bluuebunny/crossref_metadata_2025 huggingface dataset:
A rare case report of prune belly syndrome with malnutrition
Authors: Hakimi Turyalai , Ibrahimi Mohammad Akbar
Published: April 2021

Prune belly syndrome (PBS) is a rare congenital malformation of unknown etiology characterized by a triad of deficient abdominal wall musculature, undescended testicles and urinary tract malformations. Most of the patients have pulmonary, cardiac, skeletal and gastrointestinal tract anomalies. Lack of abdominal muscles leads to constipation due to inability to perform Valsalva maneuver, which helps push the stool out of the rectum during the defecation. Additionally, frequent respiratory tract infections, persisting constipation and urinary tract infections lead to the development of malnutrition in children. We report this case to raise the awareness of low socioeconomic and low-resource medical settings that malnutrition could be existed or caused by PBS. We also encourage the expansion of pediatric surgery and family medicine training to increase the number of specialist (family medicine) to report and refer PBS in earlier phase, while working in rural areas and remote provinces.
Mush, Melts and Metasediments: a History of Rhyolites from the Okataina Volcanic Centre, New Zealand, as Captured in Plagioclase
Authors: Sas May , Shane Phil , Kuritani Takeshi , Zellmer Georg F , Kent Adam J R , Nakagawa Mitsuhiro
Published: April 2021

The Okataina Volcanic Centre (OVC), located in the Taupo Volcanic Zone, New Zealand, is a dominantly rhyolitic magmatic system in an arc setting, where eruptions are thought to be driven by mafic recharge. Here, Sr–Pb isotopes, and compositional and textural variations in plagioclase phenocrysts from 10 rhyolitic deposits (two caldera, one immediately post-caldera, four intra-caldera, and three extra-caldera) are used to investigate the OVC magmatic system and identify the sources and assimilants within this diverse mush zone. Plagioclase interiors exhibit normal and reverse zoning, and are commonly in disequilibrium with their accompanying glass, melt inclusions, and whole-rock compositions. This indicates that the crystals nucleated in melts that differed from their carrier magma. In contrast, the outermost rims of crystals exhibit normal zoning that is compositionally consistent with growth in cooling and fractionating melts just prior to eruption. At the intra-crystal scale, the total suite of 87Sr/86Sr ratios are highly variable (0·7042–0·7065 ± 0·0004 average 2SE); however, the majority (95 %) of the crystals are internally homogeneous within error. At whole-crystal scale (where better precision is obtained), 87Sr/86Sr ratios are much more homogeneous (0·70512–0·70543 ± 0·00001 average 2SE) and overlap with their host whole-rock Sr isotopic ratios. Whole-crystal Pb isotopic ratios also largely overlap with whole-rock Pb ratios. The plagioclase and whole-rock isotopic compositions indicate significant crustal assimilation (≥20 %) of Torlesse-like metasediments (local basement rock) by a depleted mid-ocean ridge mantle magma source, and Pb isotopes require variable fluid-dominant subduction flux. The new data support previous petrogenetic models for OVC magmas that require crystal growth in compositionally and thermally distinct magmas within a complex of disconnected melt-and-mush reservoirs. These reservoirs were rejuvenated by underplating basaltic magmas that serve as an eruption trigger. However, the outermost rims of the plagioclase imply that interaction between silicic melts and eruption-triggering mafic influx is largely limited to heat and volatile transfer, and results in rapid mobilization and syn-eruption mixing of rhyolitic melts. Finally, relatively uniform isotopic compositions of plagioclase indicate balanced contributions from the crust and mantle over the lifespan of the OVC magmatic system.
Advancing health equity through a theoretically critical implementation science
Authors: Snell-Rood Claire , Jaramillo Elise Trott , Hamilton Alison B , Raskin Sarah E , Nicosia Francesca M , Willging Cathleen
Published: April 2021

While implementation science is driven by theory, most implementation science theories, models, and frameworks (TMF) do not address issues of power, inequality, and reflexivity that are pivotal to achieving health equity. Theories used in anthropology address these issues effectively and could complement prevailing implementation science theories and constructs. We propose three broad areas of theory that complement and extend existing TMF in implementation science to advance health equity. First, theories of postcoloniality and reflexivity foreground attention to the role of power in knowledge production and to the ways that researchers and interventionists may perpetuate the inequalities shaping health. Second, theories of structural violence and intersectionality can help us to better understand the unequal burden of health disparities in the population, thereby encouraging researchers to think beyond single interventions to initiate partnerships that can impact overlapping health vulnerabilities and influence the upstream causes of vulnerability. Finally, theories of policy and governance encourage us to examine the social-political forces of the “outer context” crucial for implementation and sustainability. The incorporation of critical theories could enhance implementation science and foster necessary reflexivity among implementation scientists. We contend that a theoretically critical implementation science will promote better science and, more importantly, support progress toward health equity.
The possible effects of mono butyl phthalate (MBP) and mono (2-ethylhexyl) phthalate (MEHP) on INS-1 pancreatic beta cells
Authors: Karabulut Gözde , Barlas Nurhayat
Published: April 2021

