Urban living can rescue Darwin's finches from the lethal effects of invasive vampire flies.

Human activity changes multiple factors in the environment, which can have positive or negative synergistic effects on organisms. However, few studies have explored the causal effects of multiple anthropogenic factors, such as urbanization and invasive species, on animals and the mechanisms that mediate these interactions. This study examines the influence of urbanization on the detrimental effect of invasive avian vampire flies (Philornis downsi) on endemic Darwin's finches in the Galápagos Islands. We experimentally manipulated nest fly abundance in urban and non-urban locations and then characterized nestling health, fledging success, diet, and gene expression patterns related to host defense. Fledging success of non-parasitized nestlings from urban (79%) and non-urban (75%) nests did not differ significantly. However, parasitized, non-urban nestlings lost more blood, and fewer nestlings survived (8%) compared to urban nestlings (50%). Stable isotopic values (δ15 N) from urban nestling feces were higher than those from non-urban nestlings, suggesting that urban nestlings are consuming more protein. δ15 N values correlated negatively with parasite abundance, which suggests that diet might influence host defenses (e.g., tolerance and resistance). Parasitized, urban nestlings differentially expressed genes within pathways associated with red blood cell production (tolerance) and pro-inflammatory response (innate immunological resistance), compared to parasitized, non-urban nestlings. In contrast, parasitized non-urban nestlings differentially expressed genes within pathways associated with immunoglobulin production (adaptive immunological resistance). Our results suggest that urban nestlings are investing more in pro-inflammatory responses to resist parasites but also recovering more blood cells to tolerate blood loss. Although non-urban nestlings are mounting an adaptive immune response, it is likely a last effort by the immune system rather than an effective defense against avian vampire flies since few nestlings survived.

Effect of urbanization and parasitism on the gut microbiota of Darwin's finch nestlings.

Host-associated microbiota can be affected by factors related to environmental change, such as urbanization and invasive species. For example, urban areas often affect food availability for animals, which can change their gut microbiota. Invasive parasites can also influence microbiota through competition or indirectly through a change in the host immune response. These interacting factors can have complex effects on host fitness, but few studies have disentangled the relationship between urbanization and parasitism on an organism's gut microbiota. To address this gap in knowledge, we investigated the effects of urbanization and parasitism by the invasive avian vampire fly (Philornis downsi) on the gut microbiota of nestling small ground finches (Geospiza fuliginosa) on San Cristóbal Island, Galápagos. We conducted a factorial study in which we experimentally manipulated parasite presence in an urban and nonurban area. Faeces were then collected from nestlings to characterize the gut microbiota (i.e. bacterial diversity and community composition). Although we did not find an interactive effect of urbanization and parasitism on the microbiota, we did find main effects of each variable. We found that urban nestlings had lower bacterial diversity and different relative abundances of taxa compared to nonurban nestlings, which could be mediated by introduction of the microbiota of the food items or changes in host physiology. Additionally, parasitized nestlings had lower bacterial richness than nonparasitized nestlings, which could be mediated by a change in the immune system. Overall, this study advances our understanding of the complex effects of anthropogenic stressors on the gut microbiota of birds.

Elevated nest temperature has opposing effects on host species infested with parasitic nest flies.

Environmental factors, such as elevated temperature, can have varying effects on hosts and their parasites, which can have consequences for the net outcome of this relationship. The individual direct effects of temperature must be disentangled to determine the net-effect in host-parasite relationships, yet few studies have determined the net-effects in a multi-host system. To address this gap, we experimentally manipulated temperature and parasite presence in the nests of two host species infested by parasitic blowflies (Protocalliphora sialia). We conducted a factorial experiment by increasing temperature (or not) and removing all parasites (or not) in the nests of eastern bluebirds (Sialia sialis) and tree swallows (Tachycineta bicolor). We then measured nestling morphometrics, blood loss, and survival and quantified parasite abundance. We predicted that if temperature had a direct effect on parasite abundance, then elevated temperature would cause similar directional effects on parasite abundance across host species. If temperature had a direct effect on hosts, and therefore an indirect effect on the parasite, parasite abundance would differ across host species. Swallow nests with elevated temperature had fewer parasites compared to nests without temperature manipulation. In contrast, bluebird nests with elevated temperatures had more parasites compared to nests without temperature manipulation. The results of our study demonstrate that elevated temperature can have differential effects on host species, which can impact infestation susceptibility. Furthermore, changing climates could have complex net-effects on parasite fitness and host health across multi-host-parasite interactions.

Timing of vasoactive agents and corticosteroid initiation in septic shock.

