Temporal multiplexing with adaptive optics for simultaneous vision.

We present and test a methodology for generating simultaneous vision with a deformable mirror that changed shape at 50 Hz between two vergences: 0 D (far vision) and -2.5 D (near vision). Different bifocal designs, including toric and combinations of spherical aberration, were simulated and assessed objectively. We found that typical corneal aberrations of a 60-year-old subject changes the shape of objective through-focus curves of a perfect bifocal lens. This methodology can be used to investigate subjective visual performance for different multifocal contact or intraocular lens designs

Objective Amplitude of Accommodation Computed from Optical Quality Metrics Applied to Wavefront Outcomes

AbstractPurposeWe studied the accuracy and precision of 32 objective wavefront methods for finding the amplitude of accommodation obtained in 180 eyes.MethodsOcular accommodation was stimulated with 0.5 D steps in target vergence spanning the full range of accommodation for each subject. Subjective monocular amplitude of accommodation was measured using two clinical methods, using negative lenses and with a custom Badal optometer.ResultsBoth subjective methods gave similar results. Results obtained from the Badal optometer where used to test the accuracy of the objective methods. All objective methods showed lower amplitude of accommodation that the subjective ones by an amount that varied from 0.2 to 1.1 D depending on the method. The precision in this prediction also varied between subjects, with an average standard error of the mean of 0.1 D that decreased with age.ConclusionsDepth of field increases subjective of amplitude of accommodation overestimating the objective amplitude obtained with all the metrics used. The change in the negative direction of spherical aberration during accommodation increases the amplitude of accommodation by an amount that varies with age

Short term administration of cyproterone acetate for contraception: Effects on testosterone secretion and semen characteristics in rams (Ovis aries) and bucks (Capra hircus)

Aim of study: To examine the influence of administering cyproterone acetate (CPA), at the beginning of the mating season, on the testosterone concentration and morphometric and functional characteristics of ram and buck semen.Area of study: Madrid, SpainMaterial and methods: Five rams and five bucks were intramuscularly administered 200 mg of CPA in 2 mL of olive oil twice per week - from July 1st to 31st in the rams, and from August 1st to 31st in the bucks. Five control animals of each species were administered 2 mL of olive oil. Blood samples and ejaculates analysed from the start of treatment until eight weeks after the last day of treatment.Main results: GLM-ANOVA showed the interaction species × CPA treatment to have effect (p<0.05) on sperm motility, progressive motility and acrosome integrity; and greater effect (p<0.01) on curvilinear velocity (VCL), straight-line velocity (VSL), viability, and morphological abnormalities. In both the rams and bucks, plasma testosterone levels fell from the first week from the start of CPA administration until three weeks after the end of treatment. In rams, the total sperm count, sperm motility, progressive motility, viability, morphological abnormalities, VCL and VSL were all negatively affected by the treatment (p<0.001); acrosome integrity was also affected (p<0.05). In bucks, sperm motility, progressive motility, VCL, VSL and morphological abnormalities were negatively affected (p<0.05).Research highlights: Treatment with CPA affected testosterone secretion, semen characteristics and sperm morphometry in both the rams and bucks, and thus it might be used as short term contraceptive protocol in small ruminants

Positive Psychology: Supervisor Leadership in Organizational Citizenship Behaviors in Nurses

Introduction: In nursing, identifying factors encouraging positive work attitudes is ex-tremely important since a nurse’s performance directly impacts the quality of the care they provide, and, therefore, their patients’ health. Objective: The main objective of this research is to analyze whether the supervisor–nurse relationship is positively correlated with a nurse’s organizational citizenship behaviors. Thus, we established a main hypothesis as follows: the quality of the supervi-sor–nurse interpersonal relationship is positively related to the job satisfaction of the nurse, controlled by moderating the effects of psychological empowerment, the perceived organizational sup-port, and leader–leader exchange. Methodology: This is a cross-sectional descriptive study with individuals as the units of analysis. The population studied comprised all the nurses and supervisors working in nine public hospitals in the autonomous community of Aragon (Spain). The sample con-sisted of 2541 nurses, 192 supervisors, and 2500 paired dyads. Self-report questionnaires were used to ensure workers’ anonymity. The dependent variable was the nurse’s organizational citizenship behaviors; the main independent variable was the supervisor’s leadership; the moderating variables were the nurse’s empowerment, the organizational support the nurse perceived, and the quality of the supervisor–superior relationship. Results: Empirical evidence demonstrates that the quality of the supervisor–nurse relationship is positively correlated with organizational citizenship behaviors. The results also confirm the moderating effect of nurses’ empowerment and of the organizational support they perceive. Discussion: Our research shows how important it is for organizations to es-tablish management practices promoting high-quality nurse–supervisor relationships; thus, hospital management should monitor both the supervisors’ performance and leadership. Conclusions: The quality of the relationship the supervisor establishes with their nurses is vitally important since it is a necessary requirement for beneficial results for the organization as a result of citizenship behavior practice

Effect of Phenylephrine on the Accommodative System.

