Fecal contamination of drinking-water in low- and middle-income countries: a systematic review and meta-analysis

Background: access to safe drinking-water is a fundamental requirement for good health and is also a human right. Global access to safe drinking-water is monitored by WHO and UNICEF using as an indicator “use of an improved source,” which does not account for water quality measurements. Our objectives were to determine whether water from “improved” sources is less likely to contain fecal contamination than “unimproved” sources and to assess the extent to which contamination varies by source type and setting.Methods and findings: studies in Chinese, English, French, Portuguese, and Spanish were identified from online databases, including PubMed and Web of Science, and grey literature. Studies in low- and middle-income countries published between 1990 and August 2013 that assessed drinking-water for the presence of Escherichia coli or thermotolerant coliforms (TTC) were included provided they associated results with a particular source type. In total 319 studies were included, reporting on 96,737 water samples. The odds of contamination within a given study were considerably lower for “improved” sources than “unimproved” sources (odds ratio [OR] = 0.15 [0.10–0.21], I2 = 80.3% [72.9–85.6]). However over a quarter of samples from improved sources contained fecal contamination in 38% of 191 studies. Water sources in low-income countries (OR = 2.37 [1.52–3.71]; p<0.001) and rural areas (OR = 2.37 [1.47–3.81] p<0.001) were more likely to be contaminated. Studies rarely reported stored water quality or sanitary risks and few achieved robust random selection. Safety may be overestimated due to infrequent water sampling and deterioration in quality prior to consumption.Conclusion: access to an “improved source” provides a measure of sanitary protection but does not ensure water is free of fecal contamination nor is it consistent between source types or settings. International estimates therefore greatly overstate use of safe drinking-water and do not fully reflect disparities in access. An enhanced monitoring strategy would combine indicators of sanitary protection with measures of water qualit

Blood-feeding in the young adult filarial worms litomosoides sigmodontis

In this study with the filarial model Litomosoides sigmodontis, we demonstrate that the worms ingest host red blood cells at a precise moment of their life-cycle, immediately after the fourth moult. The red blood cells (RBC) were identified microscopically in live worms immobilized in PBS at 4 degrees C, and their density assessed. Two hosts were used: Mongolian gerbils, where microfilaraemia is high, and susceptible BALB/c mice with lower microfilaraemia. Gerbils were studied at 12 time-points, between day 9 post-inoculation (the worms were young 4th stage larvae) and day 330 p.i. (worms were old adults). Only the very young adult filarial worms had red blood cells in their gut. Haematophagy was observed between days 25 and 56 p.i. and peaked between day 28 and day 30 p.i. in female worms. In males, haematophagy was less frequent and intense. Similar kinetics of haematophagy were found in BALB/c mice, but frequency and intensity tended to be lower. Haematophagy seems useful to optimize adult maturation. These observations suggest that haematophagy is an important step in the life-cycle of L. sigmodontis. This hitherto undescribed phenomenon might be characteristic of other filarial species including human parasites

Cost effective flat plate photovoltaic modules using light trapping

Work in optical trapping in 'thick films' is described to form a design guide for photovoltaic engineers. A thick optical film can trap light by diffusive reflection and total internal reflection. Light can be propagated reasonably long distances compared with layer thicknesses by this technique. This makes it possible to conduct light from inter-cell and intra-cell areas now not used in photovoltaic modules onto active cell areas

The Proposed Eastern Nebraska International Airport Plan

Excerpt from the prologue: Passenger growth has led to expansion of facilities at both the Omaha and Lincoln airports; but like many others in the nation, they are rapidly becoming congested. The Federal Aviation Administration, the State Government officials, and many civic leaders in Nebraska are now becoming aware of the need for establishing a regional airport for the Eastern Nebraska region in order to promote and handle international air transportation for the future. People are also beginning to think of such a modern airport as an essential factor in bringing new industries to Nebraska and in shaping the urbanization of the Midwest. Currently, facilities at Omaha\u27s Eppley Airfield are being expanded, and plans for expansion of facilities at Lincoln Municipal Airport are being formulated. The disadvantage of this approach is that airports within the region are being planned, organized and operated largely as independent entities without regard to integrated long-range regional needs. It is the purpose of this study to present the concept of an airport for the eastern Nebraska region, as one alternative for meeting future air transportation needs. The plan is conceptual in nature and is intended to serve as a general guide for public discussion of the regional airport proposal. More detailed studies for its implementation would be required. This study was initiated in the spring of 1967. Its first phase, concerning background factors and the resources of the Lincoln- Omaha region, was completed in a preliminary report in March 1968. Its second phase, the Concept Plan for a regional airport, was developed in the spring of 1969. During the fall months, at the request of Lincoln and Omaha business leaders who sponsored the publication of this study, the total work was revised and enlarged. Contents Air Transportation Development Socio-economic Considerations Physical Considerations Site Selection Metholodology Airport Financing Regional Development Concepts International Airport Plan Program for Plan Implementatio

The p66\u3csup\u3eShc\u3c/sup\u3e adaptor protein controls oxidative stress response in early bovine embryos

