A Comparison of Two Mesic Sand Forests in Mason County, Illinois

The present study included surveys of a four hectare section of Barkhausen Conservation Area and a two hectare forested section in the Sand Prairie-Scrub Oak Nature Preserve. This study examines the floristic composition and structure of these forests, and some of the ecological parameters that may be responsible for their existence. In this study, the number, size and species of all living and dead standing trees (above 10 cm dbh) were recorded for each quadrat. The relative dominance, relative density, importance value, average diameter, density in broad diameter classes and basal area were then calculated for each species. Nested circular plots were randomly located in the 25 m x 25 m quadrats in order to obtain seedling and sapling densities. Seedlings under 40 cm in height, seedlings over 40 cm in height and sapling were tallied in nested circular plots of 0.0001, 0.001, and 0.01 ha in size. Soils were tested for pH and soil texture using the Bouyoucos Hydrometer Method. Barkhausen Conservation Area which was dominated by black oak (IV = 111.2), blackjack oak (IV = 61.5), and hickory spp. (IV = 22.0); and had a density (trees/ha) of 237.9 with a basal area of 16.3 (m2/ha). A total of 20 woody species were recorded in the woods of which 9 were canopy trees and 11 were understory trees, shrubs and vines. These results are also similar to the forest of the Sand Prairie-Scrub Oak Nature Preserve which were dominated by black oak (IV = 180.4), blackjack oak (IV = 15.1), and hickory spp. (IV = 4.2); and had a density (trees/ha) of 394.5 with a basal area of 20.3 (m2/ha). This area contained 12 woody species of which 5 were canopy species and 7 were understory trees, shrubs and vines. These closed forests seem to be fairly stable in composition, since the relatively shade-intolerant dominant species tend to reproduce themselves due to the lack of competition in extremely xeric conditions, and the periodic burns which keep the canopy open. The fact that black oak and black hickory have a large number of individuals in the lower diameter classes, and have sufficient seedling and saplings for future replacement of veteran trees, tends to support these findings. Barkhausen Conservation Area and the Sand Prairie-Scrub Oak Nature Preserve are typical examples of closed forest associated with sand dunes of the Illinois River Sand Area Section

O sistema reage à mudança

A flexibilidade na condenação dos criminosos era uma das características mercantes do sistema de exílio penal estabelecido pelo Estado português nos primórdios da época moderna. Esta flexibilidade operava tanto em nível individual como em nível coletivo e definia-se em termos de ajustamentos nos prazos e nos locais das sentenças. Exemplos individuais deste processo surgem nos registos sob a forma de apelos, perdões, ou comutações de sentença s de um local para outro - apó s um apelo bem-sucedido a uma das Relações ou ao Desembargo do Paço

Cause de préoccupation : Expérience des résidents avec les traumatismes opératoires durant la une résidence en chirurgie générale dans un centre canadien

Background: The ability to provide competent operative trauma care is a core objective of general surgery training but recent publications question the ability of graduates to meet this standard. To assess the adequacy of operative trauma exposure during residency, we constructed and analyzed a retrospective trauma operative case log for general surgery residents at a Canadian trauma centre.  Methods: The Hamilton General Hospital Trauma Registry was used to identify all patients from July 2008 to June 2018 who underwent a trauma operation on the neck, chest, or abdomen.  Medical records were reviewed to determine procedure type and resident presence. Results: In our study, 417 patients underwent 570 operations (422 abdominal, 103 thoracic, and 45 neck).  For the 35 residents that completed their general surgery residency during the study, the median number of trauma laparotomies was 5, with only 14/35 (40%) present for ≥10 trauma operations.  Only 10 residents (29%) were exposed to a neck exploration and 18 (51%) exposed to a thoracic operation for trauma.    Conclusions: Operative trauma exposure amongst general surgery residents at an academic Canadian trauma centre was limited. Cumulative operative trauma surgery exposure of a typical graduating resident was inadequate when compared to Canadian and American accrediting-body standards.Contexte : La capacité d’offrir des soins de qualité en traumatisme opératoire est un objectif principal de la formation en chirurgie générale, mais des publications récentes contestent la capacité des diplômés à satisfaire cette norme. Pour évaluer le caractère adéquat de l’exposition à des traumatismes opératoires pendant la résidence, nous avons construit et analysé un registre rétrospectif des cas opératoires traumatologiques des résidents en chirurgie générale à un centre canadien de traumatologie.  Méthodes : Le registre des traumatismes du Hamilton General Hospital a été utilisé pour identifier tous les patients de juillet 2008 à juin 2018 qui ont subi une chirurgie traumatologique au cou, au thorax ou à l’abdomen.  Les dossiers médicaux ont été examinés pour établir le type de procédure et la présence de résidents. Résultats : Dans notre étude, 417 patients ont subi 570 opérations (422 à l’abdomen, 103 au thorax et 45 au cou).  Pour les 35 résidents qui ont terminé leur résidence en chirurgie générale au cours de l’étude, le nombre médian de laparotomies traumatologiques a été de cinq, avec seulement 14/35 (40 %) présents pour dix opérations traumatologiques ou plus.  Seulement 10 résidents (9 %) ont assisté à une exploration du cou et 18 (51 %) ont assisté à une chirurgie thoracique pour un trauma.    Conclusions : L’exposition aux traumatismes opératoires chez les résidents en chirurgie générale à un centre universitaire canadien de traumatologie a été limitée. L’exposition cumulative à des chirurgies traumatologiques opératoires d’un résident diplômé type était inadéquate comparativement aux normes d’agrément des organismes canadiens et américains

