A Prospective Study On Pathology Distribution Of Dizziness Patients In Neuro-Otology Department At National Hospital For Neurology & Neurosurgery, Queen Square, London

Abstract. “Dizziness” is a general term [1] and covers a variety of ‘abnormal sensations relating to perception of the body’s relationship to space’ [2]. According to the previous paper, Drachman and Hart [3] dizziness can be divided into four subtypes: vertigo, presyncope lightheadedness, disequilibrium, and other dizziness. Among all these subtypes, vertigo is one of the most commonly reported symptoms by the vestibular disordered patient nowadays [1]. Globally dizziness is one of ‘the common, chronic and untreated symptoms’ among the population in the age range of 18-65 years old. [4]. aims: To assess the pathology distribution among dizziness patients in NHNH. Method: All 97 patients were selected from an age range of 18-75 years, with a mean age of 47.92 (S.D=13.17). Method: All 97 patients were selected from an age range of 18-75 years, with a mean age of 47.92 (S.D=13.17). They were asked to fill in the VSS and MVSS questionnaires.  Results:  We were able to invite all 109 patients to participate our study within the 39 days (13 November – 21 December 2007) that’s attended the Neuro-otology clinic, NHNN. Conclusion: In this study it has been found that women commonly presented with the dizziness symptoms compared to men. Keyword: modified vertigo symptom scale, pathology, vertigo symptom scale, vestibular disordere

Quenching and morphological evolution due to circumgalactic gas expulsion in a simulated galaxy with a controlled assembly history

We examine the influence of dark matter halo assembly on the evolution of a simulated ∼L⋆ galaxy. Starting from a zoom-in simulation of a star-forming galaxy evolved with the EAGLE galaxy formation model, we use the genetic modification technique to create a pair of complementary assembly histories: one in which the halo assembles later than in the unmodified case, and one in which it assembles earlier. Delayed assembly leads to the galaxy exhibiting a greater present-day star formation rate than its unmodified counterpart, while in the accelerated case the galaxy quenches at z ≃ 1, and becomes spheroidal. We simulate each assembly history nine times, adopting different seeds for the random number generator used by EAGLE’s stochastic subgrid implementations of star formation and feedback. The systematic changes driven by differences in assembly history are significantly stronger than the random scatter induced by this stochasticity. The sensitivity of ∼L⋆ galaxy evolution to dark matter halo assembly follows from the close coupling of the growth histories of the central black hole (BH) and the halo, such that earlier assembly fosters the formation of a more massive BH, and more efficient expulsion of circumgalactic gas. In response to this expulsion, the circumgalactic medium reconfigures at a lower density, extending its cooling time and thus inhibiting the replenishment of the interstellar medium. Our results indicate that halo assembly history significantly influences the evolution of ∼L⋆ central galaxies, and that the expulsion of circumgalactic gas is a crucial step in quenching them

HRT for women with premature ovarian insufficiency: a comprehensive review

BACKGROUND: Premature ovarian insufficiency (POI), often and misleadingly referred to as ‘premature menopause’, is defined as a loss of ovarian activity before the age of 40 years and is characterized by irregular or absent periods and reduced fertility. Symptoms include those associated with the natural menopause (night sweats and vaginal dryness), and with the long-term adverse effects of estrogen deficiency (osteoporosis and cardiovascular disease): the latter is believed to explain the shorter life expectancy associated with POI. OBJECTIVE AND RATIONALE: The objective of the current review was to collect all relevant studies supporting recommendations on the indications, treatment options, and risks of hormone replacement therapy (HRT) (estrogen, progestogens and androgens) for women with POI. SEARCH METHODS: The current review was written based on the best available evidence on the topic collected for the recently published ESHRE guideline on the management of women with POI. PUBMED/MEDLINE and the Cochrane library were searched in a stepwise approach. Relevant references were summarized in evidence tables, with assessment of the quality. OUTCOMES: HRT is strongly recommended for women with POI, mainly for vasomotor and genito-urinary symptom relief. In addition, HRT has been shown to have a role in bone protection and probably also in primary prevention of cardiovascular disease. There is little evidence on the optimal type, regimen and dose of HRT; patient preference for route and method of administration of each component of HRT must be considered when prescribing, as should contraceptive needs. In women with POI, physiological replacement of estrogen (and progesterone) is essential for their health, and the controversies that surround the use of HRT in postmenopausal women do not apply. WIDER IMPLICATIONS: New areas of study on HRT for women with POI should focus on life expectancy, quality of life and neurological function. Furthermore, randomized controlled trials comparing transdermal estradiol with oral estrogens with regard to efficacy, patient satisfaction and side effects are urgently needed. STUDY FUNDING/COMPETING INTERESTS: The authors received no funding for the review. The costs for the development of the ESHRE guideline were covered by ESHRE. The authors have no conflicts of interest to disclose

The effects of Si-doped prelayers on the optical properties of InGaN/GaN single quantum well structures

