182 research outputs found
Using Ecological Niche Modeling to Predict the Response of Hydrocotyle Bonariensis to Global Climate Change
Coastal dune habitats provide valuable ecosystem services but are declining globally due to the interacting effects of multiple stressors, including global climate change (GCC). To explore the potential severity of the effects of GCC on dune plant communities of the Northern Gulf of Mexico and surrounding areas, we modeled the fundamental bioclimatic niche of a dune plant species, largeleaf pennywort (Hydrocotyle bonariensis Comm. ex Lam.), in this region. We then projected its niche to estimate habitat suitability under current and future environmental conditions. Occurrence records were mined from the Global Biodiversity Information Facility, cleaned, then thinned by spatial filtering, and WorldClim bioclimatic variables (30 arc-second resolution) were used as environmental data layers during analyses. Niche modeling was conducted using MaxEnt, and the model was projected onto a potentially accessible area (M) for the species defined by a 200-km buffer zone around the filtered occurrence points. Results suggested that our model had high predictive performance (AUC ≥ 0.9) and the projections indicated that the distribution of suitable habitat for H. bonariensis in the study region will likely be greatly reduced by GCC over the coming decades. Unlike other foredune plant species, H. bonariensis is known from non-dune habitats (e.g. estuaries, sandy coastal plains) up to moderate elevations; accordingly, our models strikingly predict potential refugial areas for this species in Central Mexico and the northern Yucatán Peninsula. Additional analyses of codistributed dune plants in the study area are needed to test the generality of these findings for dune plant communities.
Keywords: climate change; ecological niche modeling; foredune; Gulf of Mexico; North America; plantshttps://digitalcommons.jsu.edu/ce_jsustudentsymp_2022/1050/thumbnail.jp
Student Perceptions of the Use of Multimedia for Online Course Communication
A great deal of research exists in the use of multimedia communications in online classrooms as a means of furthering student engagement. However, little research exists that examines the perceptions of students when such technologies are used. Additionally, it is unclear that students are likely to engage in the use of such technologies when available. This research explores the perceptions of 69 students taking both online and hybrid undergraduate project management courses. Specifically, the study seeks to explore how students experienced the use of multimedia by their instructor and classmates in both online announcements and discussions, as well as whether these same students used or would be likely to use multimedia for similar communications. Finally, student perceptions of social presence, the degree to which one is perceived as a real person in computer-mediated communication (Gunawardena, 1995), are examined. The results of the study indicate that while students overwhelming enjoy the instructor’s use of multimedia communication, they are unlikely to engage in using these technologies themselves. A discussion of these results and recommendations for further research complete this paper
Recommended from our members
Cooperative benefit for the combination of rapamycin and imatinib in tuberous sclerosis complex neoplasia
Tuberous sclerosis (TS) is a common autosomal-dominant disorder characterized by tumors of the skin, lung, brain, and kidneys. Monotherapy with rapamycin however resulted in partial regression of tumors, implying the involvement of additional pathways. We have previously implicated platelet-derived growth factor-BB in TS-related tumorigenesis, thus providing a rationale for a combination of mTOR/PDGF blockade using rapamycin and imatinib. Here, we test this combination using a well-established preclinical model of cutaneous tumorigenesis in TS, tsc2ang1 cells derived from a skin tumor from a mouse heterozygous for tsc2. Treatment of tsc2ang1 cells with a combination of rapamycin and imatinib led to an inhibition of proliferation compared with either vehicle treatment or treatment with rapamycin or imatinib monotherapy. Combination therapy also led to a decrease in Akt activation. Potent in vivo activity in animal experiments by combination therapy was noted, without toxicity to the animals. Our findings provide a rationale for the combined use of rapamycin and imatinib, both FDA approved drugs, for the treatment of TS
Recommended from our members
Neuropsychological Assessment, Neuroimaging, and Neuropsychiatric Evaluation in Pediatric and Adult Patients with Sickle Cell Disease (SCD)
Traditionally, neuropsychological deficits due to Sickle Cell Disease (SCD) have been understudied in adults. We have begun to suspect, however, that symptomatic and asymptomatic Cerebrovascular Events (CVE) may account for an alarming number of deficits in this population. In the current brief review, we critically evaluated the pediatric and adult literatures on the neurocognitive effects of SCD. We highlighted the studies that have been published on this topic and posit that early detection of CVE via neurocognitive testing, neuropsychiatric evaluations, and neuroimaging may significantly reduce adult cognitive and functional morbidities
