periods and about one quarter of the events in summer show an enhancement in GWs. In addition, we also find that the high latitude mesopause is often seen to descend in altitude following onset of geomagnetic activity in the non-summer high latitude region

Faster Approximate String Matching for Short Patterns

We study the classical approximate string matching problem, that is, given strings $P$ and $Q$ and an error threshold $k$, find all ending positions of substrings of $Q$ whose edit distance to $P$ is at most $k$. Let $P$ and $Q$ have lengths $m$ and $n$, respectively. On a standard unit-cost word RAM with word size $w \geq \log n$ we present an algorithm using time $$O(nk \cdot \min(\frac{\log^2 m}{\log n},\frac{\log^2 m\log w}{w}) + n)$$ When $P$ is short, namely, $m = 2^{o(\sqrt{\log n})}$ or $m = 2^{o(\sqrt{w/\log w})}$ this improves the previously best known time bounds for the problem. The result is achieved using a novel implementation of the Landau-Vishkin algorithm based on tabulation and word-level parallelism.Comment: To appear in Theory of Computing System

Factorizing the hard and soft spectator scattering contributions for the nucleon form factor F_1 at large Q^2

We investigate the soft spectator scattering contribution for the FF $F_{1}$. We focus our attention on factorization of the hard-collinear scale $\sim Q\Lambda$ corresponding to transition from SCET-I to SCET-II. We compute the leading order jet functions and find that the convolution integrals over the soft fractions are logarithmically divergent. This divergency is the consequence of the boost invariance and does not depend on the model of the soft correlation function describing the soft spectator quarks. Using as example a two-loop diagram we demonstrated that such a divergency corresponds to the overlap of the soft and collinear regions. As a result one obtains large rapidity logarithm which must be included in the correct factorization formalism. We conclude that a consistent description of the factorization for $F_{1}$ implies the end-point collinear divergencies in the hard and soft spectator contributions, i.e. convolution integrals with respect to collinear fractions are not well-defined. Such scenario can only be realized when the twist-3 nucleon distribution amplitude has specific end-point behavior which differs from one expected from the evolution of the nucleon distribution amplitude. Such behavior leads to the violation of the collinear factorization for the hard spectator scattering contribution. We suggest that the soft spectator scattering and chiral symmetry breaking provide the mechanism responsible for the violation of collinear factorization in case of form factor $F_{1}$.Comment: 25 pages, 6 figures, text is improved, few typos corrected, one figure added, statement about end-point behavior of the nucleon DA is formulated more accuratel

Nucleon electromagnetic form factors in a quark-gluon core model

We study the nucleon electromagnetic form factors in a quark-gluon core model framework, which can be viewed as an extension of the Isgur-Karl model of baryons. Using this picture we derive nucleon electromagnetic dipole form factors at low Q^2 and the deviation from the dipole form at high Q^2, that are consistent with the existing experimental data.Comment: 5 pages, 3 figure

CompreHensive geriAtRician-led MEdication Review (CHARMER): protocol for a feasibility study of a hospital deprescribing behaviour change intervention

Introduction Over 50% of older adults are prescribed a medicine where the risk of harm outweighs the chances of benefit. During a hospital admission, older adults and carers expect medicines to be reviewed for appropriateness and any inappropriate medicines proactively deprescribed. While the principle of proactive deprescribing is an expectation of good prescribing practice, it is yet to become routine. The CompreHensive geriAtRician-led MEdication Review (CHARMER) study aims to develop and test a five-component behaviour change intervention to equip geriatricians and pharmacists to proactively deprescribe inappropriate medicines with older adults in hospital. This study aims to test the feasibility and acceptability of study processes and CHARMER implementation. Methods and analysis A two-arm purposive allocation feasibility study is being undertaken at four acute hospitals in England, UK (three intervention and one control). The target sample is 400 patients across all hospitals. Primary outcome measures are: (1) participant recruitment rate and (2) participant attrition rate. Secondary outcome measures are: (1) hospital readmission rate; (2) mortality rate and (3) quality of life. Quantitative data will be checked for completeness and quality, and practitioner and patient demographics descriptively analysed. We will undertake a rapid qualitative analysis on observations, interviews and study meeting minutes data. A subsequent thematic analysis will be undertaken with codes mapped to the Theoretical Domains Framework and Normalisation Process Theory. Triangulation of qualitative and quantitative data will be undertaken. Ethics and dissemination Ethics approval was obtained from Wales Research Ethics Committee 1 (IRAS ID 312494) and study approval from the Health Research Authority (22/WA/0087). Informed consent will be sought from all hospital staff involved in data collection activities and for patients involved in enhanced data collection activities. The findings of this study will be disseminated in peer-reviewed journals and conference presentations

Calibrating and adjusting expectations in life: A grounded theory on how elderly persons with somatic health problems maintain control and balance in life and optimize well-being

Aim: This study aims at exploring the main concern for elderly individuals with somatic health problems and what they do to manage this. Method: In total, 14 individuals (mean = 74.2 years; range = 68–86 years) of both gender including hospitalized and outpatient persons participated in the study. Open interviews were conducted and analyzed according to grounded theory, an inductive theory-generating method. Results: The main concern for the elderly individuals with somatic health problems was identified as their striving to maintain control and balance in life. The analysis ended up in a substantive theory explaining how elderly individuals with somatic disease were calibrating and adjusting their expectations in life in order to adapt to their reduced energy level, health problems, and aging. By adjusting the expectations to their actual abilities, the elderly can maintain a sense of that they still have the control over their lives and create stability. The ongoing adjustment process is facilitated by different strategies and result despite lower expectations in subjective well-being. The facilitating strategies are utilizing the network of important others, enjoying cultural heritage, being occupied with interests, having a mission to fulfill, improving the situation by limiting boundaries and, finally, creating meaning in everyday life. Conclusion: The main concern of the elderly with somatic health problems was to maintain control and balance in life. The emerging theory explains how elderly people with somatic health problems calibrate their expectations of life in order to adjust to reduced energy, health problems, and aging. This process is facilitated by different strategies and result despite lower expectation in subjective well-being

A Measurement of the Proton Structure Function F ⁣2(x,Q2)F_{\!2}(x,Q^2)

A measurement of the proton structure function $F_{\!2}(x,Q^2)$ is reported for momentum transfer squared $Q^2$ between 4.5 $GeV^2$ and 1600 $GeV^2$ and for Bjorken $x$ between $1.8\cdot10^{-4}$ and 0.13 using data collected by the HERA experiment H1 in 1993. It is observed that $F_{\!2}$ increases significantly with decreasing $x$, confirming our previous measurement made with one tenth of the data available in this analysis. The $Q^2$ dependence is approximately logarithmic over the full kinematic range covered. The subsample of deep inelastic events with a large pseudo-rapidity gap in the hadronic energy flow close to the proton remnant is used to measure the "diffractive" contribution to $F_{\!2}$.Comment: 32 pages, ps, appended as compressed, uuencoded fil