Search

The Warwick Postgraduate Colloquium in Computer Science (WPCCS) is an annual event for research students in the Department of Computer Science at the University of Warwick. The aims of the colloquium are to provide: (i) an experience of a conference setting for students, (ii) a place to practise presentation skills, (iii) a place to receive feedback and suggestions on their research, and (iv) an opportunity to learn about research being performed by other attendees. WPCCS has been held annually since 2003, but since 2016 many changes have been made to the event; in particular the introduction of networking aids (such as conference guides and lanyards), a new venue, the introduction of guest speakers and various efforts to encourage attendance. Meanwhile the number of submissions has increased, placing strain on the colloquium’s schedule and budget. In this paper the organising committees from 2016, 2017, and 2018 reflect critically on the experience WPCCS delivers to the attendees. We present an examination of what worked well, what did not work, and what we would like to try in the future, with the aim that these experiences are useful to the organisers of similar events.

Summary Objectives Mortality among HIV patients with tuberculosis (TB) remains high in Eastern Europe (EE), but details of TB and HIV management remain scarce. Methods In this prospective study, we describe the TB treatment regimens of patients with multi-drug resistant (MDR) TB and use of antiretroviral therapy (ART). Results A total of 105 HIV-positive patients had MDR-TB (including 33 with extensive drug resistance) and 130 pan-susceptible TB. Adequate initial TB treatment was provided for 8% of patients with MDR-TB compared with 80% of those with pan-susceptible TB. By twelve months, an estimated 57.3% (95%CI 41.5–74.1) of MDR-TB patients had started adequate treatment. While 67% received ART, HIV-RNA suppression was demonstrated in only 23%. Conclusions Our results show that internationally recommended MDR-TB treatment regimens were infrequently used and that ART use and viral suppression was well below the target of 90%, reflecting the challenging patient population and the environment in which health care is provided. Urgent improvement of management of patients with TB/HIV in EE, in particular for those with MDR-TB, is needed and includes widespread access to rapid TB diagnostics, better access to and use of second-line TB drugs, timely ART initiation with viral load monitoring, and integration of TB/HIV care.

Using radiative transfer theory I show that for a given waveband, the total radiant energy, Qt, present within the water column (per square meter of surface) is proportional to the scalar irradiance just below the surface (E0(0)) and inversely proportional to the irradiance-weighted vertical attenuation coefficient for scalar irradiance (wK0,av), in accordance with where cw is the speed of light in the water. Further, Qt~~(0)=cwa where ~(0)is the net downward irradiance just below the surface, and a is the absorption coefficient of the water for the waveband in question. The average depth, zp, of all the photons in the water column in a given waveband is equal to (wKE,av)21, the reciprocal of the irradiance-weighted vertical attenuation coefficient for net downward irradiance. This conclusion, at which we arrive on theoretical grounds, is confirmed by numerical modeling of the underwater light field. In a sunlit ocean there exists, in the water column below 1.0 m 2 of surface at any given point in time in any specified waveband, a finite number of photons. The number of photons per unit volume decreases approximately exponen- tially with depth in a manner determined by the optical properties of the water. The whole population of photons in the water column will thus have a certain average depth, zp, with a value that is also determined by the optical properties of the water. I explore in what way the total number of photons in the water column, and their average depth, are related to certain inherent and apparent optical properties of the ocean.

Average vertical attenuation coefficients, K(av), for irradiance calculated by linear regression of ln E(z )o nz through the euphotic zone or from two irradiance values in a certain depth interval, are useful but somewhat arbitrary procedures for estimating these important apparent optical properties of the ocean. A more fundamental approach is to calculate an irradiance-weighted coefficient, w K(av), integrated over the whole water column, in which for each increment of depth, the corresponding irradiance value is used to weight the estimate of the irradiance coefficient in accordance with w K(av) 5 # K(z)E(z) dz/# E(z) dz. Attenuation coefficients calculated in this way exhibit ‘‘ 00 some interesting relationships both to certain other properties of the light field and to the inherent optical properties of the water. In particular, I find that for all types of irradiance w K(av) 5 E(0)/# E(z) dz, where E(0) is the value