Mono-2-ethyhexyl phthalate (MEHP), an environmental xenoestrogen, is widely used in the production of polyvinyl chloride materials and can be easily accumulated in human body. MBP is the active monoester metabolite of di butyl phthalate that is widely used as plasticizer in many products such as plastic toys, food packaging, personal care products, as well as an additive in lubricants, eliminating foams, and lotions. The presented in-vitro cytotoxicity study focused on time-dependent and combinatory exposure scenarios. We chose these phthalates because they are posed a considerable interest because of their contribution to insulin resistance, type-2 diabetes and obesity. All experiments performed in INS-1 pancreatic beta cells show moderate cytotoxicity with a time-dependent increase in effectiveness. INS-1 cells were treated with 0.001, 0.01, 0.1, 1, or 10-μM MEHP and MBP for 24, 48, and 72 h. Our results showed that cell viability was decreased and total oxidant levels were increased. Also, mRNA expression levels with asscociated beta cells were measured and for MBP dose groups, all mRNA expression levels were decreased. In conclusion, these findings suggest that, MEHP and MBP are have a negative and distruptor role on pancreatic beta cells and it will be linked with insulin resistance and type 2 diabetes.
Mitochondrial Function and Anesthetic Sensitivity in the Mouse Spinal Cord
Authors: Woods Christian B. , Spencer Kira A. , Jung Sangwook , Worstman Hailey M. , Ramirez Jan-Marino , Morgan Philip G. , Sedensky Margaret M.
Published: April 2021

Background

Ndufs4 knockout (KO) mice are defective in mitochondrial complex I function and hypersensitive to inhibition of spinal cord–mediated response to noxious stimuli by volatile anesthetics. It was hypothesized that, compared to wild-type, synaptic or intrinsic neuronal function is hypersensitive to isoflurane in spinal cord slices from knockout mice.

Methods

Neurons from slices of the vestibular nucleus, central medial thalamus, and spinal cord from wild-type and the global Ndufs4 knockout were patch clamped. Unstimulated synaptic and intrinsic neuronal characteristics were measured in response to isoflurane. Norfluoxetine was used to block TREK channel conductance. Cholinergic cells were labeled with tdTomato.

Results

All values are reported as means and 95% CIs. Spontaneous synaptic activities were not different between the mutant and control. Isoflurane (0.6%; 0.25 mM; Ndufs4[KO] EC95) increased the holding current in knockout (ΔHolding current, 126 pA [95% CI, 99 to 152 pA]; ΔHolding current P < 0.001; n = 21) but not wild-type (ΔHolding current, 2 7 pA [95% CI, 9 to 47 pA]; ΔHolding current, P = 0.030; n = 25) spinal cord slices. Knockout and wild-type ΔHolding currents were significantly different (P < 0.001). Changes comparable to those in the knockout were seen in the wild type only in 1.8% (0.74 mM) isoflurane (ΔHolding current, 72 pA [95% CI, 43 to 97 pA]; ΔHolding current, P < 0.001; n = 13), the control EC95. Blockade of action potentials indicated that the increased holding current in the knockout was not dependent on synaptic input (ΔHolding current, 154 pA [95% CI, 99 to 232 pA]; ΔHolding current, P = 0.506 compared to knockout without blockade; n = 6). Noncholinergic neurons mediated the increase in holding current sensitivity in Ndufs4 knockout. The increased currents were blocked by norfluoxetine.

Conclusions

Isoflurane increased an outwardly rectifying potassium current in ventral horn neurons of the Ndufs4(KO) mouse at a concentration much lower than in controls. Noncholinergic neurons in the spinal cord ventral horn mediated the effect. Presynaptic functions in Ndufs4(KO) slices were not hypersensitive to isoflurane. These data link anesthetic sensitivity, mitochondrial function, and postsynaptic channel activity.

Editor’s Perspective

What We Already Know about This Topic

What This Article Tells Us That Is New
The Rates and Risk Factors of Intra-Pedicular Accuracy and Proximal Facet Joint Violation for Single-Level Degenerative Lumbar Diseases
Authors: Zhang Ren-Jie , Zhou Lu-Ping , Zhang Lai , Zhang Hua-Qing , Ge Peng , Jia Chong-Yu , Zhang Yong , Zhang Jian-Xiang , Shen Cai-Liang
Published: April 2021

Study Design.

A retrospective study.

Objective.

To compare the accuracy of pedicle screw placement and proximal facet joint violation (FJV) in single-level degenerative lumbar diseases using cortical bone trajectory (CBT) and traditional trajectory (TT) techniques, and analyze their possible risk factors.

Summary of Background Data.

CBT screws have been utilized increasingly to improve cortical bone contact to prevent screw pullout and reduce approach-related morbidity. However, the studies on intra-pedicular accuracy and proximal FJV between the two methods are rare.

Methods.

A total of 40 patients who required single-level instruments were included in the retrospective study treated with the CBT-TLIF and the TT-TLIF at a 1:1 ratio from March 2019 to August 2020. The radiographic outcomes were the intra-pedicular accuracy and proximal FJV. Moreover, the possible risk factors were assessed using bivariate and multivariate analyses.

Results.

