Radonove kćeri u okolišu kao pokazatelji biokemijskih promjena u mozgu bolesnika s Alzheimerovom i Parkinsonovom bolesti i u pušača

This paper presents an investigation of the retention of environmental radon daughters, 210Po (alpha particle emitting radio-nuclide) and 210Bi (beta particle emitting radio-nuclide), in lipid and protein fractions of the cortical grey and subcortical white matter from the frontal and temporal brain lobes of patients who had suffered from Alzheimer’s disease or Parkinson’s disease, of cigarette smokers, and of control subjects. 210Po and 210Bi radioactivity increased tenfold in the cortical grey and subcortical white protein fraction in patients with Alzheimer’s disease and smokers, and tenfold in the cortical grey and subcortical white lipid fraction in patients with Parkinson’s disease. Free radicals generated by radon daughters may add to the severity of the radio-chemical injury to the brain astrocytes. The pathognomonic distribution of radon daughters to lipids in patients with Parkinson’s disease and to proteins in patients with Alzheimer’s disease was attributed to high chlorine affinity of radon daughters. The changes in the membrane protein pores, channels, and gates in patients with Alzheimer’s disease and in the lipid bilayer in patients with Parkinson’s disease are at the core of what the authors think are two systemic brain diseases.Odredili smo radioaktivnost radonovih kćeri, 210Po (alfa čestice) i 210Bi (beta-čestice) u lipidima i proteinima iz sive mase korteksa i bijele supkortikalne supstancije iz frontalnog i temporalnog režnja mozga osoba oboljelih od Alzheimerove ili Parkinsonove bolesti, pušača i nepušača bez kliničkih znakova neurološke bolesti. Ustanovili smo da je radioaktivnost 210Pb i 210Bi bila deset puta veća selektivno u proteinima sive i bijele moždane supstancije osoba oboljelih od Alzheimerove bolesti i u pušača. Za razliku od toga, radioaktivnost radonovih kćeri bila je selektivno deset puta veća u lipidima sive i bijele supstancije mozga osoba oboljelih od Parkinsonove bolesti. Alfa čestice visoke energije predstavile su se kao neizbježni čimbenik rizika iz prirodnog okoliša za čovjekov mozak koji zajedno s popratnim stvaranjem slobodnih radikala mogu dovesti do minimalne lokalne udružene radiokemijske ozljede moždanih stanica, najvjerojatnije astrocita. Rezultati pokazuju da patognomonična distribucija afiniteta radonovih kćeri za lipide u bolesnika s Parkinsonovom bolesti i za proteine u bolesnika s Alzheimerovom bolesti odražava povećanu prisutnost lokalno raspoloživih klornih iona za koje se radonove kćeri selektivno vežu. Mislimo da promjene u sastavu proteinskih pora, kanala i vrata ugrađenih u staničnu membranu u bolesnika s Alzheimerovom bolesti, kao i promjene propusnosti dvoslojnoga lipidnog sloja te iste membrane leže u biti tih dviju teških sistemskih bolesti čovjekova mozga

Simulation of Arsenic Partitioning in Tributaries to Drinking Water Reservoirs

Arsenic released by bottom sediments was determined by experiments in which the sediments were artificially re-suspended using a particle entrapment simulator (PES) to simulate river conditions. Sediment cores were collected from various tributaries to drinking water reservoirs in Connecticut spiked with arsenic, and run in the PES at simulated bed-flow shear stresses from 0.0 to 0.6 N/m2. Under equilibrium conditions, the dissolved fraction of arsenic was found to range from 8.3 to 22.1 ug/1, which in most cases exceeded EPA Maximum Contaminant Level (MCL) of 10 ug/1. Experimental results from these simulations have shown that bed-flow shear stress causes an increased concentration of dissolved arsenic, most notably at shear stresses of 0.4,0.5, and 0.6 N/m2. For the solid phase under equilibrium, the concentrations of arsenic ranged between 71 and 275 mg/kg. The average concentration of arsenic on the solid phase as well as partitioning coefficient values (Kp) were highest at initial shear stress. This was attributed to the higher fraction of colloidal material and finer organic particles in the suspended solid mixture. Particles of such nature proved to have higher affinity to arsenic. Kp values were determined from PES data and were found to range from 4,687 to 24,090 1/kg. However, on a mass load basis, the amount of arsenic found in suspended sediment increased with the increase of shear stress. Similarly, the amount of arsenic in the solid phase increased significantly for sites with high Volatile Organic Carbon (VOC) content. Because of the influence of Total Suspended Solids (TSS) and VOC concentrations on Kp, the use of the PES is more appropriate in obtaining Kp values that would be found under real stream conditions when compared to the traditional way of measuring Kp using a jar study technique