OBJECTIVE: To evaluate the effect of time from seroconversion to a given CD4 cell count on progression to AIDS after that count after adjusting for updated CD4 cell counts. METHODS: Using pooled data from 19 seroconverter cohorts, we examined the association between the time from a CD4

ATRIPLA is licensed for use only in HIV-positive persons whose viral loads

Objectives The aim of this study was to determine whether the Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI)- or Cockcroft−Gault (CG)-based estimated glomerular filtration rates (eGFRs) performs better in the cohort setting for predicting moderate/advanced chronic kidney disease (CKD) or end-stage renal disease (ESRD). Methods A total of 9521 persons in the EuroSIDA study contributed 133 873 eGFRs. Poisson regression was used to model the incidence of moderate and advanced CKD (confirmed eGFR < 60 and < 30 mL/min/1.73 m2, respectively) or ESRD (fatal/nonfatal) using CG and CKD-EPI eGFRs. Results Of 133 873 eGFR values, the ratio of CG to CKD-EPI was ≥ 1.1 in 22 092 (16.5%) and the difference between them (CG minus CKD-EPI) was ≥ 10 mL/min/1.73 m2 in 20 867 (15.6%). Differences between CKD-EPI and CG were much greater when CG was not standardized for body surface area (BSA). A total of 403 persons developed moderate CKD using CG [incidence 8.9/1000 person-years of follow-up (PYFU); 95% confidence interval (CI) 8.0–9.8] and 364 using CKD-EPI (incidence 7.3/1000 PYFU; 95% CI 6.5–8.0). CG-derived eGFRs were equal to CKD-EPI-derived eGFRs at predicting ESRD (n = 36) and death (n = 565), as measured by the Akaike information criterion. CG-based moderate and advanced CKDs were associated with ESRD [adjusted incidence rate ratio (aIRR) 7.17; 95% CI 2.65–19.36 and aIRR 23.46; 95% CI 8.54–64.48, respectively], as were CKD-EPI-based moderate and advanced CKDs (aIRR 12.41; 95% CI 4.74–32.51 and aIRR 12.44; 95% CI 4.83–32.03, respectively). Conclusions Differences between eGFRs using CG adjusted for BSA or CKD-EPI were modest. In the absence of a gold standard, the two formulae predicted clinical outcomes with equal precision and can be used to estimate GFR in HIV-positive persons.

Knowledge about advanced chronic kidney disease (CKD) and end-stage renal disease (ESRD) in HIV-positive persons is limited. The aim of this study was to investigate incidence, predictors and outcomes for advanced CKD/ESRD and renal death.Advanced CKD was defined as confirmed (two consecutive measurements ≥ 3 months apart) estimated glomerular filtration rate (eGFR) ≤ 30 mL/min/1.73 m(2) using Cockcroft-Gault, and ESRD as haemodialysis or peritoneal dialysis for ≥ 1 month or renal transplant. Renal death was death with renal disease as the underlying cause, using Coding Causes of Death in HIV (CoDe) methodology. Follow-up was from 1 January 2004 until last eGFR measurement, advanced CKD, ESRD or renal death, whichever occurred first. Poisson regression was used to identify predictors.Of 9044 individuals included in the study, 58 (0.64%) experienced advanced CKD/ESRD/renal death [incidence rate 1.32/1000 person-years of follow-up (PYFU); 95% confidence interval (CI) 0.98-1.66]; 52% of those who experienced the endpoint had a baseline eGFR ≤ 60 mL/min/1.73 m(2) compared with 3% of those who did not. Using Kaplan-Meier methods, at 6 years from baseline, 0.83% (95% CI 0.59-1.07%) were estimated to have experienced the endpoint overall and 11.26% (95% CI 6.75-15.78%) among those with baseline eGFR ≤ 60 mL/min/1.73 m(2) . Independent predictors of the endpoint included any cardiovascular event [incidence rate ratio (IRR) 2.16; 95% CI 1.24-3.77], lower eGFR (IRR 0.64 per 5 mL/min/1.73 m(2) ; 95% CI 0.59-0.70) and lower CD4 count (IRR 0.77 per doubling; 95% CI 0.62-0.95). One year after experiencing advanced CKD or ESRD, an estimated 19.21% (95% CI 7.84-30.58%) of patients had died, mostly from extra-renal causes.The incidence of advanced CKD/ESRD/renal death was low and predictors included traditional renal risk factors, HIV-related factors and pre-existing renal impairment. The prognosis following advanced CKD/ESRD was poor. Larger studies should address possible contributions of specific antiretrovirals.

