Long-term Consolidation Research Articles

The effect of long-term consolidation on foundations underpinned by micropiles in soft clay

So far insufficient research has been done on the long-term behavior of micropiles embedded in a clay medium, even though this has a significant influence on the expected total settlement. This paper considers a square foundation placed on a clay bed and tested under vertical loads until the clay reached its bearing capacity. Subsequently, the plate was underpinned with four micropiles, and the load test was repeated. These test data were used to validate the coupled hydraulic-mechanical three-dimensional finite difference model presented in this paper. In the numerical modelling, four different load transfer scenarios were considered to simulate different approaches to adding floors to an existing building. Consolidation periods of zero months, six months, and five years between the application of the load due to the existing building, and the application of loads due to additional storeys were considered. The six-month period represents a short-term, and the five-year period a long-term scenario. Following the first consolidation period and the application of loads representing additional storeys, a second consolidation period was implemented, such that the combined length of the two consolidation periods was five years. In this study, the results showed that the installation of micropiles immediately after the completion of existing floors is most successful in controlling the settlement of additional floors later on.

Effects of Acute Sleep Deprivation on Working Memory Capacity in Undergraduate Students

Sleep is a necessary staple in our everyday lives but with advancements in society and an increase in day to day commitments it feels as though there is not enough time in the day. One of the first things to be forsaken in the hopes of maintaining a work schedule or routine is sleep. While the lack of sleep is disproportionate in most demographics, in university students in particular, a lack of sleep is a common, consistent, and necessary plague. Students can be under the impression that the effects of sleep deprivation have mostly long-term repercussions; however, prior literature has indicated that sleep deprivation impacts not just long-term consolidation but also significantly affects memory in the short-term, specifically the working memory (Xie et al. 2019; Chee et al., 2006). In this investigation, we seek to understand the effects that acute sleep deprivation has on the working memory capacity of individuals using a 2-back spatial test. A sample of convenience of upper-class undergraduate students was chosen and the participants were asked to take a specific 2-back spatial test - twice on a day that they subjectively felt as having a regular sleep schedule and twice on a day that they subjectively felt as having sleep deprivation. The team predicted that working memory 2-back task scores will be adversely affected by sleep deprivation. While there was a statistically significant difference in the working memory scores on the full sample level, this was not reflected on the individual level. This indicates that the effects of sleep deprivation are not generalizable to a full population and that they must be reviewed on a case-by-case basis. Furthermore, since greater variation was observed in the sleep deprived scores in all individuals, it implies that sleep deprivation may indirectly affect the consistency of working memory by affecting attention span and concentration.

Prophylactic Percutaneous Consolidation of Large Osteolytic Tumors of the Pelvic Ring Using Fixation by Internal Cemented Screws.

Purpose To evaluate the efficacy, durability, and safety of percutaneous fixation by internal cemented screw (FICS) for prophylactic consolidation of impending pathologic fractures of the pelvic ring. Materials and Methods In this single-institute retrospective study, patients with large, minimally symptomatic to asymptomatic osteolytic tumors of the pelvic ring that were treated with percutaneous cone-beam CT-guided FICS procedures were included (January 2014 to May 2019). Follow-up cross-section imaging and clinical reports were reviewed for procedural complications and assessment of the long-term consolidation efficacy on the basis of the development of pathologic fracture or need for additional surgical intervention. All continuous variables were expressed as a mean with standard deviation, and dichotomous variables were expressed as frequencies and percentages. Results Fifty consecutive patients (mean age, 60 years ± 12; 27 men) underwent prophylactic FICS for consolidation of 54 osteolytic tumors (mean size, 51 mm ± 21.5; range, 30-114 mm). Local tumor destruction was performed in association with FICS in 38 patients (76%) using percutaneous thermal and/or radiation therapy. Follow-up exceeded a year in 35 patients (70%), with mean follow-up of 22 months ± 18 (range, 1-67 months). Long-term consolidation efficacy was 98% (49 of 50), with the development of a pathologic fracture in only one patient 20 months after FICS. Procedural complications were limited to two patients with self-resolving hematoma, one patient with inflammatory sciatic pain, and one patient with focal pain at the ischial tuberosity. Conclusion Percutaneous FICS provides a safe and durable minimally invasive treatment for the prevention of pathologic fractures of the pelvic ring. Keywords: Interventional-MSK, Percutaneous, Skeletal-Axial, Metastases, Oncology Supplemental material is available for this article. © RSNA, 2020.

