bluuebunny/crossref_metadata_2025 huggingface dataset:
Depressão e ansiedade em adultos e idosos com síndrome de Down: Resultados preliminares de um estudo prospectivo no Brasil
Authors: Soares Cristiane Nogueira Rigoleto , Forlenza Orestes Vicente
Published: December 2020

Background

The study was conducted at a non‐governmental institution (APAE‐SP) dedicated to providing care and social inclusion for individuals with ID in São Paulo, Brazil.

Method

Twenty‐seven physically healthy young and older adults with DS (mean age: 38; range: 24‐60 years) of both genders (44,4% of females) were evaluated between March and June 2018 by a psychogeriatric team with the aid of the Glasgow Scale for Depression and Anxiety. This instrument encompasses 20 illustrated questions addressing the presence of depression symptoms (GS‐D), and 27 addressing anxiety symptoms (GS‐A). Each question yields three possible answers which may be scored as 0 (symptom absent), 1 (possible) and 2 (present). In the GS‐D subscale, a score of 13 or higher (out of a maximum score of 60 points) indicates the presence of depression, whereas the cut‐off for suspected cases according to the GS‐A subscale is 15 points (max. 81). Overall results obtained for each participant in the Glasgow Scale were cross‐validated with the informant’s report obtained by the CAMDEX‐DS schedule, reinforcing the perception of change in behavioral patterns of subjects with DS.

Results

44.4% (n=12) of the GS‐D respondents had evidence of depressive symptoms (mean score 13,2; range 0 ‐60), and 53.8% (n=14) of the GS‐A respondents had anxiety symptoms (mean score 14,7; range 0‐81). The major concern in the former group was related to the fear of death of their relatives, legal guardians and/or caregivers; anxiety symptoms were associated with the perception of lack of perspectives in their lives and inability to cope with future demands.

Conclusion

The present study indicates the presence of depression and anxiety symptoms in a large proportion of adults with DS, corroborating previous studies and emphasizing the need for the systematic assessment of psychiatric symptoms in this population. The relationship between psychiatric symptoms and incident cognitive decline is yet to be determined.
College students' attitudes towards physician‐assisted death for persons with dementia
Authors: Mashal Rachel , Santulli Robert B
Published: December 2020

Background

The number of persons with dementia is expected to increase by 50% in the next 10 years, yet there is still no cure for this devastating disease (World Health Organization, 2018). The Netherlands, Belgium, and Switzerland have legalized physician assisted death (PAD) for persons with dementia; however, no states in the U.S. have done so (Menzel & Steinbock, 2013). PAD is a controversial topic that has been subject to clinical, ethical and political debate (Emanuel et al., 2000). There is research investigating the fundamental consideration of whether PAD should be considered at all in cases of dementia (Tomlinson & Scott, 2014); however, there is a lack of research focused on answering the question: under what conditions is PAD deemed acceptable for persons with dementia? This study aimed to fill that gap. This study consisted of a survey that assessed students’ attitudes towards PAD across 16 different vignettes. 128 Dartmouth College undergraduate students completed the survey. An ordinal logistical regression analysis revealed that the gender and age of the person with dementia does not significantly affect attitudes towards PAD while illness severity and frequency of requesting PAD do. ANOVA analyses revealed that student gender and family history of dementia do not affect overall acceptability of PAD, but religious affiliation does. Atheists are more accepting of PAD than those who identify with a religious faith, and those identify as “very religious” are significantly less accepting of PAD than those who identify as less religious. The results of this study elucidate the factors that college students view as important in medical decision‐making for persons with dementia.
Influence of systemic immune responses in the brain after wound injury of tail amputation in zebrafish
Authors: Chen Xiang‐Ke , Ma Alvin Chun‐Hang , Chang Raymond Chuen‐Chung
Published: December 2020

Background

Increasing lines of evidence demonstrate that systemic immune responses triggered by either sterile or infectious inflammation can activate neuroimmune responses, resulting in developing Alzheimer’s pathology, such as phosphorylation of tau protein. Systemic inflammation can be a risk factor for developing cognitive dysfunctions and even Alzheimer’s disease. We have been using a laboratory murine model, laparotomy, to demonstrate that systemic immune responses stimulate production of cytokines and activation of microglia in the brain. However, it is still unclear how systemic monocytes/macrophages responses after sterile inflammation. As zebrafish embryo has transparent body that suitable for imaging monocytes/macrophages, we aim to use zebrafish and tail amputation for investigating which factor can affect the influence of systemic inflammation in the brain.

Method

Zebrafish was used as experimental model. Tg(coro1a:DsRed) transgenic fish was used to monitor microglia and macrophages. Tg(mpx:mCherry) was used for monitoring neutrophils, Tg(mepg1:GFP) was used for monitoring macrophages. We have used TALEN method to make knockout or mutation of IL‐1b in zebrafish. Quantitative PCR and immunohistochemical staining were used for examination. Acridine orange and TUNEL were employed for labeling apoptotic cells. Tail amputation was performed at day 3 of embryos under anesthetization with tricaine.

Result

Tail amputation recruited accumulation of monocytes/macrophages into the wound site in zebrafish tail. Surprisingly, increased number of macrophages and microglia were also found in the brain, which was tissue specific as no other organs showed similar phenomenon. Expression of mRNA for different cytokines was examined in the brain. Among which, IL‐1b was significantly increased. Therefore, we prepared IL‐1b knockout and mutated zebrafish. After amputation, the number of macrophages in the brain did not show any significant increase. To further understand why monocytes/macrophages migrate into the brain after peripheral wound injury, we found increased number of apoptotic cells in the brain after wound injury. IL‐1b had a key role in regulating migration of monocytes/macrophages.