We examined whether determinants of disease progression and causes of death differ between injecting drug users (IDUs) and non-IDUs who initiate combination antiretroviral therapy (cART).The ART Cohort Collaboration combines data from participating cohort studies on cART-naïve adults from cART initiation. We used Cox models to estimate hazard ratios for death and AIDS among IDUs and non-IDUs. The cumulative incidence of specific causes of death was calculated and compared using methods that allow for competing risks.Data on 6269 IDUs and 37 774 non-IDUs were analysed. Compared with non-IDUs, a lower proportion of IDUs initiated cART with a CD4 cell count200 cells/μL or had a prior diagnosis of AIDS. Mortality rates were higher in IDUs than in non-IDUs (2.08 vs. 1.04 per 100 person-years, respectively; P0.001). Lower baseline CD4 cell count, higher baseline HIV viral load, clinical AIDS at baseline, and later year of cART initiation were associated with disease progression in both groups. However, the inverse association of baseline CD4 cell count with AIDS and death appeared stronger in non-IDUs than in IDUs. The risk of death from each specific cause was higher in IDUs than non-IDUs, with particularly marked increases in risk for liver-related deaths, and those from violence and non-AIDS infection.While liver-related deaths and deaths from direct effects of substance abuse appear to explain much of the excess mortality in IDUs, they are at increased risk for many other causes of death, which may relate to suboptimal management of HIV disease in these individuals.

The aim of the study was to estimate the rates of cardiovascular disease (CVD) events after stopping smoking in patients with HIV infection.Patients who reported smoking status and no previous CVD prior to enrolment in the Data Collection on Adverse Events of Anti-HIV Drugs (D:A:D) study were included in this study. Smoking status is collected at each visit as current smoker (yes/no) and ever smoker (yes/no). Time since stopping smoking was calculated for persons who had reported current smoking during follow-up and no current smoking subsequently. Endpoints were: myocardial infarction (MI); coronary heart disease (CHD: MI plus invasive coronary artery procedure or death from other CHD); CVD (CHD plus carotid artery endarterectomy or stroke); and all-cause mortality. Event rates were calculated for never, previous and current smokers, and smokers who stopped during follow-up. Incidence rate ratios (IRRs) were determined using Poisson regression adjusted for age, sex, cohort, calendar year, family history of CVD, diabetes, lipids, blood pressure and antiretroviral treatment.A total of 27 136 patients had smoking status reported, with totals of 432, 600, 746 and 1902 MI, CHD, CVD and mortality events, respectively. The adjusted IRR of CVD in patients who stopped smoking during follow-up decreased from 2.32 within the first year of stopping to 1.49 after3 years compared with those who never smoked. Similar trends were observed for the MI and CHD endpoints. Reductions in risk were less pronounced for all-cause mortality.The risk of CVD events in HIV-positive patients decreased with increasing time since stopping smoking. Smoking cessation efforts should be a priority in the management of HIV-positive patients.