Exploration of nucleos(t)ide analogs cessation in chronic hepatitis B patients with hepatitis B e antigen loss.

BACKGROUNDNucleos(t)ide analogs (NAs) cessation in chronic hepatitis B (CHB) patients remains a matter of debate in clinical practice. Current guidelines recommend that patients with hepatitis B e antigen (HBeAg) seroconversion discontinue NAs after relatively long-term consolidation therapy. However, many patients fail to achieve HBeAg seroconversion after the long-term loss of HBeAg, even if hepatitis B surface antigen (HBsAg) loss occurs. It remains unclear whether NAs can be discontinued in this subset of patients.AIMTo investigate the outcomes and factors associated with HBeAg-positive CHB patients with HBeAg loss (without hepatitis B e antibody) after cessation of NAs.METHODSWe studied patients who discontinued NAs after achieving HBeAg loss. The Cox proportional hazards model was used to identify predictors for virological relapse after cessation of NAs. The cut-off value of the consolidation period was confirmed using receiver operating characteristic curves; we confirmed the cut-off value of HBsAg according to a previous study. The log-rank test was used to compare cumulative relapse rates among groups. We also studied patients with CHB who achieved HBeAg seroconversion and compared their cumulative relapse rates. Propensity score matching analysis (PSM) was used to balance baseline characteristics between the groups.RESULTSWe included 83 patients with HBeAg loss. The mean age of these patients was 32.1 ± 9.5 years, and the majority was male (67.5%). Thirty-eight patients relapsed, and the cumulative relapse rate at months 3, 6, 12, 24, 36, 60, 120, and 180 were 22.9%, 36.1%, 41.0%, 43.5%, 45.0%, 45.0%, 45.0%, and 52.8%, respectively. Twenty-six (68.4%) patients relapsed in the first 3 mo after NAs cessation, and 35 patients (92.1%) relapsed in the first year after NAs cessation. Consolidation period (≥ 24 mo vs < 24 mo) (HR 0.506, P = 0.043) and HBsAg at cessation (≥ 100 IU/mL vs < 100 IU/mL) (HR 14.869, P = 0.008) were significant predictors in multivariate Cox regression. In the PSM cohort, which included 144 patients, there were lower cumulative relapse rates in patients with HBeAg seroconversion (P = 0.036).CONCLUSIONHBeAg-positive CHB patients with HBeAg loss may be able to discontinue NAs therapy after long-term consolidation, especially in patients with HBsAg at cessation < 100 IU/mL. Careful monitoring, especially in the early stages after cessation, may ensure a favorable outcome.

Nucleoside/nucleotide analog consolidation therapy in hepatitis B e-antigen positive chronic hepatitis B patients: Three years should be preferred.

To assess the role of consolidation therapy after cessation of nucleoside/nucleotide analogs (NAs) for off-treatment outcome and to explore the optimal consolidation period in hepatitis B e-antigen (HBeAg) positive chronic hepatitis B (CHB) patients. We undertook a prospective, observational cohort study including HBeAg positive CHB patients discontinuing NAs. Virological relapse was the primary endpoint of the current study and was defined as a serum hepatitis B virus DNA more than 104 copies/ml (another assay was carried out for confirmation at least 2weeks later). Propensity score matching analysis was used to balance the baseline characteristics between HBeAg positive CHB patients with different consolidation periods. A total of 190 HBeAg positive CHB patients were included. Fifty-four patients relapsed during follow-up and the cumulative relapse rates at years 1, 3, 5, and 10 were 19.5%, 24.1%, 27.2%, and 32.1%, respectively. Most patients (61.1%) relapsed in the first 6months. After propensity score matching, significantly lower cumulative relapse rates were observed in patients with consolidation period ≥36months compared with patients with consolidation period more than 36months (29.3% vs. 52.8% at year 10; p=0.012). Cessation of NAs after HBeAg seroconversion and long-term consolidation is generally safe and feasible in HBeAg positive CHB patients. Three years of consolidation should be preferred in clinical practice.