Conclusion

Our study demonstrated that zebrafish is a good animal model to investigate how peripheral wound injury triggers neuroimmune responses. IL‐1b is a key player to regulate migration of monocytes/macrophages into the brain.
Chronic oral administration of a novel estrogen receptor beta agonist enhances memory consolidation and alleviates vasomotor symptoms in a mouse model of menopause
Authors: Fleischer Aaron W , Schalk Jayson C , Wetzel Edward A , Hanson Alicia M , Sem Daniel S , Donaldson William A , Frick Karyn M
Published: December 2020

Background

Women are at greater risk of Alzheimer’s Disease (AD) than men, and symptoms associated with the menopausal loss of circulating estrogens, including hot flashes, exacerbate cognitive decline and AD risk. Although estrogen‐based therapies reduce hot flashes and mitigate AD risk early in the menopausal transition, these treatments can increase risks of cancer, among other health issues. These adverse effects are mediated by the alpha (ERα), but not beta (ERβ), estrogen receptor isoform. Moreover, activation of ERβ facilitates memory formation and reduces hot flashes. Thus, ERβ‐selective therapies may promote memory function, reduce hot flashes, and diminish AD risk without complications associated with ERa. Our goal here was to determine whether chronic treatment with EGX358, a novel highly selective ERβ agonist developed by our group, could enhance memory and reduce hot flash‐like symptoms in a mouse model of menopause.

Methods

Eight‐week‐old ovariectomized C57BL/6 mice were orally gavaged each day for 10 weeks with vehicle, the highly potent estrogen 17β‐estradiol (E2; equal affinity for ERα and ERβ), the commercially available ERβ agonist diarylpropionitrile (DPN), or EGX358 (∼10x greater selectivity for ERβ than DPN). Compounds were administered at doses that enhance memory when delivered acutely. After two weeks of treatment, hot flash‐like symptoms were tested after subcutaneous injection of vehicle or senktide, a tachykinin receptor 3 agonist that induces hot flash‐like symptoms. Tail skin temperature was then recorded using a thermal camera for 30 minutes as a proxy for vasodilation. Six weeks later, mice were trained in object recognition (OR) and object placement (OP) tasks to test object and spatial memory, respectively. Memory in the OR and OP tasks was tested 48 and 24 hours later, respectively.

Results

E2, DPN, or EGX358 treatment reduced the senktide‐mediated increase in tail skin temperature. Furthermore, treatment with E2, DPN, or EGX358, but not vehicle, enhanced memory in the OR and OP tasks.

Conclusions

These data suggest that chronic EGX358 treatment can reduce hot flash‐like symptoms and improve spatial and object recognition memories. Therefore, ERβ activation may be a promising avenue for reducing menopause‐related hot flashes, memory dysfunction, and AD risk.
New evidence reveals weakening of association between language and thought in aMCI versus in normal aging
Authors: Sherman Janet C. , Flynn Suzanne , Henderson Charles , Lust Barbara
Published: December 2020

Background

Clinical manifestation of prodromal AD is typically evaluated through measures that assess individual cognitive domains with less focus on their relationship. Further, while decades of research identify deterioration in episodic memory as well as semantic aspects of language, there has been less focus on other aspects of linguistic computation. We provide evidence that advances our understanding of how language deficits in aMCI extend to sentence production, and how relations between performances in cognitive functions, specifically language and cognition, may differ in aMCI vs. Healthy Aging (HA).

Method

We tested 24 individuals diagnosed with aMCI based on neurologic and neuropsychological evaluations, and 22 older adults with normal cognition (Healthy Aging (HA). All subjects were administered a multi‐domain cognitive screen (ACE‐R) and a psycholinguistic assessment of complex sentence production. The ACE‐R provided a Total Score and scores on attention and orientation, memory, fluency, language, and visuospatial measures (Mioshi et al 2006, Hsieh et al 2013, Monsch et al 1994).) The psycholinguistic test assessed Elicited Imitation of complex sentences with relative clauses (RC) in an experimental design varying syntactic and semantic factors (Table 1) (Lust et al 2017).

Result

ACE‐R Total score was significantly lower for aMCI than HA. aMCI also performed significantly worse than HA on the psycholinguistic test (Table 2). For HA, not aMCI, ACE‐R Total score significantly predicted successful sentence production on the psycholinguistic test (Table 3) (Figure 1). Similarly, for HA, not aMCI, the ACE‐R language score significantly predicted psycholinguistic test performance. In contrast, ACE‐R memory performance, which was significantly lower for aMCI than HA, did not predict linguistic performance for either group. Only ACE‐R phonemic fluency predicted linguistic performance for both groups. (Table 3).

Conclusion

Results suggest a weakening of associations between overall cognitive performance and performance on a linguistic measure for aMCI relative to HA suggesting that evaluation of associations between, not only within, cognitive domains strengthen detection of early changes in AD. This finding may be further expanded by linking this clinical manifestation to neuroscientific evidence of functional connectivity in AD pathophysiology and in normal aging (e.g., Brier et al 2014, Spreng and Turner 2013).
The calcium‐containing smooth endoplasmic reticulum is a focus of risk factors for early‐ and late‐onset Alzheimer’s disease
Authors: Datta Dibyadeep , Mentone SueAnn , Morozov Yury , van Dyck Christopher H , Arnsten Amy FT
Published: December 2020

Background

Calcium dysregulation may be an important etiological event in Alzheimer’s Disease (AD). The presenilins (PS1/PS2) are components of the calcium‐storing smooth endoplasmic reticulum (SER), and PS1/PS2 mutations that cause autosomal dominant AD cause calcium leak from the SER. Recent studies of medial temporal lobe from animal models and patients with late‐onset AD have also found evidence of calcium leak from SER through PKA‐phosphorylated ryanodine receptors (pS2808RyR2). Thus, the SER may be a nexus for AD pathology. The current research used immunoelectron microscopy to visualize the SER in the aging rhesus monkey dorsolateral prefrontal cortex (dlPFC), a newly evolved brain region which subserves higher cognition and is vulnerable in AD. As aging increases calcium‐PKA signaling in dlPFC, we looked for evidence of pS2808RyR2, as well as PKA‐phosphorylated tau (pS214Tau), and for changes in the cAMP‐PKA regulatory protein, PDE4Ds. Finally, we examined the location of TREM2, a genetic risk factor for late‐onset AD that is linked to microglia, but was also observed on neuronal SER in the current study.