As for the intra-pedicular accuracy, 73 screws (91.3%) were classified as grade A, 7 screws (8.7%) classified as grade B in the CBT group. A total of 71 screws (88.8%) were graded A with remaining 8 screws (10.0%) graded B and 1 screw (1.2%) graded C in the TT group. The proportion of optimal and clinically acceptable screw positions in the two groups were not significantly different (P > 0.05). In addition, the rate of proximal FJV in CBT approach (8.3%) was significantly lower than that in the TT approach (35.0%) (P < 0.001). Multivariate analysis showed the TT insertion approach and facet angle ≥45° were the independent risk factors for proximal FJV, but no factors above affected intra-pedicular accuracy.

Conclusion.

Compared with the TT approach in TLIF, the CBT approach showed similar intra-pedicular accuracy and remarkable superiority in proximal facet joint protection. Facet angle ≥45° is the independent risk factors for proximal FJV.

Level of Evidence: 2
The Legacy of Art in Plastic Surgery
Authors: Fernandes Julio Wilson
Published: April 2021

The consistent relationship between surgery and art has been very well documented since 2000 BC. The close relationship between plastic surgery and art is historical and is still expected by the public and our patients. This article emphasizes the many links plastic surgery has with art, and presents a few practical examples of its reverberation in aesthetic and reconstructive plastic surgery procedures. Based on his surgical and actual sculpting activities in the realm of contemporary art, the author elaborates on 7 contributions art education affords the plastic surgery praxis, as an incentive and a reflection of its value to the plastic surgeon’s life.
RARE CASE OF ABIOTROPHIA DEFECTIVA BLEB-ASSOCIATED ENDOPHTHALMITIS
Authors: Mustafi Debarshi , Tom Elysse S. , Yang Dong
Published: April 2021

Purpose:

To report a rare case of Abiotrophia defectiva bleb-associated endophthalmitis.

Methods:

In this case report of a patient with bleb-associated endophthalmitis, the authors describe the features of severe and rapid onset, associated retinitis, and a favorable outcome after aggressive early intervention.

Results:

A 75-year-old woman presented decreased visual acuity of hand motions with an elevated intraocular pressure of 39 mmHg in the left eye. Her ocular history was notable for severe primary open-angle glaucoma with uneventful trabeculectomy and cataract surgery in both eyes 7 years before. Examination revealed conjunctival injection and an opaque avascular cystic bleb along with anterior chamber cellular reaction with a B-scan ultrasound concerning for vitritis. A. defectiva was isolated from the vitreous tap within 48 hours and confirmed later with 16S ribosomal RNA sequencing. After initial vitreous tap and inject and subsequent pars plana vitrectomy, her best-corrected visual acuity had improved to 20/500 at postoperative week one and then improved to 20/40 at postoperative month 2. Her examination was notable for resolved corneal edema, a deep and quiet anterior chamber, and resolved intraretinal hemorrhages.

Conclusion:

This is one of the first bleb-associated endophthalmitis cases with rapid identification of A. defectiva. A. defectiva was isolated from the initial vitreous tap within 48 hours and confirmed with 16S ribosomal RNA sequencing. This case highlights that rapid identification of A. defectiva may be indicative of a greater bacterial load and should prompt aggressive intervention and that the visual prognosis can be favorable.
Atopic Dermatitis and Staphylococcus aureus
Authors: Rustad Andrea M. , Nickles Melissa A. , Lio Peter A.
Published: April 2021

A strong association has been established between Staphylococcus aureus and atopic dermatitis (AD). Although the exact mechanism of this relationship remains unclear, many studies have characterized differences in S. aureus between individuals with AD and unaffected controls. Patients with AD have higher cutaneous colonization with S. aureus, with increased bacterial density correlating with AD severity. S. aureus virulence factors can exacerbate the immune dysregulation seen in AD. Consequently, AD treatments have shifted to focus on S. aureus as a therapeutic target, including skin bacterial transplant and probiotics. In addition, traditional mainstays of AD treatment, such as corticosteroids, have been found to induce changes in the cutaneous microbiota and S. aureus levels, underscoring its importance in the pathogenesis of AD. Nonpharmacological treatments have been investigated as well, without definitive results. Both bacteriotherapy and nonpharmacological treatments merit continued study on their effects on S. aureus colonization and role in the treatment of AD.
Clinical Skin Examination for Melanoma in Underserved Patients
Authors: Diesner Kyla J. , Stratton Delaney B. , Flamm Kristie L. , Bouchard Lindsay A. , Loescher Lois J.
Published: April 2021

Purpose

The aim of this study was to educate primary care providers (PCPs), including family nurse practitioners (FNPs), about clinical skin examination (CSE) for melanoma in underserved patients using a digitally delivered video intervention. CSE was defined as melanoma risk assessment, head-to-toe skin examination, and skin lesion assessment.

Background

Skin cancer is the most common cancer in the United States; melanoma is the deadliest type. PCPs do not typically perform CSE. Little is known about how PCPs learn about or conduct CSE for their underserved patients.

Methods

The information–motivation–behavioral skills (IMB) model guided this quality improvement project. All 14 PCPs employed in one federally qualified health center's six regional clinics were recruited. Participants completed an online pretest of the IMB model, the intervention (four brief videos covering melanoma in underserved populations and CSE), and an identical posttest 2 weeks postintervention.

