Response of micro-algae in the Kromme Estuary to managed freshwater inputs

The Kromme is a permanently open estuary that receives little freshwater input because the capacity of the dams is equivalent to the mean annual runoff from the catchment. The estuary is marine dominated and phytoplankton chlorophyll a is low because of the low freshwater pulses that introduce nutrient-rich freshwater. Water released (2 x 106 m3) from the Mpofu Dam in 1998 produced little micro-algal response in the estuary. The study reported here addresses further runoff scenarios to see which might be beneficial in stimulating microalgal production. Recent surveys together with past research were used to describe the present state and reference condition of the estuary. Average intertidal chlorophyll a was 12.9 ± 2.5 μg·g-1 of sediment and 4.9 ± 0.4 μg·g-1 of sediment during November 2003 and July 2004. These concentrations are relatively low but comparable to those found in intertidal sediments in other South African estuaries and might indicate that intertidal microalgal biomass is not severely limited by low freshwater inputs. Average water column chlorophyll a concentrations have ranged from 0.6 ± 0.1 to 5.6 ± 0.3 μg·ℓ-1. Present state conditions can thus be described as those where water column chlorophyll a seldom exceeds 5 μg·ℓ-1 and small flagellates (3.5 μm x 2.8 μm) dominate the phytoplankton. The diatoms introduced via freshwater have been lost. Under reference conditions before the Mpofu Dam was built, baseflow would have been greater than 1 m3·s-1 for approximately 8 months of the year. The flocculation of fine particles associated with the mixing of fresh and saline waters would have resulted in phytoplankton peaks (chl a >10 μg·ℓ-1) in the middle reaches of the estuary. A more suitable habitat might also have been present for the epipelic (mud associated) benthic microalgae. An assessment of the future runoff scenarios indicated that the most beneficial for the microalgae would be a flow release from the Mpofu Dam of 5 x 106 m3 in October and then again in January. This would stimulate a 25 to 33% increase in phytoplankton chlorophyll a and a doubling in intertidal benthic chlorophyll a for a period of two months following the releases. Water SA Vol 32(1)pp:71-8

The response of microalgal biomass and community composition to environmental factors in the Sundays Estuary

The Sundays Estuary is permanently open to the sea and experiences regular freshwater inflow in the form of agricultural return flows with large supplies of nutrients. The objectives of this study were to measure microalgal biomass and community composition and relate these to freshwater inflow, water quality and other environmental variables. These data can then be used in setting the ecological water requirements of the estuary. Surveys in August 2006, March 2007, February, June and August 2008 showed that salinity less than 10, expressed in practical salinity units, mostly occurred from 12.5 km from the mouth in the middle reaches of the estuary, which was also where the highest water column chlorophyll a (>20 ƒÊgE.-1) was found. The study showed that different groups of microalgae formed phytoplankton blooms during individual samplingsessions. These included blooms of green algae (August 2006), flagellates (March 2007), dinoflagellates (June 2008) and diatom species (February and August 2008). The estuary was then sampled over 5 consecutive weeks from March to April 2009 to identify environmental factors that support different microalgal bloom species. Phytoplankton blooms werefound during Weeks 1, 4 and 5 from the middle to the upper reaches of the estuary. It was shown that diatoms occurred in blooms during warm, calm conditions whereas wind-mixing and reduced temperature, as a result of a cold front during 17 to 19 March 2009, promoted the dominance of flagellates throughout the estuary although they were present at all times.Dominant diatom species (Cylindrotheca closterium, Cyclotella atomus and Cyclostephanus dubius) indicated brackish, nutrient-rich water. Nanoplankton (2.7 - 20 ƒÊm) was dominant during each week sampled and contributed 55 - 79% to the phytoplankton biomass. Maximum benthic chlorophyll a was found 12.5 km from the mouth. This study is the first to show successive chlorophyll a blooms consisting of different phytoplankton groups in an estuary, an indication of the eutrophicstate of the system

Mining and analysis of audiology data to find significant factors associated with tinnitus masker

