1,879 research outputs found
Aerated Blast-Furnace-Slag Filters for the Simultaneous Removal of Nitrogen and Phosphorus from Primary Facultative Pond Effluents
Abstract: Rock filters (RF) are a promising alternative natural wastewater treatment technology for upgrading waste stabilization pond (WSP) effluents. However, the use of RF to remove nutrients, such as nitrogen (N) and phosphorus (P), is very limited. Therefore, the present study was carried out to investigate the performance of aerated RF (ARF) systems for removing both nitrogen and phosphorus from domestic wastewater using blast furnace slag (BFS) as the filter medium. The performance of two aerated BFS filter systems, a horizontal-flow ARF and a vertical upflow ARF, was compared: for N and P removals. A further aim of the study was to determine if either or both of these BFS-ARF systems could produce effluents which complied with the nutrient removal requirements of the EU Urban Waste Water Treatment Directive (UWWTD) (91/271/EEC) for small communities. From the results of the present study it can be concluded that the both BFS-ARF are suitable unit processes for removing N and P from primary facultative pond effluents. The vertical-upflow BFS-ARF has the advantage of removing more ammonium-N (to below 1 mg N/L), but the disadvantage of removing less total-N. Further research on optimizing the design and performance of both BFS-ARF is warranted, and their performance in warm-climate countries requires to be investigated
Clathrin binding by the adaptor Ent5 promotes late stages of clathrin coat maturation
Clathrin is a ubiquitous protein that mediates membrane traffic at many locations. To function, clathrin requires clathrin adaptors that link it to transmembrane protein cargo. In addition to this cargo selection function, many adaptors also play mechanistic roles in the formation of the transport carrier. However, the full spectrum of these mechanistic roles is poorly understood. Here we report that Ent5, an endosomal clathrin adaptor in Saccharomyces cerevisiae, regulates the behavior of clathrin coats after the recruitment of clathrin. We show that loss of Ent5 disrupts clathrin-dependent traffic and prolongs the lifespan of endosomal structures that contain clathrin and other adaptors, suggesting a defect in coat maturation at a late stage. We find that the direct binding of Ent5 with clathrin is required for its role in coat behavior and cargo traffic. Surprisingly, the interaction of Ent5 with other adaptors is dispensable for coat behavior but not cargo traffic. These findings support a model in which Ent5 clathrin binding performs a mechanistic role in coat maturation, whereas Ent5 adaptor binding promotes cargo incorporation
Regulating polarity by directing traffic: Cdc42 prevents adherens junctions from Crumblin' aPart
The GTPase Cdc42 was among the original genes identified with roles in cell polarity, and interest in its cellular roles from yeast to humans remains high. Cdc42 is a well-known regulator of the actin cytoskeleton, but also plays important roles in vesicular trafficking. In this issue, Harris and Tepass (Harris, K.P, and U. Tepass. 2008. J. Cell. Biol. 183:1129–1143) provide new insights into how Cdc42 and Par proteins work together to modulate cell adhesion and polarity during embryonic morphogenesis by regulating the traffic of key cell junction proteins
Sanitation: What's the Real Problem?
The vast number of people without sanitation raises the question why this is so. It cannot be a lack of adequate sanitation technologies as these exist for all situations from dispersed rural communities to high?density low?income urban areas. Nor cannot it be money as development banks will readily fund a well?prepared sanitation proposal. The real sanitation problem must surely lie with those developing?country governments who have shown little commitment in practice to sanitation despite international sanitation advocacy since 1980. Their lack of commitment is clearly shown in the number of ‘open defecators’ in the world today. There are fortunately some countries that have done well: Malaysia, Thailand and Vietnam, for example, but they are a clear minority
Sanitización de biosólidos de plantas de tratamiento primario avanzado: ¿compostaje o estabilización alcalina?
Este estudio tuvo como propósito evaluar dos alternativas de reducción de patógenos; Compostaje y tratamiento alcalino en
los biosólidos generados en la Planta de Tratamiento de Aguas Residuales de Cañaveralejo (PTAR-C), de Cali, Colombia.
