Maintenance Of Reservoir Research Articles

Recombinant human IL-15 (rhIL-15) in combination with anti-PD-L1 (Avelumab) in SIV infected rhesus macaques leads to the expansion of a subset of CXCR3+PD1−/low CD8 T cells

Abstract The PD1/PD-L1 pathway contributes to the pathogenesis of HIV/SIV infection. Expression of PD1 by HIV/SIV-specific CD8 T cells can limit antiviral responses and expression of checkpoint receptors including PD1 by HIV infected cells can contribute to maintenance of viral reservoirs. In addition, reports have shown that IL-15 induces the expansion of effector memory CD8 T and NK cells. In this study, we hypothesized that expansion of memory CD8 T cells in the context of PD1/PD-L1 blockade may lead to enhanced anti-SIV responses. We design a study in which we evaluated the effect of rhIL-15 administered in cycles of ten days by continuous infusion in combination with weekly administration of anti-PD-L1 (Avelumab) over 24 weeks. After seven doses of anti-PD-L1 and completion of two cycles of rhIL15, cART therapy was interrupted and anti-PD-L1 administration continued to complete 24 weeks treatment. We found that administration of rhIL-15 in combination with anti-PD-L1 treatment was well tolerated. rhIL-15 infusions were associated with transient increases in proliferation of NK cells and effector memory CD8 T cells. rhIL-15/anti-PD-L1 treatment led to a sustained expression of CXCR3+ with low to undetectable expression of PD1on CD8 T cells, suggesting potential of increased tissue trafficking. Multidimensional single cell analysis showed that CXCR3+PD1−/low CD8 T cells secrete cytokine in response to viral antigens. Despite these clear biological effects, no impact was observed on rebound plasma viremia after cART discontinuation and during anti-PD-L1 administration. Futures studies should characterize the CXCR3+PD1−/low CD8 T cell subset expanded by this treatment to understand the potential impact of this subset in viral control.

Pyrethroid resistance in the pest mite, Halotydeus destructor: Dominance patterns and a new method for resistance screening

An L1024F substitution in the para gene, which encodes a subunit of the voltage-gated sodium channel, has been implicated in pyrethroid resistance in a mite pest, Halotydeus destructor, which attacks rape and other grain crops. A high-resolution melt (HRM) genotyping assay was developed for testing the relative pyrethroid susceptibility of different para genotypes and for high-throughput field screening of resistant alleles. The L1024F mutation was found to be incompletely recessive in phenotypic laboratory bioassays with the pyrethroid pesticide, bifenthrin. While the resistance ratio of heterozygotes (RS) to susceptible homozygotes (SS) was <6 in 24 h bioassays, the resistant homozygotes (RR) (with a resistance ratio > 200,000) survived the recommended field rate of bifenthrin (100 mgL−1). HRM genotyping of mites from field populations across Australia indicated the presence of resistant alleles in Western Australia and South Australia, but not in Victoria and New South Wales. The assay developed will be useful for routine screening of pyrethroid resistance, and the dominance relationships established here point to useful resistance management strategies involving the maintenance of reservoirs of susceptible mites to dilute resistant homozygotes in a population.

Insight in HIV Integration Site Selection Provides a Block-and-Lock Strategy for a Functional Cure of HIV Infection.

Despite significant improvements in therapy, the HIV/AIDS pandemic remains an important threat to public health. Current treatments fail to eradicate HIV as proviral DNA persists in long-living cellular reservoirs, leading to viral rebound whenever treatment is discontinued. Hence, a better understanding of viral reservoir establishment and maintenance is required to develop novel strategies to destroy latently infected cells, and/or to durably silence the latent provirus in infected cells. Whereas the mechanism of integration has been well studied from a catalytic point of view, it remains unknown how integration site selection and transcription are linked. In recent years, evidence has grown that lens epithelium-derived growth factor p75 (LEDGF/p75) is the main determinant of HIV integration site selection and that the integration site affects the transcriptional state of the provirus. LEDGINs have been developed as small molecule inhibitors of the interaction between LEDGF/p75 and integrase. Recently, it was shown that LEDGIN treatment in cell culture shifts the residual integrated provirus towards the inner nuclear compartment and out of transcription units in a dose dependent manner. This LEDGIN-mediated retargeting increased the proportion of provirus with a transcriptionally silent phenotype and the residual reservoir proved refractory to reactivation in vitro. LEDGINs provide us with a research tool to study the link between integration and transcription, a quintessential question in retrovirology. LEDGIN-mediated retargeting of the residual reservoirs provides a novel potential “block-and-lock” strategy as a functional cure of HIV infection.