Across Europe, almost a third of individuals infected with HIV do not enter health care until late in the course of their infection. Surveillance to identify the extent to which late presentation occurs remains inadequate across Europe and is further complicated by the lack of a common clinical definition of late presentation. The objective of this article is to present a consensus definition of late presentation of HIV infection.Over the past year, two initiatives have moved towards a harmonized definition. In spring 2009, they joined efforts to identify a common definition of what is meant by a 'late-presenting' patient.Two definitions were agreed upon, as follows. Late presentation: persons presenting for care with a CD4 count below 350 cells/μL or presenting with an AIDS-defining event, regardless of the CD4 cell count. Presentation with advanced HIV disease: persons presenting for care with a CD4 count below 200 cells/μL or presenting with an AIDS-defining event, regardless of the CD4 cell count.The European Late Presenter Consensus working group believe it would be beneficial if all national health agencies, institutions, and researchers were able to implement this definition (either on its own or alongside their own preferred definition) when reporting surveillance or research data relating to late presentation of HIV infection.

The male fetal lung begins to synthesize surfactant later in gestation than the female. This delay appears to be caused by androgens. We hypothesized that male fetal lung differentiation is delayed as a consequence of an extended phase of growth which is elicited by androgens. We observed that in vivo fetal lung protein synthesis relative to DNA synthesis peaked earlier in gestation in the female fetal lung and that this event was synchronous with the onset of differentiation. Pregnant rats were treated with dihydrotestosterone (DHT) during pregnancy, and fetal lung growth parameters were measured. Lung wet weight, dry weight, and DNA and protein concentrations were significantly elevated by DHT treatment. Type II cells and fibroblasts were isolated from lungs of DHT-treated fetuses. The number of total cells recovered was increased by 30%; the number of type II cells recovered was increased by 87%; and the number of fibroblasts recovered was increased by 42%. The type II cells which were recovered exhibited increased incorporation of [3H]thymidine into DNA and a reduced ratio of radiolabeled protein to radiolabeled DNA compared to that of cells from control lungs. Further studies were done in vitro with fibroblasts and type II cells isolated from untreated fetal rat lungs. Treatment of the fibroblasts with DHT during culture caused an increase in thymidine incorporation into DNA. This effect was not blocked by simultaneous treatment with cortisol, which normally causes reduced DNA synthesis and induces fibroblast differentiation. Treatment of the type II cells with DHT in culture caused a dose-dependent increase in cell number but a decrease in synthesis of disaturated phosphatidylcholine. These studies provide more direct evidence of the interrelationships between the control of growth and the control of differentiation in the fetal lung. DHT, a signal which delays the onset of expression of differentiation, also induces growth. We conclude that the controls of growth and of differentiation of the fetal lung are reciprocally linked.

[1] It has been shown that for a set of photons emitted, initially as a parallel flux, within the water, the average distance traversed along the original direction by the surviving photons in time interval Δt is = d exp(− bd) or, = d F(b, s, d) where d is cwΔt (cw being the speed of light in water), b is the scattering coefficient, s is the average cosine (or asymmetry factor) of the scattering phase function and F(b, s, d) may be referred to as the penetration function. The average depth traversed in time interval Δt by those photons which are emitted from a thin layer of the ocean at depth z, but not absorbed, is = cwΔtF(b, s, cwΔt) (z) where (z) is the average cosine of the light field at that depth. Computer calculations based on these equations can readily be implemented, and the validity of the calculations has been confirmed by Monte Carlo modeling.

International audience

In a prospective observational study 4485 patients from 46 clinical centres in 17 European countries were followed between April 1994 and November 1996. Information on AIDS-defining events (ADEs) were collected together with basic demographic data, treatment history and laboratory results. The centres were divided into four geographical regions (north, central, south-west and south-east) so that it was possible to identify any existing regional differences in ADEs. The regional differences that we observed included a higher risk of all forms of Mycobacterium tuberculosis infections (Tb) and wasting disease in the south-west and an increased risk of infections with the Mycobacterium avium complex (MAC) in the north. In Cox multivariable analyses, where north was used as the reference group, we observed hazard ratios of 6·87, 7·77, 2·29 and 0·16 (PPneumocystis carinii pneumonia (PCP) was less commonly diagnosed in the central region (RH=0·51, 95% CI 0·32–0·79, P=0·003) and most common in the south-east (RH=1·04, 95% CI 0·71–1·51, P=0·85). Comparisons with a similar ‘AIDS in Europe’ study that concentrated on the early phase of the epidemic reveal that most of the regional differences that were observed in the 1980s still persist in the mid-1990s.

