2,213 research outputs found
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The Ecological Recovery of Saguaro National Park after Removal of Cattle Grazing and Associated Succession
In the area that is now Saguaro National Park East, grazing began in the 1880's. Because of the impact to the iconic saguaro cactus as well as all palatable plant species in the area, ecological damage in the park were determined to be so great that anti-grazing conservationists challenged the right of grazing to continue in what was Saguaro National Monument. Ultimately, this group won a court case eliminating grazing in 1978. The Rincon Mountains, located within the park are one of many Madrean Sky Island ecosystems connecting the Rocky Mountains to the Sierra Madre mountain ranges to the south in Mexico. This area is one of the most biodiverse locations on the planet, with over 6,000 plant species (USFS, N.D.). This area is also poorly understood when considering succession and the impacts of disturbance to compositional guilds of plant species. Surveys of ten plots began in 1976 and were replicated in 2007 and 2018 in an effort to understand vegetation changes as affected by grazing management, as well as fire disturbance. The study plots were arranged into intensely grazed and lightly grazed to compare the composition of the plant community through time. Ultimately, little significance was found when considering the composition of paired plots through time, the original aim of the study. However, plant canopy cover, density and diversity continued to increase significantly from 1976 to 2007 and 2018. Major implications of our work identified perennial grasses increasing at a significant rate by 2007 and even more so by 2018, while tree species such as the commonly identified encroacher Prosopis velutina decreased significantly by 2007 and stayed steady by 2018. Grass re-establishment can be directly attributed to increased tropical moisture creating uncommon survivability conditions (speaking from historical precipitation means) in recent years previous to 2007 (1996, 1998, 2000, 2003 & 2006) and dramatically increase in the years prior to 2019 (2014-2016 & 2018). Implications here identified that past fire intensity (1989, 1994 & 1999 fires, see fire history) were likely much more intense than previously thought, and supported the scientific community’s knowledge that fire control woody species and supports perennial grasses re-establishment such as is occurring in our work. Our findings also documented that increasing winter minimums have allowed previously excluded, cold-sensitive species such as Encelia farinosa to move into the area, dominating a post-fire ecosystem. The means of succession when considering disturbance history proved quite interesting particularly when combined with climate change impacts in our research
Viability of Hunting as a Means of Wild Hog Population Management on Federal Property
The Big South Fork National River and Recreation Area allows hunter to purchase permits and hunt wild hogs on property with the intention of curbing increases in wild hog populations. In order to assess outcomes of the wild hog hunting permit program, researchers collaborated with site managers to develop protocol and solicit information from permit holders regarding number of animals seen and harvested, sex of animals harvested, geographic areas hunted, length and number of hunts, and open qualitative feedback regarding the program. All permit holders agreeing to be contacted during permit registration were called with 37.57% (N=65) of permit holder completing the telephone survey. While more hogs were seen than harvested, the total harvested hogs was 52. Results indicate hunting is not a viable option for population management in and of itself, as the number if wild hogs harvested was minimal. A longitudinal study is necessary to overcome case study (single year) limitations, such as weather, hunter economics, herd movement, herd reproduction and so forth. Salient variables may warrant consideration, including marketing of permit program, number of hunters within acceptable driving distance to hunting location, and much more. Herd management initiatives beyond hunting may be considered when necessary to control wild hog populations
Cleft Palate Is Caused by CNS Dysfunction in Gad1 and Viaat Knockout Mice
BACKGROUND: Previous studies have shown that disruption of GABA signaling in mice via mutations in the Gad1, Gabrb3 or Viaat genes leads to the development of non-neural developmental defects such as cleft palate. Studies of the Gabrb3 and Gad1 mutant mice have suggested that GABA function could be required either in the central nervous system or in the palate itself for normal palatogenesis. METHODOLOGY/PRINCIPAL FINDINGS: To further examine the role of GABA signaling in palatogenesis we used three independent experimental approaches to test whether Gad1 or Viaat function is required in the fetal CNS for normal palate development. We used oral explant cultures to demonstrate that the Gad1 and Viaat mutant palates were able to undergo palatogenesis in culture, suggesting that there is no defect in the palate tissue itself in these mice. In a second series of experiments we found that the GABA(A) receptor agonist muscimol could rescue the cleft palate phenotype in Gad1 and Viaat mutant embryos. This suggested that normal multimeric GABA(A) receptors in the CNS were necessary for normal palatogenesis. In addition, we showed that CNS-specific inactivation of Gad1 was sufficient to disrupt palate development. CONCLUSIONS/SIGNIFICANCE: Our results are consistent with a role for Gad1 and Viaat in the central nervous system for normal development of the palate. We suggest that the alterations in GABA signaling lead to non-neural defects such as cleft palate as a secondary effect due to alterations in or elimination of fetal movements
All's well that begins Wells: Celebrating 60 years of Animal Behaviour and 36 years of research on anuran social behaviour
The scientific study of frogs and toads as important systems in behavioural ecology traces its roots to an influential review published in this journal 36 years ago (Wells 1977a, ‘The social behaviour of anuran amphibians’, Animal Behaviour, 25, 666–693). In just 28 pages, Wells summarized the state of knowledge on important behaviours associated with anuran breeding and introduced an evolutionary framework ‘for understanding the relationship between social behaviour and ecology’ (page 666) that was largely lacking in earlier treatments of this group. Not only is Wells's review one of the most cited papers ever published in Animal Behaviour, it is also responsible for setting broad research agendas and shaping much of our current thinking on social behaviour in an entire order of vertebrates. As such, it is entirely appropriate that we honour Wells's review and its contributions to the study of animal behaviour in this inaugural essay celebrating 12 papers selected by the community as the most influential papers published in the 60-year history of Animal Behaviour. In our essay, we place Wells's review in historical context at the dawn of behavioural ecology, highlight the field's progress in answering some major research questions outlined in the review, and provide our own prospectus for future research on the social behaviour of anuran amphibians.