Peering into the HIV reservoir.

The main obstacle to HIV eradication is the establishment of a long-term persistent HIV reservoir. Although several therapeutic approaches have been developed to reduce and eventually eliminate the HIV reservoir, only a few have achieved promising results. A better knowledge of the mechanisms involved in the establishment and maintenance of HIV reservoir is of utmost relevance for the design of new therapeutic strategies aimed at purging it with the ultimate goal of achieving HIV eradication or alternatively a functional cure. In this regard, it is also important to take a close look into the cellular HIV reservoirs other than resting memory CD4 T-cells with key roles in reservoir maintenance that have been recently described. Unraveling the special characteristics of these HIV cellular compartments could aid us in designing new therapeutic strategies to deplete the latent HIV reservoir.

Ets-2 Acts As a Transcriptional Repressor of the Human Immunodeficiency Virus Type 1 through Binding to a Repressor-Activator Target Sequence of 5'-LTR.

HIV-1 is transcriptionally active in activated T helper (Th)-cells and inactive in naive or resting memory Th-cells. Ets-2 is a preinduction transcriptional repressor of the IL-2 gene in naive Th-cells and a candidate transcriptional repressor of HIV-1 in the same cells, because the −279 to −250 upstream region of HIV-1-LTR [repressor–activator target sequence (RATS)], that participates in HIV-1-LTR transcriptional silencing, encompasses the AAGGAG Ets-2 binding site. In this proof of concept study, we investigated whether Ets-2 represses the expression of HIV-1. To assess whether Ets-2 can repress HIV-1 transcriptional activation acting through RATS, we transfected Jurkat cells with an Ets-2 overexpression plasmid (pCDNA3-ets-2) or Ets-2 silencing plasmids (ets-2-shRNA) and, as target genes, plasmids carrying the whole HIV-1-LTR sequence (HIV-1-LTR-CAT) or two copies of the RATS sequence (2× RATS-CAT) or a point mutation in the Ets-2 binding site (2× mutantRATS-CAT) or CMV-CAT (control). Ets-2 overexpression resulted in a significant reduction of HIV-1-LTR-CAT and 2× RATS-CAT activities in stimulated cells, but not of the 2× mutantRATS-CAT or CMV-CAT. Ets-2 silencing led to increased activities of HIV-1-LTR-CAT and 2× RATS-CAT in unstimulated cells, but had no effect on the activities of 2× mutantRATS-CAT and CMV-CAT. To assess Ets-2 binding to HIV-1-LTR–RATS in naive Th-cells, we isolated naive Th-cell nuclear proteins and passed them through an Ets-2 antibody column; electrophoretic mobility shift assays were performed using an RATS probe mixed with consecutive protein eluates. Ets-2 bound to the HIV-1-LTR–RATS in a dose-dependent manner. To assess Ets-2 binding to RATS in vivo, Jurkat cells were transfected with 2× RATS-CAT and stained for the Ets-2 protein and the RATS sequence by combining immunofluorescence and fluorescence in situ hybridization techniques. In unstimulated cells, Ets-2 bound to RATS, whereas no binding was observed in stimulated cells. To test for RATS specificity, the same experiments were performed with 2× mutantRATS-CAT, and no binding of Ets-2 was observed. The results were corroborated by chromatin immunoprecipitation assays performed with the same cells. Our results show that Ets-2 is a transcriptional repressor of HIV-1. Repression of HIV-LTR-RATS mediated by Ets-2 may account for the low-level transcription and replication of HIV-1 in naive Th-cells, and contribute to the viral latency and maintenance of viral reservoirs in patients, despite long-term therapy.