Bi-Temporal Anodal Transcranial Direct Current Stimulation during Slow-Wave Sleep Boosts Slow-Wave Density but Not Memory Consolidation

Slow-wave sleep (SWS) has been shown to promote long-term consolidation of episodic memories in hippocampo–neocortical networks. Previous research has aimed to modulate cortical sleep slow-waves and spindles to facilitate episodic memory consolidation. Here, we instead aimed to modulate hippocampal activity during slow-wave sleep using transcranial direct current stimulation in 18 healthy humans. A pair-associate episodic memory task was used to evaluate sleep-dependent memory consolidation with face–occupation stimuli. Pre- and post-nap retrieval was assessed as a measure of memory performance. Anodal stimulation with 2 mA was applied bilaterally over the lateral temporal cortex, motivated by its particularly extensive connections to the hippocampus. The participants slept in a magnetic resonance (MR)-simulator during the recordings to test the feasibility for a future MR-study. We used a sham-controlled, double-blind, counterbalanced randomized, within-subject crossover design. We show that stimulation vs. sham significantly increased slow-wave density and the temporal coupling of fast spindles and slow-waves. While retention of episodic memories across sleep was not affected across the entire sample of participants, it was impaired in participants with below-average pre-sleep memory performance. Hence, bi-temporal anodal direct current stimulation applied during sleep enhanced sleep parameters that are typically involved in memory consolidation, but it failed to improve memory consolidation and even tended to impair consolidation in poor learners. These findings suggest that artificially enhancing memory-related sleep parameters to improve memory consolidation can actually backfire in those participants who are in most need of memory improvement.

The histone H3 lysine 9 methyltransferase G9a/GLP complex activity is required for long-term consolidation of spatial memory in mice

The G9a/G9a-like protein (GLP) histone lysine dimethyltransferase complex and downstream histone H3 lysine 9 dimethylation (H3K9me2) repressive mark have recently emerged as key transcriptional regulators of gene expression programs necessary for long-term memory (LTM) formation in the dorsal hippocampus. However, the role for hippocampal G9a/GLP complex in mediating the consolidation of spatial LTM remains largely unknown. Using a water maze competition task in which both dorsal hippocampus-dependent spatial and striatum-dependent cue navigation strategies are effective to solve the maze, we found that pharmacological inhibition of G9a/GLP activity immediately after learning disrupts long-term consolidation of previously learned spatial information in male mice, hence producing cue bias on the competition test performed 24 h later. Importantly, the inhibition of hippocampal G9a/GLP did not disrupt short-term memory retention. Immunohistochemical analyses revealed increases in global levels of permissive histone H3K9 acetylation in the dorsal hippocampus and dorsal striatum at 1 h post-training, which persisted up to 24 h in the hippocampus. Conversely, H3K9me2 levels were either unchanged in the dorsal hippocampus or transiently decreased at 15 min post-training in the dorsal striatum. Finally, the inhibition of G9a/GLP activity further increased global levels of H3K9 acetylation while decreasing H3K9me2 in the hippocampus at 1 h post-training. However, both marks returned to vehicle control levels at 24 h. Together, these findings support the possibility that G9a/GLP in the dorsal hippocampus is required for the transcriptional switch from short-term to long-term spatial memory formation.

Accelerated long-term forgetting in focal epilepsy: Do interictal spikes during sleep matter?

Accelerated long-term forgetting (ALF) is a particular form of amnesia mostly encountered in focal epilepsy, particularly in temporal lobe epilepsy. This type of memory loss is characterized by an impairment of long-term consolidation of declarative memory, and its mechanisms remain poorly understood. In particular, the respective contribution of lesion, seizures, interictal epileptic discharges, and sleep is still debated. Here, we provide an overview of the relationships intertwining epilepsy, sleep, and memory consolidation and, based on recent findings from intracranial electroencephalographic recordings, we propose a model of ALF pathophysiology that integrates the differential role of interictal spikes during wakefulness and sleep. This model provides a framework to account for the different timescales at which ALF may occur.