Highlights
► This essay celebrates Kent Wells's (1977, Animal Behaviour, 25, 666–693) paper, ‘The social behaviour of anuran amphibians’. ► We place the article in historical context and outline its major contributions. ► We discuss progress on anuran social behaviour since its publication in 1977. ► We provide our own prospectus on the future of anuran behavioural ecology
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Highly selective and solvent-dependent reduction of Nitrobenzene to N-phenylhydroxylamine, azoxybenzene, and aniline catalyzed by phosphino-modified polymer immobilized ionic liquid-stabilized AuNPs
Gold nanoparticles stabilized by phosphine-decorated polymer immobilized ionic liquids (AuNP@PPh2-PIILP) is an extremely efficient multiproduct selective catalyst for the sodium borohydride-mediated reduction of nitrobenzene giving N-phenylhydroxylamine, azoxybenzene, or aniline as the sole product under mild conditions and a very low catalyst loading. The use of a single nanoparticle-based catalyst for the partial and complete reduction of nitroarenes to afford three different products with exceptionally high selectivities is unprecedented. Under optimum conditions, thermodynamically unfavorable N-phenylhydroxylamine can be obtained as the sole product in near quantitative yield in water, whereas a change in reaction solvent to ethanol results in a dramatic switch in selectivity to afford azoxybenzene. The key to obtaining such a high selectivity for N-phenylhydroxylamine is the use of a nitrogen atmosphere at room temperature as reactions conducted under an inert atmosphere occur via the direct pathway and are essentially irreversible, while reactions in air afford significant amounts of azoxy-based products by virtue of competing condensation due to reversible formation of N-phenylhydroxylamine. Ultimately, aniline can also be obtained quantitatively and selectively by adjusting the reaction temperature and time accordingly. Introduction of PEG onto the polyionic liquid resulted in a dramatic improvement in catalyst efficiency such that N-phenylhydroxylamine could be obtained with a turnover number (TON) of 100 000 (turnover frequency (TOF) of 73 000 h–1, with >99% selectivity), azoxybenzene with a TON of 55 000 (TOF of 37 000 h–1 with 100% selectivity), and aniline with a TON of 500 000 (TOF of 62 500 h–1, with 100% selectivity). As the combination of ionic liquid and phosphine is required to achieve high activity and selectivity, further studies are currently underway to explore whether interfacial electronic effects influence adsorption and thereby selectivity and whether channeling of the substrate by the electrostatic potential around the AuNPs is responsible for the high activity. This is the first report of a AuNP-based system that can selectively reduce nitroarenes to either of two synthetically important intermediates as well as aniline and, in this regard, is an exciting discovery that will form the basis to develop a continuous flow process enabling facile scale-up
Nurses Alumni Association Bulletin, Fall 1995
1995-1996 Meeting Dates Calendar
1996 Annual Luncheon-Meeting Notice
Officers and Committee Chairs
Bulletin Publication Committee
1995-1996 Meeting Dates Calendar
The President\u27s Message
Financial Report
What\u27s New
Fiftieth Anniversary
Resume of Minutes of Alumni Association Meetings
Scholarship Funds at Work
CAHS Alumni Board/Diploma School
Alumni Office News
Jefferson Health System
Oldest Veteran Dies
1OOth Anniversary
Pearl Harbor Remembered
Memories
Janet Hindson Retires
Happy Birthday
Scholarship Fund donors for 1994
Committee Reports
By-Laws
Development
Bulletin
Relief Fund
Satellite
Social
Scholarship
In Memoriam, Names of Deceased Graduates
Class News
Luncheon Photos
Jefferson Alumni Identification Card
The Diploma School of Nursing Alumni Association-Mabel C. Prevost
Letter of Appreciation
Tribute To a Mother
An End Must Come
Stuff
For Senior Citizens to Chuckle Over
Membership Application
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To Order: A Chronological History and Alumni Directory From TJU Bookstore
Scholarship Fund Application
Pins, Transcripts, Class Address List, Change of Address Forms, Alumni Identification Card
Campus Map
Picture - Class of 1893-189
Effect of the 3′-Terminal Truncation of the Human interferon-Gamma Gene on Plasmid Segregation in Escherichia Coli
Effects of a recombinant gene expression on ColE1-like plasmid segregation in Escherichia coli
