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101.
102.
Aaren S. Freeman Alejandro Frischeisen April MH. Blakeslee 《Biological invasions》2016,18(6):1653-1665
Interactions between anthropogenic disturbances and introduced and native species can shift ecological communities, potentially leading to the successful establishment of additional invaders. Since its discovery in New Jersey in 1988, the Asian shore crab (Hemigrapsus sanguineus) has continued to expand its range, invading estuarine and coastal habitats in eastern North America. In estuarine environments, H. sanguineus occupies similar habitats to native, panopeid mud crabs. These crabs, and a variety of fouling organisms (both NIS and native), often inhabit man-made substrates (like piers and riprap) and anthropogenic debris. In a series of in situ experiments at a closed dock in southwestern Long Island (New York, USA), we documented the impacts of these native and introduced crabs on hard-substrate fouling communities. We found that while the presence of native mud crabs did not significantly influence the succession of fouling communities compared to caged and uncaged controls, the presence of introduced H. sanguineus reduced the biomass of native tunicates (particularly Molgula manhattensis), relative to caged controls. Moreover, the presence of H. sanguineus favored fouling communities dominated by introduced tunicates (especially Botrylloides violaceous and Diplosoma listerianum). Altogether, our results suggest that H. sanguineus could help facilitate introduced fouling tunicates in the region, particularly in locations where additional solid substrates have created novel habitats. 相似文献
103.
104.
Mandel U; Hassan H; Therkildsen MH; Rygaard J; Jakobsen MH; Juhl BR; Dabelsteen E; Clausen H 《Glycobiology》1999,9(1):43-52
Mucin-type O-glycosylation is initiated by a large family of UDP- GalNAc:
polypeptide N -acetyl-galactosaminyltransferases (GalNAc- transferases).
Individual GalNAc-transferases appear to have different functions and
Northern analysis indicates that they are differently expressed in
different organs. This suggests that O-glycosylation may vary with the
repertoire of GalNAc-transferases expressed in a given cell. In order to
study the repertoire of GalNAc-transferases in situ in tissues and changes
in tumors, we have generated a panel of monoclonal antibodies (MAbs) with
well defined specificity for human GalNAc-T1, -T2, and -T3. Application of
this panel of novel antibodies revealed that GalNAc- transferases are
differentially expressed in different cell lines, in spermatozoa, and in
oral mucosa and carcinomas. For example, GalNAc-T1 and -T2 but not -T3 were
highly expressed in WI38 cells, and GalNAc-T3 but not GalNAc-T1 or -T2 was
expressed in spermatozoa. The expression patterns in normal oral mucosa
were found to vary with cell differentiation, and for GalNAc-T2 and -T3
this was reflected in oral squamous cell carcinomas. The expression pattern
of GalNAc-T1 was on the other hand changed in tumors to either total loss
or expression in cytological poorly differentiated tumor cells, where the
normal undifferentiated cells lacked expression. These results demonstrate
that the repertoire of GalNAc-transferases is different in different cell
types and vary with cellular differentiation, and malignant transformation.
The implication of this is not yet fully understood, but it suggests that
specific changes in sites of O-glycosylation of proteins may occur as a
result of changes in the repertoire of GalNAc-transferases.
相似文献
105.
Airway epithelia play a crucial role in protecting the lung from the external environment. Ciliated airway epithelial cells contribute to mucociliary transport systems via ciliary beating and electrolyte transport mechanisms to defend against respiratory tract infection. Both of these activities are regulated by nitric oxide (NO)-dependent mechanisms. To better understand the role of the NO-cGMP signal transduction cascade in these responses, we investigated the localization of endothelial nitric oxide synthase (eNOS), soluble guanylyl cyclase (sGC), cGMP-dependent protein kinase (PKG) I-alpha, and PKG I-beta in the tracheas and lungs of normal rats by immunohistochemistry. Mouse anti-eNOS, rabbit anti-sGC, PKG I-alpha, and PKG I-beta antibodies were used. Strong immunostaining for eNOS was detected in ciliated tracheal, bronchial, and bronchiolar epithelia, in Clara cells, and in Type II alveolar cells. The pattern of sGC and PKG I-beta immunostaining showed striking parallels with that of eNOS staining. No staining was detectable in ciliated epithelium with the anti-PKG I-alpha antibody. Taken together, these observations suggest that PKG I-beta might transduce NO-sGC signaling into biological responses in ciliated respiratory epithelia.(J Histochem Cytochem 47:1369-1374, 1999) 相似文献
106.
Fan Yang Jalal Jalali Sendi R. C. Johns Makio Takeda 《Applied Entomology and Zoology》2017,52(3):401-406
Hyphantria cunea (Drury) has colonized many countries outside its native range of North America and has become a model species for studies of the colonization and subsequent adaptation of agricultural pests. Molecular genetic analyses can clarify the origin and subsequent adaptations to non-native habitats. Using the mitochondrial COI gene, we examined the genetic relationships between invasive populations (China, Iran, Japan, and Korea) and native populations (i.e., the United States). The Jilin (China) and Guilan (Iran) populations showed nine previously unknown haplotypes that differed from those found in the south–central United States, suggesting multiple colonization events and different regions of invasion. A dominant mtDNA haplotype in populations in the United States was shared by all of the populations investigated, suggesting that H. cunea with that haplotype have successfully colonized China, Iran, Japan, and Korea. 相似文献
107.
