Impact of higher-order dispersion on frequency-modulated combs.

Frequency-modulated (FM) combs form spontaneously in free-running semiconductor lasers and possess a vast potential for spectroscopic applications. Despite recent progress in obtaining a conclusive theoretical description, experimental FM combs often exhibit non-ideal traits, which prevents their widespread use. Here we explain this by providing a clear theoretical and experimental study of the impact of the higher-order dispersion on FM combs. We reveal that spectrally dependent dispersion is detrimental for comb performance and leads to a decreased comb bandwidth and the appearance of spectral holes. These undesirable traits can be mended by applying a radio frequency modulation of the laser bias. We show that electrical injection-locking of the laser leads to a significant increase of the comb bandwidth, a uniform-like spectral amplitudes, and the rectification of the instantaneous frequency to recover a nearly linear frequency chirp of FM combs.

Why Meta-Analyses of Growth Mindset and Other Interventions Should Follow Best Practices for Examining Heterogeneity: Commentary on Macnamara and Burgoyne (2023) and Burnette et al. (2023).

Meta-analysts often ask a yes-or-no question: Is there an intervention effect or not? This traditional, all-or-nothing thinking stands in contrast with current best practice in meta-analysis, which calls for a heterogeneity-attuned approach (i.e., focused on the extent to which effects vary across procedures, participant groups, or contexts). This heterogeneity-attuned approach allows researchers to understand where effects are weaker or stronger and reveals mechanisms. The current article builds on a rare opportunity to compare two recent meta-analyses that examined the same literature (growth mindset interventions) but used different methods and reached different conclusions. One meta-analysis used a traditional approach (Macnamara and Burgoyne, in press), which aggregated effect sizes for each study before combining them and examined moderators one-by-one by splitting the data into small subgroups. The second meta-analysis (Burnette et al., in press) modeled the variation of effects within studies-across subgroups and outcomes-and applied modern, multi-level meta-regression methods. The former concluded that growth mindset effects are biased, but the latter yielded nuanced conclusions consistent with theoretical predictions. We explain why the practices followed by the latter meta-analysis were more in line with best practices for analyzing large and heterogeneous literatures. Further, an exploratory re-analysis of the data showed that applying the modern, heterogeneity-attuned methods from Burnette et al. (in press) to the dataset employed by Macnamara and Burgoyne (in press) confirmed Burnette et al.'s conclusions; namely, that there was a meaningful, significant effect of growth mindset in focal (at-risk) groups. This article concludes that heterogeneity-attuned meta-analysis is important both for advancing theory and for avoiding the boom-or-bust cycle that plagues too much of psychological science.

Crush Injury and Simulated Flight Effects on Muscle Gene Expression in Female Mice.

BACKGROUND: Aeromedical evacuation provides critical care during long-distance transport of injured victims between medical facilities. Often, these victims sustain muscle trauma related to mechanical insults, such as crush. Understanding the effects of flight on injured muscle is important because the aircraft cabin represents an external environment with mild hypoxia-the cabin's altitude is 2,438 m instead of sea level. Because mild hypobaric hypoxia can alter gene expression in normal muscle and affect recovery patterns, it is beneficial to examine whether this type of hypoxia may also alter injury-related genes. OBJECTIVE: The objective of this study was to verify the hypothesis that differential gene expression occurs in response to mild hypobaric hypoxia exposure in crush-injured muscle during two early recovery (preregeneration stage) time points. METHODS: Twenty-four female mice were anesthetized, and the right gastrocnemius muscle underwent crush injury. Approximately 24 hours later, mice were exposed to normobaric normoxia or hypobaric hypoxia for 8-9 hours. After 32 or 48 hours of recovery, the mice were euthanized, and the right and left lateral gastrocnemius muscles were collected for microarray and bioinformatics analyses. RESULTS: The study hypothesis was verified. There were 353 highly upregulated, differentially expressed genes identified in the injured muscle compared to the uninjured muscle. Mid1 was upregulated in both pressure conditions regardless of injury status. There were 52 and 15 differentially expressed genes at 32 and 48 hours postinjury, respectively, in the hypobaric hypoxia-exposed, injured muscle compared to the normobaric normoxia-exposed, injured muscle. The macrophage gene Cd68 correlated with other leukocyte-related genes. DISCUSSION: These findings expand our understanding of the genetic changes that occur in muscle in response to a crush injury, including those related to the macrophage protein CD68. Nursing interventions addressing adequate functioning after crush muscle injury may need to consider the effects on Cd68 and its closely related genes. In addition, our results suggest a responsiveness of the gene Mid1 to flight-relevant hypobaric hypoxia. Changes in the expression of Mid1 may be appropriate in assessing the long-term health of flight crew members.