Method

We used high‐spatial resolution immunoEM to localize PDE4D, pS2808RyR2, pS214Tau and TREM2 in aging rhesus monkey dlPFC.

Result

The data show that the SER is a focus of age‐related pathology in association cortex, with loss of PDE4D from the SER in spines and dendrites, and increased PKA phosphorylation of pS2808RyR2, which causes calcium “leak”. We also find evidence of increased PKA phosphorylation of pS214tau aggregating on the SER and microtubules, an important step that causes tau to detach from microtubules and aggregate, and primes tau for hyperphosphorylation and neurofibrillary tangle formation. Finally, we found TREM2 focused on the SER in spines and dendrites in neurons in addition to its expected location in glia. Thus, early‐onset (PS1/PS2), late‐onset (TREM2) and aging, all target the SER in the association cortical synapses most vulnerable to AD pathology.

Conclusion

This nexus of genetic risks supports the hypothesis that calcium dysregulation is a key factor in AD neurodegeneration, an underappreciated mechanism in the AD field. Regulating internal calcium signaling in the aging cortex may provide an opportunity for therapeutic intervention at early stages of pathology.
Public, family and health staff dementia knowledge: A multicentric study
Authors: Gallo Maria Fernanda , Deschle Florencia , Berrios Waleska , Tabernero Maria Eugenia , Cores Evangelina Valeria , Peiretti Ursula , Ramirez Linda Calderon , Bustos Claudia
Published: December 2020

Background

There are currently no studies in Argentina that measures the knowledge of all types of dementia. Given the increasing prevalence of this disease, knowing the level of knowledge could be useful to provide psychoeducation tools, allowing better understanding, objetive setting and daily managment of dementia. The aim of this study is to evaluate dementia knowledge among general population, families and health staff.

Method

Dementia knowledge will be assessed whith the Dementia Knowledge Assessment Tool 2 (DKAT‐2), validated in Spanish by Parra‐Anguita et al. (2018). DKAT‐2‐Sp has 21 items, with three response optiones (Yes, No, I don’t know). The questionnaire will be distributed in form throught virtual platforms. Statistic data will be analyzed with SPSS.

Result

We expect a participation of no less than 300 respondents. Toye et. al (2013) administered DKAT‐2 in familiies and care staff, obteining a median of 14 correct responses for familires, and 16 for the staff. In 2018, Parra‐Anguita et. al evaluated dementia knowledge with DKAT‐2‐ Sp in nursing professionals and students, obtaining a mean of 15.57 in staff versus 12.85 in students, with very significant differences in incontinence, visual perception, distressing behaviors and swallowing difficulties items. For the current study, we will include general population, predicting similar results, with highest scores to be obtained by health care professionals, comparatively lower scores by family carers and lowest scores among the general population.

Conclusion

the results could be usefull to detect areas of intervention and provide psychoeducations tools for better understanding dementia.
Effects of art therapy on agitation in elderly people with dementia: An integrative review
Authors: Laranjeira Carlos
Published: December 2020

Background

The agitation behaviors manifested by the elderly are, in most cases, controlled by antipsychotic medication. However, there are several associated side effects such as: increased cognitive decline, increased risk of a stroke and even death. In terms of cognitive functions and behavioral problems, pharmacological interventions have minimal benefits and concerns about the harmful side effects caused by these antipsychotic drugs have made non‐pharmacological interventions take on a very important role. Thus, in the search for non‐pharmacological interventions to alleviate behavioral problems, special attention was paid to art therapy, which is one of the most recommended interventions.

Method

This integrative review was aimed to systematize the available evidence about the effects of art therapy on agitation in elderly people with dementia in the period from 2010 to 2020. The final sample comprised 10 studies after research at Pubmed, ISI Web and Scopus. This review included experimental, randomized and non‐randomized studies, pre‐experimental studies and case studies. The Joanna Briggs Institute (JBI) checklist was used to assess methodological quality of papers.

Result

Most studies enrolled found that art therapy was effective in improving at least one parameter of agitation in elderly people with dementia. However, 6 studies have found that art therapy has shown no benefit in terms of agitation in people with dementia. The interventions used in the various studies varied widely, both in terms of how the technique was applied and in terms of duration. The measures used to assess the results of the interventions were, for the most part, subjective and, in some cases, the instruments were not validated for the population.

