Optical trapping and surgery of living yeast cells using a single laser

We present optical trapping and surgery of living yeast cells using two operational modes of a single laser. We used a focused laser beam operating in continuous-wave mode for noninvasive optical trapping and manipulation of single yeast cell. We verified that such operational mode of the laser does not cause any destructive effect on yeast cell wall. By changing the operation of the laser to femtosecond-pulsed mode, we show that a tightly focused beam dissects the yeast cell walls via nonlinear absorption. Lastly, using the combined technique of optical microsurgery and trapping, we demonstrate intracellular organelle extraction and manipulation from a yeast cell. The technique established here will be useful as an efficient method for both surgery and manipulation of living cells using a single laser beam.The project has been funded by the Philippine Council for Advanced Science and Technology Research and Development PCASTRD. J. Ando acknowledges the support of the Japan Student Services Organization JASSO for the short-term student exchange promotion program

Nautical Chart Adequacy Evaluation Using Publicly-Available Data

The International Hydrographic Office (IHO) C-55 publication communicates the need to improve the collection, quality and availability of hydrographic data world-wide, while also monitoring and rectifying possible deficiencies and shortcomings that are presented on the chart. This task of evaluating the adequacy of nautical chart products poses a challenge to many national hydrographic offices. This stems from the dearth of readily available spatial information: namely, the lack of reliable and accessible vessel traffic data, and little means to assess the changing nature of both near-shore bathymetry and shoreline in a simple and reliable manner. In this paper, we present the potential use of automatic-identification system (AIS) data, satellite-derived bathymetry (SDB), and airborne-lidar bathymetry (ALB) to provide an operational procedure for evaluating the adequacy and completeness of information of NOAA charts. Preliminary results from three U.S. study sites are presented in this paper: Nantucket Sound, MA; Barnegat Bay Inlet, NJ; and Barataria Bay, LA. Based on the publically-available datasets it was possible to identify changes in the charts and develop a reconnaissance procedure to monitor these changes on a yearly basis

WILLINGNESS TO PAY FOR ENVIRONMENTAL SERVICES AMONG SLASH-AND-BURN FARMERS IN THE PERUVIAN AMAZON: IMPLICATIONS FOR DEFORESTATION AND GLOBAL ENVIRONMENTAL MARKETS

A Contingent Valuation survey shows that the possibility of trade in carbon sequestration services exists between utility companies and slash-and-burn farmers in the Amazon and that farmers positively value the environmental services of the forest. Global environmental markets could enhance the effectiveness of traditional forest conservation efforts while benefitting resource-poor farmers.Environmental Economics and Policy,

Enhanced diffraction by a rectangular grating made of a negative phase--velocity (or negative index) material

The diffraction of electromagnetic plane waves by a rectangular grating formed by discrete steps in the interface of a homogeneous, isotropic, linear, negative phase--velocity (negative index) material with free space is studied using the semi--analytic C method. When a nonspecular diffracted order is of the propagating type, coupling to that order is significantly larger for a negative index material than for conventional material. The computed coupling strengths reported here are in agreement with recent experiments, and illustrate the role of evanescent fields localized at the grating interface in producing this enhanced coupling.Comment: 12 pages, 4 figure

Human Decompression Modelling

At present, no decompression algorithm is able to predict safe decompression for all dive scenarios. In practice, empirical adjustments are made by experienced organisations or divers in order to improve decompression profiles for the range of depths and durations needed on any particular dive. Bubble formation and growth in the human body are the fundamental causes of decompression sickness, and it is believed that there is significant scope for incorporating better modelling of these processes into the design of decompression algorithms. VR Technology is a leading supplier of technical dive computers. The company is interested in expanding upon an existing algorithm (the Variable Gradient Model - VGM), which is used to design ascent profiles/decompression schedules and thereby mitigate the risk of decompression sickness in divers. The Study Group took the approach of trying to extend the existing Haldane model to account more explicitly for the formation of bubbles. By extending the model to include bubble dynamics it was expected that some physical understanding could be gained for the existing modifications to some of the parameters. The modelling that occurred consisted of first looking at the Haldane model and then considering a single small isolated bubble in each of the compartments and interpreting the predictions of the model in terms of decompression profiles

Dynamic clusters (Dynamic Location of Phone Call Clusters)

When mobile handsets are making a call, a measurement report is sent to the serving base station periodically which includes the signal strengths to the base station and the next six strongest signals of the surrounding base stations. Motorola asked the Study Group if it was possible to say whether we could use this information to infer if phone calls occur in clusters and if it was possible to determine the locations, size and other features of these clusters. The Study Group found clusters in 'signal space,' that is, handsets reporting similar signal strengths with the same base stations and explored methods of locating these clusters geographically

Band gap control via tuning of inversion degree in CdIn2_2S4_4 spinel

Based on theoretical arguments we propose a possible route for controlling the band-gap in the promising photovoltaic material CdIn$_2$S$_4$. Our \textit{ab initio} calculations show that the experimental degree of inversion in this spinel (fraction of tetrahedral sites occupied by In) corresponds approximately to the equilibrium value given by the minimum of the theoretical inversion free energy at a typical synthesis temperature. Modification of this temperature, or of the cooling rate after synthesis, is then expected to change the inversion degree, which in turn sensitively tunes the electronic band-gap of the solid, as shown here by accurate screened hybrid functional calculations.Comment: In press in Applied Physics Letters (2012); 4 pages, 2 figures, 1 tabl

What are the indications for urodynamic testing in older adults with incontinence?

Urodynamic testing is indicated for older adults with incontinence when the underlying cause remains unclear (Grade of Recommendation: B, based on multiple well designed, but inconsistent, randomized controlled trials [RCTs]). Simple cystometry -- specifically, measuring post void residual and bladder capacity -- is helpful in the evaluation of urinary incontinence when the cause has remained unclear. It may also offer benefit when surgery is under consideration, when there is a history of genitourinary surgery, or when a conservative therapeutic trial has not had an adequate response (Grade of Recommendation: C, based on a small number of RCTs, retrospective cohort studies and systemic reviews)

Failure of Passive Transfer in Camel Calves: 4 Cases (2010-2019)

Failure of passive transfer is a management concern for all ruminant species, but is not well described in the literature for camel calves. This case series presents four camel calves (Camelus dromedarius and Camelus bactrianus) referred to a North American veterinary teaching hospital for diagnosis and management of failure of passive transfer. Diagnostics utilized included hematology, serum biochemistry, and immunologic methods as described for crias. Management included antimicrobial, anti-inflammatory, and plasma transfusion therapies. Three of the four calves survived to discharge, and common diagnostic practices such as evaluation of total solids, total protein, immunoglobulin G, and sodium sulfite appear to be correlate to passive transfer status in these four calves. Xenotransfusion with llama plasma was well tolerated by two calves, and xenotransfusion with bovine plasma was well tolerated by an additional calf in this study. Additional work is necessary to develop validated breakpoints for diagnosis of passive transfer status in camel calves