Regional Invasive Species & Climate Change Management Challenge: Embracing the Future. Promoting adaptation and resilience to invasive species and climate change

Climate change and invasive species can interact to increase disturbances and magnify changes in ecosystem form and function (Double Trouble). Increasing resilience is one of several management approaches for enabling healthy ecosystems to persist despite these changes. While resilience can be complicated and take many forms, it can generally be thought of as the “ability [of an ecosystem] to experience disturbances or environmental change without changing to a fundamentally different state” [Holling, 1973]. The accumulating effects of climate change, invasive species, or interacting effects of multiple disturbances can push an ecosystem past a tipping point and into a new ecological state. These alternative states are characterized by a different suite of species or functions, which are difficult or impossible to recover from (e.g. a shift from a closed-canopy to an open-canopy forested wetland). Actions to increase resilience help an ecosystem to maintain or return to its fundamental structure or function after a disturbance. Resilience falls in the middle of a spectrum of management goals ranging from preventing change (resistance) to promoting change (transformation) in the species composition, structure, or functions provided by an ecosystem. Clear management goals (See Table) and an understanding of the range of disturbances affecting focal ecosystems are necessary for deciding between managing for resistance, resilience, or transformation and what actions are required for successful management outcomes

When Do Ring-Enhancing Brain Lesions Need to Be Biopsied, and Should They Be Treated Empirically First?

Other than acute cerebrovascular accidents, multiple ring-enhancing lesions are among the most common lesions encountered in neuroimaging. We herein describe the case of a 63-year-old diabetic man presenting with altered mental status, hyperglycaemia and community-acquired pneumonia who was found to have two ring-enhancing lesions involving the left frontal lobe and left basal ganglia. The lesions were biopsied to reveal positive fungal cultures and toxoplasma cysts. RPR titres returned reactive for non-treponemal antibodies and a suppressed CD4 count was found without evidence of HIV infection

Book Reviews

Book Review 1Book Title: Mammoths, Mastodonts & Elephants; Biology, Behaviour, and the Fossil RecordBook Author: Gary HaynesCambridge University Press 1991. 413 pp.Book Review 2Book Title: A Fieldguide to the Amphibians and Reptiles of Madagascar (Second Edition)Book Authors: Frank Glaw & Miguel VeneesM, Venees & F. Glaw Verlags GbR,  Köln, December 1994. 48O pagesBook Review 3Book Title: The Physiology of Reproduction; Second edition 1993Book Authors: Editors in Chief: E, Knobil & J.D. Neill Associate Editors: G.S. Greenwald, C.L. Markert & D.W. PfaffA two volume set, 3302 pages. Raven Press, New YorkBook Review 4Book Title: The Economics of Non-Human SocietiesBook Author: Gordon TullockPallas Press, March 1994 Tuscon, Arizona. 87 pages.Book Review 5Book Title: Bird Atlas of BotswanaBook Author: Huw PenryUniversity of Natal Press, Pietermaritzburg. 319 pages.Book Review 6Book Title: Colobine Monkeys: their Ecology, Behaviour and EvolutionBook Authors: A. Glyn Davies & John F. OatesCambridge University Press, Cambridge UK (1994). Pages xiii + 415.Book Review 7Book Title: Water Relations of Terrestrial ArthropodsBook Author: N.F. HadleyAcademic Press. 1994. 356 page