The in vitro production of mammalian embryos suffers from high frequencies of developmental failure due to excessive levels of permanent embryo arrest and apoptosis caused by oxidative stress. The p66Shc stress adaptor protein controls oxidative stress response of somatic cells by regulating intracellular ROS levels through multiple pathways, including mitochondrial ROS generation and the repression of antioxidant gene expression. We have previously demonstrated a strong relationship with elevated p66Shc levels, reduced antioxidant levels and greater intracellular ROS generation with the high incidence of permanent cell cycle arrest of 2-4 cell embryos cultured under high oxygen tensions or after oxidant treatment. The main objective of this study was to establish a functional role for p66Shc in regulating the oxidative stress response during early embryo development. Using RNA interference in bovine zygotes we show that p66Shc knockdown embryos exhibited increased MnSOD levels, reduced intracellular ROS and DNA damage that resulted in a greater propensity for development to the blastocyst stage. P66Shc knockdown embryos were stress resistant exhibiting significantly reduced intracellular ROS levels, DNA damage, permanent 2-4 cell embryo arrest and diminished apoptosis frequencies after oxidant treatment. The results of this study demonstrate that p66Shc controls the oxidative stress response in early mammalian embryos. Small molecule inhibition of p66Shc may be a viable clinical therapy to increase the developmental potential of in vitro produced mammalian embryos. © 2014 Betts et al

Cognitive Resources Are Recruited Consistently Across People During Story Listening

Degraded speech encoding as a result of hearing loss increases cognitive load and makes listening effortful. Standard hearing assessment does not capture this cognitive impact of hearing impairment. Speech-in-noise testing measures intelligibility for isolated sentences that are typically not engaging and lack meaningful context. These materials may not capture the processes involved in everyday listening situations, in which people are often intrinsically motivated to comprehend the speech they are hearing. The current study explored a novel approach using natural, spoken stories. We first characterized time courses of executive load during story listening in young individuals with normal hearing using a reaction time (RT) task. We then computed correlations between executive load time courses (operationalized as reaction times) to quantify their reliability. Reaction-time time courses were significantly correlated across participants, suggesting consistent cognitive recruitment across individuals. Synchronization of RTs across participants was related to ratings of story enjoyment, but not absorption, suggesting that enjoyment, one key facet of engagement, predicts the degree to which a story’s cognitive demands are experienced similarly by listeners. Correlated executive load time courses among healthy individuals may be sensitive to abnormal mental states: divergence from the canonical time courses characterized here could serve as a sensitive tool for characterizing listening effort

A model for mark size dependence on field emission voltage in heat-assisted magnetic probe recording on CoNi/Pt multilayers

A method of heat-assisted magnetic recording (HAMR) potentially suitable for probe-based storage systems is characterized. In this work, field emission current from a scanning tunneling microscope (STM) tip is used as the heating source. Pulse voltages of 2-7 V with a duration of 500 ns were applied to a CoNi/Pt multilayered film. Different types of Ir/Pt and W STM tips were used in the experiment. The results show that thermally recorded magnetic marks are formed with a nearly uniform mark size of 170 nm when the pulse voltage is above a threshold voltage. The threshold voltage depends on the material work function of the tip, with W having a threshold voltage about 1 V lower than Pt. The emission area of our tip-sample system derived from an analytic expression for field emission current is approximately equal to the mark size, and is largely independent of pulse voltage. This emission area is large compared to lateral heat diffusion in the film. Thus higher applied voltages lead to higher peak temperatures in the model of the write process, but the mark diameter remains relatively unchanged

The role of MFM signal in mark size measurement in probe-based magnetic recording on CoNi/Pt multilayers

A method of heat-assisted magnetic recording (HAMR) potentially suitable for probe-based storage systems is characterized. Magnetic marks were formed by a scanning tunneling microscopy (STM)-based thermal magnetic mechanism on a perpendicular CoNi/Pt multilayered film. Magnetic force microscopy (MFM) was applied to display those marks. The MFM signal is dependent of the lift-height during MFM scanning: smaller lift-height leads to higher resolution of the MFM image and a double-peak signal line, while higher lift-height leads to lower resolution and a single-peak signal line. Theoretical calculation of the magnetic field from the mark was executed. It agrees well with experiments, and demonstrates the method of mark size measurement in perpendicular media: full-width half-maximum (FWHM) of the measured MFM signal. \ud \u

AutoAD II: The Sequel - who, when, and what in movie audio description

Audio Description (AD) is the task of generating descriptions of visual content, at suitable time intervals, for the benefit of visually impaired audiences. For movies, this presents notable challenges -- AD must occur only during existing pauses in dialogue, should refer to characters by name, and ought to aid understanding of the storyline as a whole. To this end, we develop a new model for automatically generating movie AD, given CLIP visual features of the frames, the cast list, and the temporal locations of the speech; addressing all three of the `who', `when', and `what' questions: (i) who -- we introduce a character bank consisting of the character's name, the actor that played the part, and a CLIP feature of their face, for the principal cast of each movie, and demonstrate how this can be used to improve naming in the generated AD; (ii) when -- we investigate several models for determining whether an AD should be generated for a time interval or not, based on the visual content of the interval and its neighbours; and (iii) what -- we implement a new vision-language model for this task, that can ingest the proposals from the character bank, whilst conditioning on the visual features using cross-attention, and demonstrate how this improves over previous architectures for AD text generation in an apples-to-apples comparison

Dynamic domain motion of thermal-magnetically formed marks on CoNi/Pt multilayers

We characterized a method of heat-assisted magnetic recording, which is potentially suitable for probe-based storage systems. The field emission current from a scanning tunneling microscope tip was used as the heating source. Various pulse voltages were applied to two types of CoNi/Pt multilayered films: one is strongly coupled with low coercivity, and the other is weakly coupled with high coercivity. Experimental results show that marks achieved in strongly coupled medium are larger than that in granular one. An external magnetic field was then applied to those marks. For weak fields (lower than the coercivity of the medium) the size of marks changes distinctly in the strongly coupled medium but not in the granular one. A model of magnetic domain dynamics is built to quantitatively explain the experimental results. It agrees with experiments. Based on this model, we will be able to figure out the proposals to achieve small marks for ultrahigh recording density. © 2006 American Institute of Physics.\ud \u