Results

Data were analyzed using descriptive statistics. Six (42.9%) participants enrolled: All were FNPs (mean age = 39.83 years, mean years of PCP experience = 3.33). Scores for the IMB model all improved on posttest. Participants reported increased CSEs in practice (mean = 1.33–9.50).

Conclusion

The results show strong potential for a brief video intervention to improve FNPs' CSE skills and motivate them to use those skills with underserved patients.
“Youth Photovoice”: Promoting Youth-Driven Community Changes for HIV Prevention in Rural Malawi
Authors: Lofton Saria , Norr Kathleen F. , Jere Diana , Patil Crystal , Banda Chimwemwe
Published: April 2021

To meet the Joint United Nations Programme on HIV/AIDS global goal of no new HIV infections by 2030, it is imperative to reduce new infections among youth. Youth Photovoice was a 10-month, participatory, community-action research project developed to engage rural Malawi youth in an HIV prevention project focused on community-level outcomes. In this study, we describe how participants in Youth Photovoice engaged adults and community leaders to implement action plans, as well as the community and individual changes that occurred as a result of these collaborative efforts. Youth Photovoice participants, their parents, and local leaders in the community participated in focus groups and individual interviews. Community-level changes, such as moving initiation ceremonies to churches and changes to local business practices, were observed, along with increased community and parental involvement in youth monitoring for local events and activities. This youth-led project led to changes in the community environment that reduced exposure to situations supporting unsafe sex, uncovered ways that youth can lead collaborations with adults, and informed the implementation of plans for community action.
“Little Red Flags”: Barriers to Accessing Health Care as a Sexual or Gender Minority Individual in the Rural Southern United States—A Qualitative Intersectional Approach
Authors: Joudeh Layla , Harris Orlando O. , Johnstone Ethan , Heavner-Sullivan Smith , Propst Shantara K.
Published: April 2021

Sexual and gender minorities (SGMs) experience unique challenges when accessing sexuality and gender-affirming, safe health care services in the rural, southern United States. An identified gap in the literature is an intersectional, community-based approach to assessing the obstacles SGM individuals with intersecting identities experience when navigating comprehensive health services in rural southern communities in the United States; therefore, the present study used qualitative inquiry with an intersectional lens to describe these obstacles. The authors analyzed qualitative data from in-depth, semi-structured individual interviews with SGM individuals (N = 12). Common themes emerged that highlighted the compounding effects of the sociopolitical climate of the geographical area, religious attitudes toward SGMs, and the experience of racism. Findings of this study can inform health professions' academic curriculum, provider and support staff training, and implementation of policy that focuses on creating a diverse and inclusive health care delivery experience.
Myocardial injury in a pediatric patient with diabetic ketoacidosis
Authors: Shim Houn Joe , Yoo Byung Min , Jin Seon Mi , Kang Min Jae
Published: April 2021

Rationale:

Diabetic ketoacidosis (DKA) can cause several complications. Among them, cardiac complications are the most fatal and difficult to detect. Cardiac markers are prognostic factors for morbidity and mortality in adult patients with DKA. But, there have been very few discussed cases in pediatrics. We report a case of severe DKA in child with elevated cardiac enzymes and prolonged QT interval.

Patient concerns:

A 12-year-old girl admitted by nausea, vomiting, and lethargy for 1 day.

Diagnoses:

Her blood sugar level was initially undetectable by the capillary blood glucose meter, and blood gas analysis showed severe DKA with elevated cardiac enzymes and prolonged QT interval.

Interventions:

The patient was admitted to hospital and intensive intravenous fluid and regular insulin infusion were administered.

Outcomes:

After 5 days of supportive care, the patient was fully recovered, discharged, and followed up in an outpatient clinic.

Lessons:

Since the relationship between DKA and myocardial injury has not been clearly elucidated, pediatricians and emergency physicians should remain careful throughout the recovery time as it can lead to life-threatening conditions in various courses.
Clinical significance of apelin in the treatment of type 2 diabetic peripheral neuropathy
Authors: Xu Hua , Wang Qi , Wang Qian , Che Xuan Qiang , Liu Xue , Zhao Shumiao , Wang Shitao
Published: April 2021

Background:

Diabetic peripheral neuropathy (DPN) is one of the most common chronic complications of diabetes. As apelin is an adipocytokine closely associated with diabetes, this study explored the clinical significance of serum apelin levels in patients with type 2 DPN before and after treatment.

Methods:

In total, 44 patients with T2DM without DPN (non-DPN group), 41 patients with DPN who received antihyperglycemic treatment (DPN-A group), 44 patients with DPN who received antihyperglycemic treatment combined with nutritional neurotherapy (DPN-B group), and 40 healthy control individuals (NC group) were selected continuously enrolled in the present study. Enzyme-linked immunosorbent assays (ELISA) were performed to determine serum levels of apelin and tumor necrosis factor-α (TNF-α). Related apelin, fasting blood glucose (FBG), glycosylated hemoglobin A1c, TNF-α, body mass index, fasting C peptide, and nerve conduction velocity (NCV) were recorded in each group before and after treatment.