Conclusion

Still there is some evidence that seems to indicate some efficacy in the use of therapy by art as treatment of agitation in elderly people with dementia, the quality and heterogeneity of existing studies is limited, so it cannot be assumed that the use of a intervention using art therapy is effective in reducing agitation.
Role of mosaic aneuploidy in the development and progression of Huntington's disease
Authors: Elos Mihret , Caneus Julbert , Ahmed Md Mahiuddin , Markham Neil , Chial Heidi J , Potter Huntington
Published: December 2020

Background

Huntington disease (HD) is an autosomal dominant neurodegenerative disorder caused by a CAG trinucleotide repeat expansion mutation in the huntingtin (HTT) gene. HTT encodes the huntingtin protein, which has been shown to localize to spindle poles and is required for proper mitotic spindle orientation, chromosome segregation, and cell cycle regulation. Mutations in HTT lead to the production of a mature huntingtin protein with an expanded polyglutamine region (>35 repeats) at its N terminus. Previous studies have shown that mouse models of HD exhibit defects in microtubule function and in cell cycle regulation. HD is a progressive condition characterized by decline in cognitive and executive functions. Over the years, studies from our laboratory and others have shown elevated levels of aneuploidy in many neurodegenerative disorders that are characterized by cognitive deficits, including Alzheimer’s disease (AD) and frontotemporal lobar degeneration (FTLD). Here, we investigated whether chromosome segregation defects that lead to mosaic aneuploidy and consequent apoptosis may also contribute to neuronal loss in HD.

Method

Single cell suspensions were prepared from human brain samples (cortex and cerebellum) and fibroblast cell lines from HD donors and age‐matched controls and were processed for FISH analysis of human chromosome 21, NeuN immunostaining, and/or TUNEL staining. Single cell suspensions from cerebellum were prepared from mouse models of HD and age‐matched controls for FISH analysis of mouse chromosome 5 or 16, which is syntenic to human chromosome 21.

Result

We observed increased levels of mosaic aneuploidy and associated apoptosis in brain tissues and in cultured fibroblasts from HD donors compared to age‐matched controls. We also observed increased levels of mosaic aneuploidy in brain tissue from HD mice compared to age‐matched controls.

Conclusion

Together with our previous studies of AD and FTLD, these data provide evidence that chromosome segregation defects that lead to genomic instability may serve as a shared mechanism underlying many neurodegenerative disorders. Our findings highlight the need to further investigate the biological mechanism(s) underlying HD pathology and set the stage for novel therapeutic approaches to HD that may also be applied to other neurodegenerative disorders.
Effect of an art therapy and cognitive stimulation program in older adults with indicators of cognitive impairment
Authors: Lajo‐Alvarez Ricardo , Herrera‐Arias Leslie , Soto Marcio
Published: December 2020

Background

Neurodegenerative disease affects the cognitive, behavioral and functional status in older people. Non pharmacological interventions has shown improvement in cognitive, emotional and functional performance. For this reason, we set out to analyze the effect of a combined nonpharmacological intervention program of cognitive stimulation (CS) and art therapy (AT).

Method

A mixed factorial quasi‐experimental repeated measures design was used. 127 older adults were evaluated with clinical screening tests. Twenty‐seven participants were selected to whom a neuropsychological battery composed of measures of memory, executive function, verbal fluency and attention. The final group was made up of 13 participants who were divided into two homogeneous groups (Group 1, n = 6 and Group 2, n = 7). The treatment was applied to each group in parallel with 18 sessions (G1 = CS, G2 = AT), after which an intermediate neuropsychological evaluation was carried out. Later the treatments were changed (G1 = AT, G2 = CS). Finally, a cognitive evaluation was carried out in both groups.

Result

The results show that both groups had a significant improvement in working memory and semantic and phonological fluency tasks after cognitive and art therapy intervention. These improvements were maintained after the second treatment, being more noticeable in the group that started with CS and continued with art therapy.

Conclusion

These results show us the importance of working with non‐pharmacological strategies for the treatment of patients with indicators of cognitive impairment and the importance of working on combined interventions to improve the cognitive and functional status.
Potential drug interactions between hydroxychloroquine and anticholinesterase drugs
Authors: Santos Gustavo AA
Published: December 2020

Background

One of the main aggravating factors in the Covid‐19 pandemic is the lack of effective treatments capable of promoting a cure to date. Unfortunately, contrary to the recommendations of WHO and health authorities, in Brazil the use of Hydroxychloroquine in the treatment of SarsCov‐2 has been approved.

Method

We selected guidelines with recommendations for treatment of Covid 19, with an emphasis on the proposed treatments. Then we evaluate the main drug interactions and their potential risks.

Result

The risk of using Hydroxychloroquine in patients with Alzheimer's Disease is high, both due to the aspect of the disease itself, but also due to the drug interactions found.

Conclusion

Hydroxychloroquine is not recommended for patients with Alzheimer's Disease.
Pathological correlates of impaired self‐awareness of memory function in dementia
Authors: Gagliardi Geoffroy Pierre , Kuppe Madeline , Hanseeuw Bernard , Lois Cristina , Vannini Patrizia ,   Alzheimer’s Disease Neuroimaging Initiative
Published: December 2020

Background

Impaired self‐awareness of memory function (a.k.a. anosognosia) is a common symptom observed in Alzheimer’s disease (AD), however it’s pathological correlates remain unclear. Here we investigated the impact of amyloid and tau on memory self‐awareness in a cohort of clinically normal or impaired participants.

Method

This study included 216 clinically normal (CDR=0) and 156 clinically impaired (CDR≥0.5) participants part of the Alzheimer's Disease Neuroimaging Initiative (ADNI) project. Using the E‐Cog memory subscale, a participant‐informant discrepancy index was computed such that a negative score indicates a participant’s underestimation of difficulties as compared to the partner. Linear models were performed with discrepancy as the dependent variable, and amyloid (Florbetapir) from global region of interest (ROI) and tau (Flortaucipir) from two ROI (i.e. inferior temporal and entorhinal cortices in two separate models) as independent variables. Demographics (i.e. Age, Gender, Years of Education) were added as covariates.