Septic shock remains a health care concern associated with significant morbidity and mortality. The Surviving Sepsis Campaign Guidelines for Management of Sepsis and Septic Shock recommend early fluid resuscitation and antimicrobials. Beyond initial management, the guidelines do not provide clear recommendations on appropriate time to initiate vasoactive therapies and corticosteroids in patients who develop shock. This review summarizes the literature regarding time of initiation of these interventions. Clinical data regarding time of initiation of these therapies in relation to shock onset, sequence of treatments with regard to each other, and clinical markers evaluated to guide initiation are summarized. Early-high vasopressor initiation within first 6 h of shock onset is associated with lower mortality. Following norepinephrine initiation, the exact dose and timing of escalation to adjunctive vasopressor agents are not well elucidated in the literature. However, recent data indicate that timing may be an important factor in initiating vasopressors and adjunctive therapies, such as corticosteroids. Norepinephrine-equivalent dose and lactate concentration can aid in determining when to initiate vasopressin and angiotensin II in patients with septic shock. Future guidelines with clear recommendations on the time of initiation of septic shock therapies are warranted.

Differential effects of elevated nest temperature and parasitism on the gut microbiota of wild avian hosts.

BACKGROUND: Changes in wild animal gut microbiotas may influence host health and fitness. While many studies have shown correlations between gut microbiota structure and external factors, few studies demonstrate causal links between environmental variables and microbiota shifts. Here, we use a fully factorial experiment to test the effects of elevated ambient temperature and natural nest parasitism by nest flies (Protocalliphora sialia) on the gut microbiotas of two species of wild birds, the eastern bluebird (Sialia sialis) and the tree swallow (Tachycineta bicolor). RESULTS: We find that bacterial communities from the nestlings of each host species show idiosyncratic responses to both heat and parasitism, with gut microbiotas of eastern bluebirds more disrupted by heat and parasitism than those of tree swallows. Thus, we find that eastern bluebirds are unable to maintain stable associations with their gut bacteria in the face of both elevated temperature and parasitism. In contrast, tree swallow gut microbiotas are not significantly impacted by either heat or nest parasitism. CONCLUSIONS: Our results suggest that excess heat (e.g., as a result of climate change) may destabilize natural host-parasite-microbiota systems, with the potential to affect host fitness and survival in the Anthropocene.

COVID-19 disease trajectories among nursing home residents.

INTRODUCTION: Older adults are at greater risk of both infection with and mortality from COVID-19. Many U.S. nursing homes have been devastated by the COVID-19 pandemic, yet little has been described regarding the typical disease course in this population. The objective of this study is to describe and identify patterns in the disease course of nursing home residents infected with COVID-19. SETTING AND METHODS: This is a case series of 74 residents with COVID-19 infection in a nursing home in central Indiana between March 28 and June 17, 2020. Data were extracted from the electronic medical record and from nursing home medical director tracking notes from the time of the index infection through August 31, 2020. The clinical authorship team reviewed the data to identify patterns in the disease course of the residents. RESULTS: The most common symptoms were fever, hypoxia, anorexia, and fatigue/malaise. The duration of symptoms was extended, with an average of over 3 weeks. Of those infected 25 died; 23 of the deaths were considered related to COVID-19 infection. A subset of residents with COVID-19 infection experienced a rapidly progressive, fatal course. DISCUSSION/CONCLUSIONS: Nursing home residents infected with COVID-19 from the facility we studied experienced a prolonged disease course regardless of the severity of their symptoms, with implications for the resources needed to care for and support of these residents during active infection and post-disease. Future studies should combine data from nursing home residents across the country to identify the risk factors for disease trajectories identified in this case series.

The Family Context of Toddler Sleep: Routines, Sleep Environment, and Emotional Security Induction in the Hour before Bedtime.

Family processes during the pre-bedtime period likely have a crucial influence on toddler sleep, but relatively little previous research has focused on family process in this context. The current study examined several aspects of family process during the pre-bedtime period, including the use of bedtime routines, the qualities of the child's home sleep environment, and the promotion of child emotional security, in families of 30-month-old toddlers (N= 546; 265 female) who were part of a multi-site longitudinal study of toddler development. These characteristics were quantified using a combination of parent- and observer-reports and examined in association with child sleep using correlation and multiple regression. Child sleep was assessed using actigraphy to measure sleep duration, timing, variability, activity, and latency. Bedtime routines were examined using parents' daily records. Home sleep environment and emotional security induction were quantified based on observer ratings and in-home observation notes, respectively. All three measures of pre-bedtime context (i.e., bedtime routine inconsistency, poor quality sleep environments, and emotional security induction) were correlated with various aspects of child sleep (significant correlations:.11-.22). The most robust associations occurred between the pre-bedtime context measures and sleep timing (i.e., the timing of the child's sleep schedule) and variability (i.e., night to night variability in sleep timing and duration). Pre-bedtime variables, including bedtime routine consistency, home sleep environment quality, and positive emotional security induction, also mediated the association between family socioeconomic status and child sleep. Our findings underscore the value of considering family context when examining individual differences in child sleep.