Loss of Reservoir Capacity through Sedimentation in Hawai‘i: Management Implications for the Twenty-First Century

Hawai‘i's reservoirs face increasing scrutiny due to heightened dam safety and flood control concerns, growing water demands, and uncertain water pollution effects. To promote long-term reservoir sustainability, it is vital that we improve our understanding of reservoir capacity. Because many of Hawai‘i's reservoirs are privately owned and unmonitored, the state of Hawai‘i lacks data on actual reservoir capacity. To conduct a statewide survey of reservoir capacity, we (1) collected, organized, and analyzed existing physical data characterizing reservoir capacity in the five main Hawaiian Islands; (2) interviewed reservoir managers throughout the state to assess current knowledge of reservoir capacity and its loss due to sedimentation; and (3) analyzed images to estimate available capacity and sedimentation. Results show that sedimentation is a serious concern for managers and is rarely measured and poorly documented. Approximately 79% of the total capacity of Hawai‘i's reservoirs are currently in use, and 40% of reservoirs (representing 24% of total capacity) are affected by sedimentation. Of these reservoirs, 60% are less than 1.23 million m3 (1,000 ac-ft) in size. Lack of maintenance for sediment is especially common in privately owned reservoirs. In the face of changing land use, reservoirs could be adapted for more appropriate uses in Hawai‘i, including flood control, hydropower, and recreation. Reservoir maintenance, including assessment and removal of sediments, is a critical consideration for proper stewardship of Hawai‘i's abundant water resources.

Evaluation of sediment management for two large reservoirs in Lombok island

Sedimentation is an important issue in reservoir rehabilitation and maintenance. This problem is worsened by seasonal water scarcity as a characteristic of arid catchments. Worldwide loss of storage capacity due to sedimentation is much higher than the increase of capacity by the construction of new reservoirs. Further, sedimentation hinders the safe operation of not only shallow reservoirs but also deep reservoirs by means of turbidity currents which sporadically transport large volumes of sediments down to the dams. This study analyses the real case of Pengga reservoir and Batujai reservoir located in Central Indonesia. Selected sediment management alternatives were analysed and evaluated based on technical, social and environmental criteria. Evaluation of sediment management alternatives was conducted by utilising the REServoir CONservation (RESCON) tool. Results showed that, first, both flushing techniques and hydrosuction are feasible whereas dredging and trucking are not. Secondly, the flushing technique outweighs the Hydrosuction Sediment Removal (HSRS) method. Thirdly, application of the HSRS method in both reservoirs shares one thing in common, i.e. it requires an appropriate combination of the number of suction pipes as well as minimum suction pipe diameters. Lastly, there are some differences in the details of implementation of the flushing technique to both reservoirs.

Novel mechanisms to inhibit HIV reservoir seeding using Jak inhibitors.

Despite advances in the treatment of HIV infection with ART, elucidating strategies to overcome HIV persistence, including blockade of viral reservoir establishment, maintenance, and expansion, remains a challenge. T cell homeostasis is a major driver of HIV persistence. Cytokines involved in regulating homeostasis of memory T cells, the major hub of the HIV reservoir, trigger the Jak-STAT pathway. We evaluated the ability of tofacitinib and ruxolitinib, two FDA-approved Jak inhibitors, to block seeding and maintenance of the HIV reservoir in vitro. We provide direct demonstration for involvement of the Jak-STAT pathway in HIV persistence in vivo, ex vivo, and in vitro; pSTAT5 strongly correlates with increased levels of integrated viral DNA in vivo, and in vitro Jak inhibitors reduce the frequency of CD4+ T cells harboring integrated HIV DNA. We show that Jak inhibitors block viral production from infected cells, inhibit γ-C receptor cytokine (IL-15)-induced viral reactivation from latent stores thereby preventing transmission of infectious particles to bystander activated T cells. These results show that dysregulation of the Jak-STAT pathway is associated with viral persistence in vivo, and that Jak inhibitors target key events downstream of γ-C cytokine (IL-2, IL-7 and IL-15) ligation to their receptors, impacting the magnitude of the HIV reservoir in all memory CD4 T cell subsets in vitro and ex vivo. Jak inhibitors represent a therapeutic modality to prevent key events of T cell activation that regulate HIV persistence and together, specific, potent blockade of these events may be integrated to future curative strategies.

