Removal of emerging pollutants by a 3-step system: Hybrid digester, vertical flow constructed wetland and photodegradation post-treatments

The removal of emerging pollutants from municipal wastewater was studied for the first time using a three-step pilot-scale system: 1) hybrid digester (HD) as first step, 2) subsurface vertical flow constructed wetland (VF) as second step, and 3) photodegradation (PD) unit as third step or post-treatment. The HD and VF units were built and operated in series with effluent recirculation at pilot scale. For the PD post-treatment, three alternatives were studied at lab-scale, i) UVC irradiation at 254 nm (0.5 h exposure time), ii) UVA irradiation at 365 nm using a TiO₂-based photocatalyst and iii) sunlight irradiation using a TiO₂-based photocatalyst, the last two for 1 and 2 h. Alternative iii) was also tested at pilot-scale. Degradation of nine compounds was evaluated: acetaminophen (ACE), caffeine (CAF), carbamazepine (CBZ), ketoprofen (KET), ibuprofen (IBU), diclofenac (DCL), clofibric acid (ACB), bisphenol A (BPA), and sotalol (SOT). Overall, the HD-VF-UVC system completely removed (>99.5 %) ACE, CAF, KET, IBU, DCL and ACB, and to a lesser extent SOT (98 %), BPA (83 %) and CBZ (51 %). On the other hand, the HD-VF-UVA/TiO₂ system (at 2 h) achieved >99.5 % removal of ACE, CAF, KET, IBU and DCL while ACB, BPA, CBZ and SOT were degraded by 83 %, 81 %, 78 % and 68 %, respectively. Working also at 2 h of exposure time, in summer conditions, the HD-VF-Sol/TiO₂ system achieved >99.5 % removal of ACE, CAF, KET, IBU, DCL and ACB, and to a minor extent BPA (80 %), SOT (74 %) and CBZ (69 %). Similar results, although slightly lower for SOT (60 %) and CBZ (59 %), were obtained in the pilot sunlight plus TiO₂ catalyst unit. However, the use of sunlight irradiation with a TiO₂-based photocatalyst clearly showed lower removal efficiency in autumn conditions (i.e., 47 % SOT, 31 % CBZ).

Different factors limit early- and late-season windows of opportunity for monarch development

Seasonal windows of opportunity are intervals within a year that provide improved prospects for growth, survival, or reproduction. However, few studies have sufficient temporal resolution to examine how multiple factors combine to constrain the seasonal timing and extent of developmental opportunities. Here, we document seasonal changes in milkweed (Asclepias fascicularis)-monarch (Danaus plexippus) interactions with high resolution throughout the last three breeding seasons prior to a precipitous single-year decline in the western monarch population. Our results show early- and late-season windows of opportunity for monarch recruitment that were constrained by different combinations of factors. Early-season windows of opportunity were characterized by high egg densities and low survival on a select subset of host plants, consistent with the hypothesis that early-spring migrant female monarchs select earlier-emerging plants to balance a seasonal trade-off between increasing host plant quantity and decreasing host plant quality. Late-season windows of opportunity were coincident with the initiation of host plant senescence, and caterpillar success was negatively correlated with heatwave exposure, consistent with the hypothesis that late-season windows were constrained by plant defense traits and thermal stress. Throughout this study, climatic and microclimatic variations played a foundational role in the timing and success of monarch developmental windows by affecting bottom-up, top-down, and abiotic limitations. More exposed microclimates were associated with higher developmental success during cooler conditions, and more shaded microclimates were associated with higher developmental success during warmer conditions, suggesting that habitat heterogeneity could buffer the effects of climatic variation. Together, these findings show an important dimension of seasonal change in milkweed-monarch interactions and illustrate how different biotic and abiotic factors can limit the developmental success of monarchs across the breeding season. These results also suggest the potential for seasonal sequences of favorable or unfavorable conditions across the breeding range to strongly affect monarch population dynamics.

First Direct Measurement of ^{22}Mg(α,p)^{25}Al and Implications for X-Ray Burst Model-Observation Comparisons

Type-I x-ray bursts can reveal the properties of an accreting neutron star system when compared with astrophysics model calculations. However, model results are sensitive to a handful of uncertain nuclear reaction rates, such as ^{22}Mg(α,p). We report the first direct measurement of ^{22}Mg(α,p), performed with the Active Target Time Projection Chamber. The corresponding astrophysical reaction rate is orders of magnitude larger than determined from a previous indirect measurement in a broad temperature range. Our new measurement suggests a less-compact neutron star in the source GS1826-24.