Results:

Serum levels of apelin and TNF-α were higher in patients with diabetes than those in the NC group, as well as in the DPN group as compared to the non-DPN group; furthermore, some NCV values were significantly reduced in the DPN group. After treatment, the serum levels of apelin, TNF-α, and FBG reduced in patients with diabetes; moreover, apelin levels were found significantly lower in the DPN-B group as compared to the DPN-A group, while some NCV values significantly increased in the DPN-B group. Apelin was negatively correlated with part of NCV values and positively correlated with TNF-α and FBG (P < .01).

Conclusion:

Our results show that the increase in serum apelin levels is an important clinical reference index for DPN, while a decrease indicates that the DPN treatment is effective.
Serum leptin level as a diagnostic and prognostic marker in infectious diseases and sepsis
Authors: Birlutiu Victoria , Boicean Loredana Camelia
Published: April 2021

Background:

Infections and sepsis are common causes of morbidity and mortality, with an increasing incidence worldwide. Leptin is involved in the inflammatory process and may modulate the cytokine production, immune cell proliferation and endothelial function. There are conflicting results regarding alterations of leptin levels in infectious diseases and the outcome from sepsis.

The aim of the current article is to provide an overview of the medical literature on the correlations between variations of leptin levels and infectious diseases and sepsis.

Methods:

We performed an extensive literature search in PubMed and Google Scholar databases, using keywords to identify articles related to leptin in infectious diseases and sepsis. Searches were referenced using medical subject headings that included “leptin,” “adipokines,” “sepsis,” “infectious diseases,” “leptin deficiency,” “leptin resistance” or “hyperleptinemia.” The language of publication, journal, or country were not included as limitation criteria.

Articles or abstracts containing adequate information, such as age, sex, anthropometric indices, clinical presentation, comorbidities, and management were included in the study, whereas articles with insufficient clinical and demographic data were excluded. We assessed the quality of the studies selected.

The final review of all databases was conducted on June 18, 2020.

Results:

We find the results from the current review to be of great importance due to the possible therapeutic role of leptin analogs in states of leptin deficiency associated with infectious diseases or sepsis.

In hyperleptinemia, a therapeutic plan for obtaining leptin neutralization also needs further investigations. This could lead to the reduction of proinflammatory responses.

There is a need for further studies to demonstrate the specificity and sensitivity of leptin in the early diagnosis of sepsis and the need to measure serum leptin levels in routine evaluation of the critical patient.

Conclusion:

The multiple effects of leptin are of growing interest, but further studies are needed to elucidate the role of leptin signalling in infectious diseases and sepsis. Because very few human studies are reported, we recommend the need for further research.

Better understanding of the pathophysiology of sepsis and the implication of circulating total leptin in this process could help physicians in managing this life-threatening condition.
Postrecurrence Survival After Liver Transplantation for Liver Metastases From Neuroendocrine Tumors
Authors: Sposito Carlo , Rossi Roberta Elisa , Monteleone Michela , Coppa Jorgelina , Bongini Marco , Milione Massimo , Bhoori Sherrie , Mazzaferro Vincenzo
Published: April 2021

Background.

Liver metastases from neuroendocrine tumors (NETs) are an accepted indication for liver transplantation (LT). Despite strict patient selection, post-LT recurrence is observed in 30%–50% of cases. Postrecurrence survival is poorly investigated as well as factors influencing postrecurrence outcomes.

Methods.

Consecutive patients treated at a single institution for post-LT recurrence of NET between January 1, 2004, and December 31, 2018, were included. Baseline patients’ characteristics, data on the primary tumor, pretransplant therapies, posttransplant recurrence and treatments, and long-term outcomes were prospectively collected and retrospectively analyzed.

Results.

Thirty-two patients presented with post-LT NET recurrence occurring 82.9 mo (interquartile range, 29.4–119.1 mo) from LT, and the most common sites were abdominal lymph nodes (59.4%), peritoneum (6.3%), and lungs (6.3%). Fourteen patients (43.8%) underwent surgery with radical intent. Five- and 10-y survival after recurrence were 76.3% and 45.5%, respectively. Only time from LT to recurrence had a significant impact on postrecurrence survival, being 5-y overall survival 89.5% versus 0% for patients recurring >24 mo after LT versus ≤24 mo, respectively (P = 0.001). Moreover, for patients with Ki-67 monoclonal antibody staining >2% at recurrence, 5 y overall survival was 87.5% versus 0% for those undergoing surgery versus locoregional or systemic treatments (P = 0.011).

Conclusions.

The presented results, although based on a retrospective and relatively small series, show that excellent long-term survival is observed after post-LT NET recurrence, particularly in those patients recurring long after LT (>24 mo). An aggressive surgical treatment might result in a new chance of cure for a selected subgroup of patients.
Transcranial Direct Current Stimulation Electrode Montages May Differentially Impact Variables of Walking Performance in Individuals Poststroke: A Preliminary Study
Authors: Seamon Bryant A. , Bowden Mark G. , Kindred John H. , Embry Aaron E. , Kautz Steven A.
Published: April 2021

Purpose:

Transcranial direct current stimulation (tDCS) has mixed effects on walking performance in individuals poststroke. This is likely the result of variations in tDCS electrode montages and individualized responses. The purpose of this study was to quantify the effects of a single session of tDCS using various electrode montages on poststroke walking performance.

