Cruciform Extrusion in Methylation-State Variants of pBR322 Plasmid

The presence of DNA secondary structures in genomic DNA has been observed in both prokaryotes and eukaryotes. Specifically, sections of ssDNA may melt out and form cruciform/hairpin structures within palindromic sequences or areas of high purine content. Negative supercoiling of the DNA is necessary for energetic favorability of such an event. These noncanonical structures may serve as molecular switches, providing additional regulation of DNA transactions such as transcription and perhaps replication and recombination. Secondary structures associated with regulatory regions are of particular interest as potential sites for the binding of small molecules, which could alter the expression of genes. The effect of system-wide DNA base methylation on extrusion of secondary structures is one aspect of primary-secondary-tertiary structure interplay that has not been examined. Our study first characterized the gross qualitative effect of methylation of plasmid DNA on the formation of cruciform structures. The plasmid pBR322 was transformed into three different strains of E. coli: K12 with functional deoxycytosine and deoxyadenine methyltransferases, BL21 strain (dcm ), and K12 ER2925 with no methyltransferase activity (dam Idem). The resulting purified plasmids were then digested with mung bean nuclease (MBN); a ssDNA-specific nuclease; and then by a site-specific nuclease. The digest reaction mixtures were analyzed by gel electrophoresis for fragments characteristic of cleavage by MBN. The three strains seemed to show no difference in the presence of at least one prominent ssDNA site. Topoisomers of each plasmid were then created by the relaxation of negative supercoils in the presence of DNA intercalator and separated through gel electrophoresis. The three methylation-state variants seemed to exhibit similar structural responses. These data indicate that methylation of respective nucleotide bases does not seem to influence cruciform extrusion, through either changes in local or global conformations

Circumscribed choroidal hemangioma: A case report and literature review

AbstractChoroidal hemangioma is a rare congenital ocular tumor that can present as either circumscribed or diffuse. Circumscribed choroidal hemangioma (CCH) typically manifests as a red-orange mass within the posterior pole and appears similar to other ocular conditions, such as choroidal melanoma and choroidal metastasis. Proper diagnosis is crucial and is aided by the use of ancillary testing. CCH itself is benign but can cause secondary complications such as subretinal fluid accumulation and subsequent retinal detachment. If these conditions should arise, several treatment options are available

Circumscribed choroidal hemangioma: A case report and literature review

AbstractChoroidal hemangioma is a rare congenital ocular tumor that can present as either circumscribed or diffuse. Circumscribed choroidal hemangioma (CCH) typically manifests as a red-orange mass within the posterior pole and appears similar to other ocular conditions, such as choroidal melanoma and choroidal metastasis. Proper diagnosis is crucial and is aided by the use of ancillary testing. CCH itself is benign but can cause secondary complications such as subretinal fluid accumulation and subsequent retinal detachment. If these conditions should arise, several treatment options are available

“Born Under My Heart”: Adoptive Parents’ Use of Metaphors to Make Sense of Their Past, Present, and Future

Metaphors provide the opportunity to make sense of our experiences and share them with others. The current research qualitatively examined interviews with adoptive parents who had adopted through intercountry or private adoptions. Throughout their interviews, each participant used at least one metaphor in describing their experiences of adopting and raising their child. Overarchingly, the metaphor of “Adoption is a journey” encapsulated parents’ experiences. To demonstrate the journey, parents used metaphors to describe the past, present, and future. Metaphors of the past focused on their child’s trauma and the origin of how the child came to join their family. Metaphors used to describe the present were challenge metaphors, including child’s behaviors and finding support, coping metaphors, and balance metaphors. Lastly, metaphors of the future included guiding and commitment metaphors. In addition to metaphors, parents used symbolic rituals to connect their children with their past and current family. From metaphors, we offer several practical implications for postadoption intervention. First, interventions should be developed to meet participants where they are. Second, interventions should focus on the overall picture of adoption, as parents make sense of their past experiences and their ideals about the future. Lastly, services should focus on tools, not fixes

Camera trap arrays improve detection probability of wildlife: Investigating study design considerations using an empirical dataset.

Camera trapping is a standard tool in ecological research and wildlife conservation. Study designs, particularly for small-bodied or cryptic wildlife species often attempt to boost low detection probabilities by using non-random camera placement or baited cameras, which may bias data, or incorrectly estimate detection and occupancy. We investigated the ability of non-baited, multi-camera arrays to increase detection probabilities of wildlife. Study design components were evaluated for their influence on wildlife detectability by iteratively parsing an empirical dataset (1) by different sizes of camera arrays deployed (1-10 cameras), and (2) by total season length (1-365 days). Four species from our dataset that represented a range of body sizes and differing degrees of presumed detectability based on life history traits were investigated: white-tailed deer (Odocoileus virginianus), bobcat (Lynx rufus), raccoon (Procyon lotor), and Virginia opossum (Didelphis virginiana). For all species, increasing from a single camera to a multi-camera array significantly improved detection probability across the range of season lengths and number of study sites evaluated. The use of a two camera array increased survey detection an average of 80% (range 40-128%) from the detection probability of a single camera across the four species. Species that were detected infrequently benefited most from a multiple-camera array, where the addition of up to eight cameras produced significant increases in detectability. However, for species detected at high frequencies, single cameras produced a season-long (i.e, the length of time over which cameras are deployed and actively monitored) detectability greater than 0.75. These results highlight the need for researchers to be critical about camera trap study designs based on their intended target species, as detectability for each focal species responded differently to array size and season length. We suggest that researchers a priori identify target species for which inference will be made, and then design camera trapping studies around the most difficult to detect of those species

Methods to prioritise pop-up active transport infrastructure and their application in a national cycleway prioritisation tool

In the context of reduced public transport capacity in the wake of the COVID-19 pandemic, governments are scrambling to enable walking and cycling while adhering to physical distancing guidelines. Many pop-up options exist. Of these, road space reallocation represents a ‘quick win’ for cities with ‘spare space’ along continuous road sections that have high latent cycling potential. We developed methods to condense the complexity of city networks down to the most promising roads for road space reallocation schemes. The resulting Rapid Cycleway Prioritisation Tool has been deployed for all cities in England to help prioritise emergency funds for new cycleways nationwide. The methods and concepts could be used to support investment in pop-up infrastructure in cities worldwide

Assessing The Health Of Fringing Salt Marshes Along The Fore River And Its Tributaries

Casco Bay has experienced two significant oil spills in recent history - the Tamano Tanker spill in 1972 and the Julie N spill in 1996. In addition, the Fore River and its tributaries have experienced numerous small spills over the years, including the August 2002 fuel oil spill (2,900 gallons) and the April 2003 jet fuel spill (6,000 gallons). The impacts of these spills on the fringing salt marshes that line the edges of the Fore River and its tributaries are not well understood. Are these salt marshes resilient enough to withstand these impacts and still act as healthy marshes should? Or are they functioning at lower levels, compared to other fringing salt marshes in Casco Bay? The salt marshes that line the Fore River provide an important suite of functions and values to the citizens of southern Maine. The results of this study will help resource managers in their efforts to protect these important and unique natural resources