Cellulose acetate phthalate, a common pharmaceutical excipient, inactivates HIV-1 and blocks the coreceptor binding site on the virus envelope glycoprotein gp120

BACKGROUND: Cellulose acetate phthalate (CAP), a pharmaceutical excipient used for enteric film coating of capsules and tablets, was shown to inhibit infection by the human immunodeficiency virus type 1 (HIV-1) and several herpesviruses. CAP formulations inactivated HIV-1, herpesvirus types 1 (HSV-1) and 2 (HSV-2) and the major nonviral sexually transmitted disease (STD) pathogens and were effective in animal models for vaginal infection by HSV-2 and simian immunodeficiency virus. METHODS: Enzyme-linked immunoassays and flow cytometry were used to demonstrate CAP binding to HIV-1 and to define the binding site on the virus envelope. RESULTS: 1) CAP binds to HIV-1 virus particles and to the envelope glycoprotein gp120; 2) this leads to blockade of the gp120 V3 loop and other gp120 sites resulting in diminished reactivity with HIV-1 coreceptors CXCR4 and CCR5; 3) CAP binding to HIV-1 virions impairs their infectivity; 4) these findings apply to both HIV-1 IIIB, an X4 virus, and HIV-1 BaL, an R5 virus. CONCLUSIONS: These results provide support for consideration of CAP as a topical microbicide of choice for prevention of STDs, including HIV-1 infection

Nitrogen uptake and internal recycling in Zostera marina exposed to oyster farming: eelgrass potential as a natural biofilter

Oyster farming in estuaries and coastal lagoons frequently overlaps with the distribution of seagrass meadows, yet there are few studies on how this aquaculture practice affects seagrass physiology. We compared in situ nitrogen uptake and the productivity of Zostera marina shoots growing near off-bottom longlines and at a site not affected by oyster farming in San Quintin Bay, a coastal lagoon in Baja California, Mexico. We used benthic chambers to measure leaf NH4 (+) uptake capacities by pulse labeling with (NH4)-N-15 (+) and plant photosynthesis and respiration. The internal N-15 resorption/recycling was measured in shoots 2 weeks after incubations. The natural isotopic composition of eelgrass tissues and vegetative descriptors were also examined. Plants growing at the oyster farming site showed a higher leaf NH4 (+) uptake rate (33.1 mmol NH4 (+) m(-2) day(-1)) relative to those not exposed to oyster cultures (25.6 mmol NH4 (+) m(-2) day(-1)). We calculated that an eelgrass meadow of 15-16 ha (which represents only about 3-4 % of the subtidal eelgrass meadow cover in the western arm of the lagoon) can potentially incorporate the total amount of NH4 (+) excreted by oysters (similar to 5.2 x 10(6) mmol NH4 (+) day(-1)). This highlights the potential of eelgrass to act as a natural biofilter for the NH4 (+) produced by oyster farming. Shoots exposed to oysters were more efficient in re-utilizing the internal N-15 into the growth of new leaf tissues or to translocate it to belowground tissues. Photosynthetic rates were greater in shoots exposed to oysters, which is consistent with higher NH4 (+) uptake and less negative delta C-13 values. Vegetative production (shoot size, leaf growth) was also higher in these shoots. Aboveground/belowground biomass ratio was lower in eelgrass beds not directly influenced by oyster farms, likely related to the higher investment in belowground biomass to incorporate sedimentary nutrients

AAPM Medical Physics Practice Guideline 2.a: Commissioning and quality assurance of X-ray–based image-guided radiotherapy systems

The American Association of Physicists in Medicine (AAPM) is a nonprofit professional society whose primary purposes are to advance the science, education, and professional practice of medical physics. The AAPM has more than 8,000 members and is the principal organization of medical physicists in the United States. The AAPM will periodically define new practice guidelines for medical physics practice to help advance the science of medical physics and to improve the quality of service to patients throughout the United States. Existing medical physics practice guidelines will be reviewed for the purpose of revision or renewal, as appropriate, on their fifth anniversary or sooner. Each medical physics practice guideline represents a policy statement by the AAPM, has undergone a thorough consensus process in which it has been subjected to extensive review, and requires the approval of the Professional Council. The medical physics practice guidelines recognize that the safe and effective use of diagnostic and therapeutic radiology requires specific training, skills, and techniques, as described in each document. Reproduction or modification of the published practice guidelines and technical standards by those entities not providing these services is not authorized. 1