Detection of duo-schistosome infection from filtered urine samples from school children in Zambia after MDA.

Schistosomiasis is one of the major Neglected Tropical Diseases (NTDs) in sub-Saharan Africa. In sub-Saharan Africa, two major human schistosome species namely Schistosoma mansoni and S. haematobium often occur sympatrically largely affecting children. Recognizing the public health impact of Schistosomiasis, the World Health Organization (WHO) is urging member states to regularly treat at least 75% and up to 100%, of all school-aged children at risk of morbidity. For control strategies based on targeted mass drug administration (MDA) to succeed it is essential to have a simple and sensitive test for monitoring the success of these interventions. Current available diagnostic tests, such as egg detection in stool by Kato-Katz (KK) for S. mansoni and detection of eggs or blood (hematuria) in urine for S. haematobium have reduced sensitivity in low intensity settings. The objective of the study was to evaluate active single or duo schistosome infections in school children following MDA using molecular diagnostics (PCR) on filtered urine samples and comparing that against traditional diagnostic tests. This cross-sectional study was conducted among 111 school children aged 7–15 years in Chongwe and Siavonga Districts in Zambia. Species-specific cell-free repeat DNA fragment were amplified from 111 filtered urine samples. Our approach detected eight times more positive cases (total 77) than by KK (9) for S. mansoni and six times more (total 72) than by hematuria (11) for S. haematobium and even more against urine filtration (77 compared to only 6). The same pattern was observed when stratified for age group and sex specific analysis with 100% sensitivity and specificity devoid of any cross amplification. In addition, 69 individuals (62%) were co-infected by both parasites. We have demonstrated a significantly higher prevalence of both species than indicated by the traditional tests and the persistent maintenance of reservoir of infection after MDA. Our approach is an effective means of detecting low intensity infection, which will enhance the effectiveness of surveillance and assess the impact of MDA control programs against schistosomiasis.

PROBLEMS OF COMPATIBILITY OF FORMATION WATER AND INJECTED WATER IN THE OIL FIELDS OF WESTERN SIBERIA

A method of maintaining reservoir pressure using a system for formation pressure maintenance of oil reservoirs in the oil fields of Western Siberia is extremely wide-spread. In oil fields as a system for formation pressure maintenance are widely used almost all types of water resources including surface water, groundwater and industrial wastewater. Different calculation methods for predicting the formation and precipitation of salts based on quantitative criteria are used to forecast possible precipitation of calcium carbonate in the flooded oil reservoir areas.

Exploring investment priority for reservoir maintenance and reinforcement using public data

This study conducted disaster impact assessment on the downstream districts of the reservoirs in Gyeonggi-do, selected among the 14,323 reservoirs nationwide that are under control of local governments. There are 229 reservoirs located in Gyeonggi-do, and a GIS was used to set the range of the downstream districts for these reservoirs. For the designated downstream districts, the public data was used to build a database on the number of households, farmland, floor area of buildings, and the area of the infrastructures. As the characteristics and units of each data were different, the data was standardized through the standardization score to comprehensively evaluate the disaster impact in the lower reservoir areas. For that, each data was given equal weight. The resulting analysis shows that 14 of the reservoirs in Gyeonggi-do are older than 60 years, and that there are a great number of households, buildings, and cultivated areas in the downstream districts. Therefore, along with maintenance and reinforcement after a precise diagnosis of the reservoirs, precautions to minimize damage to the downstream districts when a reservoir collapses are urgently required. This study is investment priority for maintenance and reinforcement of reservoirs through assessment of the relative impact of disasters on downstream districts upon the collapse of a reservoir, using public data. It is expected that the results of this study may be used to establish the management direction for reservoirs and downstream districts.