Effects of hypobaric hypoxia during a simulated ultra-long-haul flight on inflammation and regeneration after muscle trauma and muscle trauma-hemorrhagic shock.

INTRODUCTION/AIMS: Because wounded warfighters or trauma victims may receive en route care to the closest medical facility via airplane transport, we investigated the effects of extended mild hypobaric hypoxia (HB), the environmental milieu of most airplanes, on inflammation and regeneration after muscle trauma or monotrauma (MT) and muscle trauma-hemorrhagic shock or polytrauma (PT). METHODS: Male C57BL/6N mice were assigned to one of six groups pertaining to injury (control/uninjured, MT, and PT) and atmospheric pressure exposure (HB and normobaric normoxia, NB). Body mass, blood and muscle leukocyte number by flow cytometry, immunohistochemistry, or both, and the muscle relative mRNA level of selected genes involved in inflammation and muscle regeneration were examined at ~1.7, 4, 8, and 14 days post trauma (dpt). At 14 dpt, the proportion of smaller- and larger-sized myofibers at the regenerating site of MT mice was determined. RESULTS: Greater body mass loss, an increased number of blood and muscle leukocytes, and differential muscle relative mRNA levels were observed in MT and PT groups compared to controls. The MT+HB or PT+HB mice demonstrated more body mass loss and altered relative mRNA level than the corresponding NB mice. Additionally, a subgroup of MT+HB mice demonstrated a greater proportion of smaller myofibers (250 to 500 µm2 ) than MT+NB mice at 14 dpt. DISCUSSION: HB exposure after muscle trauma alone may prolong regeneration. Following HB exposure, therapies that promote oxygenation may be needed during this muscle recovery.

Knockout of SLy1 decreases double-negative thymocyte proliferation and protects mice from p53-induced tumor formation.

The lymphocyte-specific adapter protein SLy1 has previously been identified as indispensable for thymocyte development and T-cell proliferation and, recently, as a cause of X-linked combined immunodeficiency in humans that recapitulates many of the abnormalities reported in SLy1KO and SLy1d/d mice. As SLy1KO NK cells show increased levels of p53, we focused our research on the interdependency of SLy1 and p53 for thymocyte development. Using RT-PCR and immunoblot analysis, we observed increased levels of p53 as well as DNA damage response proteins in SLy1KO thymocytes. To test for rescue from SLy1-induced deficiencies in thymocyte development like reduced thymocyte numbers and reduced DN to DP progression, we generated a mouse model with T cell-specific p53-deficiency on an SLy1KO background and analyzed lymphocyte populations in these mice and respective controls. Astonishingly, SLy1KO -typical deficiencies were retained, showing that SLy1 is mechanistically independent of p53. Studies of apoptosis and proliferation in SLy1KO thymocytes revealed decreased proliferation in the DN3 subpopulation as a possible reason for the decreased thymocyte number. In mice with p53-deficient T cells, we observed tumor formation leading to reduced survival, preferentially in SLy1WT mice. Thus, we suggest that a SLy1-deficiency reduces proliferation, resulting in less hematologic tumors initiated by the p53-deficiency.

Effect of the Graphene Quantum Dot Content on the Thermal, Dynamic-Mechanical, and Morphological Properties of Epoxy Resin.