Para el compostaje se utilizó: Biosólidos; Biosólidos (B) + cachaza (C)+ residuos de poda (P); Biosolido (B) + Residuos
Organicos de mercado (ROPM) + residuos de poda (P), por 61 días. El tratamiento alcalino se desarrollo por 13 días. Cal
apagada y ceniza de carbón fue aplicada a: Biosólidos y al producto final del compostaje. Fueron 8, 15 y 30 % (peso/peso)
las concentraciones aplicadas de ambos tipos de alcalinizantes. pH, humedad, temperatura, demanda química de Oxigeno
(DQO, Nitrogeno Total Kjeldahl (NTK), Nitrogeno amoniacal (N- NH , huevos de helmintos y coliformes fecales (CF) se 4)
monitorearon en ambos experimentos. Los resultados mostraron que la mejor mezcla de compost fue (B + C + P), eliminado
patógenos, manteniendo la clasificación del material como Clase B, con una media geométrica para CF de 4x10-3 UFC g-1,
indicando que el proceso no alcanza la clase A. La estabilización alcalina mostró que la ceniza para todas las dosis aplicadas
produjo una calidad microbiológica de CF similar al compost, mostrando cierta debilidad de este material en su poder
higienizante desde el punto de vista costo-eficiencia. Cal apagada al 15 y 30% produjo mejor calidad microbiológica con
cero UFC g-1 de CF, alcanzando el estándar de clase A según la Agencia de Proteccion Ambiental. Esta situación puede estar
asociada al incremento de pH. Para el 8% (peso/peso) la calidad fue menor a las dos anteriores y no alcanzó el estándar de
clase A
Exomer complex regulates protein traffic at the TGN through differential interactions with cargos and clathrin adaptor complexes
[EN] Protein sorting at the trans-Golgi network (TGN) usually requires the assistance of cargo adaptors. However, it remains to be examined how the same complex can mediate both the export and retention of different proteins or how sorting complexes interact among themselves. In Saccharomyces cerevisiae, the exomer complex is involved in the polarized transport of some proteins from the TGN to the plasma membrane (PM). Intriguingly, exomer and its cargos also show a sort of functional relationship with TGN clathrin adaptors that is still unsolved. Here, using a wide range of techniques, including time-lapse and BIFC microscopy, we describe new molecular implications of the exomer complex in protein sorting and address its different layers of functional interaction with clathrin adaptor complexes. Exomer mutants show impaired amino acid uptake because it facilitates not only the polarized delivery of amino acid permeases to the PM but also participates in their endosomal traffic. We propose a model for exomer where it modulates the recruitment of TGN clathrin adaptors directly or indirectly through the Arf1 function. Moreover, we describe an in vivo competitive relationship between the exomer and AP-1 complexes for the model cargo Chs3. These results highlight a broad role for exomer in regulating protein sorting at the TGN that is complementary to its role as cargo adaptor and present a model to understand the complexity of TGN protein sorting.Ministerio de Economía, Industria y
Competitividad, Gobierno de España
(Ministeri d'Economia, Indústria i
Competitivitat), Grant/Award Number:
CICYT/FEDER BFU2017-84508-P;
Consejería de Educación, Junta de Castilla
y León (Ministry of Education, Government
of Castile-Leon), Grant/Award Number:
SA116G19; Ministerio de Economía, Industria y Competitividad, Gobierno de
España (Ministeri d'Economia, Indústria
i Competitivitat), Grant/Award Number:
RTC-2017-6468-2-AR; Ministerio de
Economía, Industria y Competitividad,
Gobierno de España (Ministeri d'Economia,
Indústria i Competitivitat), Grant/Award
Number: BIO2016-77776-P; Foundation
for the National Institutes of Health (FNIH),
Grant/Award Number: R01 GM092741Anton-Plagaro, C.; Sánchez, N.; Valle, R.; Mulet, JM.; Duncan, MC.; Roncero, C. (2021). Exomer complex regulates protein traffic at the TGN through differential interactions with cargos and clathrin adaptor complexes. The FASEB Journal. 35(6):1-26. https://doi.org/10.1096/fj.202002610R12635
Energy metabolism regulates clathrin adaptors at the trans -Golgi network and endosomes
Localization of endosomal clathrin adaptors is regulated by glucose availability via an unknown mechanism. Studies in intact and permeabilized cells show that clathrin adaptor localization is precisely tuned by cellular ATP concentration. These data provide evidence for how membrane traffic is coordinated with overall proliferation rates.Glucose is a master regulator of cell behavior in the yeast Saccharomyces cerevisiae. It acts as both a metabolic substrate and a potent regulator of intracellular signaling cascades. Glucose starvation induces the transient delocalization and then partial relocalization of clathrin adaptors at the trans-Golgi network and endosomes. Although these localization responses are known to depend on the protein kinase A (PKA) signaling pathway, the molecular mechanism of this regulation is unknown. Here we demonstrate that PKA and the AMP-regulated kinase regulate adaptor localization through changes in energy metabolism. We show that genetic and chemical manipulation of intracellular ATP levels cause corresponding changes in adaptor localization. In permeabilized cells, exogenous ATP is sufficient to induce adaptor localization. Furthermore, we reveal distinct energy-dependent steps in adaptor localization: a step that requires the ADP-ribosylation factor ARF, an ATP-dependent step that requires the phosphatidyl-inositol-4 kinase Pik1, and third ATP-dependent step for which we provide evidence but for which the mechanism is unknown. We propose that these energy-dependent mechanisms precisely synchronize membrane traffic with overall proliferation rates and contribute a crucial aspect of energy conservation during acute glucose starvation
