Is conservation based on best available science creating an ecological trap for an imperiled lagomorph?

Habitat quality regulates fitness and population density, making it a key driver of population size. Hence, increasing habitat quality is often a primary goal of species conservation. Yet, assessments of fitness and density are difficult and costly to obtain. Therefore, species conservation often uses “best available science,” extending inferences across taxa, space, or time, and inferring habitat quality from studies of habitat selection. However, there are scenarios where habitat selection is not reflective of habitat quality, and this can lead to maladaptive management strategies. The New England cottontail (Sylvilagus transitionalis) is an imperiled shrubland obligate lagomorph whose successful recovery hinges on creation of suitable habitat. Recovery of this species is also negatively impacted by the non‐native eastern cottontail (Sylvilagus floridanus), which can competitively exclude New England cottontails from preferred habitat. Herein, we evaluate habitat quality for adult and juvenile New England and eastern cottontails using survival and density as indicators. Our findings did not support selection following an ideal free distribution by New England cottontails. Instead, selected resources, which are a target of habitat management, were associated with low survival and density and pointed to a complex trade‐off between density, survival, habitat, and the presence of eastern cottontails. Further, movement distance was inversely correlated with survival in both species, suggesting that habitat fragmentation limits the ability of cottontails to freely distribute based on habitat quality. While habitat did not directly regulate survival of juvenile cottontails, tick burden had a strong negative impact on juvenile cottontails in poor body condition. Given the complex interactions among New England cottontails, eastern cottontails, and habitat, directly assessing and accounting for factors that limit New England cottontail habitat quality in management plans is vital to their recovery. Our study demonstrates an example of management for possible ecological trap conditions via the application of incomplete knowledge.     

An alternatively-spliced exon in the 5'-UTR of human ALAS1 mRNA inhibits translation and renders it resistant to haem-mediated decay

Haem controls its own synthesis in non-erythroid cells primarily by regulation of ALAS1 mRNA stability. Alternative splicing of human ALAS1 generates two mRNAs with different 5'-UTRs: a major one, where exon 1B is omitted, and a minor form containing exon 1B. We show that, unlike the major ALAS1 mRNA, the minor form was resistant to haem-mediated decay. Furthermore, we demonstrate that the ALAS1 5'-UTR alone did not confer haem-mediated decay upon a heterologous mRNA and the inclusion of exon 1B inhibited translation. These data suggest that translation of ALAS1 mRNA itself might be required for destabilisation in response to haem.     

DNA adopts normal B-form upon incorporation of highly fluorescent DNA base analogue tC: NMR structure and UV-Vis spectroscopy characterization

The influence of the highly fluorescent tricyclic cytosine base analogue (tC) on duplex DNA conformation is investigated. The duplex properties are characterized by absorbance and circular dichroism (CD) for all combinations of neighbouring bases to tC, and an NMR structure is determined for one tC-containing sequence. For the oligonucleotides with one tC incorporated instead of cytosine, the melting temperature is increased on average by 2.7°C above that for the unmodified ones. CD spectra are practically identical for modified and unmodified sequences, indicating an unperturbed B-DNA conformation. The NMR structure determination of the self-complementary sequence 5′-CTC(tC)ACGTGGAG shows a DNA conformation consistent with B-form for the whole duplex. The root-mean-square distance for the nucleotides of the eight central base pairs between the 10 structures with lowest CYANA target functions and a mean structure is 0.45 ± 0.17 Å. The NMR data confirm correct base pairing for tC by the observation of both intrastrand and interstrand imino proton NOEs. Altogether, this suggests that tC works well as a cytosine analogue, i.e. it is situated in the base stack, forming hydrogen bonds with G in the complementary strand, without distorting the DNA backbone conformation. This first example of an artificial, highly fluorescent DNA base that does not perturb the DNA conformation could have valuable applications for the study of the structure and dynamics of nucleic acid systems.     