'To live and die [for] Dixie': Irish civilians and the Confederate States of America
Around 20,000 Irishmen served in the Confederate army in the Civil War. As a result, they left behind, in various Southern towns and cities, large numbers of friends, family, and community leaders. As with native-born Confederates, Irish civilian support was crucial to Irish participation in the Confederate military effort. Also, Irish civilians served in various supporting roles: in factories and hospitals, on railroads and diplomatic missions, and as boosters for the cause. They also, however, suffered in bombardments, sieges, and the blockade. Usually poorer than their native neighbours, they could not afford to become 'refugees' and move away from the centres of conflict. This essay, based on research from manuscript collections, contemporary newspapers, British Consular records, and Federal military records, will examine the role of Irish civilians in the Confederacy, and assess the role this activity had on their integration into Southern communities. It will also look at Irish civilians in the defeat of the Confederacy, particularly when they came under Union occupation. Initial research shows that Irish civilians were not as upset as other whites in the South about Union victory. They welcomed a return to normalcy, and often 'collaborated' with Union authorities. Also, Irish desertion rates in the Confederate army were particularly high, and I will attempt to gauge whether Irish civilians played a role in this. All of the research in this paper will thus be put in the context of the Drew Gilpin Faust/Gary Gallagher debate on the influence of the Confederate homefront on military performance. By studying the Irish civilian experience one can assess how strong the Confederate national experiment was. Was it a nation without a nationalism
Home-Based Work and Home-Based Workers (1800-2021)
Home-Based Work and Home-Based Workers (1800-2021) is about the past and present of home-based work and homebased workers between 1800 and 2021 from a global perspective.; Readership: All interested in social and economic history, and especially in the past and present of home-based work and homebased workers
Identification of CCR8: A Human Monocyte and Thymus Receptor for the CC Chemokine I-309
The human CC chemokine I-309 is a potent monocyte chemoattractant and inhibits apoptosis in thymic cell lines. Here, we identify a specific human I-309 receptor, and name it CCR8 according to an accepted nomenclature system. The receptor has seven predicted transmembrane domains, is expressed constitutively in monocytes and thymus, and is encoded by a previously reported gene of previously unknown function named, alternatively, CY6, TER1, and CKR-L1. After transfection with the CY6 open reading frame, a mouse pre–B cell line exhibited calcium flux and chemotaxis in response to I-309 (EC50 = 2 nM for each), whereas 20 other chemokines were inactive. Signaling was sensitive to pertussis toxin, suggesting coupling to a Gi-type G protein. These properties parallel those of endogenous I-309 receptors expressed in an HL-60 clone 15 cell line model. The apparent monogamous relationship between I-309 and CCR8 is unusual among known CC chemokines and known CC chemokine receptors. CCR8 may regulate monocyte chemotaxis and thymic cell line apoptosis
Class A Orphans in GtoPdb v.2023.1
Table 1 lists a number of putative GPCRs identified by NC-IUPHAR [161], for which preliminary evidence for an endogenous ligand has been published, or for which there exists a potential link to a disease, or disorder. These GPCRs have recently been reviewed in detail [121]. The GPCRs in Table 1 are all Class A, rhodopsin-like GPCRs. Class A orphan GPCRs not listed in Table 1 are putative GPCRs with as-yet unidentified endogenous ligands.Table 1: Class A orphan GPCRs with putative endogenous ligands GPR3GPR4GPR6GPR12GPR15GPR17GPR20 GPR22GPR26GPR31GPR34GPR35GPR37GPR39 GPR50GPR63GPR65GPR68GPR75GPR84GPR87 GPR88GPR132GPR149GPR161GPR183LGR4LGR5 LGR6MAS1MRGPRDMRGPRX1MRGPRX2P2RY10TAAR2 In addition the orphan receptors GPR18, GPR55 and GPR119 which are reported to respond to endogenous agents analogous to the endogenous cannabinoid ligands have been grouped together (GPR18, GPR55 and GPR119)
Class A Orphans (version 2020.5) in the IUPHAR/BPS Guide to Pharmacology Database
Table 1 lists a number of putative GPCRs identified by NC-IUPHAR [194], for which preliminary evidence for an endogenous ligand has been published, or for which there exists a potential link to a disease, or disorder. These GPCRs have recently been reviewed in detail [150]. The GPCRs in Table 1 are all Class A, rhodopsin-like GPCRs. Class A orphan GPCRs not listed in Table 1 are putative GPCRs with as-yet unidentified endogenous ligands.Table 1: Class A orphan GPCRs with putative endogenous ligands
GPR3
GPR4
GPR6
GPR12
GPR15
GPR17
GPR20
GPR22
GPR26
GPR31
GPR34
GPR35
GPR37
GPR39
GPR50
GPR63
GRP65
GPR68
GPR75
GPR84
GPR87
GPR88
GPR132
GPR149
GPR161
GPR183
LGR4
LGR5
LGR6
MAS1
MRGPRD
MRGPRX1
MRGPRX2
P2RY10
TAAR2
In addition the orphan receptors GPR18, GPR55 and GPR119 which are reported to respond to endogenous agents analogous to the endogenous cannabinoid ligands have been grouped together (GPR18, GPR55 and GPR119)
- …