Objectives: The objective of this research is to find the factors associated with tinnitus masker from the literature, and by using the large amount of audiology data available from a large NHS (National Health Services, UK) hearing aid clinic. The factors evaluated were hearing impairment, age, gender, hearing aid type, mould and clinical comments. Design: The research includes literature survey for factors associated with tinnitus masker, and performs the analysis of audiology data using statistical and data mining techniques. Setting: This research uses a large audiology data but it also faced the problem of limited data for tinnitus. Participants: It uses 1,316 records for tinnitus and other diagnoses, and 10,437 records of clinical comments from a hearing aid clinic. Primary and secondary outcome measures: The research is looking for variables associated with tinnitus masker, and in future, these variables can be combined into a single model to develop a decision support system to predict about tinnitus masker for a patient. Results: The results demonstrated that tinnitus maskers are more likely to be fit to individuals with milder forms of hearing loss, and the factors age, gender, type of hearing aid and mould were all found significantly associated with tinnitus masker. In particular, those patients having Age<=55 years were more likely to wear a tinnitus masker, as well as those with milder forms of hearing loss. ITE (in the ear) hearing aids were also found associated with tinnitus masker. A feedback on the results of association of mould with tinnitus masker from a professional audiologist of a large NHS (National Health Services, UK) was also taken to better understand them. The results were obtained with different accuracy for different techniques. For example, the chi-squared test results were obtained with 95% accuracy, for Support and Confidence only those results were retained which had more than 1% Support and 80% Confidence. Conclusions: The variables audiograms, age, gender, hearing aid type and mould were found associated with the choice of tinnitus masker in the literature and by using statistical and data mining techniques. The further work in this research would lead to the development of a decision support system for tinnitus masker with an explanation that how that decision was obtained

Mosquito Abundance, Bed net Coverage and Other Factors Associated with Variations in Sporozoite Infectivity Rates in Four Villages of Rural Tanzania.

Entomological surveys are of great importance in decision-making processes regarding malaria control strategies because they help to identify associations between vector abundance both species-specific ecology and disease intervention factors associated with malaria transmission. Sporozoite infectivity rates, mosquito host blood meal source, bed net coverage and mosquito abundance were assessed in this study. A longitudinal survey was conducted in four villages in two regions of Tanzania. Malaria vectors were sampled using the CDC light trap and pyrethrum spray catch methods. In each village, ten paired houses were selected for mosquitoes sampling. Sampling was done in fortnight case and study was undertaken for six months in both Kilimanjaro (Northern Tanzania) and Dodoma (Central Tanzania) regions. A total of 6,883 mosquitoes were collected including: 5,628 (81.8%) Anopheles arabiensis, 1,100 (15.9%) Culex quinquefasciatus, 89 (1.4%) Anopheles funestus, and 66 (0.9%) Anopheles gambiae s.s. Of the total mosquitoes collected 3,861 were captured by CDC light trap and 3,022 by the pyrethrum spray catch method. The overall light trap: spray catch ratio was 1.3:1. Mosquito densities per room were 96.5 and 75.5 for light trap and pyrethrum spray catch respectively. Mosquito infectivity rates between villages that have high proportion of bed net owners and those without bed nets was significant (P < 0.001) and there was a significant difference in sporozoite rates between households with and without bed nets in these four villages (P < 0.001). Malaria remains a major problem in the study areas characterized as low transmission sites. Further studies are required to establish the annual entomological inoculation rates and to observe the annual parasitaemia dynamics in these communities. Outdoor mosquitoes collection should also be considered

Positivity of the English language

Over the last million years, human language has emerged and evolved as a fundamental instrument of social communication and semiotic representation. People use language in part to convey emotional information, leading to the central and contingent questions: (1) What is the emotional spectrum of natural language? and (2) Are natural languages neutrally, positively, or negatively biased? Here, we report that the human-perceived positivity of over 10,000 of the most frequently used English words exhibits a clear positive bias. More deeply, we characterize and quantify distributions of word positivity for four large and distinct corpora, demonstrating that their form is broadly invariant with respect to frequency of word use.Comment: Manuscript: 9 pages, 3 tables, 5 figures; Supplementary Information: 12 pages, 3 tables, 8 figure

Search for High Mass Photon Pairs in p-pbar --> gamma-gamma-jet-jet Events at sqrt(s)=1.8 TeV