Different amounts of graphene quantum dots (CQDs) (0, 1, 2.5, and 5 wt%) were incorporated into an epoxy matrix. The thermal conductivity, density, morphology, and dynamic mechanical thermal (DMTA) properties were reused from the study of Seibert et al.. The Pearson plot showed a high correlation between mass loading, thermal conductivity, and thermal diffusivity. A poorer correlation with density and heat capacity was observed. At lower CQD concentrations (0.1 wt%), the fracture surface showed to be more heterogeneous, while at higher amounts (2.5 and 5 wt%), a more homogeneous surface was observed. The storage modulus values did not change with the CQD amount. But the extension of the glassy plateau increased with higher CQD contents, with an increase of ~40 °C for the 5 wt% compared to the 2.5 wt% and almost twice compared to the neat epoxy. This result is attributed to the intrinsic characteristics of the filler. Additionally, lower energy dissipation and a higher glass transition temperature were observed with the CQD amount. The novelty and importance are related to the fact that for more rigid matrices (corroborated with the literature), the mechanical properties did not change, because the polymer bridging mechanism was not present, in spite of the excellent CQD dispersion as well as the filler amount. On the other hand, thermal conductivity is directly related to particle size and dispersion.

Intervention initiatives to raise young people's interest and participation in STEM.

For nearly a decade, two science interventions anchored in project-based learning (PBL) principles have been shown to increase student science learning in 3rd grade and high school physical science classes. Both interventions employed a randomized control trial of several thousand students (N = 3,271 in 3rd grade and N = 4,238 in 10th, 11th, and 12th grades). Incorporating a rich background of research studies and reports, the two interventions are based on the ideas of PBL as well as the National Academies of Science's publications, including how children learn; how science learning and instruction can be transformed; and the performance expectations for science learning articulated in the Next Generation of Science Standards. Results show significant positive increases in student academic, social, and emotional learning in both elementary and secondary school. These findings can be traced, in part, to carefully crafted experiential participatory activities and high-quality instructional materials which act as strong facilitators for knowledge acquisition and use. Reviewing the innovations undertaken by these two interventions, this article describes the importance of studying social and emotional factors 'in situ', using the Experience Sampling Method (ESM), that can motivate and engage students in science learning in both elementary and secondary school. Using these 'in situ' data collection (N = 596 students in 3rd and N = 1412 students in 10th, 11th, and 12th grades) along with case studies and repeated measures analysis gave deep insights into emotional and social development for young children and adolescents. These methods should continue to be considered when trying to understand key factors of improving engagement in science.

SARS-CoV-2 surveillance with environmental surface sampling in public areas.

Contaminated surfaces are one of the ways that coronavirus disease 2019 (COVID-19) may be transmitted. SARS-CoV-2 can be detected on environmental surfaces; however, few environmental sampling studies have been conducted in nonclinical settings. The objective of this study was to detect SARS-CoV-2 RNA on environmental surfaces in public areas in Las Vegas, Nevada. In total, 300 surface samples were collected from high-touch surfaces from high-congregate public locations and from a public health facility (PHF) that was visited by COVID-19 patients. Environmental samples were analyzed with quantitative reverse-transcriptase polymerase chain reaction (RT-qPCR) using SARS-CoV-2 specific primers and probes for three target genes. Results showed that 31 out of 300 (10.3%) surface samples tested positive for SARS-CoV-2, 24 at the PHF and 7 in high-congregate public locations. Concentrations ranged from 102 to 106 viral particles per 3 ml sample on a wide variety of materials. The data also showed that the N gene assay had greater sensitivity compared to the S and ORF gene assays. Besides frequently touched surfaces, SARS-CoV-2 was detected in restrooms, on floors and surfaces in contact with floors, as well as in a mop water sample. The results of this study describe the extent and distribution of environmental SARS-CoV-2 contamination in public areas in Las Vegas, Nevada. A method using the N gene PCR assay was developed for SARS-CoV-2 environmental monitoring in public areas. Environmental monitoring with this method can determine the specific sites of surface contamination in the community and may be beneficial for prevention of COVID-19 indirect transmission, and evaluation and improvement of infection control practices in public areas, public health facilities, universities, and businesses.