Strategic Planning as a Conflict-Mediating Routine

This paper shows how strategic planning may function as a conflict-mediating routine. We conducted a five-year case study in a large financial services joint venture firm co-owned by a Latin American state bank and a European multinational financial company. The controlling companies have different business objectives for the JV: the former prioritizes short-term financial results, while the latter prioritizes long-term consolidation of the business. We present the case in the form of a narrative of findings, which shows how we pursue and uncover different levels of organizational reality and, more specifically, the different roles played by strategic planning. The paper makes two contributions: first, to studies of routines as praxis capable of supporting the solution of conflicts that arise from the presence of different business logics; and second, to business practice, as it provides guidance on considering additional roles taken by strategic planning.

Reconfiguration of the cortical-hippocampal interaction may compensate for Sharp-Wave Ripple deficits in APP/PS1 mice and support spatial memory formation.

Hippocampal-cortical dialogue, during which hippocampal ripple oscillations support information transfer, is necessary for long-term consolidation of spatial memories. Whereas a vast amount of work has been carried out to understand the cellular and molecular mechanisms involved in the impairments of memory formation in Alzheimer’s disease (AD), far less work has been accomplished to understand these memory deficiencies at the network-level interaction that may underlie memory processing. We recently demonstrated that freely moving 8 to 9-month-old APP/PS1 mice, a model of AD, are able to learn a spatial reference memory task despite a major deficit in Sharp-Wave Ripples (SWRs), the integrity of which is considered to be crucial for spatial memory formation. In order to test whether reconfiguration of hippocampal-cortical dialogue could be responsible for the maintenance of this ability for memory formation, we undertook a study to identify causal relations between hippocampal and cortical circuits in epochs when SWRs are generated in hippocampus. We analyzed the data set obtained from multielectrode intracranial recording of transgenic and wild-type mice undergoing consolidation of spatial memory reported in our previous study. We applied Directed Transfer Function, a connectivity measure based on Granger causality, in order to determine effective coupling between distributed circuits which express oscillatory activity in multiple frequency bands. Our results showed that hippocampal-cortical coupling in epochs containing SWRs was expressed in the two frequency ranges corresponding to ripple (130–180 Hz) and slow gamma (20–60 Hz) band. The general features of connectivity patterns were similar in the 8 to 9-month-old APP/PS1 and wild-type animals except that the coupling in the slow gamma range was stronger and spread to more cortical sites in APP/PS1 mice than in the wild-type group. During the occurrence of SWRs, the strength of effective coupling from the cortex to hippocampus (CA1) in the ripple band undergoes sharp increase, involving cortical areas that were different in the two groups of animals. In the wild-type group, retrosplenial cortex and posterior cingulate cortex interacted with the hippocampus most strongly, whereas in the APP/PS1 group more anterior structures interacted with the hippocampus, that is, anterior cingulate cortex and prefrontal cortex. This reconfiguration of cortical-hippocampal interaction pattern may be an adaptive mechanism responsible for supporting spatial memory consolidation in AD mice model.

Evaluation of usage of silicon-doped hydroxyapatite ceramics for treatment of fragmented bone fractures in dogs