A search has been carried out for events in the channel p-barp --> gamma gamma jet jet. Such a signature can characterize the production of a non-standard Higgs boson together with a W or Z boson. We refer to this non-standard Higgs, having standard model couplings to vector bosons but no coupling to fermions, as a "bosonic Higgs." With the requirement of two high transverse energy photons and two jets, the diphoton mass (m(gamma gamma)) distribution is consistent with expected background. A 90(95)% C.L. upper limit on the cross section as a function of mass is calculated, ranging from 0.60(0.80) pb for m(gamma gamma) = 65 GeV/c^2 to 0.26(0.34) pb for m(gamma gamma) = 150 GeV/c^2, corresponding to a 95% C.L. lower limit on the mass of a bosonic Higgs of 78.5 GeV/c^2.Comment: 9 pages, 3 figures. Replacement has new H->gamma gamma branching ratios and corresponding new mass limit

Search For Heavy Pointlike Dirac Monopoles

We have searched for central production of a pair of photons with high transverse energies in $p\bar p$ collisions at $\sqrt{s} = 1.8$ TeV using $70 pb^{-1}$ of data collected with the D\O detector at the Fermilab Tevatron in 1994--1996. If they exist, virtual heavy pointlike Dirac monopoles could rescatter pairs of nearly real photons into this final state via a box diagram. We observe no excess of events above background, and set lower 95% C.L. limits of $610, 870, or 1580 GeV/c^2$ on the mass of a spin 0, 1/2, or 1 Dirac monopole.Comment: 12 pages, 4 figure

DNA damage signalling prevents deleterious telomere addition at DNA breaks

The response to DNA damage involves regulation of multiple essential processes to maximize the accuracy of DNA damage repair and cell survival 1. Telomerase has the potential to interfere with repair by inappropriately adding telomeres to DNA breaks. It was unknown whether cells modulate telomerase in response to DNA damage, to increase the accuracy of repair. Here we report that telomerase action is regulated as a part of the cellular response to a DNA double-strand break (DSB). Using yeast, we show that the major ATR/Mec1 DNA damage signalling pathway regulates telomerase action at DSBs. Upon DNA damage, MEC1-RAD53-DUN1-dependent phosphorylation of the telomerase inhibitor Pif1 occurs. Utilizing a separation of function PIF1 mutation, we show that this phosphorylation is required for the Pif1-mediated telomerase inhibition that takes place specifically at DNA breaks, but not telomeres. Hence DNA damage signalling down-modulates telomerase action at a DNA break via Pif1 phosphorylation, thus preventing aberrant healing of broken DNA ends by telomerase. These findings uncover a novel regulatory mechanism that coordinates competing DNA end-processing activities and thereby promotes DNA repair accuracy and genome integrity

Ratio of the Isolated Photon Cross Sections at \sqrt{s} = 630 and 1800 GeV

The inclusive cross section for production of isolated photons has been measured in \pbarp collisions at $\sqrt{s} = 630$ GeV with the \D0 detector at the Fermilab Tevatron Collider. The photons span a transverse energy ($E_T$) range from 7-49 GeV and have pseudorapidity $|\eta| < 2.5$. This measurement is combined with to previous \D0 result at $\sqrt{s} = 1800$ GeV to form a ratio of the cross sections. Comparison of next-to-leading order QCD with the measured cross section at 630 GeV and ratio of cross sections show satisfactory agreement in most of the $E_T$ range.Comment: 7 pages. Published in Phys. Rev. Lett. 87, 251805, (2001

Observation of associated near-side and away-side long-range correlations in √sNN=5.02 TeV proton-lead collisions with the ATLAS detector

Two-particle correlations in relative azimuthal angle (Δϕ) and pseudorapidity (Δη) are measured in √sNN=5.02  TeV p+Pb collisions using the ATLAS detector at the LHC. The measurements are performed using approximately 1  μb-1 of data as a function of transverse momentum (pT) and the transverse energy (ΣETPb) summed over 3.1<η<4.9 in the direction of the Pb beam. The correlation function, constructed from charged particles, exhibits a long-range (2<|Δη|<5) “near-side” (Δϕ∼0) correlation that grows rapidly with increasing ΣETPb. A long-range “away-side” (Δϕ∼π) correlation, obtained by subtracting the expected contributions from recoiling dijets and other sources estimated using events with small ΣETPb, is found to match the near-side correlation in magnitude, shape (in Δη and Δϕ) and ΣETPb dependence. The resultant Δϕ correlation is approximately symmetric about π/2, and is consistent with a dominant cos⁡2Δϕ modulation for all ΣETPb ranges and particle pT