We report on the outcome of a study of patients hospitalised with community acquired pneumonia (HCAP) at a Danish university hospital.In a retrospective study of 243 consecutive patients with radiographically verified HCAP, data on clinical and laboratory findings and outcome parameters were collected. Three groups were established according to the initial choice of antibiotic(s): penicillin only (n = 160); non-allergic patients starting broader spectrum therapy (n = 54); and patients with suspected penicillin allergy (n = 29).The overall mortality within three months was 12% and the readmission rate within three months was 20%. The three treatment groups were comparable with respect to most demographic and clinical criteria at baseline. No significant differences in outcome between the groups were found: the mortality was 12.5%, 13.0%, and 10.3%, respectively, p = 0.94, and the readmission rate 20.3%, 24.0%, and 14.8%, respectively; p = 0.63.Patients treated for community-acquired pneumonia at a Danish university hospital had clinical outcomes fully at height with findings from other countries, and half of the patients were successfully treated with penicillin monotherapy. No differences in clinical outcomes were documented between patients treated empirically with broad-spectrum therapy and penicillin monotherapy. Therefore, penicillin seems to be a reasonable first choice for initial therapy of HCAP in Denmark as in other regions with similar patterns of microbial pathogens and resistance.

The clinicopathological features of human immunodeficiency virus (HIV)-associated lymphoma were investigated in a retrospective study of 85 adult patients in eastern Denmark diagnosed during the period 1990-1996. The possible pathogenetic role of Epstein-Barr virus (EBV) and human herpesvirus 8 (HHV-8) in these tumours was also studied. Seventy patients (82%) presented with extranodal disease and 26 (31%) had CNS involvement at diagnosis. Diffuse large cell B-cell lymphoma was the most frequent histological subtype, comprising 65 of 79 cases available for microscopic re-evaluation (82%) and including 20 of 23 evaluable patients with CNS lymphoma (87%). EBV RNA was demonstrated by in situ hybridization in 51 of 65 evaluable tumours (79%) and in 14 of 16 cases (88%) with CNS-lymphoma. Three cases showed a T-cell phenotype. The presence of HHV-8 DNA was analysed by PCR in 32 cases. A strong band consistent with tumour cell infection was detected in only one case, weaker bands being seen in 4 cases. None of these patients had primary effusion lymphomas. In conclusion, Danish AIDS-related lymphomas are of predominantly high-grade B-cell type with extranodal localization and atypical presentation. Our results provide further evidence that EBV plays a major role in the pathogenesis of large cell AIDS-related lymphoma, whereas HHV-8 does not appear to contribute significantly to the development of solid lymphomas in this group of patients.

To describe changes in haemoglobin over time and to determine the joint prognostic value of the current haemoglobin, CD4 lymphocyte count and viral load among patients from across Europe.The analysis included 6725 patients from EuroSIDA, an observational, prospective cohort of patients with HIV from across Europe.Normal haemoglobin was defined as haemoglobin greater than 14 g/dl for men and 12 g/dl for women; mild anaemia was 8-14 g/dl for men and 8-12 g/dl for women; severe anaemia was defined as less than 8 g/dl for both males and females. Linear regression techniques were used to estimate the annual change in haemoglobin; standard survival techniques were used to describe disease progression and risk of death.At recruitment to the study, 40.4% had normal levels of haemoglobin, 58.2% had mild anaemia and 1.4% had severe anaemia. At 12 months after recruitment, the proportion of patients estimated to have died was 3.1% [95% confidence interval (CI) 2.3-3.9] for patients without anaemia, 15.9% for patients with mild anaemia (95% CI 14.5-17.2) and 40.8% for patients with severe anaemia (95% CI 27.9-53.6; P0.0001). In a multivariate, time-updated Cox proportional hazards model, adjusted for demographic factors, AIDS status and each antiretroviral treatment as time-dependent covariates, a 1 g/dl decrease in the latest haemoglobin level increased the hazard of death by 57% [relative hazard (RH) 1.57; 95% CI 1.41-1.75; P0.0001], a 50% drop in the most recent CD4 lymphocyte count increased the hazard by 51% (RH 1.51; 95% CI 1.35-1.70; P0.0001) and a log increase in the latest viral load increased the hazard by 37% (RH 1.37; 95% CI 1.15-1.63; P = 0.0005).Severe anaemia occurred infrequently among these patients but was associated with a much faster rate of disease progression. Among patients with similar CD4 lymphocyte counts and viral load, the latest value of haemoglobin was a strong independent prognostic marker for death.