<p>Abstract</p> <p>Background</p> <p>Segregation of expression plasmids leads to loss of recombinant DNA from transformed bacterial cells due to the irregular distribution of plasmids between the daughter cells during cell division. Under non-selective conditions this segregational instability results in a heterogeneous population of cells, where the non-productive plasmid-free cells overgrow the plasmid-bearing cells thus decreasing the yield of recombinant protein. Amongst the factors affecting segregational plasmid instability are: the plasmid design, plasmid copy-number, host cell genotype, fermentation conditions etc. This study aims to investigate the influence of transcription and translation on the segregation of recombinant plasmids designed for constitutive gene expression in <it>Escherichia coli </it>LE392 at glucose-limited continuous cultivation. To this end a series of pBR322-based plasmids carrying a synthetic human interferon-gamma (hIFNγ) gene placed under the control of different regulatory elements (promoter and ribosome-binding sites) were used as a model.</p> <p>Results</p> <p>Bacterial growth and product formation kinetics of transformed <it>E. coli </it>LE392 cells cultivated continuously were described by a structured kinetic model proposed by Lee et al. (1985). The obtained results demonstrated that both transcription and translation efficiency strongly affected plasmid segregation. The segregation of plasmid having a deleted promoter did not exceed 5% after 190 h of cultivation. The observed high plasmid stability was not related with an increase in the plasmid copy-number. A reverse correlation between the yield of recombinant protein (as modulated by using different ribosome binding sites) and segregational plasmid stability (determined by the above model) was also observed.</p> <p>Conclusions</p> <p>Switching-off transcription of the hIFNγ gene has a stabilising effect on ColE1-like plasmids against segregation, which is not associated with an increase in the plasmid copy-number. The increased constitutive gene expression has a negative effect on segregational plasmid stability. A kinetic model proposed by Lee et al. (1985) was appropriate for description of <it>E. coli </it>cell growth and recombinant product formation in chemostat cultivations.</p
A review of new and existing non-extractive techniques for monitoring marine protected areas
Publication history: Accepted - 23 June 2023; Published - 19 July 2023.Ocean biodiversity loss is being driven by several anthropogenic threats and significant efforts are required to halt losses and promote healthy marine ecosystems. The establishment of a network of Marine Protected Areas (MPAs) can help restrict damaging activities and have been recognised as a potential solution to aid marine conservation. When managed correctly they can deliver both ecological and socio-economic benefits. In recent times, MPA designations have increased rapidly while many countries have set future MPA targets for the decades ahead. An integral element of MPA management is adequate monitoring that collects data to assess if conservation objectives are being achieved. Data acquired by monitoring can vary widely as can the techniques employed to collect such data. Ideally, non-destructive and non-invasive methods are preferred to prevent damage to habitats and species, though this may rule out a number of traditional extractive sampling approaches such as dredges and trawls. Moreover, advances in ocean observation technologies enable the collection of large amounts of data at high resolutions, while automated data processing is beginning to make analyses more logistically feasible and less time-consuming. Therefore, developments to existing marine monitoring techniques and new emerging technologies have led to a diverse array of options when choosing to implement an MPA monitoring programme. Here, we present a review of new and existing non-extractive techniques which can be applied to MPA monitoring. We summarise their capabilities, applications, advantages, limitations and possible future developments. The review is intended to aid MPA managers and researchers in determining the suitability of available monitoring techniques based on data requirements and site conditions.This research was funded through the Marine Protected Area Monitoring and Management (MarPAMM) project, which is supported by the European Union’s INTERREG VA Programme, managed by the Special EU Programmes Body (SEUPB) with matching funding from the Government of Ireland, the Northern Ireland Executive, and the Scottish Government. This research was also carried out with the support of the Marine Institute under the Marine Research Programme with the support of the Irish Government
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