Result

We found that clinically impaired individuals were significantly older (p = 0.01), more educated (p < 0.001), and included more women (p = 0.01) as compared to the clinically normal group. In general, clinically impaired individuals had lower awareness scores as compared to clinically normal individuals (p < 0.001). A significant three‐way interaction was observed between clinical status and biomarkers (i.e., amyloid and tau burden, p = 0.009 and 0.033 for entorhinal and inferior temporal cortices, respectively). Post hoc analyses revealed no significant difference between groups in individuals at low levels of pathology (p > 0.05; Figures A and B, right panels). However, at higher levels of pathology (i.e., both amyloid and tau), clinically impaired individuals demonstrated significantly lower awareness scores as compared to clinically normal participants (Figures A and B, left panels).

Conclusion

These findings better characterize the evolution of anosognosia in AD. Specifically, data suggest that impaired self‐awareness of memory function is associated with higher levels of amyloid and tau, providing further support that discordant subjective and objective measures may be important for clinical consideration.
Hippocampal subfield bold signal and mnemonic discrimination task performance in cognitive aging
Authors: Kern Kathryn L , Wehr Rachel K Nauer , Storer Thomas W , Schon Karin
Published: December 2020

Background

Cognitive aging is associated with impaired episodic memory formation (Small et al., 1999), which requires the neurocomputational process of pattern separation to disambiguate similar stimulus input. Pattern separation relies on the dentate gyrus (DG) (Yassa & Stark, 2011), a hippocampal subfield that is susceptible to age‐related change (Small et al., 2011). Cognitive aging is also associated with impaired performance on putative measures of behavioral pattern separation (Yassa et al., 2010), called mnemonic discrimination tasks in humans. Prior work using high‐resolution fMRI suggests that age‐related impairments in mnemonic discrimination are linked to aberrant activation patterns in the DG/CA3 (Yassa et al., 2010). Whereas aging is associated with impaired DG integrity and mnemonic discrimination ability, cardiorespiratory fitness is associated with enhanced DG integrity and improved mnemonic discrimination ability. Given that cardiorespiratory fitness has been positively linked to DG/CA3 integrity in young adults (Nauer et al., 2019), it is conceivable that in older adults, cardiorespiratory fitness will modulate age‐related changes in DG/CA3 activation, which in turn, will dampen age‐related impairments in mnemonic discrimination.

Methods

18 older adults (55‐85 years) and 18 young adults (18‐35 years) underwent a submaximal treadmill test to estimate cardiorespiratory fitness and high‐resolution fMRI to examine hippocampal subfield BOLD signal during encoding and retrieval of a mnemonic discrimination task (MDT).

Results

In older adults, we found increased right DG/CA3 BOLD signal in incorrect mnemonic discrimination trials contrasted with correct mnemonic discrimination trials, specifically during stimulus retrieval. Additionally, in both young and older adults, we found that right DG/CA3 BOLD signal in the mnemonic discrimination fMRI contrast during stimulus encoding marginally significantly predicted MDT corrected accuracy. Finally, in both young and older adults, fitness significantly negatively predicted left DG/CA3 BOLD signal in the mnemonic discrimination fMRI contrast during stimulus retrieval.

Conclusions

These results suggest that DG/CA3 BOLD signal relates to performance on a MDT designed to tax pattern separation, and that cardiorespiratory fitness modulates BOLD signal in these subregions. Altogether, these results suggest a link between fitness, DG/CA3 functional integrity, and mnemonic discrimination that may be critical to understanding how to dampen age‐related impairments in episodic memory.
Caspase‐6‐mediated tau cleavage and pathology in Alzheimer’s disease and other tauopathies
Authors: Piergies Antonia MH , Theofilas Panos , Petersen Cathrine , Ehrenberg Alexander J , Li Song , Morales Dulce Ovando , Eser Rana A , Yang Teddy , Khan Shireen , Chin Brian , Ng Raymond , Arkin Michelle , Grinberg Lea Tenenholz
Published: December 2020

Background

Caspases are being explored as targets for pharmacological treatment of tauopathies due to their role in tau cleavage, which leads to tau aggregation and neuronal loss. Tau truncated at Asp421, a residue cleaved by effector caspases, is found in four common tauopathies: Alzheimer’s disease (AD), corticobasal degeneration (CBD), Pick’s disease (PiD), and progressive supranuclear palsy (PSP) (Newman et al., 2005). We previously demonstrated that active caspase‐6 colocalizes with neurons containing phosphorylated tau during early AD stages and that the number of neurons positive for both active caspase‐6 and p‐tau increases throughout AD's progression. However, how caspase‐6 activity differs between tauopathies involving different tau isoforms is unknown. This study compares caspase‐6 activation and caspase‐6 cleavage of tau between AD, argyrophilic grain disease (AGD), CBD, PiD, and PSP using novel neoepitope antibodies against caspase‐6‐cleaved tau.

Method

Using multiplex immunofluorescence on tissue microarrays, we measured levels of neuronal active caspase‐6, tau cleaved at C‐terminal residue D402 (D402), tau cleaved at N‐terminal residue D13 (D13), and tau phosphorylated at Ser202 (p‐tau; CP13) in the middle frontal gyrus (MFG) of well‐characterized AD, AGD, CBD, PiD, and PSP cases and controls. We used semi‐automated methods to calculate the percentage of neurons positive for each marker.

Result

We found similar percentages of neuronal p‐tau in every tauopathy except AGD, as expected. Only AD and PiD showed substantial percentages of neuronal caspase‐6‐cleaved tau (Figure 1, Table 1). The mean percentages of neuronal D402 and D13 were up to 121.88‐fold higher in AD and up to 16.75‐fold higher in PiD compared to the other tauopathies (Figure 1, Table 1). In PiD, on average, 79.82‐87.61% of neurons positive for D402 or D13 were also positive for p‐tau. Interestingly, in AD, only an average of 50.70‐58.98% of neurons positive for D402 or D13 showed p‐tau positivity (Figure 2).