Accommodation is controlled by the action of the ciliary muscle and mediated primarily by parasympathetic input through postganglionic fibers that originate from neurons in the ciliary and pterygopalatine ganglia. During accommodation the pupil constricts to increase the depth of focus of the eye and improve retinal image quality. Researchers have traditionally faced the challenge of measuring the accommodative properties of the eye through a small pupil and thus have relied on pharmacological agents to dilate the pupil. Achieving pupil dilation (mydriasis) without affecting the accommodative ability of the eye (cycloplegia) could be useful in many clinical and research contexts. Phenylephrine hydrochloride (PHCl) is a sympathomimetic agent that is used clinically to dilate the pupil. Nevertheless, first investigations suggested some loss of functional accommodation in the human eye after PHCl instillation. Subsequent studies, based on different measurement procedures, obtained contradictory conclusions, causing therefore an unexpected controversy that has been spread almost to the present days. This manuscript reviews and summarizes the main research studies that have been performed to analyze the effect of PHCl on the accommodative system and provides clear conclusions that could help clinicians know the real effects of PHCl on the accommodative system of the human eye

ETV5 transcription program links BDNF and promotion of EMT at invasive front of endometrial carcinomas

Myometrial infiltration represents a main clinical determinant of endometrial carcinomas (EC) presenting as aggressive high-grade deeply invasive neoplasms, substantially associated with risk of recurrence and death. The up-regulation of ETV5 transcription factor linked to the promotion of epithelial to mesenchymal transition is considered as a basic mechanism underlying the initial steps of EC invasion. In this work, we aimed to investigate the transcription program of tumor invasion regulated by ETV5. We performed a comparative Chip-on-chip analysis at invasive front and superficial area of human EC. ETV5 specific binding to promoter regions of genes related to cellular migration, adhesion and invasion at deep invasion tumor areas highlighted the relevance of neural networks associated with cellular plasticity. Interestingly, brain-derived neurotrophic factor (BDNF) demonstrated a principal role orchestrating ETV5-mediated epithelial-to-mesenchymal transition in endometrial cancer. Impairment of the BDNF/tropomyosin-related kinase B (TrkB)/extracellular signal-regulated kinase axis in endometrial cancer cell lines reversed the aggressive and invasive phenotype promoted by the up-regulation of ETV5 at the invasive front of EC. Likewise, BDNF directly impacted on the efficiency of ETV5 promoted metastasis in a mice model of endometrial distant dissemination. These results translate the recognized role of BDNF/TrkB on neural plasticity into a relevant cancer metastasis event; suggest common mechanisms shared by neural development and tumor invasion; and offer new therapeutic opportunities specifically directed against disseminated disease in endometrial cancer

Review of concepts in therapeutic decision-making in HER2-negative luminal metastatic breast cancer

Purpose: Hormone receptor (HR)-positive, Human epidermal growth factor receptor 2 (HER2)-negative metastatic breast cancer (MBC) requires a therapeutic approach that takes into account multiple factors, with treatment being based on anti-estrogen hormone therapy (HT). As consensus documents are valuable tools that assist in the decision-making process for establishing clinical strategies and optimize the delivery of health services, this consensus document has been created with the aim of developing recommendations on cretiera for hormone sensitivity and resistance in HER2-negative luminal MBC and facilitating clinical decision-making. Methods: This consensus document was generated using a modification of the RAND/UCLA methodology, which included the definition of the project and identification of issues of interest, a non-exhaustive systematic review of the literature, an analysis and synthesis of the scientific evidence, preparation of recommendations, and external evaluation with a panel of 64 medical oncologists specializing in breast cancer. Results: A Spanish panel of experts reached consensus on 32 of the 32 recommendations/conclusions presented in the first round and were accepted with an approval rate of 100% about definition of metastatic disease not susceptible to local curative treatment, definition of hormone sensitivity and hormone resistance in metastatic luminal disease and therapeutic decision-making. Conclusion: We have developed a consensus document with recommendations on the treatment of patients with HER2-negative luminal MBC that will help to improve therapeutic benefits

Beryllium abundances in stars hosting giant planets

We have derived beryllium abundances in a wide sample of stars hosting planets, with spectral types in the range F7V-K0V, aimed at studying in detail the effects of the presence of planets on the structure and evolution of the associated stars. Predictions from current models are compared with the derived abundances and suggestions are provided to explain the observed inconsistencies. We show that while still not clear, the results suggest that theoretical models may have to be revised for stars with Teff<5500K. On the other hand, a comparison between planet host and non-planet host stars shows no clear difference between both populations. Although preliminary, this result favors a ``primordial'' origin for the metallicity ``excess'' observed for the planetary host stars. Under this assumption, i.e. that there would be no differences between stars with and without giant planets, the light element depletion pattern of our sample of stars may also be used to further investigate and constraint Li and Be depletion mechanisms.Comment: A&A in press -- accepted on the 22/02/2002 (11 pages, 6 figures included