Genetic analysis of signal peptides in amphibian antimicrobial secretions

Amphibian secretion is an important source of bioactive molecules that naturally protect the skin against noxious microorganisms. Collectively called antimicrobial peptides (AMPs), these molecules have a wide spectrum of action, targeting viruses, bacteria and fungi. Like many membrane and secreted proteins, AMPs have cleavable signal sequences that mediate and translocate the nascent polypeptide chains into the endoplasmic reticulum. Although it is accepted that the signal peptides (SPs) are simple and interchangeable, there is neither sequence nor structure that is conserved among all gene families. They derived from a common ancestor but developed different traits as they adapt to distinct environmental pressures. The aim of this study was to provide anoverview of the diversity of SPs of the frog, taking into account reported cDNA sequences and the evolutionary relationship among them. We analysed more than 2000 records that reported the relative abundance, diversity and evolutionary divergence based on the peptide signals of frog AMPs. We conclude that the physical properties of the sequence are more important than the specific peptidesin AMP SPs. Since there is significant overlapping among related genera, differences in secretion from different peptide types should be regulated by additional levels, such as posttranscriptional modifications or 5-UTR sequences.

Hepatitis C virus core protein up-regulates anergy-related genes and a new set of genes, which affects T cell homeostasis

Hepatitis C virus (HCV) infection is the main cause for chronic hepatitis, leading to cirrhosis and hepatic carcinoma. Virally induced immune dysfunction has been called as the cause for viral persistence. Previous results demonstrate that CD4 Jurkat cells stably expressing the HCV core protein show an increased activation of NFAT transcription factor and an impaired IL-2 promoter activity, affecting intracellular signaling pathways in a manner that mimics clonal anergy. We had shown previously that NFAT activates a transcriptional program, ensuing in immunological tolerance. In the present work, we have engineered lentiviral vectors expressing the HCV core to analyze the events, which unfold in the initial phase of HCV core-induced anergy. We show that genes initially described to be up-regulated by ionomycin-induced anergy in mice are also up-regulated in humans, not only by ionomycin but also by HCV core expression. We also show that HCV core is sufficient to cause NFAT nuclear translocation and a slow-down in cell-cycle progression, and using whole genome microarrays, we identify novel genes up-regulated in Jurkat cells expressing HCV core. The relevance of our results is highlighted by the presence of HCV in CD4 T cells from HCV chronically infected patients.

[The interaction between corn and Burkholderia (Pseudomonas) cepacia]

Burkholderia (Pseudomonas) cepacia is a plant growth promoting rhizobacteria that could improve maize productivity. In this work we studied some properties of B. cepacia strain 0057 in relation to interaction with maize. Spermosphere effect, chemostatic response, indolic compounds and siderophores production were evaluated. We observed inhibitory effect on bacterial growth by maize seeds and their soluble extracts. Root exudates had positive chemiostatic effect. We founded indolic compounds production (20.1 micrograms/ml) and siderophore presence. We think that this microorganisms could improve maize production.

Production of a positive direct antiglobulin test due to suramin

Drugs and chemicals containing multiple reactive carbonyl groups have been postulated to produce nonimmunologic positive direct antiglobulin tests (DATs) both in vitro and in vivo. Suramin sodium, a reverse transcriptase inhibitor that was under investigation as a potential treatment for human immunodeficiency virus infection, has six reactive carbonyl groups. Because of suramin's chemical structure, it was hypothesized that the drug might cause a positive DAT in vitro and possibly in vivo. Suramin was found to produce a positive DAT in vitro at concentrations of 2100 mg/L or greater but did not cause a positive DAT in five patients with acquired immunodeficiency syndrome who were treated with suramin, probably because the serum levels of suramin were too low in these patients (peak therapeutic blood levels ranged from 171 to 443 mg/L).