None of the methods of osteosynthesis provides the consolidation of bone fragments which have lost contact with soft tissues. It makes extremely difficult treating of this type fractures. Bone defect between the fragments and absence of a primary biological matrix complicates revascularization, causes long-term life of the connective tissue and cells of cartilaginous phenotype in the fracture zone. It is leads to a long-term consolidation of the fracture. Composites of hydroxyapatite and calcium phosphates are considered as bioactive and therefore the most promising for bone defects replacing. The aim of this investigation was clinical, radiological and hematological evaluation using of silicon-doped ceramics for fragmented bone fractures in dogs. For study was chosen dogs with accidental fragmented fractures of tubular bones which treated by extracortical osteosynthesis method. Animal was divided into two groups. A bone defects were filled with ceramics (GTlKg-3) for experimental animal group (n = 7), while no filling of bone defects in control animal group(n = 7) was performed. Protocol of anesthesia included medetomidine, butorphanol tartrate and epidural anesthesia with 2 % lidocaine solution. Animals of the control group began to lean on the injured limb from the 12–15th day after surgery, while the animal of research group from the 8-9th day. Complete limb repair in dogs of the control group occurred on the 38–42th day, but such period for experimental group animals was shorter – 25–27th day after the osteosynthesis. X-ray investigation (60th day) of experimental group dogs showed new formed bone tissue with osteosclerotic zones without a periosteal reaction, bone tissue, with a normal view of the epiphyseal areas and the bone marrow cavity. This is evidence of localized reparative osteogenesis (within bone trauma only), and completed fracture consolidation. At the same time in cases of the control group we found lower X-ray density of new bone, periosteum was thickened with excessive proliferation of the endosteum, especially below the site of bone injury. Thus, in case the absence of hydroxyapatite matrix in bone defects there were compensatory increasing proliferation of periosteum and endoosteum. Fragmented fractures of tubular bones in dogs have occurred by erythrocytopenia, that quickly disappear due to the reparative osteogenesis in dog of experimental group. These animals have had leukocytosis increasing due to the first three days after osteosynthesis as a reaction to the implantation of a calcium-phosphorus composite material. Dogs of control group have had second wave of leukocytosis increasing on forty-second day associated with elongated remodeling process. Areparative osteogenesis can be accelerated in 1.5 times in case of replacement of bone defects with silicon doped hydroxyapatite ceramics. It is possibility realized thru moderate reduction of active phase of inflammation and acceleration of proliferative phase, mainly from endosteum side with early mineralization of bone regenerate. The dynamics of hematology parameters is a typical for the tubular bone consolidation that indicates about moderate inflammation and demonstrate biological tolerance of silicon-doped hydroxyapatite ceramics.

Image-guided Percutaneous Fixation with Internal Cemented Screws of Impending Femoral Neck Pathologic Fractures in Patients with Metastatic Cancer: Safety, Efficacy, and Durability.

Background Prophylactic image-guided procedures performed by interventional radiologists for impending pathologic fractures are becoming more pertinent, as patients with metastatic cancer have extended overall survival because of advanced therapies. Purpose To evaluate the efficacy, safety, and palliative durability of collimated-beam CT-guided percutaneous fixation with internal cemented screws (FICS) for impending pathologic fractures of the femoral neck. Materials and Methods This single-institute retrospective study examined all patients with metastatic cancer treated between February 2010 and October 2019 with collimated-beam CT-guided percutaneous FICS procedures for preventive consolidation of impending femoral neck pathologic fractures. The short-term palliative efficacy was assessed through comparison of visual analog scale (VAS) scores before and 1 month after FICS. A review of cross-section imaging and clinic reports identified any procedural complications. Long-term consolidation efficacy was defined as the absence of any screw dislodgement or development of a pathologic fracture at completion of the study. The Wilcoxon test was used for the mean comparison of paired nonparametric variables. Results Sixty-one consecutive patients (mean age, 59 years ± 11 [standard deviation]; 35 women) underwent preventive FICS for consolidation of impending pathologic femoral neck fracture with a mean follow-up of 533 days ± 689. Two patients died of cancer within the first month. Complications were limited to three self-resolving hematomas. The mean VAS score decreased 1 month after FICS from 4.2 ± 3.2 to 1.8 ± 2.0 (P < .001). The long-term consolidation efficacy was 92% (54 of 59 patients), with three of 59 patients (5%) subsequently developing fractures despite FICS and an additional two of 59 patients (3%) with durable FICS undergoing definitive total hip arthroplasty surgery because of local tumor progression. Conclusion Percutaneous fixation with internal cemented screws as performed by the interventional radiologist is a safe nonsurgical treatment that provides an effective palliative result and durable prevention for impending pathologic fractures of the femoral neck. © RSNA, 2020 Online supplemental material is available for this article.