Membrane-associated guanylate kinases (MAGUKs) act as scaffolds to coordinate signaling events through their multiple domains at the plasma membrane. The MAGUK SH3 domain is noncanonical and its function remains unclear. To identify potential binding partners of MAGUK SH3, the synapse-associated protein 102 (SAP102) SH3 domain was used as bait in a yeast two-hybrid screen of a mouse embryonic cDNA library. A mouse homologue of the Drosophila discs large tumor suppressor (Dlg, also known as SAP97) bound preferentially to SAP102 SH3. The 4347bp cDNA sequence encoded an 893 amino acid protein with 94% identity to mouse SAP97. A deleted region (33-aa) strongly suggests this is a novel splice variant, which we call Embryonic-dlg/SAP97 (E-dlg). The interaction of SAP102 and E-dlg was confirmed in mammalian cells. E-dlg can also bind to potassium channel Kv1.4 in a pull-down assay. E-dlg was highly expressed in embryonic and some adult mouse tissues, such as brain, kidney, and ovary. Furthermore, in situ hybridization showed that E-dlg was mostly expressed in olfactory bulb and cerebellum. 相似文献
108.
T.R.R. Pintelon D.A. Graf von der Schulenburg M.L. Johns 《Biotechnology and bioengineering》2009,103(4):767-779
While biological clogging of porous systems can be problematic in numerous processes (e.g., microbial enhanced oil recovery—MEOR), it is targeted during bio‐barrier formation to control sub‐surface pollution plumes in ground water. In this simulation study, constant pressure drop (CPD) and constant volumetric flow rate (CVF) operational modes for nutrient provision for biofilm growth in a porous system are considered with respect to optimum (minimum energy requirement for nutrient provision) permeability reduction for bio‐barrier applications. Biofilm growth is simulated using a Lattice‐Boltzmann (LB) simulation platform complemented with an individual‐based biofilm model (IbM). A biomass detachment technique has been included using a fast marching level set (FMLS) method that models the propagation of the biofilm–liquid interface with a speed proportional to the adjacent velocity shear field. The porous medium permeability reduction is simulated for both operational modes using a range of biofilm strengths. For stronger biofilms, less biomass deposition and energy input are required to reduce the system permeability during CPD operation, whereas CVF is more efficient at reducing the permeability of systems containing weaker biofilms. Biotechnol. Bioeng. 2009;103: 767–779. © 2009 Wiley Periodicals, Inc. 相似文献
109.
Rob C. Johns Dan T. Quiring & Don P. Ostaff 《Entomologia Experimentalis et Applicata》2009,132(3):264-274
Heterogeneity in the quality of oviposition and feeding sites within plants can significantly influence the distribution and abundance of herbivorous insects, but remains poorly understood. Field surveys and a manipulative study were conducted to evaluate the influence of variation within the crown of black spruce, Picea mariana (Mill.) B.S.P. (Pinaceae), on adult oviposition and larval feeding behavior of yellowheaded spruce sawfly, Pikonema alaskensis Rohwer (Hymenoptera: Tenthredinidae). Most eggs were laid in the mid to lower crown of 1.5–2 m tall trees. However, most of the few eggs that were laid in the upper crown (i.e., whorl 2) were female. Fourth and fifth instars dispersed acropetally, from the mid and lower to the upper crown, causing high defoliation in the upper crown. Late-instar females were generally more abundant than males on the leader, the most apical shoot on a tree where eggs and early instars rarely occurred, strongly suggesting that more females than males disperse acropetally. This hypothesis was supported in a manipulative experiment, where only 15–20% of larvae in all-male broods, but almost three-quarters of larvae in mixed broods, dispersed to the upper crown. To our knowledge, this is only the second study to explicitly demonstrate preferential allocation of progeny sex through oviposition site selection by a herbivorous insect, and the first study to unambiguously demonstrate sex-biased dispersal by the juveniles of an insect whose adult females can fly. This study emphasizes the important role of intra-plant variation in shaping both oviposition site selection and the dispersal behavior of juvenile phytophagous insects within their hosts, and suggests that sex-biased foraging behaviors may be necessary for some insects to accommodate the respective needs of immature females and males within heterogeneous host plants. 相似文献
110.
Brian A. Johns Jason G. Weatherhead Scott H. Allen James B. Thompson Edward P. Garvey Scott A. Foster Jerry L. Jeffrey Wayne H. Miller 《Bioorganic & medicinal chemistry letters》2009,19(6):1807-1810
The use of a 1,3,4-oxadiazole in combination with an 8-hydroxy-1,6-naphthyridine ring system has been shown to deliver potent enzyme and antiviral activity through inhibition of viral DNA integration. This report presents a detailed structure–activity investigation of the C5 position resulting in low nM potency for several analogs with an excellent therapeutic index. 相似文献