Mechanisms of HIV persistence in HIV reservoirs.

The establishment and maintenance of HIV reservoirs that lead to persistent viremia in patients on antiretroviral drugs remains the greatest challenge of the highly active antiretroviral therapy era. Cellular reservoirs include resting memory CD4+ T lymphocytes, implicated as the major HIV reservoir, having a half-life of approximately 44months while this is less than 6hours for HIV in plasma. In some individuals, persistent viremia consists of invariant HIV clones not detected in circulating resting CD4+ T lymphocytes suggesting other possible sources of residual viremia. Some anatomical reservoirs that may harbor such cells include the brain and the central nervous system, the gastrointestinal tract and the gut-associated lymphoid tissue and other lymphoid organs, and the genital tract. The presence of immune cells and other HIV susceptible cells, occurring in differing compositions in anatomical reservoirs, coupled with variable and poor drug penetration that results in suboptimal drug concentrations in some sites, are all likely factors that fuel the continued low-level replication and persistent viremia during treatment. Latently, HIV-infected CD4+ T cells harboring replication-competent virus, HIV cell-to-cell spread, and HIV-infected T cell homeostatic proliferation due to chronic immune activation represent further drivers of this persistent HIV viremia during highly active antiretroviral therapy.

The role of wetland in water quality purification and maintenance of coastal reservoirs: a case of Qingcaosha Reservoir

Qingcaosha Reservoir (QR) is typical fresh water storage and salty water avoidance featured coastal reservoir, which is located in south branch of Yangtze River Estuary, China. Due to the location of QR, pollutants and short-term salt tides have threatened the clean fresh water intake of the reservoir. There are 289 km 2 shoal wetlands in upstream of QR. After the continuous purification of wetlands, water quality of raw water has been improved. Qingcaosha shoal, Zhongyangsha shoal, Beixiaohong shoal and Dongbeixiaohong shoal are on the circumference. From the water quality monitoring data after the reservoir operation, the average value of NH 4 + -N, NO 3 - -N, TN, TP in the outlet are 81%, 65%, 77% and 66% of the inlet respectively after flowing through the natural wetland in the reservoir. The wetlands can solve two major problems facing the coastal zone reservoirs that enhance intake water quality and stabilize water quality. In the design of coastal reservoirs, we suggest that we should make the full use of existing wetlands, enhance the function of wetland water purification through ecological engineering methods, and construct artificial wetlands as a supplement.

Matter Element Analysis in Benefit Evaluation of Reservoir Reinforcement

Aiming at evaluating the benefit of the reservoir reinforcement project, this paper constructed a benefit evaluation index system. Analytic Hierarchy Process (AHP) is used to determine the weights of different indexes. Matter Element Analysis (MEA) is applied to evaluate the index system. The effect of the project is analyzed for the reservoir management and maintenance in the future. Taking the Black Bay Reservoir, which is in Yichang, Hubei province China, as an example, the value of each index was quantified by qualitative and quantitative analysis and evaluation criteria which have been determined, in order to evaluate the benefit of the project. According to the evaluation results, the Black Bay Reservoir reinforcement benefit reached the general level and most of the benefit indexes achieved the expected ones, which were basically consistent with the actual situation.

Underwater robotic system for reservoir maintenance

In this paper a description and practical implementation of the developed prototype of an underwater hybrid robot is presented. The solution is based on the guidelines of Cracow waterworks (Municipal Waterworks and Sewer Enterprise, MPWiK S.A.). The prototype of the hybrid robot consists of a crawler robot and a ROV. Robots’ design, mathematical models of kinematics and dynamics of the crawler robot, ROV’s vision system architecture with image processing methods for surface crack detection and robot position and attitude estimation are investigated and examined. Results obtained from experimental validation of the developed prototype are presented and discussed. Finally, the paper establishes future research directions.

Total HIV-1 DNA, a Marker of Viral Reservoir Dynamics with Clinical Implications.