[Recommendation for standardized medical care for children and adolescents with long COVID]. / Einheitliche Basisversorgung von Kindern und Jugendlichen mit Long COVID: Stellungnahme einer multidisziplinären Arbeitsgruppe der DGKJ-Konvent-Gesellschaften (Stand: Februar 2022).

This current consensus paper for long COVID complements the existing AWMF S1 guidelines for long COVID with a detailed overview on the various clinical aspects of long COVID in children and adolescents. Members of 19 different pediatric societies of the DGKJ convent and collaborating societies together provide expert-based recommendations for the clinical management of long COVID based on the currently available but limited academic evidence for long COVID in children and adolescents. It contains screening questions for long COVID and suggestions for a structured, standardized pediatric medical history and diagnostic evaluation for patients with suspected long COVID. A time and resource-saving questionnaire, which takes the clinical complexity of long COVID into account, is offered via the DGKJ and DGPI websites as well as additional questionnaires suggested for an advanced screening of specific neurocognitive and/or psychiatric symptoms including post-exertional malaise (PEM) and myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS). According to the individual medical history as well as clinical signs and symptoms a step by step diagnostic procedure and a multidisciplinary therapeutic approach are recommended.

[Suicidality in older adults]. / Suizidalität im Alter.

Older people have the highest suicide risk compared to all other age groups. Expressions of no longer wanting to live are also found in a large number of older people. The reasons are usually multifactorial and sometimes go back a long way in the personal biography. Limitations resulting from physical illness, mental disorders and social problems make an important contribution. Doctors are often the contact person, even though many older people avoid direct communication in this respect. It is important to perceive and actively address indirect notes, because suicidality is also changeable in very old age. Suicide prevention includes the multimodal treatment of the physical and mental illness, including the (re)activation of resources; however, it also begins in advance, when differentiated images of old age are communicated at the societal level, social participation of older people is practised and the quality of life is maintained until the end.

Validity and reliability of the Glittre-ADL test in individuals with idiopathic pulmonary fibrosis.

BACKGROUND: Patients with idiopathic pulmonary fibrosis (IPF) often present with dyspnea, fatigue, and desaturation. These symptoms can be highly limiting, as they lead to a decrease in performing activities of daily living (ADL). Therefore, it is essential to evaluate the degree of functional limitation of these individuals. OBJECTIVE: The present study aimed to evaluate the validity and reliability of the Glittre-ADL test (TGlittre) and its association with self-reported limitation in ADL and health-related quality of life (HRQoL) in patients with IPF. METHODS: Twenty-seven individuals with IPF (60.5 ± 10.6 years), with forced vital capacity 2.26 ± 1.03 L (51.09 ± 20.62% of predicted) were assessed for the time spent in TGlittre, 6-minute walking distance (6MWD), limitation in ADL and HRQoL. RESULTS: TGlittre was reliable (intraclass correlation coefficient3,1 = 0.96; P < .001); however, a learning effect of 10.6% was observed between the first and second execution of TGlittre. The time spent in TGlittre correlated with 6MWD, limitation in ADL, and disease-specific HRQoL (P < .05). CONCLUSION: TGlittre is valid and reliable for assessing functional capacity in patients with IPF. Still, it presents a learning effect and should be performed twice when assessing functional capacity in clinical practice.

U.S. and Finnish high school science engagement during the COVID-19 pandemic.

When the COVID-19 pandemic struck, research teams in the United States and Finland were collaborating on a study to improve adolescent academic engagement in chemistry and physics and the impact remote teaching on academic, social, and emotional learning. The ongoing "Crafting Engaging Science Environments" (CESE) intervention afforded a rare data collection opportunity. In the United States, students were surveyed at the beginning of the school year and again in May, providing information for the same 751 students from before and during the pandemic. In Finland, 203 students were surveyed during remote learning. Findings from both countries during this period of remote learning revealed that students' academic engagement was positively correlated with participation in hands-on, project-based lessons. In Finland, results showed that situational engagement occurred in only 4.7% of sampled cases. In the United States, students show that academic engagement, primarily the aspect of challenge, was enhanced during remote learning. Engagement was in turn correlated with positive socioemotional constructs related to science learning. The study's findings emphasise the importance of finding ways to ensure equitable opportunities for students to participate in project-based activities when learning remotely.