Socio-Economic Incentives As A Factor In Eliminating The Shortage Of Medical Personnel In Rural Health Care

The study determines the impact of regional measures of socio-economic stimulation of medical personnel on the process of employment in medical institutions in rural areas. The analysis of Federal and regional legislation regulating the process of encouraging doctors to find employment in the rural health system is carried out. It was found that measures of socio-economic support for the provision of ready-made housing in the framework of regional events, contributed to a more active involvement and long-term consolidation of medical personnel in rural areas.

Social Fear Memory Requires Two Stages of Protein Synthesis in Mice.

It is well known that long-term consolidation of newly acquired information, including information related to social fear, require de novo protein synthesis. However, the temporal dynamics of protein synthesis during the consolidation of social fear memories is unclear. To address this question, mice received a single systemic injection with the protein synthesis inhibitor, anisomycin, at different time-points before or after social fear conditioning (SFC), and memory was assessed 24 h later. We showed that anisomycin impaired the consolidation of social fear memories in a time-point-dependent manner. Mice that received anisomycin 20 min before, immediately after, 6 h, or 8 h after SFC showed reduced expression of social fear, indicating impaired social fear memory, whereas anisomycin caused no effects when administered 4 h after SFC. These results suggest that consolidation of social fear memories requires two stages of protein synthesis: (1) an initial stage starting during or immediately after SFC, and (2) a second stage starting around 6 h after SFC and lasting for at least 5 h.

Strategic Planning as a Conflict-Mediating Routine: A Multilevel Study

This paper aims to contribute to strategy as practice studies by showing how strategic planning may function as a conflict-mediating routine. We conducted a five-year case study in a large financial services firm jointly owned by a Brazilian state bank and a European multinational financial company. These companies have different business objectives: the former prioritizes short-term financial results, while the latter prioritizes long-term consolidation of the business. We present the case in the form of a narrative of findings, which shows how we pursue and uncover different levels of organizational reality and, more specifically, the different roles played by strategic planning. The paper makes three contributions: first, to multilevel empirical studies of strategy as practice, dealing with macrostructures, intermediate structures and micropractices; second, to studies of routines as praxis capable of supporting the solution of conflicts that arise from the presence of different business logics; and third, to business practice, as it provides guidance on considering additional roles taken by strategic planning.

Comparison of the performance of a novel nanolime doped with ZnO quantum dots with common consolidants for historical carbonate stone buildings

Decohesion of building materials caused by weathering translates into the need for recurrent interventions with consolidating treatments that often turn out useless for desired long-term consolidation owing to their poor in-depth penetration. Due to this, it is important to develop new products that allow evaluating their penetration in situ. In this work, three commercial consolidants (Estel 1200®, NanoEstel® and Nanorestore®) widely used in stone conservation were compared with a new consolidant nanocomposite (Nanorepair UV). This nanocomposite, which consists of calcium hydroxide nanoparticles doped with zinc oxide quantum dots, allows both consolidation and in situ evaluation of the penetration depth of the treatment, a key variable to assess effectiveness when an in-depth consolidation is required. The treatments were assayed on limestones from two quarries widely used in the construction of monuments in southern Spain.The development of new products devoted to our Cultural Heritage entails specific requirements such as effectiveness, durability and compatibility with the original materials without changing their aesthetic features. The compatibility was studied by colorimetric methods and SEM images to detect the formation of surface layers. The effectiveness of the treatments was quantified by both peeling test and ultrasound propagation speed. Finally, the durability was studied by an accelerated weathering test induced by salt crystallization.The results showed that nanolimes had higher effectiveness and better durability than silica treatments as consolidants for limestones. In addition, Nanorepair UV provided an additional functionality since it allowed measuring the treatment penetration depth in a simple and economical way, by means of ultraviolet illumination, while allowed to distinguish treated areas from untreated ones.