Methods:

Individuals with chronic stroke (n = 16) participated in a double-blind, randomized cross-over study with sham stimulation and three tDCS electrode montages. Gait speed, paretic step ratio, and paretic propulsion were assessed prestimulation and poststimulation at self-selected and fastest comfortable speeds. Changes in muscle activation patterns with self-selected walking were quantified by the number of modules derived from nonnegative matrix factorization of EMG signals for hypothesis generation.

Results:

There was no significant effect of active stimulation montages compared with sham. Comparisons between each participant's best response to tDCS and sham show personalized tDCS may have a positive effect on fastest comfortable overground gait speed (P = 0.084), paretic step ratio (P = 0.095) and paretic propulsion (P = 0.090), and self-selected paretic step ratio (P = 0.012). Participants with two or three modules at baseline increased module number in response to the all experimental montages and sham, but responses were highly variable.

Conclusions:

A single session of tDCS may affect clinical and biomechanical walking performance, but effects seem to be dependent on individual response variability to different electrode montages. Findings of this study are consistent with responses to various tDCS electrode montages being the result of underlying neuropathology, and the authors recommend examining how individual factors affect responses to tDCS.
Long-Term Risk of Developing Dementia After Electroconvulsive Therapy for Affective Disorders
Authors: Hjerrild Simon , Kahlert Johnny , Buchholtz Poul-Erik , Rosenberg Raben , Videbech Poul
Published: April 2021

Objectives

Severe depression is associated with an increased risk of developing dementia, however, whether treatment with electroconvulsive therapy (ECT) modify this risk remains unknown.

Methods

In this matched cohort study, 1089 consecutive in-patients with affective disorders, receiving ECT during the period 1982 to 2000, were matched with 3011 in-patients with affective disorders not treated with ECT (non-ECT), and 108,867 individuals randomly selected from the background population. The comparison cohorts were matched on sex, age, and the non-ECT cohort was further matched according to diagnoses and admission period and hospital. Dementia diagnoses were retrieved from the national patient health registry. Analyses were adjusted for disease severity, somatic, and psychiatric comorbidities.

Results

The cumulative incidence of dementia was 13.45% (10.75–16.46%) in the ECT cohort after 34 years of follow-up, 10.53% (8.5–12.81%) in the non-ECT cohort, and 8.43% (8.17–8.7%) in the background cohort. Using the ECT cohort as reference and age as the underlying time scale, the adjusted hazard ratio of developing dementia was 0.73 (0.52–1.04) in the non-ECT cohort and 0.61 (0.49–0.76) in the background cohort. The stratified analysis based on age at index (<65 years; 65–80 years; >80 years) found no age-related difference in the risk of developing dementia between the ECT cohort and non-ECT cohort.

Conclusions

The ECT treatment of affective disorders was not associated with an increased long-term risk of developing dementia compared with in-patients with affective disorders not treated with ECT.
Synthesis of self-assembled hierarchical AlPO-34 microspheres by using an ionic liquid and its application in heavy metal removal
Authors: Zhou Liang , Li Hongjian , Han Runlin
Published: April 2021

Hierarchical AlPO-34 molecular sieves microspheres were synthesized in a [BMIm]Br ionic liquid without template or complex post-treatment process. The formation mechanism of such framework structures and their morphology were investigated. [BMIm]Br was proven to serve as both solvent and sole provider of the structure directing agent. The organic amine in the compound affects the framework density of the crystals and promotes the formation of a chabazite (CHA) type framework. After ageing for 1 h the AlPO-34 microspheres are formed due to the aggregation properties of the ionic liquid. The hierarchical mirosphere has a relatively high Brunauer–Emmett–Teller surface area and a considerably uniform mesoporous channel network. The hierarchical AlPO-34 microspheres were used as absorbers of heavy metal cations and showed a higher loading capacity and distribution coefficient compared with the AlPO-34-NH.
Control theory helps to resolve the measles paradox
Authors: Anelone Anet J. N. , Hancock Edward J. , Klein Nigel , Kim Peter , Spurgeon Sarah K.
Published: April 2021

Measles virus (MV) is a highly contagious respiratory morbillivirus that results in many disabilities and deaths. A crucial challenge in studying MV infection is to understand the so-called ‘measles paradox’—the progression of the infection to severe immunosuppression before clearance of acute viremia, which is also observed in canine distemper virus (CDV) infection. However, a lack of models that match
in vivo
data has restricted our understanding of this complex and counter-intuitive phenomenon. Recently, progress was made in the development of a model that fits data from acute measles infection in rhesus macaques. This progress motivates our investigations to gain additional insights from this model into the control mechanisms underlying the paradox. In this paper, we investigated analytical conditions determining the control and robustness of viral clearance for MV and CDV, to untangle complex feedback mechanisms underlying the dynamics of acute infections in their natural hosts. We applied control theory to this model to help resolve the measles paradox. We showed that immunosuppression is important to control and clear the virus. We also showed under which conditions T-cell killing becomes the primary mechanism for immunosuppression and viral clearance. Furthermore, we characterized robustness properties of T-cell immunity to explain similarities and differences in the control of MV and CDV. Together, our results are consistent with experimental data, advance understanding of control mechanisms of viral clearance across morbilliviruses, and will help inform the development of effective treatments. Further the analysis methods and results have the potential to advance understanding of immune system responses to a range of viral infections such as COVID-19.
Problem solving in European bison (Bison bonasus): two experimental approaches
Authors: Caicoya Alvaro L. , Colell Montserrat , Ensenyat Conrad , Amici Federica
Published: April 2021