There is no current curative treatment for HIV-related Kaposi's sarcoma. The identification of human herpesvirus-8 as a possible aetiological agent suggests potential efficacy of anti-viral agents. We report here on the complete histological remission of Kaposi's sarcoma following treatment with protease inhibitors, even in patients with limited virological response and persistence of HHV-8.

Highly active antiretroviral therapy (HAART) has improved rates of CD4-lymphocyte recovery and decreased the incidence of HIV-1-related morbidity and mortality. We assessed whether prophylaxis against Pneumocystis carinii pneumonia (PCP) can be safely discontinued after HAART is started.We investigated 7333 HIV-1-infected patients already enrolled in EuroSIDA, a continuing prospective observational cohort study in 52 centres across Europe and Israel. We did a person-years analysis of the rate of discontinuation of PCP prophylaxis and of the incidence of PCP after the introduction of HAART into clinical practice from July, 1996.The rate of discontinuation of primary and secondary PCP prophylaxis increased up to 21.9 discontinuations per 100 person-years of follow-up after March, 1998. 378 patients discontinued primary (319) or secondary (59) prophylaxis a median of 10 months after starting HAART. At discontinuation for primary and secondary prophylaxis, respectively, the median CD4-lymphocyte counts were 274 cells/microL and 270 cells/microL, the median plasma HIV-1 RNA load 500 copies/mL, and the median lowest recorded CD4-lymphocyte counts 123 cells/microL and 60 cells/microL. During 247 person-years of follow-up, no patient developed PCP (incidence density 0 [95% CI 0-1.5]).The risk of PCP after stopping primary prophylaxis, especially in patients on HAART with a rise in CD4-lymphocyte count to more than 200 cells/microL, is sufficiently low to warrant discontinuation of primary PCP prophylaxis. Longer follow-up is needed to confirm a similarly low risk for stopping secondary PCP prophylaxis.

To analyse use of antiretroviral therapy within Europe between 1994 and 1997.From September 1994, the EuroSIDA study (cohorts I-III) has prospectively followed unselected HIV-infected patients from 50 clinical centres in 17 European countries (total, 7230).Patients under follow-up at half-year intervals from September 1994 (n=2871) to September 1997 (n=3682) were classified according to number of drugs currently used (none, one, two, three, four or more). Use of antiretroviral therapy was stratified by CD4 cell count (200 versusor = 200 x 10(6)/l) and by region of Europe (south, central, or north). Frequency data were compared by chi2 test and logistic regression modelling.The proportion of patients on antiretroviral monotherapy diminished over time (1994, 42%; 1997, 3%), as did the proportion of patients without therapy (from 37 to 9%). Over time, the proportion of patients on triple (from 2 to 55%) and quadruple (from 0 to 9%) therapy increased, whereas use of dual therapy peaked in 1996 and subsequently fell. In the three regions of Europe, changes in use of antiretroviral therapy differed substantially. However, as of September 1997, only minor differences persisted. The proportion of patients on dual, triple, and quadruple therapy were as follow: south, 33, 52 and 5%, respectively; central, 23, 55 and 14%, respectively; north, 16, 59 and 10%, respectively. In September 1997, odds for use of three or more drugs including at least one protease inhibitor did not differ significantly between regions.Use of antiretroviral therapy in Europe has changed dramatically towards combination treatment in the last few years. Regional differences in use of antiretroviral therapy have decreased, and by September 1997 only minor differences remained. Antiretroviral therapy with three or more drugs and use of protease inhibitors has become more common in all regions of Europe.