A Desert Tortoise–Common Raven Viable Conflict Threshold

Since 1966, common raven (Corvus corax; raven) abundance has increased throughout much of this species’ Holarctic distribution, fueled by an ever-expanding supply of anthropogenic resource subsidies (e.g., water, food, shelter, and nesting substrate) to ecoregion specific raven population carrying capacities. Consequently, ravens are implicated in declines of both avian and reptilian species of conservation concern, including the California (USA) endangered and federally threatened Mojave desert tortoise (Gopherus agassizii; desert tortoise). While ravens are a natural predator of desert tortoises, the inter-generational stability of desert tortoise populations is expected to be compromised as annual juvenile survival is suppressed below 0.77 through a combination of raven depredation and other sources of mortality. To estimate the extent to which raven depredation suppresses desert tortoise recruitment within the Mojave Desert of California, we collected data from 274 variable-radius point counts, 78 desert tortoise decoy stations, and 8 control stations during the spring of 2020. Additionally, we complied a geodatabase of previously active raven nests, observed between 2013 and 2020. Raven density estimates from 4 monitoring areas ranged between 0.63 (eastern most) and 2.44 (western most) raven km-2 (95% CI: 0.35–1.14 and 1.33–4.48, respectively). We used a Bayesian shared frailty model to estimate the effects of raven density and distance to the nearest previously active raven nest on the annual “survival” of juvenile desert tortoise decoys (75-mm Midline Carapace Length), which we then converted into survival estimates for 0- to 10-year-old desert tortoises by adjusting exposure to reflect natural activity patterns. At the 1.72-km median distance from the nearest previously active raven nest, the estimated annual survival of desert tortoises decreased as raven density increased, ranging among conservation areas from 0.774 (eastern most) to 0.733 (western most). Accordingly, our model predicts that desert tortoise populations exposed to raven densities in excess of 0.89 raven km-2, at a distanc

A convenient and efficient synthesis of (S)-lysine and (S)-arginine homologues via olefin cross-metathesis

A convenient five step synthesis of (S)-homolysine, incorporating a key olefin cross-metathesis step in the chain extension methodology, has been developed, together with a six step related synthesis of a new homologue of arginine, (S)-bishomoarginine

Defective phagocyte association during infection of Galleria mellonella with Yersinia pseudotuberculosis is detrimental to both insect host and microbe

Adhesins facilitate bacterial colonization and invasion of host tissues and are considered virulence factors, but their impact on immune-mediated damage as a driver of pathogenesis remains unclear. Yersinia pseudotuberculosis encodes for a multivalent adhesion molecule (MAM), a mammalian cell entry (MCE) family protein and adhesin. MAMs are widespread in Gram-negative bacteria and enable enteric bacteria to colonize epithelial tissues. Their role in bacterial interactions with the host innate immune system and contribution to pathogenicity remains unclear. Here, we investigated how Y. pseudotuberculosis MAM contributes to pathogenesis during infection of the Galleria mellonella insect model. We show that Y. pseudotuberculosis MAM is required for efficient bacterial binding and uptake by hemocytes, the host phagocytes. Y. pseudotuberculosis interactions with insect and mammalian phagocytes are determined by bacterial and host factors. Loss of MAM, and deficient microbe–phagocyte interaction, increased pathogenesis in G. mellonella. Diminished phagocyte association also led to increased bacterial clearance. Furthermore, Y. pseudotuberculosis that failed to engage phagocytes hyperactivated humoral immune responses, most notably melanin production. Despite clearing the pathogen, excessive melanization also increased phagocyte death and host mortality. Our findings provide a basis for further studies investigating how microbe- and host-factors integrate to drive pathogenesis in a tractable experimental system

3D simulation of the Hierarchical Multi-Mode Molecular Stress Function constitutive model in an abrupt contraction flow

YesA recent development of the Molecular Stress Function constitutive model, the Hierarchical Multi-Mode Molecular Stress Function (HMMSF) model has been shown to fit a large range of rheometrical data with accuracy, for a large range of polymer melts. We develop a 3D simulation of the HMMSF model and compare it to experimental data for the flow of Lupolen 1840H LDPE through an abrupt 3D contraction flow. We believe this to be the first finite element implementation of the HMMSF model. It is shown that the model gives a striking agreement with experimental vortex opening angles, with very good agreement to full-field birefringence measurements, over a wide range of flow rates. A method to give fully-developed inlet boundary conditions is implemented (in place of using parabolic inlet boundary conditions), which gives a significantly improved match to birefringence measurements in the inlet area, and in low stress areas downstream from the inlet. Alternative constitutive model parameters are assessed following the principle that extensional rheometer data actually provides a ‘lower bound’ for peak extensional viscosity. It is shown that the model robustly maintains an accurate fit to vortex opening angle and full-field birefringence data, provided that both adjustable parameters are kept such that both shear and extensional data are well fitted