Dos and Don'ts in Designing School-Based Awareness Programs for Suicide Prevention.

Background: Despite the promising evidence for the effectiveness of school-based awareness programs in decreasing the rates of suicidal thoughts and suicide attempts in young people, no guidelines on the targets and methods of safe and effective awareness programs exist. Aims: This study intends to distill recommendations for school-based suicide awareness and prevention programs from experts. Method: A three-stage Delphi survey was administered to an expert panel between November 2018 and March 2019. A total of 214 items obtained from open-ended questions and the literature were rated in two rounds. Consensus and stability were used as assessment criteria. Results: The panel consisted of 19 participants in the first and 13 in the third stage. Recommended targets included the reduction of suicide attempts, the enhancement of help-seeking and peer support, as well as the promotion of mental health literacy and life skills. Program evaluation, facilitating access to healthcare, and long-term action plans across multiple levels were among the best strategies for the prevention of adverse effects. Limitations: The study is based on opinions of a rather small number of experts. Conclusion: The promotion of help-seeking and peer support as well as facilitating access to mental health-care utilities appear pivotal for the success of school-based awareness programs.

Mild hypobaric hypoxia influences splenic proliferation during the later phase of stress erythropoiesis.

Tissue trauma and hemorrhagic shock are common battlefield injuries that can induce hypoxia, inflammation, and/or anemia. Inflammation and hypoxia can initiate adaptive mechanisms, such as stress erythropoiesis in the spleen, to produce red blood cells and restore the oxygen supply. In a military context, mild hypobaric hypoxia-part of the environmental milieu during aeromedical evacuation or en route care-may influence adaptive mechanisms, such as stress erythropoiesis, and host defense. In the present study, healthy (control), muscle trauma, and polytrauma (muscle trauma and hemorrhagic shock) mice were exposed to normobaric normoxia or hypobaric hypoxia for ∼17.5 h to test the hypothesis that hypobaric hypoxia exposure influences splenic erythropoiesis and splenic inflammation after polytrauma. This hypothesis was partially supported. The polytrauma + hypobaric hypoxia group exhibited more splenic neutrophils, fewer total spleen cells, and fewer splenic proliferating cells than the polytrauma+normobaric normoxia group; however, no splenic erythroid cell differences were detected between the two polytrauma groups. We also compared splenic erythropoiesis and myeloid cell numbers among control, muscle trauma, and polytrauma groups. More reticulocytes at 1.7 days (40 h) post-trauma (dpt) and neutrophils at 4 dpt were produced in the muscle trauma mice than corresponding control mice. In contrast to muscle trauma, polytrauma led to a reduced red blood cell count and elevated serum erythropoietin levels at 1.7 dpt. There were more erythroid subsets and apoptotic reticulocytes in the polytrauma mice than muscle trauma mice at 4 and 8 dpt. At 14 dpt, the red blood cell count of the polytrauma + normobaric normoxia mice was 12% lower than that of the control + normobaric normoxia mice; however, no difference was observed between polytrauma + hypobaric hypoxia and control + hypobaric hypoxia mice. Our findings suggest muscle trauma alone induces stress erythropoiesis; in a polytrauma model, hypobaric hypoxia exposure may result in the dysregulation of splenic cells, requiring a treatment plan to ensure adequate immune functioning.

[Why do we require clinical guidelines for suicide prevention?] / Warum brauchen wir Leitlinien für Suizidprävention?