Utility of preoperative blood screening before hip and knee arthroplasty

Background: It is engrained in medical training that routine blood screening prior to arthroplasty is necessary for optimal patient care. There is little evidence to support their utility and the aggregate cost to the health system. The purpose of this study was to evaluate preoperative blood screening by identifying the frequency of an abnormal result and to examine the influence of age, gender and body mass index on the frequency of abnormal blood pathology. Methods: This is a retrospective review of 1000 patients from a single centre who underwent elective primary hip or knee arthroplasty from 2015 to 2017. Abnormal blood results were identified and clinically relevant intervals were created for routine markers. Results: A total of 939 patients had available pathology results with 84% identified as having an abnormal result and 47% having a clinically important range. Abnormal liver function tests and ferritin were most common. With increasing age, there was a significant increase in rates of abnormal clinically important range, renal dysfunction, abnormal haemoglobin and erythrocyte sedimentation rate. Males and patients with body mass index \u3e40 had an increased rate of abnormal results, particularly liver function tests. Conclusion: The ordering of preoperative investigations prior to lower limb arthroplasty is recommended by the National Institute for Health and Care Excellence guidelines, alleviating concern of post-operative complications and covering medicolegal issues. Our study determined a high frequency of abnormal results, justifying routine blood screening is recommended prior to surgery, particularly for the elderly, males and obese patients

Domain Model Explains Propagation Dynamics and Stability of Histone H3K27 and H3K36 Methylation Landscapes

Chromatin states must be maintained during cell proliferation to uphold cellular identity and genome integrity. Inheritance of histone modifications is central in this process. However, the histone modification landscape is challenged by incorporation of new unmodified histones during each cell cycle, and the principles governing heritability remain unclear. We take a quantitative computational modeling approach to describe propagation of histone H3K27 and H3K36 methylation states. We measure combinatorial H3K27 and H3K36 methylation patterns by quantitative mass spectrometry on subsequent generations of histones. Using model comparison, we reject active global demethylation and invoke the existence of domains defined by distinct methylation endpoints. We find that H3K27me3 on pre-existing histones stimulates the rate of de novo H3K27me3 establishment, supporting a read-write mechanism in timely chromatin restoration. Finally, we provide a detailed quantitative picture of the mutual antagonism between H3K27 and H3K36 methylation and propose that it stabilizes epigenetic states across cell division

Niche Occupation Limits Adaptive Radiation in Experimental Microcosms

Adaptive radiations have played a key role in the evolution of biological diversity. The breadth of adaptive radiation in an invading lineage is likely to be influenced by the availability of ecological niches, which will be determined to some extent by the diversity of the resident community. High resident diversity may result in existing ecological niches being filled, inhibiting subsequent adaptive radiation. Conversely, high resident diversity could result in the creation of novel ecological niches or an increase in within niche competition driving niche partitioning, thus promoting subsequent diversification. We tested the role of resident diversity on adaptive radiations in experimental populations of the bacterium Pseudomonas fluorescens that readily diversify into a range of niche specialists when grown in a heterogeneous environment. We allowed an undiversified strain to invade resident communities that varied in the number of niche specialists. The breadth of adaptive radiation attainable by an invading lineage decreased with increasing niche occupation of the resident community. Our results highlight the importance of niche occupation as a constraint on adaptive radiation

A Semantic Information Model for Capturing and Communicating Design Decisions

A semantic information model to improve reuse and communication of engineering design knowledge is presented in this paper. We consider design to be a process involving a sequence of decisions informed by the current state of information. As such, the information model developed is structured to reflect the conceptualizations of engineering design decisions with a particular emphasis on semantically capturing design rationale. Through the approach presented, knowledge reuse is achieved by communicating design rationale. A case study is presented to illustrate two key features of the approach: (1) seamless integration of separate modular domain ontologies and instance knowledge related to engineering design that are needed to support decision making and (2) the explicit documentation of design rationale through design decisions

Genetic Architecture of a Reinforced, Postmating, Reproductive Isolation Barrier between Neurospora Species Indicates Evolution via Natural Selection