The ability to solve novel problems is crucial for individual fitness. However, studies on problem solving are usually done on few taxa, with species with low encephalization quotient being rarely tested. Here, we aimed to study problem solving in a non-domesticated ungulate species, European bison, with two experimental tasks. In the first task, five individuals were presented with a hanging barrel filled with food, which could either be directly accessed (control condition) or which could only be reached by pushing a tree stump in the enclosure below it and stepping on it (experimental condition). In the second task, five individuals were repeatedly fed by an experimenter using a novel bucket to retrieve food from a bag. Then, three identical buckets were placed in the enclosure, while the experimenter waited outside with the bag without feeding the bison, either with a bucket (control condition) or without it (experimental condition). In the first task, no bison moved the stump behind the barrel and/or stepped on it to reach the food. In the second task, two individuals solved the task by pushing the bucket within the experimenter's reach, twice in the experimental and twice in the control condition. We suggest that bison showed a limited ability to solve novel problems, and discuss the implications for their understanding of the functional aspects of the tasks.
Graphite phases in chemical vapour deposited grown ZrC/graphite layers
Authors: Pretorius Jan A. , Malherbe Johan B.
Published: April 2021

The graphitic phases detected in chemical vapour deposited (CVD) ZrC layers were characterized by glancing angle X-ray diffraction. The layers were deposited at different temperatures ranging from 1250 to 1450°C in steps of 50°C. The precursors used were ZrCl
4
and CH
4
in the presence of hydrogen and argon. A total of seven graphitic phases were detected, five of which have been reported in the literature. However, two new hexagonal graphitic phases, P-6m2 (187) and P-62c (190), were also detected. It is proposed that the appearance of these two (new) phases was due to the influence of impurities in the growth region on the growth kinetics. A comprehensive phase identification process was followed to index all observed diffraction lines, followed by Rietveld analysis, to report on phase composition and crystalline properties. A distinct increase in overall graphite phase composition is observed at the higher CVD temperatures, which confirms the impact from graphitization.
Towards quantifying the mass extinction debt of the Anthropocene
Authors: Spalding Christopher , Hull Pincelli M.
Published: April 2021

To make sense of our present biodiversity crises, the modern rate of species extinctions is commonly compared to a benchmark, or ‘background,’ rate derived from the fossil record. These estimates are critical for bounding the scale of modern diversity loss, but are yet to fully account for the fundamental structure of extinction rates through time. Namely, a substantial fraction of extinctions within the fossil record occurs within relatively short-lived extinction pulses, and not during intervals characterized by background rates of extinction. Accordingly, it is more appropriate to compare the modern event to these pulses than to the long-term average rate. Unfortunately, neither the duration of extinction pulses in the geological record nor the ultimate magnitude of the extinction pulse today is resolved, making assessments of their relative sizes difficult. In addition, the common metric used to compare current and past extinction rates does not correct for large differences in observation duration. Here, we propose a new predictive metric that may be used to ascertain the ultimate extent of the ongoing extinction threat, building on the observation that extinction magnitude in the marine fossil record is correlated to the magnitude of sedimentary turnover. Thus, we propose that the ultimate number of species destined for extinction today can be predicted by way of a quantitative appraisal of humanity's modification of ecosystems as recorded in sediments—that is, by comparing our future rock record with that of the past. The ubiquity of habitat disruption worldwide suggests that a profound mass extinction debt exists today, but one that might yet be averted by preserving and restoring ecosystems and their geological traces.
Social consequences of energetically costly nest construction in a facultatively social bee
Authors: Ostwald Madeleine M. , Fox Trevor P. , Harrison Jon F. , Fewell Jennifer H.
Published: April 2021

Social groups form when the costs of breeding independently exceed fitness costs imposed by group living. The costs of independent breeding can often be energetic, especially for animals performing expensive behaviours, such as nest construction. To test the hypothesis that nesting costs can drive sociality by disincentivizing independent nest founding, we measured the energetics of nest construction and inheritance in a facultatively social carpenter bee (Xylocopa sonorinaSmith), which bores tunnel nests in wood. We measured metabolic rates of bees excavating wood and used computerized tomography images of nesting logs to measure excavation volumes. From these data, we demonstrate costly energetic investments in nest excavation of a minimum 4.3 kJ per offspring provisioned, an expense equivalent to nearly 7 h of flight. This high, potentially prohibitive cost of nest founding may explain why females compete for existing nests rather than constructing new ones, often leading to the formation of social groups. Further, we found that nest inheritors varied considerably in their investment in nest renovation, with costs ranging more than 12-fold (from 7.08 to 89.1 kJ energy), probably reflecting differences in inherited nest quality. On average, renovation costs were lower than estimated new nest construction costs, with some nests providing major savings. These results suggest that females may join social groups to avoid steep energetic costs, but that the benefits of this strategy are not experienced equally.
Can an introduced predator select for adaptive sex allocation?
Authors: Heinsohn R. , Au J. , Kokko H. , Webb M. H. , Deans R. M. , Crates R. , Stojanovic D.
Published: April 2021