Conclusion

1) Caspase‐6‐cleavage of tau appears to be a more defining feature of tauopathies involving 3‐repeat isoforms of tau than 4‐repeat tauopathies. 2) Caspase‐6‐cleaved tau inclusions do not necessarily colocalize with p‐tau inclusions. 3) Future research on the therapeutic potential of caspase modulators should focus on AD and PiD.
The presence of moderate extrapyramidal signs predicts poorer outcomes in a community‐based cohort of multi‐ethnic demented elders
Authors: Kociolek Anton J. , Fernandez Kayri K. , Gu Yian , Cosentino Stephanie , Zhu Carolyn W. , Stern Yaakov
Published: December 2020

Background

Extrapyramidal signs (EPS) are a common feature of Alzheimer's Disease (AD) associated with worse outcomes in observational studies of dementia. Prior studies have been primarily conducted in predominately white, clinic‐based samples. Less is known regarding the role of EPS in the disease course of dementia in ethnic minority and non‐clinic‐based populations.

Method

Predictors 3 (P3) is a multi‐ethnic community‐based cohort study of dementia. Recruitment began in 2011 and is ongoing. Participants are evaluated annually by trained investigators. 142 P3 participants with a baseline diagnosis of probable dementia were selected for this study. Moderate EPS was defined as a score of 2 or more on selected items from the Unified Parkinson's Disease Rating Scale. The cognitive endpoint was defined as a score of <= 10 on the Folstein MMSE, the functional endpoint as a score of >= 10 on the 17‐point Blessed Dementia Rating Scale, and the institutional equivalent endpoint as need for equivalent to nursing home care. Adjusted Cox models were fitted for time to death and cognitive, functional, and institutional equivalent endpoints with baseline moderate EPS as predictor. Effect modification was assessed by fitting cross‐product terms for moderate EPS by ethnicity, sex, age, education, and APOE polymorphism.

Result

Mean follow‐up time was 3.61 years (range: 0.29 ‐ 7.50, SD = 1.95). 33 participants (23.2%) had moderate EPS at baseline. 53 died (37.3%), 23 (17.2%) reached the cognitive endpoint, 45 (36.3%) the functional endpoint, and 44 (37.9%) the institutional equivalent endpoint post‐baseline. Moderate EPS at baseline was significantly associated with an increased hazard of death (HR = 2.57, 95% CI = 1.30, 5.10) and of reaching the functional endpoint (5.59, 95% CI = 2.36, 13.27). Associations between moderate EPS and the cognitive and institutional equivalent endpoints were not statistically significant. No evidence was found for effect modification of associations on either additive or multiplicative scales.

Conclusion

In a multi‐ethnic community‐dwelling cohort of demented elders, we found that baseline moderate EPS significantly predicted time to death and time to functional endpoint, but not time to cognitive and institutional equivalent care endpoints. These findings confirm those of previous studies conducted on predominately white, clinic‐based samples.
Effects of thickness and hydrophobicity of double microporous layer on the performance in proton exchange membrane fuel cells
Authors: Lin Guangyi , Liu Shouyi , Qu Siyuan , Qu Guangkai , Li Tianya , Liang Zhenning , Hu Yafei , Liu Fumin
Published: December 2020

In this paper, a multi‐layer gas diffusion layer (GDL) is designed. The GDL consists of a single carbon paper backing layer and dual microporous layers (MPLs). Moreover, the effects of thickness and hydrophobicity of double MPL on the performance of proton exchange membrane fuel cells are investigated. From the test results of the water contact angle, conductivity, pore size distribution, and the polarization curve, it is found that the thickness adjustment increases the number of 0.5 to 7 μm and 20 to 100 μm pores in GDL, which is more conducive to water discharge. Therefore, the thickness adjustment is more favorable to the cell performance under high humidity. While the gradient hydrophobic design makes the MPL of the modified intermediate layer have a certain water‐retaining capacity to humidify the reaction gas, which has better effect under low humidity. At last, the results show that the optimized GDL meets a limit power density of 1.772 W/cm2 under 60% humidification and 1.600 W/cm2 under 100% humidification.
Can some microbes promote host stress and benefit evolutionarily from this strategy?
Authors: Aktipis Athena , Guevara Beltran Diego
Published: December 2020

Microbes can influence host physiology and behavior in many ways. Here we review evidence suggesting that some microbes can contribute to host stress (and other microbes can contribute to increased resilience to stress). We explain how certain microbes, which we call “stress microbes,” can potentially benefit evolutionarily from inducing stress in a host, gaining access to host resources that can help fuel rapid microbial replication by increasing glucose levels in the blood, increasing intestinal permeability, and suppressing the immune system. Other microbes, which we term “resilience microbes,” can potentially benefit from making hosts more resilient to stress. We hypothesize that “stress microbes” use a fast life history strategy involving greater host exploitation while “resilience microbes” use a slow life history strategy characterized by more aligned evolutionary interests with the host. In this paper, we review the evidence that microbes affect host stress and explain the evolutionary pressures that could lead microbes to manipulate host stress, discuss the physiological mechanisms that are known to be involved in both stress and microbial activity, and provide some testable predictions that follow from this hypothesis.
Faszination Malakologie
Authors: Sturm Robert
Published: December 2020