Environmental Drivers of Ranavirus in Free-Living Amphibians in Constructed Ponds

Amphibian ranaviruses occur globally, but we are only beginning to understand mechanisms for emergence. Ranaviruses are aquatic pathogens which can cause?>?90% mortality in larvae of many aquatic-breeding amphibians, making them important focal host taxa. Host susceptibilities and virulence of ranaviruses have been studied extensively in controlled laboratory settings, but research is needed to identify drivers of infection in natural environments. Constructed ponds, essential components of wetland restoration, have been associated with higher ranavirus prevalence than natural ponds, posing a conundrum for conservation efforts, and emphasizing the need to understand potential drivers. In this study, we analyzed 4 years of Frog virus 3 prevalence and associated environmental parameters in populations of wood frogs (Lithobates sylvaticus) and green frogs (Lithobates clamitans) in a constructed pond system. High prevalence was best predicted by low temperature, high host density, low zooplankton concentrations, and Gosner stages approaching metamorphosis. This study identified important variables to measure in assessments of ranaviral infection risk in newly constructed ponds, including effects of zooplankton, which have not been previously quantified in natural settings. Examining factors mediating diseases in natural environments, particularly in managed conservation settings, is important to both validate laboratory findings in situ, and to inform future conservation planning, particularly in the context of adaptive management.     

MPowering ecologists: community assembly tools for community assembly rules

Null model tests of presence–absence data (‘NMTPAs’) provide important tools for inferring effects of competition, facilitation, habitat filtering, and other ecological processes from observational data. Many NMTPAs have been developed, but they often yield conflicting conclusions when applied to the same data. Type I and II error rates, size, power, robustness and bias provide important criteria for assessing which tests are valid, but these criteria need to be evaluated contingent on the sample size, null hypothesis of interest, and assumptions that are appropriate for the data set that is being analyzed. In this paper, we confirm that this is the case using the software MPower, evaluating the validity of NMTPAs contingent on the null hypothesis being tested, assumptions that can be made, and sample size. Evaluating the validity of NMTPAs contingent on these factors is important towards ensuring that reliable inferences are drawn from observational data about the processes controlling community assembly.     

Tailored α-methylene-γ-butyrolactones and their effects on growth suppression in pancreatic carcinoma cells

A selected series of racemic α-methylene-γ-butyrolactones (AMGBL) were synthesized via allylboration and screened against three human pancreatic cancer cell lines (Panc-1, MIA PaCa-2, and BxPC-3). This systematic study established a discernible relationship between the substitution pattern of AMGBL and their anti-proliferative activity. β,γ-diaryl-AMGBLs, particularly those with a trans-relationship exhibited higher potency than parthenolide and LC-1 against all three cell lines.     

Growth factor binding and bioactivity in human kidney epithelial cell cultures

Summary Insulinlike growth factors (IGF) and epidermal growth factor (EGF) are produced in renal tissue, as are specific receptors for these hormones. To evaluate the significance of these observations to regulation of renal tubular cell proliferation, we have examined the interaction of IGF and EGF with cultured human proximal tubular epithelial cells (HPT). HPT cells showed specific binding of IGF-1, insulin, and EGF. IGF-1 binding was inhibited by antibody to the type 1 IGF receptor (α-IR3). Insulin receptors and type 1 IGF receptors were identified by bifunctional cross-linking. IGF-1, insulin, and EGF stimulated [³H]thymidine incorporation by 77, 73, and 87%, respectively. Haft maximal stimulation by IGF-1, insulin, and EGF was produced with 4×10⁻⁹ M, 2.5×10⁻⁸ M, and 8×10⁻¹⁰ M concentrations of these hormones. α-IR3 inhibited stimulation of thymidine incorporation by IGF-1 and insulin but had no effect in EGF-stimulated thymidine incorporation. EGF and high concentrations of insulin both stimulated cell proliferation by 83 and 79%, respectively. These data are consistent with regulation of tubular epithelial proliferation by IGF-1, insulin, and EGF and suggest that the mitogenic activity of both insulin and IGF-1 is mediated by the type 1 IGF receptor. Supported by grants CA37887 and DK32889 from the National Institutes of Health, Bethesda, MD, and by a Medical University of South Carolina institutional grant.     

Effect of nasal balloon autoinflation in children with otitis media with effusion in primary care: an open randomized controlled trial