In this paper, we report on the effects of including Si-doped (In)GaN prelayers on the low temperature optical properties of a blue-light emitting InGaN/GaN single quantum well. We observed a large blue shift of the photoluminescence peak emission energy and significant increases in the radiative recombination rate for the quantum well structures that incorporated Si-doped prelayers. Simulations of the variation of the conduction and valence band energies show that a strong modification of the band profile occurs for the quantum wells on Si-doped prelayers due to an increase in strength of the surface polarization field. The enhanced surface polarization field opposes the built-in field across the quantum well and thus reduces this built-in electric field. This reduction of the electric field across the quantum well reduces the Quantum Confined Stark Effect and is responsible for the observed blue shift and the change in the recombination dynamics.This work was carried out with the financial support of the United Kingdom Engineering and Physical Sciences Research Council under Grant Nos. EP/I012591/1 and EP/ H011676/1.This is the accepted manuscript version of the article. The final version is available from AIP at http://scitation.aip.org/content/aip/journal/apl/105/9/10.1063/1.4894834

A comparison of the optical properties of InGaN/GaN multiple quantum well structures grown with and without Si-doped InGaN prelayers

In this paper, we report on a detailed spectroscopic study of the optical properties of InGaN/GaN multiple quantum well structures, both with and without a Si-doped InGaN prelayer. In photoluminescence and photoluminescence excitation spectroscopy, a 2nd emission band, occurring at a higher energy, was identified in the spectrum of the multiple quantum well structure containing the InGaN prelayer, originating from the first quantum well in the stack. Band structure calculations revealed that a reduction in the resultant electric field occurred in the quantum well immediately adjacent to the InGaN prelayer, therefore leading to a reduction in the strength of the quantum confined Stark effect in this quantum well. The partial suppression of the quantum confined Stark effect in this quantum well led to a modified (higher) emission energy and increased radiative recombination rate. Therefore, we ascribed the origin of the high energy emission band to recombination from the 1st quantum well in the structure. Study of the temperature dependent recombination dynamics of both samples showed that the decay time measured across the spectrum was strongly influenced by the 1st quantum well in the stack (in the sample containing the prelayer) leading to a shorter average room temperature lifetime in this sample. The room temperature internal quantum efficiency of the prelayer containing sample was found to be higher than the reference sample (36% compared to 25%) which was thus attributed to the faster radiative recombination rate of the 1st quantum well providing a recombination pathway that is more competitive with non-radiative recombination processes.This work was carried out with the financial support of the United Kingdom Engineering and Physical Sciences Research Council under Grant Nos. EP/I012591/1 and EP/ H011676/1.This is the final version of the article. It first appeared from AIP Publishing via http://dx.doi.org/10.1063/1.494132

Pump-probe measurements of gain in a terahertz quantum cascade laser

The gain recovery time of a bound-to-continuum terahertz frequency quantum cascade laser, operating at 1.98 THz, has been measured using broadband terahertz-pump-terahertz-probe spectroscopy. The recovery time is found to reduce as a function of current density, reaching a value of 18 ps as the laser is brought close to threshold. We attribute this reduction to improved coupling efficiency between the injector state and the upper lasing level as the active region aligns

Spotting the diffusion of New Psychoactive Substances over the Internet

Online availability and diffusion of New Psychoactive Substances (NPS) represent an emerging threat to healthcare systems. In this work, we analyse drugs forums, online shops, and Twitter. By mining the data from these sources, it is possible to understand the dynamics of drugs diffusion and their endorsement, as well as timely detecting new substances. We propose a set of visual analytics tools to support analysts in tackling NPS spreading and provide a better insight about drugs market and analysis

Quenching and morphological evolution due to circumgalactic gas expulsion in a simulated galaxy with a controlled assembly history

We examine the influence of dark matter halo assembly on the evolution of a simulated $\sim L^\star$ galaxy. Starting from a zoom-in simulation of a star-forming galaxy evolved with the EAGLE galaxy formation model, we use the genetic modification technique to create a pair of complementary assembly histories: one in which the halo assembles later than in the unmodified case, and one in which it assembles earlier. Delayed assembly leads to the galaxy exhibiting a greater present-day star formation rate than its unmodified counterpart, whilst in the accelerated case the galaxy quenches at $z\simeq 1$, and becomes spheroidal. We simulate each assembly history nine times, adopting different seeds for the random number generator used by EAGLE's stochastic subgrid implementations of star formation and feedback. The systematic changes driven by differences in assembly history are significantly stronger than the random scatter induced by this stochasticity. The sensitivity of $\sim L^\star$ galaxy evolution to dark matter halo assembly follows from the close coupling of the growth histories of the central black hole (BH) and the halo, such that earlier assembly fosters the formation of a more massive BH, and more efficient expulsion of circumgalactic gas. In response to this expulsion, the circumgalactic medium reconfigures at a lower density, extending its cooling time and thus inhibiting the replenishment of the interstellar medium. Our results indicate that halo assembly history significantly influences the evolution of $\sim L^\star$ central galaxies, and that the expulsion of circumgalactic gas is a crucial step in quenching them