Suramin antiviral therapy in the acquired immunodeficiency syndrome. Clinical, immunological, and virologic results

The human T-lymphotropic virus type III/lymphadenopathy-associated virus (HTLV-III/LAV) requires reverse transcriptase for viral replication. We treated 12 patients who had acquired immunodeficiency syndrome and active HTLV-III/LAV viremia with suramin, a potent competitive inhibitor of reverse transcriptase, in six weekly induction doses of 1 g, followed by weekly maintenance doses of 500 mg. Three of eleven evaluable patients had complete inhibition of viral reverse transcriptase levels, lasting at least 18 weeks in each. Two additional patients had marked reduction in reverse transcriptase activity. Nadir serum suramin levels at the end of the induction phase correlated with the level of reverse transcriptase reduction. Toxicity included hepatic transaminase elevation, fever, malaise, rash, proteinuria, paresthesias, reversible neutropenia, and adrenal insufficiency. Objective clinical improvement was documented in 1 patient, but no patient had improvement in immune function and 7 patients had recurrent opportunistic infections. Although suramin may suppress HTLV-III/LAV viremia, its significant toxicity and lack of effect on immune variables indicate that alternative therapy will be required.

Serum beta-2 microglobulin levels in homosexual men with AIDS and with persistent, generalized lymphadenopathy

In order to investigate the nature of the immune disorders associated with the acquired immune deficiency syndrome (AIDS) and the AIDS-related condition of persistent, generalized lymphadenopathy (PGL), serum beta-2 microglobulin (beta 2-M) levels were determined in patients with AIDS and PGL and in asymptomatic homosexual and heterosexual controls. Sixteen of 20 (80%) patients with AIDS exhibited elevated beta 2-M levels. In contrast, 20 of 44 (45%) patients with PGL, 4 of 20 (20%) asymptomatic homosexuals, and only 3 of 46 (7%) heterosexuals had increased serum beta 2-M levels (P less than 0.001). When considering mean levels of beta 2-M, only the asymptomatic control individuals had normal values. AIDS patients had significantly higher mean beta 2-M levels when compared to all other groups (P less than 0.05). The mean level for PGL patients was greater than that in the homosexual and heterosexual controls (P less than 0.05). No relationship was found between presence of antibody to human T-lymphotropic retrovirus (HTLV-III) and beta 2-M levels in the patients with AIDS or PGL. The authors conclude that beta 2-M is elevated in patients with AIDS and PGL, suggesting an increased turnover of a certain subpopulation of lymphocytes in these patients. Beta 2-M levels also appear to parallel disease activity, as well as immune dysfunction, with the greatest elevation occurring in patients with AIDS, followed by those with PGL, and asymptomatic homosexuals. Beta 2-M levels may be a useful confirmatory marker in AIDS and its related disorders.

Results of initial lymph node biopsy in homosexual men with generalized lymphadenopathy

Persistent, generalized lymphadenopathy (PGL) is considered part of the acquired immunodeficiency syndrome (AIDS)-related complex. The clinical course is usually benign, although some patients may evolve to AIDS. Characteristic features on lymph node biopsy have been described. Recently, large series of PGL have been reported in which many study patients have not undergone initial diagnostic biopsy. The value of such biopsy has been questioned. We report the clinical, pathologic, and laboratory findings in six homosexual men initially considered as potential candidates for study of the natural history of PGL. They were excluded by initial lymph node biopsy, which revealed small-cleaved lymphoma in two, focal Kaposi's sarcoma in two, disseminated mycobacterium tuberculosis in one, and histoplasma encapsulatum in one. The clinical and laboratory data from these six patients were compared with those from 34 patients with biopsy-proven PGL; no statistically significant difference in any prebiopsy clinical parameter was found. We conclude that initial lymph node biopsy may reveal changes other than reactive hyperplasia in homosexual men with generalized lymphadenopathy.

Correlation between T.S.P., F.S.P. and visibility in a high altitude city (Mexico City)

the metropolitan area of Mexico City is located in a high altitude basin (2 240 m above sea level) at a latitude of 19 degrees 26'13" North. It has a population of 15 million inhabitants, and the motor vehicles cruising in the city amount to 1.5 million and around 21% of the total industrial activity of the country is sited in the metropolitan area. All this activity has created an acute air pollution problem in the area which, as a direct result, has resulted in decreased visibility and possible health effects.