HIV-1 DNA persists in infected cells despite combined antiretroviral therapy (cART), forming viral reservoirs. Recent trials of strategies targeting latent HIV reservoirs have rekindled hopes of curing HIV infection, and reliable markers are thus needed to evaluate viral reservoirs. Total HIV DNA quantification is simple, standardized, sensitive, and reproducible. Total HIV DNA load influences the course of the infection and is therefore clinically relevant. In particular, it is predictive of progression to AIDS and death, independently of HIV RNA load and the CD4 cell count. Baseline total HIV DNA load is predictive of the response to cART. It declines during cART but remains quantifiable, at a level that reflects both the history of infection (HIV RNA zenith, CD4 cell count nadir) and treatment efficacy (residual viremia, cumulative viremia, immune restoration, immune cell activation). Total HIV DNA load in blood is also predictive of the presence and severity of some HIV-1-associated end-organ disorders. It can be useful to guide individual treatment, notably, therapeutic de-escalation. Although it does not distinguish between replication-competent and -defective latent viruses, the total HIV DNA load in blood, tissues, and cells provides insights into HIV pathogenesis, probably because all viral forms participate in host cell activation and HIV pathogenesis. Total HIV DNA is thus a biomarker of HIV reservoirs, which can be defined as all infected cells and tissues containing all forms of HIV persistence that participate in pathogenesis. This participation may occur through the production of new virions, creating new cycles of infection and disseminating infected cells; maintenance or amplification of reservoirs by homeostatic cell proliferation; and viral transcription and synthesis of viral proteins without new virion production. These proteins can induce immune activation, thus participating in the vicious circle of HIV pathogenesis.

First report of hepatitis E virus viremia in healthy blood donors from Nepal.

The aim of this study was to detect the prevalence of hepatitis E virus (HEV) in healthy blood donors so as to decipher the maintenance of (HEV) reservoir if any. Five hundred and eighty-one blood samples along with clinical information were collected from central blood bank, Kathmandu between February and March 2014. Samples were tested for hepatitis B virus surface antigen, anti-hepatitis C virus antibodies, anti-hepatitis A virus IgM, HEV antigen, HEV viral load and anti-HEV antibodies (IgM and IgG) by ELISA. Only those samples positive with anti-HEV IgM were tested for HEV RNA by reverse transcriptase nested PCR. Age adjusted prevalence of IgM anti HEV and IgG anti HEV were 3.6 and 8.3% respectively. No significant difference in Median ALT levels was noted between HEV RNA positive and negative subjects. Sequence analysis of HEV shows all genotype belongs to genotype 1a. Phylogenetic analysis shows the virus has homology of 95% with strain from India and Nepal outbreak of April 2014. This study sheds light on how inter epidemic reservoirs can be maintained in healthy population with asymptomatic cases. This raises an important question regarding nature of HEV as well as its tendency to circulate in blind sight and also cause periodic outbreaks in endemic setting like Kathmandu.

Molecular Determinants Directing HIV-1 Gag Assembly to Virus-Containing Compartments in Primary Macrophages.