AGN Populations in Large Volume X-ray Surveys: Photometric Redshifts and Population Types found in the Stripe 82X Survey
Multi-wavelength surveys covering large sky volumes are necessary to obtain
an accurate census of rare objects such as high luminosity and/or high redshift
active galactic nuclei (AGN). Stripe 82X is a 31.3 deg X-ray survey with
and -Newton observations overlapping the legacy Sloan Digital
Sky Survey (SDSS) Stripe 82 field, which has a rich investment of
multi-wavelength coverage from the ultraviolet to the radio. The wide-area
nature of this survey presents new challenges for photometric redshifts for AGN
compared to previous work on narrow-deep fields because it probes different
populations of objects that need to be identified and represented in the
library of templates. Here we present an updated X-ray plus multi-wavelength
matched catalog, including counterparts, and estimated photometric
redshifts for 5961 (96% of a total of 6181) X-ray sources, which have a
normalized median absolute deviation, = 0.06 and an outlier
fraction, = 13.7%. The populations found in this survey, and the
template libraries used for photometric redshifts, provide important guiding
principles for upcoming large-area surveys such as and 3 (in
X-ray) and the Large Synoptic Survey Telescope (LSST; optical).Comment: Accepted for publication by The Astrophysical Journal (33 pages, 20
figures, 13 tables). Final catalog of counterparts and photo-z supplementing
the paper available here:
http://stripe82x.com/docs/stripe82x-photometric-redshifts-and-multiwavelength-data-catalog
The actin-microtubule cross-linking activity of Drosophila Short stop is regulated by intramolecular inhibition
Actin and microtubule dynamics must be precisely coordinated during cell migration, mitosis, and morphogenesis—much of this coordination is mediated by proteins that physically bridge the two cytoskeletal networks. We have investigated the regulation of the Drosophila actin-microtubule cross-linker Short stop (Shot), a member of the spectraplakin family. Our data suggest that Shot's cytoskeletal cross-linking activity is regulated by an intramolecular inhibitory mechanism. In its inactive conformation, Shot adopts a “closed” conformation through interactions between its NH2-terminal actin-binding domain and COOH-terminal EF-hand-GAS2 domain. This inactive conformation is targeted to the growing microtubule plus end by EB1. On activation, Shot binds along the microtubule through its COOH-terminal GAS2 domain and binds to actin with its NH2-terminal tandem CH domains. We propose that this mechanism allows Shot to rapidly cross-link dynamic microtubules in response to localized activating signals at the cell cortex
The 31 Deg Release of the Stripe 82 X-ray Survey: The Point Source Catalog
We release the next installment of the Stripe 82 X-ray survey point-source
catalog, which currently covers 31.3 deg of the Sloan Digital Sky Survey
(SDSS) Stripe 82 Legacy field. In total, 6181 unique X-ray sources are
significantly detected with {\it XMM-Newton} () and {\it Chandra}
(). This catalog release includes data from {\it XMM-Newton} cycle
AO 13, which approximately doubled the Stripe 82X survey area. The flux limits
of the Stripe 82X survey are erg s cm,
erg s cm, and erg
s cm in the soft (0.5-2 keV), hard (2-10 keV), and full bands
(0.5-10 keV), respectively, with approximate half-area survey flux limits of
erg s cm, erg s
cm, and erg s cm. We matched the X-ray
source lists to available multi-wavelength catalogs, including updated matches
to the previous release of the Stripe 82X survey; 88\% of the sample is matched
to a multi-wavelength counterpart. Due to the wide area of Stripe 82X and rich
ancillary multi-wavelength data, including coadded SDSS photometry,
mid-infrared {\it WISE} coverage, near-infrared coverage from UKIDSS and VHS,
ultraviolet coverage from {\it GALEX}, radio coverage from FIRST, and
far-infrared coverage from {\it Herschel}, as well as existing 30\%
optical spectroscopic completeness, we are beginning to uncover rare objects,
such as obscured high-luminosity AGN at high-redshift. The Stripe 82X point
source catalog is a valuable dataset for constraining how this population grows
and evolves, as well as for studying how they interact with the galaxies in
which they live.Comment: accepted for publication in ApJ; 23 pages (emulateapj
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