Der vorliegende Beitrag widmet sich der malakologischen Kartierung des Stadtgebietes von Salzburg, wobei zur Erhebung der im urbanen Raum auftretenden aquatischen Weichtierarten eine Vielzahl an Probenorten herangezogen und eine Standardsammelprozedur verwendet wurde. Insgesamt wird die Stadt Salzburg gegenwärtig von 24 Wasserschnecken‐ und 14 Muschelspezies besiedelt, was etwa 55 Prozent aller in Österreich dokumentierten Arten entspricht. In naturnahen Biotopen, welche sich vor allem im Norden und Süden der Stadt befinden, sind Biozönosen mit bis zu 20 Molluskenarten vertreten, während durch starke anthropogene Einwirkung gekennzeichnete Gewässer eine deutliche Verarmung an Spezies zeigen. Insgesamt steht die malakologische Forschung im urbanen Raum noch am Beginn ihrer Entwicklung.
Komplexe Geruchsnavigation beim Tabakschwärmer
Authors: Hille‐Rehfeld Annette
Published: December 2020

Blütenbestäuber wie derTabakschwärmer folgen bei ihrer Nahrungssuche dem Blütenduft, und Nektar als Belohnung verstärkt ihre angeborene Präferenz für bestimmte Duftstoffe. Durch Veränderungen des Duftbuketts, beispielsweise infolge von Oxidationsreaktionen unter Einwirkung von Ozon, verlieren die Blüten vorübergehend ihre olfaktorische Attraktivität. Nach visueller Orientierung und Belohnung durch Nektar kann der oxidierte Duftstoff durch assoziatives Lernen zum alternativen Signal werden.
Die Brückenechse im Stammbaum der Landwirbeltiere
Authors: Kronberg Inge
Published: December 2020

Zu den heute lebenden Landwirbeltierarten gehören weltweit schätzungsweise 7.000 Amphibien, 6.000 Säugetiere, 10.000 Vögel, 10.000 Echsen und Schlangen, 350 Schildkröten, 25 Krokodile, aber nur eine einzige Art der Brückenechsen: Sphenodon punctatus, in der Sprache der Maori „Tuatara“ genannt [1]. Die aktuelle Genomsequenzierung liefert einerseits einen Einblick in die Evolution der Landwirbeltiere und andererseits in die arteigenen Besonderheiten wie Sehvermögen, Immunabwehr und Langlebigkeit dieser seltenen Tierart. Die Untersuchungen verliefen in Zusammenarbeit mit Maoris, die die Tuatara als Kulturschatz ansehen.
Verflechtung zwischen Chlamydomonas und Aspergillus
Authors: Sander Johannes
Published: December 2020

Flechten, also Symbiosen zwischen Pilz und Alge, sind weit verbreitet. Möglicherweise gehörten sie zu den ersten Landbesiedlern. Eine jetzt entdeckte Beziehung zwischen den Modellorganismen Chlamydomonas reinhardtii und Aspergillus nidulans gibt Einblicke in die mögliche Evolution dieser Beziehung.
Fahndung nach einem Gen gegen überflüssige Pfunde
Authors: Staiger Dorothee
Published: December 2020

Wer schaut nicht neidisch auf die Mitmenschen, die nach Belieben essen und trotzdem nicht an Gewicht zunehmen. Ein internationales Forscherteam hat nun ein Gen entdeckt, das bei sehr schlanken Personen häufig Mutationen aufweist. Eine Deaktivierung dieses Gens bei Mäusen kurbelt die Verbrennung von Nahrungsfetten an und verhindert, dass die Tiere an Gewicht zulegen. Ob damit möglicherweise ein neuer Ansatz gefunden werden kann, Übergewicht beim Menschen zu behandeln, bedarf weitergehender Untersuchungen.
Nachrichten des Verbandes Biologie, Biowissenschaften & Biomedizin in Deutschland
Authors: Dietz Karl‐Josef
Published: December 2020

Wissenschaft & Gesellschaft

VBIO zum Konzeptentwurf für das Monitoringzentrum Biodiversität

Entwurf des Insektenschutzgesetzes liegt vor – VBIO nimmt Stellung

Ausbildung & Karriere

Online Berufsfelder‐Infoabend

Ausschreibung: Gute Lehre in Pandemiezeiten

AK Schulbiologie

Landesverbände

Landesverbände im VBIO in Corona‐Zeiten

Verband

Bundesdelegiertenversammlung 2020
Wieviele Mikrobenarten gibt es? (Teil 1)
Authors: Engelhardt Harald
Published: December 2020

Derzeit sind über 20 000 Arten von Mikroorganismen, gemeint sind hier Bakterien und Archaeen, beschrieben und benannt. Die Mikrobiologen sind sich einig darüber, dass die bekannten Spezies tatsächlich nur einen kleinen Ausschnitt der mikrobiellen Diversität darstellen. Über die Anzahl der auf unserer Erde lebenden Arten gehen die Schätzungen allerdings weit auseinander. Dabei dreht sich die Diskussion gar nicht um eine ungefähre Zahl, sondern um deren Größenordnung.
Pommes und Kartoffelchips – der Siegeszug einer Stärkeknolle
Authors: Rösemann Ulrich
Published: December 2020

Schon vor 4000 Jahren wurden Kartoffeln in Peru gegessen. Die Inkas verbreiteten den Anbau in Südamerika und nutzten die Kartoffel gleichrangig neben Mais. In den Anden waren fast 600 Varietäten der Kartoffel bekannt. Als die Konquistadoren die Inkakultur zerstörten, wurde die Knolle zum Beuteanteil, der nach Europa verschifft wurde. So soll die Kartoffel 1570 Europa erreicht haben.
Triarchic Model of Grit Dimensions as Predictors of Career Outcomes
Authors: Ting Lo Chi , Datu Jesus Alfonso Daep
Published: December 2020