The subcellular sites of HIV-1 assembly, determined by the localization of the structural protein Gag, vary in a cell-type-dependent manner. In T cells and transformed cell lines used as model systems, HIV-1 assembles at the plasma membrane (PM). The binding and localization of HIV-1 Gag to the PM are mediated by the interaction between the matrix (MA) domain, specifically the highly basic region, and a PM-specific acidic phospholipid, phosphatidylinositol-4,5-bisphosphate [PI(4,5)P2]. In primary macrophages, prominent accumulation of assembling or assembled particles is found in the virus-containing compartments (VCCs), which largely consist of convoluted invaginations of the PM. To elucidate the molecular mechanism of HIV-1 Gag targeting to the VCCs, we examined the impact of overexpression of polyphosphoinositide 5-phosphatase IV (5ptaseIV), which depletes cellular PI(4,5)P2, in primary macrophages. We found that the VCC localization and virus release of HIV-1 are severely impaired upon 5ptaseIV overexpression, suggesting an important role for the MA-PI(4,5)P2 interaction in HIV-1 assembly in primary macrophages. However, our analysis of HIV-1 Gag derivatives with MA changes showed that this interaction contributes to Gag membrane binding but is dispensable for specific targeting of Gag to the VCCs per se We further determined that deletion of the NC domain abolishes VCC-specific localization of HIV-1 Gag. Notably, HIV-1 Gag localized efficiently to the VCCs when the NC domain was replaced with a leucine zipper dimerization motif that promotes Gag multimerization. Altogether, our data revealed that targeting of HIV-1 Gag to the VCCs requires NC-dependent multimerization. In T cells and model cell lines, HIV-1 Gag localizes to the PM in a manner dependent on the MA-PI(4,5)P2 interaction. On the other hand, in primary macrophages, HIV-1 Gag localizes to convoluted intracellular membrane structures termed virus-containing compartments (VCCs). Although these compartments have been known for decades, and despite the implication of viruses in VCCs being involved in virus reservoir maintenance and spread, the viral determinant(s) that promotes Gag targeting to VCCs is unknown. In this study, we found that the MA-PI(4,5)P2 interaction facilitates efficient Gag membrane binding in macrophages but is not essential for Gag targeting to VCCs. Rather, our results revealed that NC-dependent multimerization promotes VCC targeting. Our findings highlight the differential roles played by MA and NC in HIV-1 Gag membrane binding and targeting and suggest a multimerization-dependent mechanism for Gag trafficking in primary macrophages similar to that for Gag localization to uropods in polarized T cells.

Effects of Stormwater and Snowmelt Runoff on ELISA-EQ Concentrations of PCDD/PCDF and Triclosan in an Urban River.

The aim of the study was to determine the effects of stormwater and snowmelt runoff on the ELISA EQ PCDD/PCDF and triclosan concentrations in the small urban Sokołówka River (Central Poland). The obtained results demonstrate the decisive influence of hydrological conditions occurring in the river itself and its catchment on the quoted PCDD/PCDF ELISA EQ concentrations. The lowest PCDD/PCDF values of 87, 60 and 67 ng EQ L-1 in stormwater, the river and its reservoirs, respectively, were associated with the highest river flow of 0.02 m3 s-1 and high precipitation (11.2 mm) occurred five days before sampling. In turn, the highest values of 353, 567 and 343 ng EQ L-1 in stormwater, the river and its reservoirs, respectively, were observed during periods of intensive snow melting (stormwater samples) and spring rainfall preceded by a rainless phase (river and reservoir samples) followed by low and moderate river flows of 0.01 and 0.005 m3 s-1. An analogous situation was observed for triclosan, with higher ELISA EQ concentrations (444 to 499 ng EQ L-1) noted during moderate river flow and precipitation, and the lowest (232 to 288 ng EQ L-1) observed during high river flow and high precipitation preceded by violent storms. Stormwater was also found to influence PCDD/PCDF EQ concentrations of the river and reservoirs, however only during high and moderate flow, and no such effect was observed for triclosan. The study clearly demonstrates that to mitigate the high peaks of the studied pollutants associated with river hydrology, the increased in-site stormwater infiltration and purification, the development of buffering zones along river course and the systematic maintenance of reservoirs to avoid the accumulation of the studied micropollutants and their subsequent release after heavy rainfall are required.

Phylogenetics and Phyloanatomy of HIV/SIV Intra-Host Compartments and Reservoirs: The Key Role of the Central Nervous System.

The ability of the human immunodeficiency virus type 1 (HIV-1) to persist in anatomic compartments and cellular reservoirs is a major obstacle for eradication of replicationcompetent virus in the infected host. We extensively review recent advancements in phylogenetic and phylogeographic techniques that provide a unique opportunity for studies of intra-host HIV-1 compartmentalization and the detection of potential reservoirs. We show that infected macrophages in the central nervous system (CNS) harbor viral subpopulations that play a key role in the emergence of escape variants and viral rebound following discontinuation of antiretroviral therapy. An HIV cure, therefore, cannot be achieved without the effective targeting of the virus in the CNS, for which in depth knowledge of viral population dynamics contributing to the development and maintenance of latent reservoirs is critical.