Experimental Study of Compression Behavior of Indian Black Cotton Soil in Oedometer Condition

The clayey soil containing montmorillonite minerals exhibits both time-dependent compression called creep and swelling behavior, which is time-dependent expansion. Both the creep and swelling characteristics of the clayey soils have a significant influence on the deformation and failure of geotechnical structures. Study of time-dependent stress–strain behavior of a clayey soil is a great concern for construction purposes. In this paper, the long-term time-dependent behavior of Indian Black Cotton (BC) soil is investigated under a series of test in Oedometer apparatus at different loading pattern. The experimental result shows that non-linear function is suitable for prediction of long-term creep and swelling behavior of BC soil. Using the non-linear function, the behavior of the strain rate with time and the effective stress is studied. The strain rate, after the end of primary consolidation, decreases non-linearly to attain an equilibrium after reaching an equilibrium condition, and it is independent of the loading. The experimental result indicates that BC soil shows the repeated ability to swell at different stages of loading–reloading cycles. The experimental results along with the performance evaluation of the analytical model to predict long-term consolidation and creep behavior of BC soil are presented and discussed in details.

0087 Childhood Naps Promote Short-Term Destabilization but Long-Term Consolidation of Emotional Memories

Abstract Introduction Early childhood naps have been shown to support emotional memory consolidation, but this benefit only emerges the following day. It is unknown whether consolidation occurs during the nap itself, or if napping only prepares memories for overnight consolidation. In this study, we used a forced-choice recognition task to determine whether naps protect emotional memories against post-nap interference, which would indicate the occurrence of consolidation. Methods Preschool children (33–67 months; N=63) viewed neutral faces paired with negative or neutral descriptions. Following a nap or an equal interval awake (within-subjects, order counterbalanced, ~1 week apart), half of these participants (N=33) were presented with an interfering set of faces and descriptions, while the other half (N=30) did not receive interference. For all participants, recognition of the original faces was probed after encoding, after the nap or wake interval, and the next morning. Results To assess the influence of napping on changes in emotional memory, 2 (stimulus valence: negative vs. neutral) x 2 (condition: nap vs. wake) repeated-measures ANOVAs were performed. Recall of negative and neutral items did not immediately differ between the nap and wake conditions for the participants who received no interference. 24 hours later, these children trended towards recalling negative and neutral items better if they had napped the previous day (condition main effect: F(1,29)=3.539, p=0.070). In contrast, participants who received interference recalled fewer negative items than neutral items immediately following a nap (p=0.034), while this difference did not emerge following an interval awake. Conclusion Our results suggest that naps initially destabilize emotional memories rather than protecting them against interference. However, this initial destabilization may reflect the partial processing of memories during naps, perhaps allowing for enhanced long-term consolidation. Overall, our findings provide important insight into the mechanism of nap-dependent emotional processing. Support Supported by NIH R01 HL111695 and an Honors Research Grant from Commonwealth Honors College

Understanding the Early Evolutionary Stages of a Tandem Drosophilamelanogaster-Specific Gene Family: A Structural and Functional Population Study.

Gene families underlie genetic innovation and phenotypic diversification. However, our understanding of the early genomic and functional evolution of tandemly arranged gene families remains incomplete as paralog sequence similarity hinders their accurate characterization. The Drosophila melanogaster-specific gene family Sdic is tandemly repeated and impacts sperm competition. We scrutinized Sdic in 20 geographically diverse populations using reference-quality genome assemblies, read-depth methodologies, and qPCR, finding that ∼90% of the individuals harbor 3–7 copies as well as evidence of population differentiation. In strains with reliable gene annotations, copy number variation (CNV) and differential transposable element insertions distinguish one structurally distinct version of the Sdic region per strain. All 31 annotated copies featured protein-coding potential and, based on the protein variant encoded, were categorized into 13 paratypes differing in their 3′ ends, with 3–5 paratypes coexisting in any strain examined. Despite widespread gene conversion, the only copy present in all strains has functionally diverged at both coding and regulatory levels under positive selection. Contrary to artificial tandem duplications of the Sdic region that resulted in increased male expression, CNV in cosmopolitan strains did not correlate with expression levels, likely as a result of differential genome modifier composition. Duplicating the region did not enhance sperm competitiveness, suggesting a fitness cost at high expression levels or a plateau effect. Beyond facilitating a minimally optimal expression level, Sdic CNV acts as a catalyst of protein and regulatory diversity, showcasing a possible evolutionary path recently formed tandem multigene families can follow toward long-term consolidation in eukaryotic genomes.

Characteristic behavior in long-term consolidation for subtropical soils

Characteristic behavior in long-term consolidation for subtropical soils