Recent studies have emphasized the importance of applying positive psychological theories in the context of career development (Hull et al., 2020; Vela et al., 2015, 2019). However, limited research has been carried out on how specific positive personality traits might contribute to optimal career functioning. We addressed this gap by exploring the link of a triarchic model of grit dimensions (i.e., perseverance of effort, consistency of interests, and adaptability to situations) to career maturity, career decision‐making self‐efficacy, and career goal setting among Hong Kong Chinese secondary school students. Perseverance of effort positively predicted career goal setting and career decision‐making self‐efficacy. Consistency positively predicted career goal setting and career maturity. Adaptability to situations positively predicted career maturity, career decision‐making self‐efficacy, and career goal setting. Results point to the importance of designing school‐based grit interventions to facilitate optimal career‐related functioning.
Answered Callings, Unanswered Callings, or No Calling: Examining a Nationally Representative Sample
Authors: Marsh Dylan R. , Alayan Alexandra J. , Dik Bryan J.
Published: December 2020

Research suggests that workers with unanswered callings have poorer outcomes than those without callings; however, these studies have used small or homogeneous samples (Berg et al., 2010; Gazica & Spector, 2015). We aimed to replicate this finding using a nationally representative sample of 445 full‐time workers. We compared key work and life criterion variables across three groups: individuals with answered callings, unanswered callings, and no calling at all. Results linked answered callings to benefits but, unlike earlier studies, suggested that unanswered callings were no worse than lacking a calling. These findings call into question the narrative that unanswered callings are associated with adverse effects, suggesting that career counselors may be able to facilitate discernment of a calling without having a negative impact on those for whom that calling goes unanswered. Research designed to test causal influences of these dynamics is an important next step for understanding the experiences of individuals with answered callings, unanswered callings, or no calling at all.
Influence of Mindfulness, Emotion Regulation, and Perceived Social Support on Burnout
Authors: Newton Therese L. , Ohrt Jonathan H. , Guest Jessie D. , Wymer Brooker
Published: December 2020

We used canonical correlation analysis to examine the predictive nature of three facets of wellness (mindfulness, emotion regulation, and perceived social support) on burnout in counselors‐in‐training (N = 136). The cognitive reappraisal construct made a significant contribution to the wellness predictor variate. Implications for counselor training programs are discussed.
Novel Core‐Dual Shell Si@MoO2@C Nanoparticles as Improved Anode Materials for Lithium‐Ion Batteries
Authors: Huang Shengyang , Qin Xue , Miao Xinyu , Xu Xiaorui , Lei Chanrong , Wei Tianyu
Published: December 2020

Silicon anode is one of the most potential large capacity anodes for the refreshing new generation of lithium‐ion batteries. However, the volume changes greatly and the conductivity of Si anode is poor during the lithiation/delithiation process, resulting in inferior discharge/charge performance. To overcome these challenges, we design a core‐dual shell Si@MoO2@C composite by solvent evaporation method and sol‐gel method. The dual shell can surmount the considerable volume expansion as well as further the Li+/e− transport under the synergistic actions of the inner MoO2 and the outer carbon. The MoO2 shell can release the expansion pressure of Si as well as involve the storage of lithium effectively. The Si@MoO2@C anode shows a high ICE (about 80.3 %), a good specific capacity after 100 cycles (1171.7 mAh g−1 at 1 A g−1), and a capacity retention of about 90.1 % (vs 2nd cycle). The excellent electrochemical performances are ascribed to the delicate design of the core‐dual shell structure apparently, which make the Si@MoO2@C to be considered as an extremely promising anode material for LIBs.
Determining the Electrochemical Oxygen Evolution Reaction Kinetics of Fe3S4@Ni3S2 Using Distribution Function of Relaxation Times
Authors: Malik Bibhudatta , Vijaya Sankar Kalimuthu , Konar Rajashree , Tsur Yoed , Nessim Gilbert Daniel
Published: December 2020

We designed a heterostructure of Fe3S4@Ni3S2, as a potent oxygen evolution reaction (OER) electrocatalyst in an alkaline medium. Intriguingly, Fe3S4@Ni3S2 exhibits low onset potential of 290 mV and overpotential of 360 mV at a current density of 10 mA cm−2. We examined the OER kinetics of Fe3S4@Ni3S2 using distribution function of relaxation times (DFRT), which are attained with the help of impedance spectroscopy genetic programming (ISGP). ISGP reveals the occurrences of three events of OER, manifested as peaks in the DFRT, such as active material or pores (P2), charge transfer (P1’), and production rate of intermediates (P1) in case of Fe3S4@Ni3S2 at different faradic overpotentials. The effective resistance of each phenomenon can be easily calculated. It decreases with an increase in conductivity at high overpotentials for all the three, which suggests the high performance of the as‐synthesized composite due to faster kinetics. Further, structural investigation of the catalyst employing x‐ray photoelectron spectroscopy is elaborated and it is suggested that the catalyst activation takes place by the constant exchange of anions between electrode and electrolyte during electrochemical oxidation.
Cheryl Dembe: Eine Frau gibt nicht auf
Authors: Roth Klaus
Published: December 2020

Im Januar 1971 ging ein Hochschullehrer am Chemie‐Departement der Chicagoer Universität mit seiner Doktorandin ihre Forschungsarbeiten durch. Er war von den Ergebnissen absolut überzeugt und forderte sie auf, das Material zusammenzustellen und als Doktorarbeit einzureichen. Völlig unverhofft verstarb der Doktorvater eine gute Woche später. Das änderte für die Doktorandin alles