A role for natural selection in reinforcing premating barriers is recognized, but selection for reinforcement of postmating barriers remains controversial. Organisms lacking evolvable premating barriers can theoretically reinforce postmating isolation, but only under restrictive conditions: parental investment in hybrid progeny must inhibit subsequent reproduction, and selected postmating barriers must restore parents' capacity to reproduce successfully. We show that reinforced postmating isolation markedly increases maternal fitness in the fungus Neurospora crassa, and we detect the evolutionary genetic signature of natural selection by quantitative trait locus (QTL) analysis of the reinforced barrier. Hybrid progeny of N. crassa and N. intermedia are highly inviable. Fertilization by local N. intermedia results in early abortion of hybrid fruitbodies, and we show that abortion is adaptive because only aborted maternal colonies remain fully receptive to future reproduction. In the first QTL analysis of postmating reinforcement in microbial eukaryotes, we identify 11 loci for abortive hybrid fruitbody development, including three major QTLs that together explain 30% of trait variance. One of the major QTLs and six QTLs of lesser effect are found on the mating-type determining chromosome of Neurospora. Several reinforcement QTLs are flanked by genetic markers showing either segregation distortion or non-random associations with alleles at other loci in a cross between N. crassa of different clades, suggesting that the loci also are associated with local effects on same-species reproduction. Statistical analysis of the allelic effects distribution for abortive hybrid fruitbody development indicates its evolution occurred under positive selection. Our results strongly support a role for natural selection in the evolution of reinforced postmating isolation in N. crassa

MRI-derived g-ratio and lesion severity in newly diagnosed multiple sclerosis

Myelin loss is associated with axonal damage in established multiple sclerosis. This relationship is challenging to study in vivo in early disease. Here, we ask whether myelin loss is associated with axonal damage at diagnosis, by combining non-invasive neuroimaging and blood biomarkers. We performed quantitative microstructural MRI and single molecule ELISA plasma neurofilament measurement in 73 patients with newly diagnosed, immunotherapy naïve relapsing-remitting multiple sclerosis. Myelin integrity was evaluated using aggregate g-ratios, derived from magnetization transfer saturation (MTsat) and neurite orientation dispersion and density imaging (NODDI) diffusion data. We found significantly higher g-ratios within cerebral white matter lesions (suggesting myelin loss) compared with normal-appearing white matter (0.61 vs 0.57, difference 0.036, 95% CI 0.029 to 0.043, p < 0.001). Lesion volume (Spearman’s rho rs= 0.38, p < 0.001) and g-ratio (rs= 0.24 p < 0.05) correlated independently with plasma neurofilament. In patients with substantial lesion load (n = 38), those with higher g-ratio (defined as greater than median) were more likely to have abnormally elevated plasma neurofilament than those with normal g-ratio (defined as less than median) (11/23 [48%] versus 2/15 [13%] p < 0.05). These data suggest that, even at multiple sclerosis diagnosis, reduced myelin integrity is associated with axonal damage. MRI-derived g-ratio may provide useful additional information regarding lesion severity, and help to identify individuals with a high degree of axonal damage at disease onset. York, Martin et al. simultaneously measured g-ratio and plasma neurofilament in 73 relapsing-remitting multiple sclerosis patients at diagnosis using advanced MRI and single molecule ELISA. They demonstrate that g-ratio of cerebral white matter lesions varies at diagnosis, and show that high g-ratio of lesions is associated with elevated plasma neurofilament

Procalcitonin Is Not a Reliable Biomarker of Bacterial Coinfection in People With Coronavirus Disease 2019 Undergoing Microbiological Investigation at the Time of Hospital Admission

Abstract Admission procalcitonin measurements and microbiology results were available for 1040 hospitalized adults with coronavirus disease 2019 (from 48 902 included in the International Severe Acute Respiratory and Emerging Infections Consortium World Health Organization Clinical Characterisation Protocol UK study). Although procalcitonin was higher in bacterial coinfection, this was neither clinically significant (median [IQR], 0.33 [0.11–1.70] ng/mL vs 0.24 [0.10–0.90] ng/mL) nor diagnostically useful (area under the receiver operating characteristic curve, 0.56 [95% confidence interval, .51–.60]).</jats:p