Effectiveness and Safety of Direct Oral Anticoagulants versus Warfarin in Obese Patients with Acute Venous Thromboembolism.

STUDY OBJECTIVE: Studies on the use of direct oral anticoagulants (DOACs) in obese patients are limited. Current guidelines advise against DOAC use in patients with a body weight more than 120 kg or body mass index higher than 40 kg/m2 . Therefore, the aim of this study was to evaluate the effectiveness and safety of DOACs versus warfarin for the treatment of acute venous thromboembolism (VTE) in obese patients. DESIGN: Retrospective matched cohort study. SETTING: Integrated delivery system of 40 academic, community, and specialty hospitals. PATIENTS: A total of 1840 adults with a primary admission diagnosis of acute VTE who received a DOAC (apixaban, dabigatran, or rivaroxaban [632 patients] or warfarin [1208 patients]) while hospitalized between January 1, 2011, and October 1, 2015, and who had a body weight more than 100 kg and less than 300 kg, were included. Patients in the warfarin group were matched in a 2:1 ratio to patients who received a DOAC based on history of VTE, chronic kidney disease, race, and age. MEASUREMENTS AND MAIN RESULTS: The primary outcome was recurrence of VTE within 12 months of the index admission date. Secondary outcomes included occurrence of pulmonary embolism (PE) and deep vein thrombosis (DVT) events separately within the study time frame, as well as bleeding within 12 months of the index admission date. No significant difference in the recurrence of VTE was observed between patients who received a DOAC compared with those who received warfarin (6.5% vs 6.4%, p=0.93). Likewise, no significant differences in the occurrence of PE and DVT were seen between the DOAC- and warfarin-treated patients (3.7% vs 3.8%, p=0.94, and 3% vs 3.5%, p=0.56, respectively). Bleeding occurred in 1.7% and 1.2% of patients in the DOAC and warfarin groups, respectively (p=0.31). CONCLUSION: To our knowledge, this is the largest clinical study to date showing that patients with obesity can be treated effectively and safely with a DOAC compared with warfarin for acute VTE. Thus DOACs should be considered a reasonable alternative to warfarin for treatment of acute VTE in obese patients.

The Usefulness of Diffusion Tensor Imaging and Tractography in Surgery of Brainstem Cavernous Malformations.

BACKGROUND: Diffusion tensor imaging (DTI) estimates the course and connectivity patterns of white matter tracts. The objective of this study is to evaluate whether findings in the brain stem modify the preoperative surgical trajectory planning or postoperative outcome in patients with brain stem cavernous malformations. METHODS: Ten patients with symptomatic brainstem cavernous malformation underwent surgical resection. Five patients received preoperative DTI evaluation and the remaining 5 did not. Reconstructed DTI tracts consisted of corticospinal, medial lemnisci, and cerebellar peduncles. The surgical planning and postoperative outcome were evaluated. RESULTS: In 5 patients with no preoperative DTI evaluation, surgical planning was based on anatomic landmark and the 2-point technique. The other 5 patients underwent preoperative DTI, and findings were factored into the selection of the surgical approach. In 3 of the 5 cases with DTI evaluation, the 2-point technique suggested a similar trajectory. In the other 2, the DTI findings suggested a different approach to avoid damage to the white matter tract. Two patients in the group with no DTI had immediate postoperative new or worsened deficit, which improved at long-term follow-up. No patient in the DTI group had a new neurologic deficit. CONCLUSIONS: Compared with the standard magnetic resonance imaging, DTI provided improved visualization of cavernous malformation involvement in eloquent fiber tracts of the brainstem. This additional information might help in selecting a more appropriate surgical trajectory in selected lesions. Larger patient cohorts are needed to assess the effect of this modality in patients' outcome.

Synthesis and charge-transfer dynamics in a ferrocene-containing organoboryl aza-BODIPY donor-acceptor triad with boron as the hub.

A N,N'-bis(ferroceneacetylene)boryl complex of 3,3'-diphenylazadiisoindolylmethene was synthesized by the reaction of an N,N'-difluoroboryl complex of 3,3'-diphenylazadiisoindolylmethene and ferroceneacetylene magnesium bromide. The novel diiron complex was characterized by a variety of spectroscopic techniques, electrochemistry, and ultrafast time-resolved methods. Spectroscopy and redox behavior was correlated with the density functional theory (DFT) and time-dependent DFT calculations. An unexpected degree of coupling between the two Fc ligands was observed. Despite a lack of conjugation between the donor and acceptor, the complex undergoes very rapid (τ = 1.7 ± 0.1 ps) photoinduced intramolecular charge separation followed by subpicosecond charge recombination to form a triplet state with a lifetime of 4.8 ± 0.1 µs.