Parameters Affecting Partitioning of 6 PCB Congeners in Natural Sediments

Polychlorinated biphenyls (PCBs) released by bottom sediments were determined by experiments in which the sediments were artificially resuspended using sediment contaminated with PCBs in a particle entrainment simulator (PES). Sediment cores, spiked with PCBs, were collected from the Housatonic River in Connecticut and run in the PES at simulated shear stresses from 0 to 0.6 N m(-2). Experimental results from these simulations have shown that mean concentration of PCBs in the solid phase for sites with high volatile organic carbon (VOC) were significantly greater than samples with low VOC; the reverse was true for the water phase. In addition, on a mass load basis, the amount of PCBs found in sediment increased when shear stresses were increased from 0 to 0.6 N m(-2), beyond which shear stress did not affect mass loads in the water column. Partition coefficients (Kp) were determined from PES sediment and water data for the following congeners: PCB 28, PCB 52, PCB 101, PCB 138, PCB 153, PCB 180. Kp was determined to be inversely proportional to total suspended solids (TSS), but directly proportional to chlorine content of the congener. Because of the strong influence of TSS and VOC concentrations on Kp values, agitation of samples using a PES better simulated real environmental conditions when compared to jar studies where no agitation was employed. Therefore, a device like the PES is more appropriate in obtaining Kp that would be found under real stream flow conditions when compared to the traditional way of measuring Kp using the jar study technique

Parameters Influencing Sediments Resuspension and the Link to Sorption of Inorganic Compounds

In the aquatic environment, the accumulation of chemicalcontaminants by sediments poses a potential threat to endemiclife forms and drinking water resources. Trace metals such asCd, Cu, Cr, Ni, Pb, and toxic organic compounds, are among awide variety of contaminants having an affinity for sediments.In this study, experiments were performed simulating sedimentresuspension in the lower Housatonic River, Connecticut, using aParticle Entrainment Simulator. Analyses of grain sizedistributions, porosities and total organic contents of thesediments suggested that these parameters influence theredistribution and entrainment of settleable solids in the watercolumn. These findings were established by evaluating the impactof one parameter on sediment resuspension as a function ofstream flow with the other two characteristics being heldconstant. Total suspended solids and volatile suspended solidsresuspension concentration ranged from 3.2 to 20648.3 mg L^sup -1^,and 1.5 to 1823.8 mg L^sup -1^, respectively, with subsequentincreases in flow rates from 9 to 6 dynes cm^sup -2^. The resuspension concentrations were augmentedby sediment porosity (22.0 to 57.5%), percent finer grain-size distributions at 0.1 mm, and total organic content (2.7 g kg^sup -1^ to 29.0 g kg^sup -1^). Using K^sub p^ values, and the dissolvedcontaminant levels of various trace metals, the particulatecontaminant levels of the metals were determined under variousoscillation rates. As sediment resuspension increased withincreased stream flow, there was an overall general increasefrom 0.02 to 33.6 μg L^sup -1^ in the particulatecontaminant levels of Cd, Cu, Cr, Ni and Pb

Wet Weather Impact on Trihalomethane Formation Potential in tributaries to Drinking Water Reservoirs

During rain storm events, land surface runoff and resuspension of bottom sediments cause an increase in Trihalomethane (THM) precursors in rivers. These precursors, when chlorinated at water treatment facilities will lead to the formation of THMs and hence impact drinking water resources. In order to evaluate the wet weather impact on the potential formation of THMs, river samples were collected before, during and after three rain storms ranging from 15.2 to 24.9 mm precipitation. The samples were tested for THM formation potential and other indicators including UV254 absorbance, turbidity and volatile suspended solid (VSS). Average levels of THMs increased from 61 microg/l during dry weather to 131 microg/l during wet weather, and then went back to 81 microg/l after rain ended. Wet weather values of THM are well above the maximum contaminant level (MCL) 80 microg/l, set by EPA for drinking water. THM indicators also exhibited similar trends. Average levels increased from 0.6 to 1.8 abs; 2.6 to 6 ntu; and 7.5 to 15 mg/l respectively for UV254, turbidity and VSS. A positive correlation was observed between THM formation and THM indicators. The t-test of significance (p-value) was less than 0.05 for all indicators, and R values ranged from 0.85 to 0.92 between THMs and the indicators, and 0.72 to 0.9 among indicators themselves

Informal Executive Actions and Agency Guidance: Legal and Political Implications for Immigration and Other Policy Areas

This paper is a study of the use of various forms of informal executive actions used by presidents and cabinet officials to guide the policy implementation of federal agencies. Among these are policy manuals, guidance statements, statements of administration policy, and announcements of executive priorities. The recent executive action regarding immigration announced by President Obama is also an example of this kind of behavior. The paper will rely upon the analysis of legal scholars who have examined the causes and consequences of informal executive actions. We will examine the implications that these actions have for public participation, transparency, consistency in decision-making, and inter-branch comity. The analysis will be applied to President Obama’s recent action regarding immigration enforcement