Selected esters of D-glucose were recently proposed as tools to provide the sugar to cells, whilst bypassing the carrier system for hexose transport across the plasma membrane. In the present study, alpha-D-glucose pentaacetate, beta-D-glucose pentaacetate, alpha-D-mannose pentaacetate and, to a lesser extent, 6-O-acetyl-D-glucose, all tested at a 1.7 mM concentration, were found to increase lactate production above basal value in rat erythrocytes. Over 90 min incubation, the increment in lactate production ranged from about 1.2 (alpha-D-glucose pentaacetate) to 0.6 (6-O-acetyl-D-glucose) micromol/microl of erythrocytes. Little or no change in lactate production was observed in cells exposed to beta-L-glucose pentaacetate, alpha-D-glucose pentaethylsuccinate, alpha-D-galactose pentaacetate or beta-D-galactose pentaacetate. The metabolic response to alpha-D-glucose pentaacetate was resistant to 3-O-methyl-D-glucose (10-80 mM) which suppressed, however, that evoked by D-glucose. D-mannoheptulose (10 mM) virtually failed to affect the response to D-glucose and its pentaacetate ester. On the contrary, 2-deoxy-D-glucose (10.6 mM) inhibited to the same relative extent (55% decrease) lactate production in erythrocytes exposed to either unesterified D-glucose or alpha-D-glucose pentaacetate. The tetraacetic ester of 2-deoxy-D-glucose was more efficient than unesterified 2-deoxy-D-glucose in inhibiting lactate production from alpha-D-glucose pentaacetate. It is proposed that selected esters of saccharides represent useful tools to bypass defects in hexose transport, and to increase their nutritional or therapeutic efficiency.

The spectral energy distribution of the emergent radiant flux from the ocean is determined by the inherent optical properties of the water, especially the absorption coefficients. To interpret the remotely sensed spectral distribution in terms of ocean composition we need a database relating seawater absorption spectra to composition, especially in terms of phytoplankton concentration and type, and soluble and detrital color. Measurement of seawater absorption spectra is difficult because absorption is so low, and because of the confounding effects of scattering. The use of the integrating cavity absorption meter to overcome these problems is discussed, and an account is also given of the potential and limitations of seeking to estimate absorption coefficient values form in-water spectral irradiance data.© (1997) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

Beginning systematically with the fundamentals, the fully-updated third edition of this popular graduate textbook provides an understanding of all the essential elements of marine optics. It explains the key role of light as a major factor in determining the operation and biological composition of aquatic ecosystems, and its scope ranges from the physics of light transmission within water, through the biochemistry and physiology of aquatic photosynthesis, to the ecological relationships that depend on the underwater light climate. This book also provides a valuable introduction to the remote sensing of the ocean from space, which is now recognized to be of great environmental significance due to its direct relevance to global warming. An important resource for graduate courses on marine optics, aquatic photosynthesis, or ocean remote sensing; and for aquatic scientists, both oceanographers and limnologists.

The nature — that is, the characteristics, and the properties — of the light environment in the ocean is determined by two things: first, by the nature of the light flux incident on the surface of the ocean from above, and second, by the optical properties of the oceanic water itself. The underwater light environment is what results from the operation of the latter on the former. In this paper we shall consider (a) the nature of the incident solar flux; (b) the inherent optical properties of the ocean, how they are measured and what components of the aquatic medium they are due to; and (c) how the characteristics of the underwater light field are measured, and what these measurements reveal about the light environment in the ocean.