At present, there are no German guidelines regarding suicidal behaviors in adulthood despite their relevance to public health and the well-established evidence about their prevention. This paper first describes the history and background of working with guidelines. The current status of guidelines for mental illness in Germany is presented and examined for suicide-preventive content. The need for evidence-based suicide prevention and a specific guideline for suicide prevention in adults is discussed.Only via targeted suicide prevention strategies and interventions for the respective risk groups, and by paying particular attention to age and gender specificity in the outpatient as well as inpatient sector, can a high level of care for all patients be ensured. Such strategies have to pay specific attention to the interface between the individual care sectors and need to take comprehensive, easily accessible, needs-based, and affordable sustainable medical care into account. This applies to the outpatient and inpatient sectors as well as to their interfaces. Suicidality is a cross-diagnosis syndrome that occurs in different care contexts and requires complex treatment; therefore, intersectoral and multiprofessional aspects must particularly be addressed in the guideline. Scientific evidence and interdisciplinary expert consensus on the management of suicidal behavior in medical care can help reduce morbidity and mortality associated with suicidality. In August 2021, the funding of an S3 guideline "Management of Suicidality" was approved by the Federal Joint Committee.

Improving care for SUD patients with complex trauma-relationships between childhood trauma, dissociation, and suicidal behavior in female patients with PTSD and SUD.

Background: Posttraumatic disorders are among the most frequent co-occurring diagnoses in patients with substance use disorders (SUD). Individuals with this dual diagnosis often present with special treatment needs, especially after childhood traumatic experiences (CT). Along with posttraumatic stress disorder (PTSD) and dissociative symptoms, suicidal behaviors belong to the clinical challenges in this group of patients and may influence the course and outcome of SUD treatment. Therefore, a better understanding of the relationships between different forms of CT, psychopathology and suicidal behaviors seems to be important to tailor adequate concepts of care. Materials and methods: We examined 343 female patients with SUD and Posttraumatic stress disorder (PTSD). All patients completed the Childhood Trauma Questionnaire (CTQ), the Dissociative Experiences Scale-Taxon (DES-T) and the Structured Clinical Interview Axis I Disorders (SCID-I). To determine relationships between different symptoms with potential importance for concepts of treatment, we conducted analyses of moderated mediation for different models. We examined the direct and indirect effects of associations between the type of CT, dissociation and suicidal behavior, as well as the moderation effect of PTSD. Results: All participants met DSM-criteria for either full PTSD (75.2%) or subsyndromal PTSD (24.8%). Almost all (94.5%) received at least one substance dependence diagnosis and the remaining 5.5% met substance abuse criteria. Most participants (93.3%) reported at least one type of childhood trauma. In all models, dissociation was a risk factor for suicidal ideation (SI) and for suicide attempts (SA). In both, participants with subsyndromal PTSD and participants with full PTSD, dissociation mediated the relationship between childhood sexual abuse and SI as well as SA. Moreover, we report direct effects between different childhood traumas and SI and SA. Furthermore, emotional abuse was a significant predictor of dissociation. Discussion: In our sample of female patients with SUD and co-occurring PTSD, dissociation significantly increased suicidal behavior and served as a mediator of the relationship between childhood sexual abuse and suicidal behavior. Our findings underline the need to include interventions to address dissociative symptoms and other more complex consequences of childhood trauma into concepts of care for patients with SUD.

Femtosecond pulses from a mid-infrared quantum cascade laser.

The quantum cascade laser has evolved to be a compact, powerful source of coherent mid-infrared light; however, its fast gain dynamics strongly restricts the formation of ultrashort pulses. As such, the shortest pulses reported so far were limited to a few picoseconds with some hundreds of milliwatts of peak power, strongly narrowing their applicability for time-resolved and nonlinear experiments. Here we demonstrate an approach capable of producing near-transform-limited subpicosecond pulses with several watts of peak power. Starting from a frequency-modulated phase-locked state, ultrashort high-peak-power pulses are generated via spectral filtering, gain modulation-induced spectral broadening and external pulse compression. We assess their temporal nature by means of a novel asynchronous sampling method, coherent beat note interferometry and interferometric autocorrelation. These results open new pathways for nonlinear physics in the mid-infrared.