Background:Otitis media with effusion is a common problem that lacks an evidence-based nonsurgical treatment option. We assessed the clinical effectiveness of treatment with a nasal balloon device in a primary care setting.Methods:We conducted an open, pragmatic randomized controlled trial set in 43 family practices in the United Kingdom. Children aged 4–11 years with a recent history of ear symptoms and otitis media with effusion in 1 or both ears, confirmed by tympanometry, were allocated to receive either autoinflation 3 times daily for 1–3 months plus usual care or usual care alone. Clearance of middle-ear fluid at 1 and 3 months was assessed by experts masked to allocation.Results:Of 320 children enrolled, those receiving autoinflation were more likely than controls to have normal tympanograms at 1 month (47.3% [62/131] v. 35.6% [47/132]; adjusted relative risk [RR] 1.36, 95% confidence interval [CI] 0.99 to 1.88) and at 3 months (49.6% [62/125] v. 38.3% [46/120]; adjusted RR 1.37, 95% CI 1.03 to 1.83; number needed to treat = 9). Autoinflation produced greater improvements in ear-related quality of life (adjusted between-group difference in change from baseline in OMQ-14 [an ear-related measure of quality of life] score −0.42, 95% CI −0.63 to −0.22). Compliance was 89% at 1 month and 80% at 3 months. Adverse events were mild, infrequent and comparable between groups.Interpretation:Autoinflation in children aged 4–11 years with otitis media with effusion is feasible in primary care and effective both in clearing effusions and improving symptoms and ear-related child and parent quality of life. Trial registration: ISRCTN, No. 55208702.Otitis media with effusion, also known as glue ear, is an accumulation of fluid in the middle ear, without symptoms or signs of an acute ear infection. It is often associated with viral infection.^1–3 The prevalence rises to 46% in children aged 4–5 years,⁴ when hearing difficulty, other ear-related symptoms and broader developmental concerns often bring the condition to medical attention.^3,5,6 Middle-ear fluid is associated with conductive hearing losses of about 15–45 dB HL.⁷ Resolution is clinically unpredictable,^8–10 with about a third of cases showing recurrence.¹¹ In the United Kingdom, about 200 000 children with the condition are seen annually in primary care.^12,13 Research suggests some children seen in primary care are as badly affected as those seen in hospital.^7,9,14,15 In the United States, there were 2.2 million diagnosed episodes in 2004, costing an estimated $4.0 billion.¹⁶ Rates of ventilation tube surgery show variability between countries,^17–19 with a declining trend in the UK.²⁰Initial clinical management consists of reasonable temporizing or delay before considering surgery.¹³ Unfortunately, all available medical treatments for otitis media with effusion such as antibiotics, antihistamines, decongestants and intranasal steroids are ineffective and have unwanted effects, and therefore cannot be recommended.^21–23 Not only are antibiotics ineffective, but resistance to them poses a major threat to public health.^24,25 Although surgery is effective for a carefully selected minority,^13,26,27 a simple low-cost, nonsurgical treatment option could benefit a much larger group of symptomatic children, with the purpose of addressing legitimate clinical concerns without incurring excessive delays.Autoinflation using a nasal balloon device is a low-cost intervention with the potential to be used more widely in primary care, but current evidence of its effectiveness is limited to several small hospital-based trials²⁸ that found a higher rate of tympanometric resolution of ear fluid at 1 month.^29–31 Evidence of feasibility and effectiveness of autoinflation to inform wider clinical use is lacking.^13,28 Thus we report here the findings of a large pragmatic trial of the clinical effectiveness of nasal balloon autoinflation in a spectrum of children with clinically confirmed otitis media with effusion identified from primary care.     

Sex-Specific Elk Resource Selection during the Anthrax Risk Period

Anthrax, caused by the spore-forming bacterium Bacillus anthracis, is a zoonosis affecting animals and humans globally. In the United States, anthrax outbreaks occur in wildlife and livestock, with frequent outbreaks in native and exotic wildlife species in Texas, livestock outbreaks in the Dakotas, and sporadic mixed outbreaks in Montana. Understanding where pathogen and host habitat selection overlap is essential for anthrax management. Resource selection and habitat use of ungulates may be sex-specific and lead to differential anthrax exposure risks across the landscape for males and females. We evaluated female elk (Cervus canadensis) resource selection in the same study areas as male elk in a previous anthrax risk study to identify risk of anthrax transmission to females and compare transmission risk between females and males. We developed a generalized linear mixed-effect model to estimate resource selection for female elk in southwest Montana during the June to August anthrax transmission risk period. We then predicted habitat selection of female and male elk across the study area and compared selection with the distribution of anthrax risk to identify spatial distributions of potential anthrax exposure for the male and female elk. Female and male elk selected different resources during the anthrax risk period, which resulted in different anthrax exposure areas for females and males. The sex-specific resource selection and habitat use could infer different areas of risk for anthrax transmission, which can improve anthrax and wildlife management and have important public health and economic implications. © 2020 The Wildlife Society.