Most species produce equal numbers of sons and daughters, and sex differences in survival after parental care do not usually affect this pattern. Temporary overproduction of the scarcer sex can be adaptive when generations overlap, the sexes differ in life-history expectations, and parents can anticipate future mating opportunities. However, an alternative strategy of maximizing the competitiveness of the more abundant sex in these circumstances remains unexplored. We develop theory showing how mothers can maximize reproductive value when future mate competition will be high by producing more sons in the advantageous early hatching positions within their broods. Our model for optimal birth order was supported by long-term data of offspring sex in a parrot facing catastrophic female mortality caused by introduced predators. Swift parrots (
Lathamus discolor
) suffer high female mortality due to introduced sugar gliders (
Petaurus breviceps
) creating fluctuating male-biased adult sex ratios. Offspring hatched early within broods fledged in better condition, and in support of our model were more likely to be male in years with higher adult female mortality. We found a highly significant rank-order correlation between observed and predicted birth sex ratios. Our study shows the potential for mothers to maximize reproductive value via strategic biases in offspring sex depending on the advantages conferred by birth order and the predictability of future mate competition. Our long-term data support the predictions and appear to suggest that sex allocation strategies may evolve surprisingly quickly when anthropogenic pressures on populations are severe.
Disentangling the mechanisms linking dispersal and sociality in supergene-mediated ant social forms
Authors: Fontcuberta Amaranta , De Gasperin Ornela , Avril Amaury , Dind Sagane , Chapuisat Michel
Published: April 2021

The coevolution between dispersal and sociality can lead to linked polymorphisms in both traits, which may favour the emergence of supergenes. Supergenes have recently been found to control social organization in several ant lineages. Whether and how these ‘social supergenes’ also control traits related to dispersal is yet unknown. Our goal here was to get a comprehensive view of the dispersal mechanisms associated with supergene-controlled alternative social forms in the antFormica selysi.We measured the production and emission of young females and males by single-queen (monogyne) and multiple-queen (polygyne) colonies, the composition of mating aggregations, and the frequency of crosses within and between social forms in the wild. We found that males and females from alternative social forms did not display strong differences in their propensity to leave the nest and disperse, nor in their mating behaviour. Instead, the social forms differed substantially in sex allocation. Monogyne colonies produced 90% of the females flying to swarms, whereas 57% of the males in swarms originated from polygyne colonies. Most crosses were assortative with respect to social form. However, 20% of the monogyne females did mate with polygyne males, which is surprising as this cross has never been found in mature monogyne colonies. We suggest that the polygyny-determining haplotype free rides on monogyne females, who establish independent colonies that later become polygyne. By identifying the steps in dispersal where the social forms differ, this study sheds light on the behavioural and colony-level traits linking dispersal and sociality through supergenes.
Macroevolution of dimensionless life-history metrics in tetrapods
Authors: Babich Morrow Cecina , Ernest S. K. Morgan , Kerkhoff Andrew J.
Published: April 2021

Life-history traits represent organisms' strategies to navigate the fitness trade-offs between survival and reproduction. Eric Charnov developed three dimensionless metrics to quantify fundamental life-history trade-offs. Lifetime reproductive effort (LRE), relative reproductive lifespan (RRL) and relative offspring size (ROS), together with body mass can be used to classify life-history strategies across the four major classes of tetrapods: amphibians, reptiles, mammals and birds. First, we investigate how the metrics have evolved in concert with body mass within tetrapod lineages. In most cases, we find evidence for correlated evolution among body mass and the three dimensionless metrics. Second, we compare life-history strategies across the four classes of tetrapods and find that LRE, RRL and ROS delineate a space in which the major tetrapod classes occupy mostly unique subspaces. These distinct combinations of life-history strategies provide us with a framework to understand the impact of major evolutionary transitions in energetics, physiology and ecology.
Recurrent speciation rates on islands decline with species number
Authors: Yamaguchi Ryo , Iwasa Yoh , Tachiki Yuuya
Published: April 2021

In an archipelagic system, species diversity is maintained and determined by the balance among speciation, extinction and migration. As the number of species increases, the average population size of each species decreases, and the extinction likelihood of any given species grows. By contrast, the role of reduced population size in geographic speciation has received comparatively less research attention. Here, to study the rate of recurrent speciation, we adopted a simple multi-species two-island model and considered symmetric interspecific competition on each island. As the number of species increases on an island, the competition intensifies, and the size of the resident population decreases. By contrast, the number of migrants is likely to exhibit a weaker than proportional relationship with the size of the source population due to rare oceanic dispersal. If this is the case, as the number of species on the recipient island increases, the impact of migration strengthens and decelerates the occurrence of further speciation events. According to our analyses, the number of species can be stabilized at a finite level, even in the absence of extinction.