Indian mustard [Brassica juncea (L.) Czern.] is a more productive oilseed than canola (B. napus L.) in hot regions of Russia, India, China, and Canada with somewhat unreliable rainfalls, whereas canola is the higher yielding species in more temperate, wetter regions. The specific agronomic features of the species, and their performance in various Australian regions are reviewed. The discovery of the genes for low erucic acid oil production in the seeds of Indian mustard began the conversion of this ancient crop to a canola-type oilseed for dry areas. Initially, many accessions were field-tested at Wagga Wagga and Canberra, but 2 seed-borne diseases, leaf and stem blight and seed rot, were destructive. Accessions from South Asia were severely damaged by the blight caused by Pseudomonas syringae pv. maculicola Young, Dye & Wilkie 1978, whereas most of the cultivars from latitudes above 45°N were resistant. A phytotron procedure was developed for screening seedlings. The segregation pattern in F2 families from resistant × susceptible crosses suggested that reactions to a typical Pseudomonas isolate were controlled largely by co-dominant resistance (PsmR ) and susceptibility (PsmS ) alleles at one locus. F3 families with field resistance equal to the PsmR/PsmR parents were readily recovered, indicating that few or no modifying genes affected disease reactions. Resistant families selected from each of 6 crosses yielded 13.8% more seed (P < 0.001) than the corresponding segregating and susceptible families when these were tested at Canberra and Wagga Wagga. The disease became unimportant when most entries in field trials were resistant. A seed-rotting disease caused by a yeast with distinctive ascospores closely resembling those of Nematospora sinecauda Holley, Allan-Wotjas & Phipps-Todd 1984 occurred in some imported and locally grown seed samples, but was eliminated by hot water treatment of seed prior to sowing and by control of the presumed insect vector, Nysius vinitor (Bergroth), during seed maturation in the field. No previous record of the occurrence of this disease in Australia was found in the literature by a plant pathologist. The availability of breeding lines with low erucic acid seed oil, Pseudomonas resistance, and a predominance of propenyl glucosinolate in the meal permitted the development of a cold-pressed, edible oil industry by a family company (Yandilla Mustard Oil Enterprise) at Wallendbeen, NSW. The original oil has a mild nutty flavour, but now a larger proportion of the market requires a pungent, mustard-flavoured oil containing a trace of propenyl isothiocyanate, the hydrolytic product of the corresponding glucosinolate in the meal. The full-flavoured meal is sold for table mustard and pickle manufacture, as a stock feed ingredient containing approximately 30% protein and 18% oil, and for the distillation, by another small company at Cowra, NSW, of propenyl isothiocyanate, which is used as a flavouring and preservative in food, especially in Japan. This review describes the breeding of cultivars for cold-pressed oil production, as an off-shoot of the canola-grade B. juncea project. Five successively improved, Pseudomonas-resistant cultivars were developed by crossing and pedigree selection for higher yield under a range of limiting conditions, and released for cold-pressed, low erucic acid oil production. The rate of yield increase in the cultivars released between 1989 and 2001 was 2.4% per annum as judged from small plot yields of all cultivars in each of 4 years at Wallendbeen. Flowering time adjustment provided a one-off improvement, but continued progress seems possible by field selection for traits such as increased resistance to the Sclerotinia and Alternaria pathogens, resistance to acid soils, waterlogging, frost at flowering, heat and drought during seed maturation, and increased efficiency of nutrient utilisation. The nutraceutical properties of mustard oil, and the chemical differences among current B. juncea seed products, are described. Possible future developments are discussed.

It is shown that where micros is the average cosine of scattering, then for any set of photons that undergoes exactly n scatterings per photon, the average cosine after scattering is micro(0)micro(s)(n), where micro(0) is the average cosine of the photon flux before scattering. For a set of photons that has traversed distance d through a medium with scattering coefficient b, the average cosine is micro(0) exp[-bd(1 - micro(s))]. For water bodies in which loss of upward-scattered photons through the surface is small enough to be disregarded, the value of micro(c) (the average cosine of all the photons instantaneously present in the water column) for any given incoming flux of photons with average cosine micro(0) is determined entirely by the inherent optical properties of the water in accordance with micro(c)= micro(0)/[1 + (b/a)(1 - micro(s))], where a and b are the absorption and scattering coefficients.